UBC Theses and Dissertations

UBC Theses Logo

UBC Theses and Dissertations

The use of oxidation-reduction potential (orp) as a process a process control parameter in wastewater.. Wareham, David Geraint 1992

You don't seem to have a PDF reader installed, try download the pdf

Item Metadata

Download

Media
[if-you-see-this-DO-NOT-CLICK]
ubc_1992_spring_wareham_david_gerain.pdf [ 11.31MB ]
Metadata
JSON: 1.0050500.json
JSON-LD: 1.0050500+ld.json
RDF/XML (Pretty): 1.0050500.xml
RDF/JSON: 1.0050500+rdf.json
Turtle: 1.0050500+rdf-turtle.txt
N-Triples: 1.0050500+rdf-ntriples.txt
Original Record: 1.0050500 +original-record.json
Full Text
1.0050500.txt
Citation
1.0050500.ris

Full Text

THE USE OP OXIDATION-REDUCTION POTENTIAL (ORP) AS A PROCESS CONTROL PARAMETER IN WASTEWATER TREATMENT SYSTEMS by DAVID GERAINT WAREHAM B.A.Sc.(Civil Engineering), The University of Waterloo, 19 M.A.Sc.(Civil Engineering), The University of Waterloo, 19  A THESIS SUBMITTED IN PARTIAL FULFILLMENT OF THE REQUIREMENTS FOR THE DEGREE OF DOCTOR OF PHILOSOPHY in THE FACULTY OF GRADUATE STUDIES (Department of Civil Engineering)  We accept this thesis as conforming to the required standard  THE UNIVERSITY OF BRITISH COLUMBIA January 1992 David Geraint Wareham, 1992  In presenting this  thesis  in  partial fulfilment  degree at the University of  British Columbia,  of  the  Iagree  requirements  for an advanced  that the Library shall make it  freely available for reference and study. I further agree that permission for extensive copying of this thesis for scholarly purposes may be granted by the head of department  or  by  his  or  her  representatives.  It  is  understood  that  copying  my or  publication of this thesis for financial gain shall not be allowed without my written permission.  (Signature)  Department of  Civil Engineering  The University of British Columbia Vancouver, Canada  Date  DE-6 (2/88)  J a n u a r y 27 1992  ii ABSTRACT This research  explored  the use of  Oxidation-Reduction  Potential to control two lab-scale sequencing batch reactor (SBR) wastewater treatment processes. The treatment schemes investigated were the aerobic-anoxic digestion of activated sludge  (AASD) and the excess biological phosphorus  (Bio-P)  removal process. Evaluation of each process consisted of a consideration of the reactor performances coupled with the control  stability  achieved  using  two  different  operating  strategies. The first strategy was known as "Fixed-Time Control" (FT), since it represents the "classical" management approach; control is based on conditions externally "fixed" by an operator. For the AASD set of experiments, the "fixed" variable was the ratio of air-on to air-off (3 hours each). For the Bio-P experiments, it was the time of addition of acetate to the reactor (1 hour 25 minutes into the non-aerated sequence). The second strategy was known as "Real-Time Control" (RT), since it represents an optimization technique whereby control conditions are continuously evaluated as time progresses. The Real-Time aspect of control is derived from the fact that ORP measurements  evaluate  the  reactor  conditions  on-line,  by  invoking a bacterial vision of the process scheme. For the AASD experiments, this evaluation took the form of proportioning the ratio of air-on to air-off, based upon the bacterial "need" for sufficient time to reduce the nitrates completely to nitrogen gas (denitrification). Sufficient time is  i determined by the distinctive breakpoint (correlated to nitrate disappearance) occurring in the ORP-time profile. The first experiment (AASD#1), therefore, had an air-on/airoff ratio of 3 hours air-on/nitrate-breakpoint-determined airoff. The second experiment (AASD#2) had the length of aeration time determined by a match to the previous length of time for denitrification, as determined by the breakpoint. In the Bio-P experiments, the ORP breakpoint was used to "trigger" the addition of acetate to the reactor, thus ensuring the maximum amount of carbon was available for storage by Bio-P organisms. Comparisons between the two reactors revealed that for the AASD strategies, the Real-Time reactor had essentially the same solids degradation as the Fixed-Time reactor  (14% - 21%),  depending upon the strategy considered, the type of solids (TSS or VSS) and the method of mass balancing used. The RT reactor was observed to obtain marginally better nitrogen removal (up to 6 % in some cases) over the FT reactor. Evaluation of the ORP parameter as a "response indicator", by subjecting the AASD reactors to unsteady process input conditions, revealed that the Real-Time reactor more readily accommodated disturbances to the system. Neither reactor in the Bio-P experiment was particularly successful in consistently removing phosphorus. A potentially useful screening protocol was developed for evaluating reactor performances, based upon the time-of-occurrence of the nitrate breakpoint, assessed against whether it hindered or aided the purpose of acetate addition to a Bio-P SBR.  iv TABLE OF CONTENTS Page ABSTRACT  ii  TABLE OF CONTENTS  iv  LIST OF TABLES  vi  LIST OF FIGURES  viii  ACKNOWLEDGEMENTS  xii  GLOSSARY OF TERMS 1 INTRODUCTION  xiii 1  1.1 Proj ect Need  1  1.2 Research Approach and Objectives  4  2 OPERATING THEORY AND LITERATURE REVIEW  7  2.1 Oxidation-Reduction Potential (ORP) 7 2.1.1 Redox Theory 7 2.1.2 Microbiological Aspects: Intracellular Redox.... 11 2.1.3 Physical Characteristics: Probe Operation 18 2.2 Applications of Oxidation-Reduction Potential 21 2.2.1 General Activated Sludge Processes 21 2.2.2 Fermentation Studies: ORP Control 24 2.2.3 ORP Control of Wastewater Treatment Processes... 2 6 2.3 ORP and Aerobic-Anoxic Sludge Digestion (AASD) 29 2.4 Biological Phosphorus (Bio-P) Removal and ORP 34 2.5 Sequencing Batch Reactors (SBRs) 37 2.5.1 Overview of Operation 37 2.5.2 SBR Applications in Wastewater Treatment 41 3 EXPERIMENTAL METHODS AND ANALYTICAL TECHNIQUES 43 3.1 Source of Feed Sewage and Sludge 43 3.2 Experimental Set-Up and Design 45 3.2.1 General Structural Configuration 45 3.2.2 Electronic Hardware 50 3.2.3 Computer Software 54 3.3 Raw Feed Collection Procedures 61 3 .4 Operating Control Strategies 62 3.4.1 Aerobic-Anoxic Sludge Digestion #1 (AASD#1).... 62 3.4.2 Aerobic-Anoxic Sludge Digestion *2 (AASD*2).... 66 3.4.3 Biological Phosphorus Removal (Bio-P) 67  V  TABLE OP CONTENTS CONT'D Page 3.5 Analytical and Sampling Techniques 3.5.1 General Procedures 3.5.2 Suspended Solids Measurements 3.5.3 pH, Alkalinity, Diss. Oxygen and Temperature.... 3.5.4 ORP Measurements 3.5.5 Nitrogen Analysis 3.5.6 Phosphorus Analysis 3.5.7 Estimates of Carbon Content 3.6 Sample Preservation and Storage Techniques 3 . 7 Statistical Techniques 4 AEROBIC-ANOXIC SLUDGE DIGESTION EXPERIMENTS  69 69 70 71 71 72 73 74 74 76 77  4.1 Review of Special Features of ORP Curves 77 4.2 Operational Characteristics 83 4.2.1 Technical Considerations 83 4.2.2 Experimental Pre-Run Conditions 90 # 4.3 Behaviourial Trends: AASD 1 Experimental Conditions... 92 4.3.1 Operating Characteristic and ORP Profiles 92 4.3.2 General Observations: Chemical Parameters 98 4.3.3 Mass Balances: Solids, Nitrogen and Phosphorus. 108 4.3.4 Evaluation: Unsteady Process Input Conditions.. 112 4.4 Behaviourial Trends: AASD*2 Experimental Conditions.. 123 4.4.1 Operating Characteristics and ORP Profiles 123 4.4.2 General Observations: Chemical Parameters 132 4.4.3 Mass Balance Perspective 137 4.4.4 Evaluation: Unsteady Process Input Conditions.. 141 5 BIOLOGICAL PHOSPHORUS REMOVAL EXPERIMENTS 5.1 Operating Characteristics and ORP Profiles 5.2 Chemical Characteristics of Bio-P Experiments 5.3 Evaluation of Reactors: Breakpoint Categories 6 CONCLUSIONS AND RECOMMENDATIONS  149 149 160 185 195  6.1 Conclusions  195  6.2 Recommendations  198  REFERENCES APPENDIX APPENDIX APPENDIX APPENDIX APPENDIX APPENDIX APPENDIX APPENDIX  A B C D E F G H  201 -  Derivation of Nernst Equation Intracellular Redox and Energy Calculations... Software Flowcharts all Experiments Software Code all Experiments Chemical Data AASD*1, AASD#2 Experiments Mass Balances - AASD*1 and AASD#2 Calculations for Bio-P Experiments Chemical Data for Bio-P Experiments  212 214 216 227 258 270 289 291  vi LIST OF TABLES Table 2.1  Page Selected List of Electrode Half-Reactions and their Standard Electrode Potentials  9  3 .1  Components of Experimental Apparatus  48  3.2  Subroutines and Functions in Each Experiment  56  3. 3 3.4  Timing of Phases in a Bio-P SBR  68  Sample Preservation, Analysis and Storage Techniques  75  4.1  Selected List of Chemical Statistics: AASD*1  99  4.2  Mass Balances for Fixed-Time Reactor: AASD#1  110  4.3  Mass Balances for Real-Time Reactor: AASD#1  110  4.4  Particulars of Sodium Nitrate Spikes: AASD#1  114  4.5  Particulars of Ammonium Chloride Spikes: AASD#1  114  4.6  Particulars of Hydrogen Peroxide Spikes: AASD#1  114  4.7  Failures Associated with FT Reactor Operation: AASD#1 Failures Associated with RT Reactor Operation:  124  AASD*1  124  4.9  Selected List of Chemical Statistics: AASD#2  133  4.10  Mass Balances for Fixed-Time Reactor: AASD#2  139  4.11  Mass Balances for Real-Time Reactor: AASD#2  139  4.12  Particulars of Sodium Nitrate Spike: AASD*2  142  4.13  Particulars of Ammonium Chloride Spike: AASD#2  142  4.14  Particulars of Hydrogen Peroxide Spike: AASD*2  142  4.15  Failures Associated with FT Reactor Operation: AASD*2 Failures Associated with RT Reactor Operation: AASD*2 Solids, Nitrogen and Phosphorus Chemical Data: Bio-P#l  4.8  4.16 5.1  146 146 162  vii LIST OF TABLES CONT'D Table 5.2  Page Solids, Nitrogen and Phosphorus Chemical Data: Bio-P*2  163  5.3  Carbon, Oxygen, Alkalinity and pH Data: Bio-P*l  172  5.4  Carbon, Oxygen, Alkalinity and pH Data: Bio-P#2  172  5.5  Breakpoint Classification Categories: Bio-P#l  193  5.6  Breakpoint Classification Categories: Bio-P*2  193  viii  LIST OP FIGURES Figure  Page  2.1  Typical Bacterial Electron Transport Chain  14  2.2  Diagram of ORP Electrode and Operation  20  2.3  Diagram of 5 Operating Periods of Bio-P SBRs  40  3 .1  UCT Bio-P Process  44  3. 2  UBC Bio-P Process  44  3. 3  Schematic of Experimental System  46  3.4  Schematic of AASD and Bio-P Sequencing Batch Reactors  3. 5  47  Impedance Diagram of ORP-Amplif ier Circuit  52  3.6  Illustration of Linear Ring-Buffer Concept  59  3.7  Illustration of BREAKPT Capture of Nitrate Knee  59  4.1  Fixed-Time ORP Profile Under AASD Conditions  78  4.2  Real-Time ORP Profile Under AASD*1 Conditions  81  4.3  Effect of Relatively Fresh Feed on Reactor ORP Curves  84  4.4  Overlay of First-Difference and ORP-Time Profiles  84  4.5  Linear Diagram of Components Identifying Problem Areas Reactor Interaction Effects Due to Improper Grounding ORP Profile Affected by Intermittent Electrical  4.6 4.7  Noise 4. 8 4.9  85 87 89  Complete Deterioration of ORP Profile Unusual Response Pattern: No Nitrate Breakpoint  89 91  4.10 Unusual Response Pattern: No Diss. Oxygen Breakpoint... 91 4.11 "Switch Over Day": FT to RT Control - AASD#1  93  4.12 Temporal Reproducibility of ORP Curves in RT Reactor... 94 v  ix LIST OP FIGURES CONT'D Figure  Page  4.13 Spatial Reproducibility of 3 ORP Electrodes in Same Reactor  96  4.14 Anoxic-Zone-Length: Cyclical Pattern Due to Daily Feed  97  4.15 Anoxic Periods Greater Than the 3 Hour Fixed-Time Limit  97  4.16 Daily Variation in Feed and Reactor TSS: AASD#1  101  4.17 Parallel Plot: Feed Sludge AASD*1 TSS/VSS Ratio  101  4.18 Fluctuations in Total Nitrogen Content: AASD#1  102  4.19 Fluctuations in Total Phosphorus Content: AASD*1  102  4.20 Fixed-Time Reactor: pH vs. Time for AASD#1  107  4.21 Real-Time Reactor: pH vs. Time for AASD#1  107  4.22 General Case of Mass-Balance Around Reactor  109  4.23 High Spike of Sodium Nitrate to FT Reactor: AASD#1.... 115 4.24 High Spike of Sodium Nitrate to RT Reactor: AASD#1.... 115 4.25 Low Spike of Ammonium Chloride to FT Reactor: AASD*1. . 116 4.26 Low Spike of Ammonium Chloride to RT Reactor: AASD*1. . 116 4.27 High Spike of Hydrogen Peroxide to FT Reactor: AASD*1. 117 4.28 High Spike of Hydrogen Peroxide to RT Reactor: AASD*1. 117 4.29 Typical "Incomplete Nitrification Failure"  119  4.30 "False-Knee" Failure in Real-Time ORP Profile  119  4.31 Fixed-Time Reactor Response to Missed Feed: AASD#1.... 122 4.32 Real-Time Reactor Response to Missed Feed: AASD*1  122  4.33 "Switch Over Day": FT to RT Control - AASD*2  126  4.34 Real-Time ORP Profile Under AASD#2 Conditions  127  4.35 RT Profile AASD*2 - Missed Feed Day Nov/11/90  128  4.36 RT Profile AASD*2 - Missed Feed Day Nov/12/90  128  X  LIST OF FIGURES CONT'D Figure  Page  4.37 "Missed-Knee" Failure in Real-Time ORP Profile  130  4.38 Two "Missed-Knee" Failures During Single Day  131  4.39 Daily Variation in Feed and Reactor TSS: AASD*2  135  4.40 Daily Variation in Feed and Reactor VSS: AASD#2  135  4.41 Fluctuations in Total Nitrogen Content: AASD#2  136  4.42 Fluctuations in Total Phosphorus Content: AASD#2  136  4.43 Daily Variation in Feed and Reactor pH: AASD#2  138  4.44 Daily Variation in Alkalinity: AASD#2  138  4.45 Spike of Sodium Nitrate to FT Reactor: AASD#2  143  4.46 Spike of Sodium Nitrate to RT Reactor: AASD#2  143  4.47 Spike of Ammonium Chloride to FT Reactor: AASD#2  144  4.48 Spike of Ammonium Chloride to RT Reactor: AASD*2  144  4.49 Spike of Hydrogen Peroxide to FT Reactor: AASD#2  145  4.50 Spike of Hydrogen Peroxide to RT Reactor: AASD*2  145  4.51 Spike of Potassium Cyanide to FT Reactor: AASD*2  148  4.52 Spike of Potassium Cyanide to RT Reactor: AASD*2  148  5.1  "Ideal" ORP Profile Under Bio-P Conditions  151  5.2  Software Failure Due to Rapid Denitrification  151  5.3  Fixed-Time Reactor Track Study: Bio-P*l  153  5.4  Real-Time Reactor Track Study: Bio-P#l  153  5.5  VFA-Caused Breakpoints in Fixed-Time Reactor  155  5. 6  VFA-Caused Breakpoints in Real-Time Reactor  155  5.7  Fixed-Time Reactor Track Study: Bio-P#2  156  5.8  Real-Time Reactor Track Study: Bio-P*2  158  5.9  Decline in Carbon Content: Stored in Cold Room  159  xi LIST OF FIGURES CONT'D Figure  Page  5.10 Decline in Carbon Content: Stored in Feed Bucket  159  5.11 Delay in Time of Nitrate Breakpoint Occurrence  161  5.12 Two Day Track of Delayed Nitrate Breakpoint  161  5.13 Variation in Feed and Effluent TSS: Bio-P*l  164  5.14 Variation in Feed and Effluent TSS: Bio-P*2  164  5.15 Variation in Reactor TSS: Bio-P*l  166  5.16 Variation in Reactor TSS: Bio-P*2  166  5.17 Reactor Plot of Percent N and P: Bio-P*l  168  5.18 Reactor Plot of Percent N and P: Bio-P#2  168  5.19 Track of Ortho-P Concentrations: Bio-P*l  169  5.20 Track of Ortho-P Concentrations: Bio-P*2  169  5.21 Variation in Feed and Reactor COD: Bio-P*l  173  5.22 Variation in Feed and Reactor COD: Bio-P*2  173  5.23 Carbon (TC, IC, TOC) Plots for Feed: Bio-P#l  174  5.24 Carbon (TC, IC, TOC) Plots for Feed: Bio-P#2  174  5.25 Carbon (TC, IC, TOC) Plots for FT RCTR: Bio-P#l  176  5.26 Carbon (TC, IC, TOC) Plots for FT RCTR: Bio-P*2  176  5.27 Variation in pH Feed, FT and RT RCTRS: Bio-P*l  178  5.28 Variation in pH Feed, FT and RT RCTRS: Bio-P*2  178  5.29 Breakpoints Classified According to Acetate Use  188  5.3 0 Nine Day Track of Denitrification Time  188  5.31 Disruption of Reactor Due to Solenoid Failure  190  5.32 Disruption of Reactor Due to Mixer Failure  192  ACKNOWLEDGEMENTS The interdisciplinary nature of this research is reflected in the variety of backgrounds, associated with the many individuals to whom I have become indebted, during the course of my stay at UBC. Firstly, I would like to thank my supervisors, Drs. K. J. Hall and D. S. Mavinic for their patience and guidance during the difficult times of this research. Furthermore, I am indebted to the Natural Sciences and Engineering Research Council of Canada (NSERC) for the financial support they provided via grants to my supervisors. I would like to acknowledge both the excellent technical assistance and the moral support of Susan Liptak, Paula Parkinson, Romy So, and Jufang Zhou, who cheerfully demonstrated the use of the lab instruments and always co-operated to the fullest extent, making the lab a pleasant environment within which to work. I am also grateful to Guy Kirsch, for his skilled modifications to the lab apparatus, to Paul Milligan, John Wong and Dr. Peter Lawrence for their advice and assistance in solving the electrical problems, to Rod Nussbaumer and Jim Greig for their software support and Fred Koch for his explanation of fundamentals. Thanks are owed to my many fellow graduate students, among others, Yves Comeau, Kirk Morrison, Pat Coleman, Bruce Anderson, Fongsatitkul Prayoon, and Takis Elefsiniotis, all of whom provided their unique brand of advice, humour and comradery, making my UBC experience most enjoyable. Special thanks are in order for Tim Ma for his companionship, availability and general willingness to discuss any of life's intricacies both inside and outside of the laboratory. Also valued is the on-going interest and support of both my families in Ontario. Their many calls of encouragement were deeply appreciated. Finally, I would like to thank my beloved wife Julia, whose constant love, encouragement and spiritual support has been a real boon to me, as together we have endeavoured to know Him who is the author of all knowledge.  GLOSSARY OF TERMS General Terms AASD Aerobic-Anoxic Sludge Digestion (*1 and # 2) ATP/ADP Adenosine Triphosphate/Diphosphate Bardenpho Barnard Denitrif ication Phosphorus Removal Process Bio-P Biological Phosphorus Removal (*1 and *2) COD Chemical Oxygen Demand D.O Dissolved Oxygen F:M Food:Microorganism Ratio HRT Hydraulic Retention Time MLSS/MLVSS....Mixed Liquor Suspended Solids/Volatile SS N (%) Nitrogen NAD/NADH+ Nicotinamide Adenine Dinucleotide ORP Oxidation-Reduction Potential P (%) Phosphorus PHA/B/V Poly-B-hydroxyalkanoates/butyrates/valerates RCTR Reactor SBR Sequencing Batch Reactor SCFA Short Chain Fatty Acids SRT Sludge (Solids) Retention Time TC/TOC/IC Total/Total Organic/Inorganic Carbon TKN/TP Total Kjeldahl Nitrogen/ Total Phosphorus UBC/UCT University of British Columbia/Cape Town VFA Volatile Fatty Acid Important Terms Specific to Program Acetate Acetate not added to RT reactor yet Baseaddr% The Base Address of the A//D Board (&H220) ChanO%/15%....Lower (0) and Upper (15) Bounds of channels Delta2a/2b/2c.The Critical ORP Slope Difference (-1.25) Flagdiff No Preceding Point in First Difference SUB Flagloop For Breaking into and out of Scanning Loop Flag.RT Real-Time Control Requested by User Flagscrn Flag to Invoke Graphics Display Ioadr% The Base Address of the Relay Board (&H330) KY.ESC For Escaping/Terminating Program KY.LN For <No> Decision Finished Viewing Probes KY.LY For <Yes> Decision to Select Other Probes Max.Anox Fail-Safe Limit to Resupply the Air Maxavoid Variable Safety Factor Before Search for Knee Nitrate Flag Signalling Nitrate Breakpoint Detected Num.Channels..Number of Channels to be Scanned (16) Num.Pts Dimensioning of Screen Display (181) Numrings The number of Rings in the Buffer (5) Num.Scans Number of Scans/2 minute interval (60) Realtime Flag - Initially no Real-Time Control Renew Flag to Clear/Reset Breakpoint Subroutine Ringsize The width of the BREAKPT Ring (5) Scan.Time Polling interval for the probes (2 seconds). VFAPass Counter to time the VFA Pump Operation VFAPump Flag to Signal VFA Pump On or Off  1 CHAPTER 1 INTRODUCTION 1.1  Project Need The fundamental theories of wastewater treatment have been  well understood for many years. In recent times however, the emphasis has moved towards acquiring better control of the unit processes, thereby treating a waste more efficiently. A greater ability to control inherently returns benefits in the form of less wasteful unit operations, since specific control parameters can be fine-tuned at will to optimize system performance. Classical examples in wastewater treatment include matching aeration supply to oxygen demand (to avoid overaeration) and correlating food supply to microbial biomass. The escalating demand for better control has generated in its wake a demand for increased reliability and development of sensing instruments. At the forefront of this movement are instruments capable of making in  situ measurements, a fact already  attested  to  by the  development of the on-line dissolved oxygen probe. Even more recently the advent of the microcomputer has brought automation to the sewage treatment field. For example the International Association on Water Pollution Research and Control (IAWPRC) has sponsored a series of workshops (London and Paris  (1973), London and Stockholm  (1981), Houston and Denver  (1977) , Munich and Rome  (1985), and Yokohama and Kyoto  (1990)), specifically devoted to the interchange of technical information  on  instrumentation  and  control  wastewater treatment and transport systems.  of  water  and  2 Instrumentation, control, and automation (ICA) is clearly an expanding field for research and development and interest in its application to wastewater treatment systems  (and water  supply in general) shows no signs of abatement. In the very early years computers were employed simply as "plotters", recording operational data and doing elementary evaluations, such as printing maintenance lists (Lohmann, 1985) and/or tracking the number of occurrences in which data exceeded threshold  limit values. In the eighties and now nineties,  computers are moving beyond the data acquisition / process monitoring  stage,  to  being  increasingly  used  for  more  sophisticated wastewater treatment applications. Examples abound and range from complex forms of information management, linked through workstations (Williams et al., 1986), to process control (Vaccari et al., 1988). When coupled with reliable sensors they can provide rapid information, particularly with regards to real-time disturbances. At the very least, computers commonly alert operators to problem  area(s),  sophistication  to  while  some  computers  analyze  both  the  problem  possess scope  enough and  to  implement remedial action. In addition a computer offers a major advantage over traditional hardwired systems (composed of timers and relays) due to the relative ease with which the sequencing logic can accommodate (through changes in either its format or time-base) improvements in the operating procedure. As will be emphasized in Chapter 2, interest in OxidationReduction Potential (ORP) has recently been renewed, partly as  a result of the search for new process control parameters to couple with the innovative technologies being developed. Earlier criticisms regarding the meaningfulness of ORP measurements in biological systems (Harrison, 1972) have been re-evaluated in light of the knowledge that the emphasis can be transferred from the absolute value of the ORP (which is admitted to having debateable usefulness (other than in the most general sense of an  environment  being  oxidizing  or  reducing))  to  the  ORP  variation with time. For example, there is no question that ORPtime profiles  in acclimated  sludges undergoing  alternating  aerobic-anoxic sequences, contain certain distinctive features which can be correlated with known physical and chemical events of theoretical and engineering interest (Peddie et al, 1988b). One such feature is the nitrate breakpoint or "knee" associated with the disappearance of nitrates in the ORP-time profile.  (Section  4.1). This phenomenon  correlates to the  bacterial transformation from respiratory to non-respiratory processes, and has been well documented (Koch and Oldham, 1985) in both aerobic-anoxic sludge digestion  (Jenkins, 1988) and  biological phosphorus removal (Comeau et al., 1987a) processes. The regular occurrence of this feature provides a powerful impetus for process control. The major truth evident here is that although the ORP probe does not achieve a well-defined  thermodynamically-reversible  equilibrium value (suggesting a specific solution composition of speciated ions), this should not hinder its use as a process control parameter in wastewater treatment systems. As long as  4 the system is sufficiently electroactive to generate (at least at the electrode level) an observable biologically-meaningful response pattern, it reflects a reality which ultimately can be exploited for control purposes. Thus this research addresses the need to re-evaluate the usefulness of the ORP probe as a process control parameter in light of the recent advances in computer and control technology. For example, the marked instability so often characteristic of past ORP measurements  in biological  wastewater  and  sludge  treatment systems, can be easily smoothed out as part of the interfacing equipment before the signal is processed by the host computer. Elimination of these extreme fluctuations allows the computer  to more readily  control  the process, based  upon  consistent detection of a real and reproducible feature in the ORP-time profile. 1.2  Research Approach and Objectives The basic objective of this research is to demonstrate the  usefulness  of  Oxidation-Reduction  Potential,  control of Sequencing Batch Reactor processes.  More  precisely,  for  automated  (SBR) sewage treatment  ORP-based  process  control  is  demonstrated in two specific wastewater treatment processes, the first accommodating the solids residuals generated from a sewage treatment plant (Aerobic-Anoxic Sludge Digestion (AASD)) and the second  investigating  bio-nutrient  treatment  of  raw  sewage  (Biological Phosphorus (Bio-P) Removal). Control is based, in both cases, on the nitrate breakpoint phenomena which occurs in the ORP profile with time (Section 4.1).  5 Two operating strategies (more fully discussed in Chapter 3) are considered in the AASD set of experiments (Chapter 4). The first strategy (AASD*1 - Section 3.4.1) compares a control reactor (Fixed-Time Control) (operating with a "Fixed" 3 hour air-on,  3  hour  air-off  aerobic/anoxic  sequence)  to  an  experimental reactor (Real-Time Control) operating with a cycle partition of 3 hours air-on but a variable length of time for air-off, contingent upon computer detection of the nitrate knee. The second strategy (AASD#2 - Section 3.4.2) compares a control reactor operating as above (Fixed-Time mode), with an experimental reactor, now operating with the length of aeration time determined by a match to the previous time for air-off (i.e. the length of the preceding anoxic cycle). At the time this research was proposed, no information was available on whether an ORP-driven, 50/50 air-on/air-off mode of operation, would collapse in on itself due to the rapid on/off sequences. Conceivably, if the process showed stability  (under what is  likely a "stressful" operating strategy), there could be grounds for investigating an operating strategy which further shortened the cycle length, operating between an ORP-detected "nitrate knee" and an ORP-detected "dissolved oxygen elbow" (Section 4.1). This would essentially represent an oscillating balance between nitrification and denitrification, thus considerably saving the air supply associated with the dissolved oxygen plateau of the ORP-time curve (Section 4.1). The Bio-P experiments (Chapter 5) compare a control reactor (operating with a "Fixed" time, (1 hour 25 minutes) for the  addition of volatile fatty acids to the anaerobic regime) to an experimental reactor using nitrate breakpoints, to time the addition of acetate to the anaerobic phase of the cycle. In both sewage processes an attempt has been made to evaluate  the  effectiveness  of  ORP  as  a  process  control  parameter. In the AASD experiments, this included detailing the stability and responsiveness of the ORP controlled system to several stresses, (both artificial and natural). In the Bio-P experiment, this involved categorizing the nitrate breakpoints according to whether or not their time of occurrence maximized the objective of VFA addition to the process. For example, some breakpoints occurred well after the addition of VFAs, meaning that some of the acetate was likely used by denitrifers to reduce nitrates, rather than being exclusively used by Bio-P organisms for carbon storage.  7 CHAPTER 2 OPERATING THEORY AND LITERATURE REVIEW 2.1  Oxidation-Reduction Potential (ORP) 2.1.1  Redox Theory Many ubiquitous processes found in the natural world  can be reduced to electro-chemical reactions involving the transfer of electrons from one species to another. A substance which gains electrons is said to be reduced (in a reduction reaction), while a substance which loses electrons is said to be oxidized (in an oxidizing reaction). Since some species gain or lose electrons more readily than others, (a function of the number of electrons in the outer shell and the size of the atom or  ion  (Westcott,  1976)),  a  table  of  Standard  Electrode  Potentials can be compiled and is to be found in any standard text on water chemistry (ex. Benefield et al., 1982). To  assign  a  Standard  Electrode  Potential to a  substance, unit activities of its oxidized and reduced forms are connected via a platinum wire and salt bridge, to a hydrogen half-cell containing water (pH = 0 , (1 M H+) , T = 25 °C) and hydrogen gas at one atmosphere pressure. The electrode potential is the voltage that would have to be applied  to prevent  electrons flowing to or from the test half cell. By convention, a positive voltage means that the electrons are flowing from the hydrogen half-cell to the sample, while a negative voltage is defined when the electron flow is from the sample to the hydrogen half-cell.  8 Table 2.1 shows a selected subset of some of the half-reactions pertinent to this research (written as reduction equations). All of the equations shown are those substances which have a strong affinity for accepting electrons. They are allocated large positive potentials with respect to the hydrogen half-cell (arbitrarily assigned a zero volt potential), since the reaction as written has a strong tendency to proceed to the right. In contrast, those substances which lose electrons most easily  (i.e. have the least tendency to exist in a reduced  state), would be assigned more negative potentials with respect to the hydrogen half-cell. As indicated, the reactions are half-reactions, that is, for every reduction equation there exists a complementary oxidation equation. Thus both the oxidized and reduced forms of a particular redox couple can concurrently exist in solution. Therefore, oxidation-reduction potential (ORP) is a measurement which establishes the ratio of oxidants to reductants prevailing within a solution of water or wastewater (ASTM, 1983). In contrast to pH which measures a specific acid/base couple  (in  effect  the  hydrogen  ion  activity),  the  ORP  measurement is non-specific (i.e. not a specific redox couple); instead, it senses the prevailing net direction of all electron transfers occurring, and thus the net solution potential is in effect the electron activity (Petersen, 1966).  9  Table 2.1 Selected List of Electrode Half-Reactions and their Standard Electrode Potentials E° (Volts)  Reaction H+ + e" <=> 1 / 2 H 2 ( g )  0.00  C 0 2 ( g ) + 8H+ + 8 e " <=> CH 4(g) + 2H 2 0  +0.17  A  +0.22  9C1<s)  +  e  "  < = >A  +C1  9(S)  "  S0 4 2 " + 9H+ + 8 e " <=> HS" + 4H 2 0  +0.24  H<  +0.27  ?2C12<s>  SO I  2-  +  2e  ~<  = > 2H  9<i>  +  2C1  '  + 10H* + 8 e " <=> H,S,. % + 4H,0 2'-'Cg)  2(aq) +  2 e  +0.34 +0.62  ' <=> S I "  N0 3 " + 2H+ + 2 e " <=> N0 2 " + H 2 0  +0.84  N0 3 " + 10H + + 8 e " <=> NH4+ + 3H 2 0  +0.88  N0 2 " + 8H+ + 6e" <=> NH4+ + 2H 2 0  +0.89  2N0 3 * + 12H + + l O e " <=> N 2(  +1.24  0 „ a , + 4H+ + 4 e " <=>  }  + 6H 2 0  2H,0  2Caq)  +1.27  2  C r 2 0 7 2 " + 14H + + 6 e " <=> 2Cr 3 + + 7H 2 0  +1.33 +1.39  C1  2(aq)  Note:  +  2 e  *  <  =  >  2 C 1  "  (1) All reactions with respect to the hydrogen standard electrode and at T = 25°C. (2) List drawn from larger list presented in Snoeyink and Jenkins, 1980 W a t e r Chemistry)  10 The ORP is expressed in mathematical form by the Nernst equation as shown below. For the Reaction:  Ox + ne" =  Red  (2.1)  The Nernst Equation: Eh = E° + RT ln{Ox/Red} nF where: Ox  (2.2)  - Oxidized species.  Red - Reduced species. n  - number of electrons participating in the reaction.  Eh  - the voltage difference (V) between the oxidation-  reduction half cell and the standard hydrogen electrode. E°  - the voltage difference occurring in a pure system  (i.e. when the activities of all oxidants and reductants are unity and at 25 °C) . R  - Universal Gas Constant (8.315 joules/ °K/mole).  T  - temperature - degrees Kelvin.  F  - Faraday Constant (96,500 coulombs/equivalents).  {}  - the activity of the oxidized and reduced species. The derivation of the Nernst equation, arising from  consideration of the interaction between the Gibbs Free energy equation and the Van't Hoff equation is included in Appendix A. In practice, the gaseous hydrogen electrode is rarely used  as  the reference  electrode, due to  certain  physical  difficulties, such as bubbling hydrogen gas at 1 atmosphere pressure through a solution. The Eh however, can always be obtained by adding the measured potential to the potential of the reference electrode. The most common reference electrodes are the Ag/AgCl and the calomel electrode (Section 2.1.3).  11 2.1.2  Microbiological Aspects: Intracellular Redox Molecular oxygen is the most powerful oxidizing  agent found in natural water systems, since anything stronger would begin to react with the abundant surrounding water and liberate oxygen. Redox reactions initiated with oxygen as the oxidizing agent, should be quite slow based on theoretical considerations, since the solubility of oxygen in water is low (Henry's Law predicts 2xl0"4 mol/L). Moreover, kinetic restraints arise since the synchronous transfer of 4 electrons (Table 2.1) to completely reduce oxygen to water is highly improbable, since most electron donors supply at best one or two electrons per molecule. It is a well known fact however, that organic matter can be metabolized by living cells. Micro-organisms do not actually perform the chemical reactions, instead they catalyze them and use the material for purposes such as deriving energy for metabolic processes or as source materials for biosynthesis (Snoeyink and Jenkins, 1980). Thus the biochemical reduction of oxygen to water  can  take place  extremely  rapidly  because  biological systems have circumvented the need for multi-stage reduction (i.e. separate one or two electron steps) by using enzymes in which several electron donor centres are present in the  same  molecule  and  which  ultimately  provide  all  four  electrons required (Eilbeck and Mattock, 1987). This fundamental principle is exploited in biological treatment systems designed to specifically oxidize the organic constituents in wastewater. A detailed description of the many and various  12 metabolic  pathways,  specific  enzymes,  energy  balances  and  methods of phosphorylation etc. is beyond the needs of this research; however, any good text on microbiology (ex. Tortora et al. (1982)) can supply most of the necessary details. For the brief  purpose  of  illustration  however,  the  biochemical  degradation of the energy-yielding carbohydrate glucose will be considered. Equation 2.3 describes the complete oxidation of this cellular fuel in the presence of oxygen to carbon dioxide and water. C H  6 12°6  +  60  2  ==>  6C0  2  +  6H  2°  A G 0 = -686 kcal/mole (2.3)  If a bacterial cell were to burn glucose in this manner  (i.e. one step), it would literally burn itself up.  Instead, the cell invokes a metabolic pathway that involves numerous stages, each catalyzed by its own specific enzyme and characterized by a free energy change that is rarely more than a few (ex. 10) kcal/mole (Dyson, 1974). The first step usually involves the removal of two hydrogen atoms (with the accompanying two electrons) via the enzyme  dehydrogenase.  This  is  followed  by  several  other  sequential stages in which some of the intermediate products produced are broken down yet again. In terms of the specific route taken, numerous metabolic pathways exist (depending upon the physical environment and the ability of a specific organism to utilize a particular path); however, the most common pathway is the Tricarboxylic Acid (Krebs or TCA) Cycle (when respiration is occurring aerobically) and the Glycolytic (Embdon-Meyerhoff) Pathway (when non-respiratory processes such as fermentation are  13 employed). The TCA cycle becomes an extension to the glycolytic pathway when oxygen or a combined form of it becomes available to an organism that can use this path. At several points in the pathway the energy in the electrons is captured by one of a class of electron deficient carrier molecules such as nicotinamide adenine dinucleotide (NAD+) , which is reduced to a high energy level compound NADH. Since NAD* is generally in short supply in the cell, the rest of the cells efforts are directed towards regenerating the pool of NAD* by one of several mechanisms. Again if NAD+ was regenerated by directly combining with oxygen, NADH + H+ + 1/2 0 2 ==> NAD+ + H20  A G ° = -53.8 kcal/mole (2.4)  the resulting free energy change' of 53.8 kcal/mole (calculated in Appendix B) , would still be too large to be captured by a single adenosine triphosphate (ATP) molecule (or its equivalent) and much of the energy would be lost as heat (Boyd, 1984). The most efficient way to regenerate NAD+  (i.e. maximizing the  capture of energy) is to transfer the electrons from NADH to oxygen in a series of discrete steps via the electron transport chain. The electron transport chain (Figure 2.1) located in the cytoplasmic membrane of prokaryotes, consists of a series of closely linked electron carrying species, such as flavins, quinones and certain proteins containing metal ions. The NADH passes its electrons to the first carrier molecule in the chain and in the process regenerates NAD+. Each couple then reduces the  14  Inner Portion NADH > + H  Cell Membrane  Outer Portion  Electron Carrier Molecules  NAD ~H  1Q,+ 2H  - H  \\0  ATPase  H  Figure 2.1 Typical Bacterial Electron Transport Chain (Adapted from Tortora et al., (1982))  15 next in line until the terminal electron acceptor is reached and reduced to its final form. Each of the electron carriers in the respiratory chain has its own characteristic ORP. Electrons gravitate from more negative carrier molecules to more positive ones and therefore this governs the structure of the chain. Moreover, there  is a small decline  in free energy between adjacent  molecules in the chain. The magnitude of the energy release is directly proportional to the difference in magnitude of the intracellular redox potentials of adjacent molecules. At certain strategic points (three when oxygen is the final electron acceptor), there is a sufficient drop in free energy that a high energy phosphate can be donated to adenosine diphosphate (ADP) to form ATP (a process known as oxidative phosphorylation). ATP is the most common energy reserve molecule or retrievable form of energy currency in which the microorganism stores energy; however, other energy reserve molecules do exist. The micro-organism can draw upon this energy bank by coupling ATP hydrolysis to unfavourable reactions that need to be driven such as some biosynthesis processes. It is estimated that for every mole of glucose oxidized aerobically to C02 and water (via the glycolytic pathway/TCA combination), 38 ATP-like molecules are formed (Boyd, 1984). As shown in Appendix B, this represents a 39-45 % capture of the original  energy  (686  cal/mole) stored in a mole of glucose molecules. This can be compared with the mere 2 ATP molecules generated by the incomplete oxidation of glucose under anaerobic  conditions  (i.e.  ATP  generation  by  substrate  level  phosphorylation) by organisms that halt at the end of the glycolytic pathway. Thus aerobic organisms grow much faster than anaerobic organisms because the potential for energy release during  aerobic  respiration  is much greater  than  anaerobic  conditions, since many electron pairs are released and shuttled down the chain to produce ATP. A facultative organism for example might require 48 hours of optimal growth conditions to produce a population of cells that, under aerobic conditions, could be established in 16 hours or less (Boyd, 1984) . Many micro-organisms possess the capability of using an  alternate  terminal  electron  acceptor  in  the  electron  transport chain, if their primary choice is unavailable. For example, Pseudomonas and Bacillus can use nitrates; however, they only utilize them when the concentration of dissolved oxygen is minute or nonexistent, since fundamentally they are unable to extract as much energy per mole out of doing so. Again, when nitrate is utilized, the reaction to produce N2 (gas) is favoured over the reduction of N03" through N02" to  NH4+  because it yields more useable energy to the micro-organism catalyzing it (using the enzyme nitrate reductase) (Snoeyink and Jenkins, 1980). Again, this is a function of the intracellular redox levels of the various reaction couples. Other bacteria are restricted to the use of one electron acceptor such as Desulfovibrio which reduces sulphate (S04"2) to hydrogen sulphide (H2S) . Still others use carbonate (C03"2) to form methane (CH4) . A few microbes anaerobically use  17 compounds such as fumardc acid as the final electron acceptor. Depending  upon  the  electron  donor,  the micro-  organism, the pathway chosen and the terminal electron acceptor, the number of ATP molecules generated from the chain may be only 1 or 2 rather than 3 when free oxygen is used. As mentioned, this essentially translates to the difference in the oxidation reduction potential between the donor  (NADH) and the final  electron acceptor. In this general sense the intracellular redox level helps to determine  the type of biological  community  that  develops. The exact relationships between the intracellular redox level, the NADH level and the extracellular ORP probe measurement  is  Stephanopoulos  subject  to  on-going  research  (1987), Armiger et al.  (Wang  and  (1990)). Nicotinamide  adenine nucleotides are known to be the coenzymes of a good fraction of the intracellular oxidation-reaction steps, and therefore by following the NADH/NAD* level important process control strategies can be formulated. In fact, Armiger et al (1990) have already demonstrated how a fluorescence method (which measures the ratio of NADH to NAD*) can be used to provide a characteristic "fingerprint" of the optimal operation of a bionutrient removal process. This procedure is very similar to the method used in this research except that it assesses the reductive (rather than the oxidative) status of the sludge. Whatever intracellular  and  the  exact  extracellular  redox  relationship is, there  between is little  question that the external ORP reading is a direct reflection of  18 the activity at the cellular level. This is not to imply that ORP is the sole governing mechanism that drives the community type. It can be appreciated that in a wastewater treatment system there is both a complex mix of micro-organisms and a virtual "cocktail" of organic wastes. Which reactions are used is still very much a function of the physical environment. However, whether a particular ORP value is the cause or effect of a given bacterial population is of secondary importance, for the correlation between the two is real enough (Whitfield, 1969) such that a link of this kind can be effectively exploited. 2.1.3  Physical Characteristics: Probe Operation Electro-chemical  theory  suggests  two  kinds  of  electro-chemical cells. The electrolytic cell occurs when nonspontaneous reactions are forced to proceed by the external application of a voltage across the two electrodes. Thus, electrical energy is consumed during the reaction. Conversely, the  Galvanic  cell,  representative, spontaneous  is  of an  occurrence  which  type  the  electro-chemical of  electrode  ORP cell  electrode in which  reactions  is the  produces  electrical energy. The ORP electrode consists of a reference electrode (ex.  silver/silver  chloride  or calomel)  and  an  indicating  electrode constructed of a highly noble metal (ex. platinum or gold). The reference electrode or cathode has a fixed potential since the concentration of the cation associated with the electrode metal is maintained through the solubility-product principle. The reference electrode is separated from the test  solution by a porous ceramic plug which allows charged ions to pass through to each solution preventing charge differentials building up and halting the reactions. A highly noble (inert) metal is chosen as the anode primarily because its potential for oxidation is less than that of any oxidizable components in the test solution.  The anode  therefore ideally should not participate in any reaction, but rather just provide a surface for the oxidation of the solution constituents. The area of the noble metal in contact with the test solution should be approximately 1 cm2 (ASTM 1983) .  A  sketch of the ORP electrodes used throughout the duration of this research is shown in Figure 2.2. In order to describe how the probe functions, it is assumed that reducing  initially the probe  environment,  respiration  processes  that prevail  is,  is immersed one  in  (ex. sludge  in a highly  which  anaerobic  which  has  been  unaerated for several hours). The organic materials in the sludge are continuously subjected to degradation by bacterial enzymes and thus a variety of numerous, successive and parallel biological reactions occur as electrons are shuttled back and forth between oxidized and reduced species. Some of the electrons will naturally gravitate along the platinum wire to the cathode, since the Ag/AgCl reference electrode has a large positive electrode potential of +.22 volts (Table 2.1). The silver chloride paste will then undergo a reduction equation forming solid silver and free chloride ions as shown in Equation 2.5.  20  Rubber Cap  Shielded Coaxial Cable  Electrolytic Gel Saturated 4.2 N KCI Fills the Interior of the Electrode  Sliver Metal Strip Coated with AgCI Paste Eauatlon  AgCl w + e" = = > Ag, CATHODE  Glass Exterior  Ceramic Porous Junction Allows passage of K  Organic Material is laced with Electrons  and CI Ions to Maintain  9  Electroneutralfty  °J c°,  ®. Platinum Band (Noble Metal)  ANODE  Oz + 4e" + 4H + = = >  Figure 2.2 Diagram of ORP Electrode and Operation  2^0  21  AgCl(s)  +  e" ==>  Ag(s) +  CI'  (2.5)  Again by convention, when the flow of the electrons is from the test solution to the reference electrode the ORP value recorded is negative. Upon introducing a continuous supply of oxygen into the solution, many of the electrons normally travelling to the reference  electrode will be enzymatically  rerouted  towards  reducing the oxygen to water, since it has an even larger positive potential (E° = 1.27 (Table 2.1)) than the reference Ag/AgCl electrode. As the number of electrons travelling along the platinum wire diminishes, so too will the ORP value become more positive. Eventually the flow of electrons will reverse itself, consistent with the definition that when the flow is from the reference electrode to the test solution the ORP is defined positively. Therefore, in any given water system, the variation of ORP potential with time may serve as a relative guide to the oxidizing or reducing conditions in that system (Bockris, 1972). 2.2  Applications of Oxidation-Reduction Potential 2.2.1  General Activated Sludge Processes A survey of the relevant literature indicates that  interest in ORP as applied to activated  sludge processes,  flourished for the most part during the middle years of this century. Researchers  such as Rohlich  (1948), Hood  (1948),  Eckenfelder and Hood (1951), and Nussberger (1953) investigated and debated the significance of ORP measurements, primarily in aerobic treatment processes. It quickly became evident that  exact  potentials  for  aerobic  and  treatment process were questionable  anaerobic  regimes  (Rohlich, 1948),  of  a  since  measurements varied widely both between plants and amongst probes inserted in the same tank within a given plant. However, Rohlich (1948) did maintain that the time-potential ORP curves could be used to maintain better operational control of a sewage treatment plant. Despite initial optimism, a note of caution dictated that perhaps the most that could be said was that ORP showed promise, as a diagnostic tool to indicate whether aerobic or anaerobic conditions prevailed (Hood, 1948). Nussberger (1953) (in an effort to practically integrate ORP into the routine operation of a step-aeration sewage treatment plant) developed a series of characteristic ORP curves, which he proposed could be used as a guideline to indicate whether a plant was being under- or overloaded, and under- or overaerated. The next spate of papers occurred roughly 10 years later, commencing with the research of Grune and Chueh (1958). This again involved investigating ORP variability in sewage treatment  plants.  Some  of  the  research  however  began  to  concentrate more closely on the practical aspects of control such as aeration. For example, O'Rourke et al, (1963) used ORP to estimate the utilization of the aeration capacity of an aeration basin. Rudd et al., (1961) and Roberts and Rudd (1963) demonstrated that the diurnal rise in ORP (corresponding to the noonday decline in sewage throughput to the plant) could be used to scale back aeration on-line time, thus realizing significant  23 economic benefits. In an interesting  discussion to Grune and Chueh 's  paper, Eckenfelder (1958), in commenting about his own work, notes that both the rate of change of the ORP potential and the ultimate ORP value reached is of importance. In several tests, inflection points (sharp breaks in the ORP profile with time) could be correlated to the disappearance of an oxidant or reductant such as oxygen or sulphate. This seems to be the earliest recorded reference to a breakpoint phenomena. The wide fluctuations in ORP readings are partly a result of the fact that, in biological systems, the ORP is a mixed potential, that is, it is a potential that is derived from many concurrent electro-chemical reactions, none of which (in open systems) are in equilibrium. As Stumm (1966), and Morris and Stumm  (1967) comment  "... for a multi-redox  component  system, that is not in equilibrium.... the redox potential (which  is  by  conceptual  and  operational  equilibrium potential) becomes meaningless."  definition,  an  Harrison (1972)  concluded that the overall redox potential seemed to be of little value in studies of growing microbial cultures. Such criticisms  coupled  with  the  appearance  of  a  reliable  commercially-available dissolved oxygen probe (Koch and Oldham, 1985) tended to effectively dissipate the initial interest displayed in discovering the role ORP played in sewage treatment processes. For the most part, ORP was all but forgotten for the next two decades except for some sporadic citations such as  Dickenson (1969). He sought to characterize the relative ease with which an aerated sludge could oxidize a substrate, based upon the recovery profile of the ORP-time curve, after the sludge had received a slug dose of the substrate of interest. Other notable exceptions were researchers such as Blanc and Molof  (1973)  who  continued  to  direct  efforts  towards  understanding the role ORP measurements played in anaerobic systems where, by definition, the D.O. probe was not applicable. In particular, in some anaerobic digestion studies, they were able to correlate specific ORP ranges (-450mv to -550mv, Ec) to good production of methane. 2.2.2  Fermentation Studies: ORP Control The  use  of  oxidation-reduction  potential  in  fermentation research has been the focal point of several studies for a considerable period of time  (Wimpenny, 1969,  Wimpenny and Necklen, 1971, and Kjaergaard, 1976). Many aerobic microbial fermentation processes take place at concentrations of dissolved oxygen (D.O.), which are impossible to measure using commercial dissolved oxygen probes. It is important however, to have some tool which can effectively provide information about the degree of oxygen limitation to the culture (Kjaergaard, 1977). The useful operating range of the redox probe is much larger than the D.O. probe due to the availability of negative redox potentials. Thus, Shibai et al. (1974) was able to show a good correlation between Eh and very low oxygen concentrations (as measured  by  an  oxygen  fermentation processes.  analyzer)  in  studying  inosine  25 In a review of several investigations into ORP values and microbial cultures, Kjaergaard (1977) noted special interest evidenced in the fluctuations in the ORP value as it related  to  the  efficiency  of  production  of  particular  metabolites. Their own work experimented with the regulated addition of glucose controlled by maintaining a constant redox potential in the medium. Upon depletion of the initial glucose media,  the  microbial  oxygen  consumption  would  decrease,  reflected in an increase in both the oxygen level and ORP value. Since ORP is more readily measurable in the micro-aerophilic range than D.O., any change in its value could be easily detected and used to close a relay. This initiated a pump which delivered glucose until the redox potential returned to its original value. Since the additional glucose was used by the microorganism before a new pulse was added, the growth of the organism (and consequently the production of the metabolite) was also regulated. The use of ORP setpoints in fermentation studies has continued to grow and further work (Kjaergaard and Joergensen, 1979, 1981) led to the proposition that ORP could be classed as a "state variable" in fermentation systems operating at minute dissolved oxygen levels. Dahod  (1982),  investigating  the  production  of  penicillin, maintained that ORP was a much better parameter than dissolved oxygen for fermentation process control, primarily because D.O. measures only the oxidizing potential of the 0 2 metabolic chain, while redox measures the oxidizing potential of  all the species formed in the broth (i.e. all oxidation chains). This can be critical when mass transfer limitations create a discrepancy between the oxygen concentration in the bulk phase and the actual oxygen availability (Wang and Stephanopoulos, 1987). This will cause other electron acceptors to be employed. Radjai et al. (1984) searched for the best redox conditions to optimize the production of amino acids such as homoserine, valine and lysine. The flow of dissolved oxygen to the fermentation broth was varied by manipulating the agitator speed and the change in the ORP value was recorded. The specific ORP value corresponding to the optimum production rate of the amino acid was noted and this value was once again used as an ORP setpoint in further pure culture work. 2.2.3  ORP Control of Wastewater Treatment Processes Interest in ORP and its applications to wastewater  treatment systems has been rekindled as advances in automation have led to a search for reliable process control parameters. Burbank (1981), discusses several field experiences, in which operators examined the ORP fluctuations with time and made appropriate operating decisions for the plant. Many of their resolutions  correspond  to  the  type  of  observations  and  guidelines Nussberger had proposed almost 3 0 years earlier. Poduska and Anderson (1981) discuss the use of ORP to control hydrogen sulphide odours, which develop during warm weather spells in lagoons storing aerobically digested sludge. Application of a local industry's wastestream (40 % NaN03) was shown  to  be  effective  in  eliminating  odours  due  to  the  preferential selection of electron acceptors (ie. N03" over S04"2) in metabolism. A specific ORP setpoint was not used; however, a high positive ORP value (> +100 mv) was shown to be effective in controlling odours. Eilbeck (1984) investigated breakpoint chlorination of free and metal complexed ammonia, in wastestreams originating from metal finishing and electronic industries. Redox titration curves were superimposed on the chlorine breakpoint curves and the sharp jump in redox when the residual chlorine broke through was noted. Prior to the breakpoint, the ORP remained constant as chloramine complexes were formed with hypochlorous acid. Thus the  redox  breakpoint,  detecting  when  a  residual  became  available, was of great assistance in ascertaining dosage rates. Rimkus et al. (1985) used ORP to control raw sewage odours generated when low weather flows into the Chicago O'Hare Water Reclamation Plant (a combined sewer inlet) led to the production  of  hydrogen  sulphide.  A  computer  continuously  analyzed ORP signal inputs and when the ORP dropped below +100 mv, sodium hypochlorite was added to increase the ORP. Sekine et al., (1985) described an activated sludge process which used ORP as a supervisory index for nitrification. A circuit converted the ORP value into a nitrification rate (based on experimental observations) and made a time-series correction to the D.O. value to obtain good nitrification. Watanabe et al. (1985), in a series of lab experiments, used an ORP setpoint of approximately -150 mv to control the addition of an  external  carbon  source  (methanol)  in  order  to  ensure  28 denitrification. As the biomass exhausted the carbon, the ORP would rise above the setpoint and initiate methanol addition. In this way , ORP became a control index for methanol regulation and allowed consistent effluent NOx-N levels of less than 1 mg/L. Charpentier et al., (1987) discussed both laboratory and full scale applications of ORP control in France. In a low loaded activated sludge plant, various NH4* and N03" effluent concentrations were recorded along with the attendant variations in ORP. Subsequently, ORP values of -80 to +120 mv were targeted and air was cycled on and off to the aeration basin, at a rate just sufficient to keep the ORP between these limits. In this way, consistent effluent nitrogen levels were maintained. They concluded that with redox based control, electricity consumption could  be  more  accurately  determined,  thanks  to  constant  regulation of the aerators correlated to specific pollution levels. Research  into  ORP  continues  to  progress  as  investigators have recognized the potential ORP offers for in situ process control. Heduit and Theunot (1989) mention that the constants in the relationship between the D.O. concentration and ORP (of the form Eh = a + b log[02]) depend upon the sludge loading, the aeration conditions, the sludge concentration and other redox species. Charpentier et al., (1989) furthered this work by investigating relationships between effluent nitrogen and ORP. They found that targeting upper and lower ORP values in the aeration cycle, simultaneously optimized the effluent quality  29 and electrical costs. De la Menardiere  (1991) in a similar  study, observed high removal levels for carbon, nitrogen and phosphorus as a function of targeting different ranges for the ORP values in the aeration basin. Both of these latter two studies  make  some  poignant  observations  relating  to  ORP  inflection points and nitrate disappearance. They comment about the possibility of new ORP applications using these inflection points in the control of biological nutrient removal processes. 2.3  ORP and Aerobic Anoxic Sludge Digestion (AASD) One of the most significant expenditures associated with  the construction and operation of a pollution control plant, is the cost of stabilization and disposal of the waste activated sludge solids. Estimates vary but are generally in the range of 40-50 % of the total cost (both capital and operating) of the wastewater treatment plant  (Rich,  (1982), Evans and Filman  (1988)). For small plants (< 5 MGD) an attractive option is to aerobically digest the sludge, since this method is not as prone to process upsets, which can periodically afflict the anaerobic digesters  in  larger plants. Aerobic  digestion  is somewhat  similar to extended aeration, except that there is assumed to be no influent source of carbon other than that derived through the auto-oxidation  (endogenous  respiration)  of  the  bacterial  protoplasm itself. An obvious disadvantage of aerobically digesting sludge is the energy cost associated with a continuous supply of air. In addition, since aerobic digestion processes tend to consume alkalinity as shown in Equation 2.7  (the bacterial mass is  assumed to be represented by the chemical formula Cgli^C^ (Hoover et al., 1952)), there is an added chemical cost to maintain the pH in the neutral range. C5H7N02 + 702 ==> 5C02 + 3H20 + N03" + H+ Currently,  there  are  at  least  20  (2.7)  digesters  in B.C.  aerobically treating waste activated sludge (Minister of Supply and Services Canada, 1981). Recently, a modified form of the conventional aerobic sludge digestion process has been proposed (Hashimoto et al., 1982). This involves an additional anoxic tank which receives the nitrate-rich effluent of the aerobic tank and denitrifies it according to the equation below. C5H7N02 + 4N03" ==> 5C02 + NH3 + 2N2 +40H"  (2.8)  This not only reduces more volatile suspended solids but also acts to reduce the total nitrogen content generated in the sludge digestion process. A more innovative design that appears to significantly offset the major disadvantages of aerobic digestion, is the practice of cycling the air in an on/off manner. This method intrinsically  induces  considerable  savings  in  energy  (air  supplied) as well as reduces or even eliminates the extra chemical cost (since, during the anoxic portion, alkalinity is recovered  (Equation 2.8)). Moreover there is no need for an  additional tank as the previous solution (Hashimoto et al., (1982)) proposed. The first published research into this sludge digestion method appears to be that of Warner et al., (1985) . They discuss aerobic-anoxic theory as a subset of the general activated  31 sludge model, originally developed by Dold, Ekama and Marais (1980) and extended by van Haandel, Ekama and Marais (1981). This model, based on steady state activated sludge theory, is flexible enough to incorporate nitrification-denitrification, variable influent conditions and series reactor configurations. It  can  predict  alkalinity  COD  changes,  removal, oxygen  nitrification-denitrification, demand  and  volatile  solids  degradation. The  major  conclusions  of  this  research  (from  both  theoretical considerations and lab scale experimental data) was that the incorporation of anoxic intervals in aerobic digestion of waste activated sludge, did not appear to adversely affect the degradation rate of the active bug mass, provided the anoxic portion of the cycle was not overly long. According to their observations the anoxic segment should not comprise more than 50 to 60 % of the total cycle length, nor should the duration of any single anoxic portion of the cycle be greater than 3 hours. It was also noticed that, for the digesters operating at a 50 % anoxic time, the nitrate generated by the nitrification reaction (during the  aerobic portion  of the cycle) was  completely  denitrified during the anoxic portion of the cycle. This meant that sufficient alkalinity was generated to keep the pH stable and in the neutral range. The balancing effect of alkalinity and pH resulting from an alternating aerobic-anoxic sequence has subsequently been well documented  (Peddie et al., (1988a),  (1988b), Jenkins, (1988)). Matsuda et al., (1988) followed the transformation of  32 nitrogen and phosphorus in the solid and liquid phases, while comparing  aerobic-anoxic  vs.  continuous  aerobic  sludge  digestion. Some interesting profiles were presented; however, their major conclusion was that the reduction rate of sludge solids and the behaviour of nitrogen intermittent  aeration  (controlled  by  and phosphorus under a D.O.  criteria) was  substantially equivalent to that undergoing continuous aeration. Therefore, intermittent aeration could be considered a viable method of sludge digestion with its attendant economic benefits. Jenkins  and  Mavinic  (1989a)  investigated  the  solids  degradation obtained using three different sludge digestion operating strategies (aerobic/anoxic (2.5 air-on/ 3.5 air-off), aerobic with lime addition and straight aerobic). Further to this, when operating the digesters at 3 different SRTs (10, 15 and 20 days) and two different temperatures (10 °C and 20 °C) , it appeared that cycling the air flow gave comparable results in terms of percent TVSS reduction, while using only 42 % of the air  that  continuous  aerobic/anoxic  aeration  would  employ.  sludge digestion maintained  In  addition,  a neutral mixed  liquor pH at almost no extra cost. They postulated that comparable results were attainable because the bacteria made more efficient use of the air, since prior to initiation of the air, the driving force would be quite high, (enabling greater oxygen transfer efficiency once air resupply commenced). Furthermore, during the anoxic portion of the cycle, endogenous respiration would still be in effect (with nitrates as the terminal electron acceptor),  so that some  33 reduction  in  solids  would  continue  to  occur.  Microbial  degradation by nitrates and more efficient oxygen transfer efficiency was essentially the same rationale offered earlier by Ip et al., (1987), who investigated the savings in aeration energy  costs  (controlled  encountered  when air was  cycled  on and  off  by a D.O. probe) to a normal continuous flow  activated sludge system. In  a  subsequent  paper, Jenkins  and  Mavinic,  (1989b)  detailed the benefits accrued from the AASD operating strategy in terms of improved supernatant quality  (ex. reduction of  nitrates through denitrification during the anoxic portion of the cycle) . They also used ORP as a tool to monitor the aerobic/anoxic sludge digesters and clearly showed that the ORP profile  with  time  was  reproducible  from  cycle  to cycle.  Moreover, in developing an overall rating system to evaluate the performance of the three digestion modes, the potential for automation, based upon ORP, resulted in AASD receiving the highest ranking in this category (Jenkins 1988). Finally, Kim and Hao (1990) investigated aerobic-anoxic sludge digestion, specifically focusing in on the kinetics of the anoxic phase and how it related VSS degradation to the endogenous nitrogen respiration (ENR) rate. They recognize that the in situ placement of an N03" probe could modify the duration of the cycle period in a SBR to accommodate the required nitrate consumption pattern. This is a very similar concept to the one explored in this research.  2.4  Biological Phosphorus (Bio-F) Removal and ORP Perhaps  of  most  significance  in  terms  of  rekindling  interest in ORP, was the development of bio-nutrient removal processes (Koch and Oldham, 1985). These designs incorporate a non-aerated regime in the process train, a domain in which the dissolved oxygen probe is rendered inadequate but the ORP probe remains useful. In conventional activated  sludge systems, the typical  phosphorus content (based on dry weight) is 1.5 to 2.0 percent (U.S. EPA, 1987). This is primarily composed of the phosphorus taken up by microbes  for use  in biomass  synthesis  (i.e.  phospholipids, nucleotides, and nucleic acids etc.). In the late fifties and  early  sixties, researchers  such as Levin and  Shapiro, (1965) and Shapiro et al., (1967) reported that up to 80 % of the phosphorus in activated sludge could be removed by vigourous aeration, while much of this was re-released at the bottom of the secondary clarifier, under conditions of low or zero dissolved oxygen. It was apparent, therefore, that some microbes could take up phosphorus in excess of normal metabolic requirements, a phenomenon that eventually became known as excess biological phosphorus (Bio-P) removal. As mentioned, the Bio-P process modifies the activated sludge process by including a non-aerated zone prior to the aerobic  reactor.  Addition  of  simple  short-chain  carbon  substrates to this zone, (ex. volatile fatty acids such as acetate or propionate) result in a phosphorus release to the liquid, accompanied by a corresponding microbial carbon storage  in the form of either poly-B-hydroxybutyrate (PHB) or poly-Bhydroxyvalerate (PHV). Together, these carbon storage compounds are known generically as poly-B-hydroxyalkanoates (PHA) (Comeau et al., 1987b). When the biomass is subsequently limiting,  aerobic  conditions,  those  subjected to carbonbacteria  which  have  previously sequestered carbon in reserves, seem to evidence a competitive advantage over other organisms. In fact, in the aerobic zone, the competition is restricted to that fraction of carbon which is not so readily biodegradable; thus, Bio-P organisms, drawing upon their exclusive access to the stored carbon, proliferate in greater numbers and, in doing so, take up not only the phosphorus they initially released in the anaerobic zone, but also much more than normal metabolism would dictate. A typical biological phosphorus removal plant might have up to 6-10 percent P in the sludge (U.S. EPA, 1987). This P seems to be complexed into polyphosphate reserves which the bacteria can break down and utilize for "maintenance/survival" energy, when again subjected to conditions in which there are no usable terminal  electron  acceptors  available  (i.e.  anaerobic  conditions). In the early stages of Bio-P research, Shapiro et al., (1967)  considered  ORP  significant  enough  to  monitor  and  suggested it as a possible factor governing phosphate release. He  observed  that  the rapid  release  of phosphorus  in the  anaerobic zone appeared to occur around an ORP value of -150 millivolts. However, Randall et al., (1970) concluded that  36 phosphate release was not a function of, nor dependent upon, ORP since release often occurred before any significant change in the ORP level. Countering this, Barnard  (1976) proposed that ORP had  potential in characterizing the degree of anaerobiosis at the front end of a Bio-P plant. He stated this because it appeared that a certain minimum level of ORP had to be reached to ensure good P removal. Barnard eventually developed a modification of his Bardenpho  (Barnard Denitrification Phosphorus) nutrient  removal process, titled the Phoredox process, because of the lower redox potentials that could be achieved in the anaerobic zone. However, Barnard later abandoned the theory of a minimum anaerobic stress level in favour of the availability of simple carbon substrates as being the prerequisite for good P release. In a series of batch experiments Koch and Oldham, (1985) traced the ORP-time profile, in essence temporally modelling the spatial progress of a biomass/organic waste through a Bio-P plant.  One  reproducible  important  discovery  nitrate breakpoint  was  the  existence  (or knee)  of  a  in the ORP-time  profile, corresponding to the transformation between respiratory and non-respiratory processes. This breakpoint also correlated to the onset of anaerobic phosphate release, a key phenomenon in biological phosphorus removal. Koch and Oldham's experiments acted both to dispel some of the theoretical ambiguity in interpreting the ORP measurement and to counter the lack of enthusiasm which had plagued the use of  ORP  over  the  last  several  years.  Further  to  these  experiments, routine monitoring and visual inspection of ORP levels has become an integral part of recent biological nutrient removal research carried out at the University of British Columbia (Comeau et al., 1987a, 1987b, Zhou (1991)). Additional work by Koch et al., (1988) sought correlations between ORP values and nitrate, ortho-phosphate and dissolved oxygen concentrations, in several biological regimes particular to the bio-nutrient removal process. Several equations were derived relating ORP to dissolved oxygen, nitrate and phosphate concentrations. Since these equations are all sludge specific, no attempt has been made to verify them in this research. Furthermore, the sludge specificity of the equations makes the applicability of such equations questionable. The authors of the above research do acknowledge observed shifts over the course of the experiment, in the coefficients for regressions; therefore, there is certain to be variation in this research, done a few years later with a totally different sludge. This research, therefore, has elected to avoid regressions of this nature, abandoning them  in favour of highlighting  general  behavioral trends, not only for the Bio-P experiments (Chapter 5) but also for the AASD set of experiments (Chapter 4 ) . 2.5  Sequencing Batch Reactors (SBRs) 2.5.1  Overview of Operation Sequencing batch reactors are in essence, modern day  versions of the draw-and-fill systems used in the early days of sewage treatment (U.S. EPA, 1986). The original systems were fairly time intensive in nature, since they required an operator  38 to manually feed and draw the reactors at appropriate times, and initiate the various sequences during the day. The use of drawand-fill reactors tended to fade naturally with the advent of modern continuous flow through systems (CFS); however, since the SBR system merely provides in time what the CFS provides in space,  these  latter  systems  were  adopted  primarily  from  operational considerations and not from any process-related weaknesses of the batch system (Arora et al., 1985). Recent advances in technology such as the use of timer  controlled  microprocessors  pumps,  etc. have  solenoids, obviated  the  level need  sensors for  and  operator  controlled functions and revived interest in SBR technology. Following the convention adopted by the studies done at the University of Notre Dame, Indiana (Irvine and Busch, 1979) the operation of an SBR can be divided into 5 discrete operating periods entitled... (i)  FILL  - the receiving of the raw waste;  (ii)  REACT  - the time to complete the desired reaction(s);  (iii) SETTLE - the time to separate the organisms from the treated effluent; (iv)  DRAW  - the discharge of both the treated effluent and waste solids (if necessary) and;  (v)  IDLE  - the time after the effluent is discharged and before refilling.  One  or  more  of  these  periods  may  be  omitted  depending upon the control strategy desired, however at the very least all tanks must contain the FILL and DRAW periods (as for  39 example  in an equalization  tank).  A  sketch  of the  5  periods  during one cycle is shown in Figure 2.3. Advantages of an SBR system are numerous and make it ideal for small communities which experience wide variations in influent flows and strength. Some of the more obvious benefits include (Arora et a l . , (i)  (1985)...  Acting as an equalization tank during FILL it has an ability to balance peak flows and absorb shock loads;  (ii)  The effluent may be held until it meets specific objectives;  (iii) The MLVSS cannot be washed out by hydraulic surges; (iv)  There is no need for return activated sludge  (RAS)  pumping since the mixed liquor is always in the tank and; (v)  Solid-liquid separation occurs under near ideal quiescent conditions since short circuiting is nonexistent during the settle period. Furthermore there is no need for an extra tank for clarification since the same tank can serve as both a biological reactor and a clarifier. Probably the most readily apparent advantage is the  SBR's  flexibility  microprocessor  timer  of  operation.  settings,  Easy  allows  adjustment  timed  intervals  of to  the be  changed to permit different modes of operation. For example, a portion  of the REACT period  can be reserved  for  aeration  to  allow for nitrification while another portion can be dedicated to the denitrification process. Biological phosphorus  removal  40  INFLUENT Max Volume Min Volume  REACT  FILL  forat Add Substrate  do  DRAW  SETTLE  IDLE  Activated Sludge Intel face  Waste to Control SRT  Remove  cto  Clarified Effluent  Figure 2.3 Diagram of 5 Operating Periods of Bio-P SBRs  strategies can also be implemented in this way. Furthermore, a liquid level sensor could be adjusted to allow only a fraction of the tank capacity to be used during the early years of the design  life,  without wasting power  through  overaeration.  Finally, if more than one tank is used in series, tanks can be put on or offline to allow for seasonal variation. 2.5.2  SBR Applications in Wastewater Treatment Several recent studies at the University of Notre  Dame  (Alleman and Irvine  (1980a, 1980b), Palis and Irvine  (1985)), the University of California, Davis (Silverstein and Schroeder (1983), Abufayed and Schroeder (1986a, 1986b), and the University McCartney  of  Manitoba  (Oleszkiewicz  and Oleszkiewicz  and  Berquist  (1988, 1990)) have  (1988),  investigated  nitrification and denitrification in sequencing batch reactors. Primarily monitoring several SBR performance characteristics, most of the studies were able to consistently remove a very high percentage of the organic carbon and nitrogen in the wastewater. Sequencing Batch reactors have also be used to remove phosphorus both chemically (Ketchum and Ping-Chao Liao (1979), Ketchum et al. (1987)) and biologically (Manning and Irvine  (1985), Vlekke et al., (1988)). Again the inherent  flexibility of an SBR system allows the proper mix of anoxic, anaerobic and aerobic conditions necessary for Bio-P removal. In particular a control strategy must be selected which at a minimum eliminates oxidized nitrogen and dissolved oxygen during the FILL (anaerobic) period and allows for aeration during the REACT period (Manning and Irvine, 1985).  The increased interest in SBRs has been reflected in the number of studies done on full scale applications in recent years. Irvine et al., (1983, 1985, and 1987) have examined the operational performance of full scale SBRs at Culver, Indiana and Grundy Centre, Iowa under high and low loaded conditions and depending on the study have reported excellent effluent quality in terms of BOD5, SS, N and P removal despite varying influent conditions. Melcer et al., (1987) examined the conversion of small municipal wastewater treatment plants in Manitoba to sequencing batch reactors and reported that it was technically and economically feasible to convert the existing small-scale package plants and septic tanks to SBRs over the flow ranges studied (4 to 227 m3/d) .  43 CHAPTER 3 EXPERIMENTAL METHODS AND ANALYTICAL TECHNIQUES 3.1  Source of Feed Sewage and Sludge The  University  of  British  Columbia's  Environmental  Engineering Group manages a pilot-scale sewage treatment plant located  about  2 kilometres  south  of  the UBC  campus. The  facility, housed in a renovated tractor trailer unit, generally operates  in  specifically,  a  biological  phosphorus  it is a modified version  removal  mode.  More  of the well known  University of Cape Town (UCT) process (Figure 3.1), routinely depicted in papers published by South African researchers (eg. Seibritz  et  al., 1983).  This modified  configuration  will  henceforth be referred to as the UBC version (Figure 3.2) to distinguish it from its UCT predecessor. The process, treating primarily campus wastewater (and a small fraction of household domestic waste) is designed so that the operator can choose (by way of baffle insertion) the proper mix of alternating aerobic, anoxic and anaerobic sequences necessary to ensure good biological phosphorus removal. The sludge age is usually maintained at an average age of 2 0 days; however, flexibility in piping, valves and pumps, allows SRT variations as desired. The pilot-plant facility has two process trains, labelled side "A" ( the control) and side "B" (the experimental) . Either raw sludge or raw sewage was collected from the pilot plant as the needs of the experiment dictated. For the AASD experiments, sludge was collected from the aeration basin of the control  44 LEGEND Anaerobic Anoxic  [  Anoxic  | Aerobic  Aerobic  Waste  Secondary Clarffler Effluent  Figure 3.1 UCT Bio-P Process  LEGEND Anaerobic Anoxic Aerobic  Anoxic Secondary Clarifler Side A  Effluent  Sludge Fermerrter (Mixed)  Side B  (Not used)  Figure 3.2  UBC Bio-P Process  45 ("A") side in the manner which will be described in Section 3.3. The side "A" configuration includes a primary sludge fermenter to generate volatile fatty acids for later addition to the anaerobic portion of the process. In addition, external equalization tanks, plus a primary clarifier, are merged into the process train so that the aerated sludge is fairly "clean" in the sense of being uniform in nature and having very little, if any, of the organic and inorganic "problem" materials that sometimes create difficulties for a sewage treatment plant. Thus, no pre-treatment of waste sludge was required. For the Bio-P set of experiments, raw sewage was obtained  from  the  equalization  tanks  in  the  manner  also  described in Section 3.3. 3.2  Experimental Set-Up and Design 3.2.1  General Structural Configuration A block diagram highlighting the major components of  the research different  apparatus, is shown  structural  arrangements  in Figure of  the  3.3.  Slightly  Sequencing  Batch  Reactors (SBRs) were used for the AASD and Bio-P experiments respectively, and these are illustrated in the schematic of Figure 3.4. Table 3.1 itemizes the particular model numbers of many of the experimental components. In general, the reactors were made of plexiglass (Diameter = 12 cm., Volume = 5.4 litres) and filled to the 4.8 litre mark with either activated depending  upon  the  experiment.  sludge and/or raw sewage Spigots  for  sampling  and  solenoids for decanting etc. were placed at strategic heights  46  Fixed-Time (Control)  Reactor  Real-Time (Experimental) Reactor  12BrtA/D Converter Board  Air Compressor  Air Pressure Regulator  Note: In actual reactor all 6 probes (i.e 3/reactor) connect to computer  Figure 3.3 Schematic of Experimental System  47  Variable Speed Mixers  Variable Speed Mixers  5.4 L Vol. 12 cm. 0 Plexiglass  Overflow  4.8 L Vol.  4.8 L Vol. Max Acetate Addition  2.4 L Vol. MIn  3=n  Sampling Ports  Effluent Drawoff  [f=£.  Waste  Sludge Waste Influent Settled Sludge  Wastewater  Air Supply AASDSBR  BIO-P SBR  Figure 3.4 Schematic of AASD and Bio-P Sequencing Batch Reactors  Table 3.1 Components EXPERIMENTAL COMPONENT  Experimental Apparatus DESCRIPTION OF ITEM  Air Pressure Regulators - 2  Parker Model # 07R218AB  Air Solenoids - 2  MAC 113B-112CCAA  Air Flow Meters - 2  Cole-Parmer PR0034-FM32-15ST  Mixing Motors - 2  Dayton DC Model #47539A  ORP Probes - 3/Reactor  Broadley-James #P114101-10BC  Computer  Morse Shuttle 386-SX AT  Analog-to-Digital Card  Data Translation DT2814  Input/Output Control Card  Metrabyte Model PIQ12  Standby Power Supply  American Power Conv. UPS-SX  49 and utilized according to the operating strategy. Wasting and feeding of the sludge in the AASD experiments was done manually, while  for  the  Bio-P  experiments  the  liquids  were  pumped  automatically, entering and exiting the reactors at appropriate levels. Air for both experimental sets was supplied by an in-house compressor at 410 - 550 kPa (60 - 80 psi) . Two pressure regulators, connected  in series at the air supply outlet,  subsequently reduced this pressure to approximately 100 kPa (15 psi). The airline was then split into two separate lines, with each line passing through an air solenoid (ON/OFF regulation controlled  by  computer)  before  continuing  on  through  an  adjustable air flow meter (rated range 55-165 mL/min). The lines then looped around below the reactor underside to flow through a diffusing stone before entering the reactor. The AASD digesters (and Bio-P reactors when in nonquiescent conditions) were completely mixed by a stainless steel shaft with an appropriate blade design. Visually, complete horizontal and vertical mixing appeared to be achieved. At three strategic points Broadley-James Corporation combination oxidation-reduction potential probes were inserted into  each  reactor.  These  probes  use  a  Ag/AgCl  reference  electrode with a platinum band as the noble metal. The probes were affixed physically to one end of a piece of rigid plastic tubing which subsequently slid, with minimum resistance inside the sleeve of yet another plastic tube. This latter tube opened up through a ball valve into the interior of the reactor, acting  50 as a conduit to allow the ORP probe to slide, with some degree of ease, into and out of the reactor. An O-ring seal sandwiched between the two cylinder walls prevented liquid being forced by back-pressure from the reactor. The three probes were labelled a, b, and c to denote the front, side and back of the reactor from the perspective of facing the experiment on the computer side of the research bench. Thus, in referring to the ORP probe in the front of the right reactor (labelled RCTR#2 - Section 3.4.1) the nomenclature 0RP2a would be used. 3.2.2  Electronic Hardware In the experimental environs used in this research,  the ORP probes generate a low-level voltage electrical signal in the range of -300 to +300 mV. Furthermore, the total electrode resistance is generally in the order of 10 Kohms (Petersen, 1966), thus an application of Ohm's law reveals that the current is quite small (around 30 microamps). Moreover, due to the physical construction of the probe, even larger resistances (in the order of Mohms) are possible. These subsequently produce extremely small currents, thus coaxial shielded cable was used from the probe to the computer to protect the signal from induced currents. Magnetic stirrers and water baths are among the commonest sources of noisy readings (Midgley and Torrence, 1978); however, all electric motors and any ancillary apparatus containing  relay  switches  (ex. ovens  and  hotplates)  were  suspect. The source impedance of the probe was measured and  51 observed to be greater than 15 Mohms  (Milligan, 1989). The  probes were therefore connected to a custom-built amplifier (having a large input impedance (100 Mohms)) in order to more accurately measure the voltage. Figure 3.5 indicates the theory behind this, by replacing the ORP probe with an ideal voltage source (0 internal resistance) in series with a resistor having the corresponding source impedance. The largest value of Vin will occur when the input impedance of the amplifier is much larger than the internal resistance of the source (Weber and Maclean, 1979) . Sporadic results (documented in Section 4.2.1) were initially obtained due to the lack of a common ground between the coaxial shield of the probe cable (left floating) and the amplifier chassis, whose differential inputs were also both floating. Furthermore, unshielded wire inside the amplifier resulted in rampant pick-up of electrical noise. Modifications to the amplifier and elimination of ground loops eventually corrected these problems, leading to reasonably  stable ORP  measurements. As shown previously  (Figure 3.3), the amplifier  output connected to a junction box which relayed the signal through an electronic cable into the back of the computer. Inside the computer, an analog to digital (A/D) card (16 singleended  input  channels) converted  the  signal  (via a  12-bit  monolithic converter) into binary code which could be processed by the host computer. Working with a range of -500 mV to +500 mV (1 Volt) an ORP resolution (change) of 1000 mV/212 = 0.25 mV  52  ^ORP AAAA WW  J  :  ; i  V  ORP  £ R > INPUT  IN  ( ^ i Model of ORP Signal Source  Input Model of the Amplifier  V = Voltage of the ORP Source ORP R O R p = Internal Resistance of the ORP Probe R lupin- = Input Impedance of the Amplifier I = Current V  = The Voltage across the Amplifier = I R IN  INPUT  ORP V  ORP  =  R  ' ORP +  Thus:  V IN  '  R  INPUT "  ' (  R  ORP +  R  INPUT)  *•"  ORP ' ( "ORP  R  R  INPUTJ  INPUT)  'ORP  Thus:  IFR INPUT > > >  (R ORP  ORP  = +  '  =  + 1  INPUT R  ORP  then V  =  V ^  Figure 3.5 Impedance Diagram of ORP-Amplifier Circuit  INPUT'  difference was obtainable. At  various  stages  in  the  research,  different  computers were dedicated to the project; however, most of the preliminary work was performed on a Laser Turbo XT-2 computer operating at various times with a Central Point Software, Juko ST and finally  Phoenix, BIOS on its motherboard.  For the  majority of the control runs a Morse 386-SX AT computer was used. To provide protection from brown-outs and power failures, an uninterruptible power supply (UPS) was purchased into which the computer and all power cords were plugged. When the input power line voltage dropped below an acceptable level (15 % below nominal), the UPS automatically transferred to battery operation (in less than 3 milliseconds) providing an output wave in the form of a sinewave approximation. During the course of this research, several momentary blackouts occurred and in all cases the UPS performed admirably and kept the process operating. For control purposes, a commercial I/O control card was purchased which  fitted  into an expansion  slot in the  computer's motherboard. The interface card provided 24 TTL/DTL compatible digital I/O lines, split into three 8 bit ports (Metrabyte Corporation, 1989). The I/O lines were linked to a bank of solid state relays (16) mounted on the inside of the box housing the computer. These, in turn, were wired to two socket power bars (mounted on the outside of the computer box) which were  modified  so  that  each  outlet  could  be  controlled  independently by a single solid state relay. The pumps and solenoids were plugged into this latter bank of sockets and thus  54 control, originating from software switching bits (1 = ON, 0 = OFF), was finally established. 3.2.3  Computer Software The  successful  implementation  of  a  computer  controlled system is very much an "evolutionary" process. This is most evident in the development of the computer software. For example, the AASD*1 control software (Section 3.4.1), underwent 7 major structural modifications (not including numerous small adaptive measures taken to refine the program) before arriving at its "final version" form. The software was written using QUICKBASIC 4.5, a mature  form  of  the  original  BASIC  language  developed  at  Dartmouth College over 25 years ago. Not only is it very popular (Shammas, 1988) , it is much more powerful than its earlier predecessors due to the advent of callable subroutines, numeric and alpha-numeric labels (used to direct program flow), and powerful new decision making constructs  (Microsoft, 1987a,  1987b, 1987c). The lone exception to the QUICKBASIC 4.5 language was the software used to access the A/D board which was written for expediency in Microsoft Assembler Language by an in-house UBC computer technician. The prime advantage of QUICKBASIC 4.5 is that it can be written  in a modular  fashion. That  is, a function or  subroutine can be written, debugged and then installed as a separate module into any main program, written at various times and for different needs. Thus, the majority of subroutines and functions written for this research are common to both the AASD  55 experiments and the Bio-P experiments, with subtle differences reflected in the structural flow of the main control program and occasionally the order in which common subroutines are invoked. The Bio-P experiments also use separate controllers to operate some of the pumps and solenoids, in order to minimize the complexity  of  the  main  Bio-P  control  program.  Table  3.2  catalogues the main control and subroutine/function modules incorporated into all three operating strategy programs. Flowcharts of all subroutines, functions and main control programs have been relegated to Appendix C, while the associated software code can be found in Appendix D. A detailed description of the mechanics of the program is not necessary here; however, some general comments are offered below. The structure of the main control programs (i.e. one for each AASD operating control strategy and one for the Bio-P experiment) is fairly sequential with the majority of control actions dictated by flag switches; these are set and reset to TRUE and FALSE respectively, in order to activate or deactivate specific relays. ORP data files are written to the hard disk with a nomenclature specifying the type of reactor (Fixed-Time (FT) or Real-Time (RT)) appended to the date (ex. 90-04-21.RT). Message files for both reactors coexist under an appropriately dated file (ex. 90-04-21.msg). Due to some initial incompatibilities between the software and hardware, the programs are designed to alternate between graphics continuous  and  text mode, rather  than  graphics mode. Thus, the user  can  operating  in  periodically  56  Table 3.2 Subroutines and Functions in Each Experiment Main Programs  AASD*1 AASD*2 BIO-P  Functions  Global.bi Typrobe$ Jinkey% Getscanl%  Subroutines  Inform Filename Initrelays Relayswitch Refresh ORPscreen Axes Paxis Scans Diff Writing Transfer Plot Breakpt Layout Update  57 interact  with  the  computer  to  graphically  access  recent  historical plots of the ORP-time profile. When a plot is requested, the computer transfers the ORP data of the probe selected, to a common array, and after refreshing the screen, uses the PLOT subroutine to lay out the profile. The ORP probes are scanned by accessing the ON TIMER (Scantime) event-trapping Quickbasic 4.5 feature, which directs program flow (every number of seconds equal to Scantime) to a READPROBE subroutine which further invokes a function GETSCAN1%. After a certain number of scans have elapsed, the computer interrupts this loop to "drop" through the rest of the program where it calculates first-differences, writes data to disk files, checks flags according to externally-timed conditions, searches for the breakpoint (if in the appropriate phase of the cycle), and scans the keyboard buffer for user requests. The subroutine BREAKPT requires a more detailed explanation, since it is the cornerstone upon which control is based. BREAKPT operates as a "Linear Ring-Buffer", a term coined to describe the effect of a moving window along the slope of the ORP curve. BREAKPT is invoked when the computer registers (by way of a flag) that the air supply has ceased. After an initial delay to acquire stability (as air bleeds from the line) , the computer begins to load the first Ring (5 points wide) with ORP first-difference points  (i.e. the first-difference or slope  between two adjacent ORP values) until the Ring is complete. When the Ring is complete, an average of all five firstdifferences in the Ring is calculated and assigned to Ring(l)  58 which also receives the title "FirstRing" in the Ring-Buffer. (Note: The actual software variable names have the appropriate letter appendages, corresponding to the probe in question, ex. Ring2a(l) and FirstRing2A etc.) The next first difference point drawn into the RingBuffer (i.e. Pt 6) becomes the last point of (i.e. completes) Ring(2), while Ring(2)*s first point corresponds to the second point already in the Buffer. An average first-difference for Ring(2) is now calculated based on points 2 to 6. In other words each succeeding point is admitted into the Buffer to complete the Ring formed by abandoning the point occurring 6 points earlier. Finally, the terminal Ring in the Ring-Buffer (Ring(5)) is reached and is assigned the title "LastRing" (Figure 3.6). The value of LastRing is then compared to FirstRing and if it is substantially more negative (in this case DELTA is set to -1.25) the breakpoint is assumed to have occurred. The slope difference limit is somewhat arbitrary and is a function of the probe responsiveness. Preliminary testing, consisting of alternately  tightening  and  loosening  the  knee  constraint,  indicated that a value of -1.25 for all probes was sufficient to detect the knee in the majority of cases (Figure 3.7). In the event that the slope change between LastRing (Ring(5)) and FirstRing (Ring(l)) is less than DELTA (i.e. more positive), the entire Ring-Buffer shifts, with the next firstdifference point flowing in to complete Ring(6)  (which now  becomes LastRing). Concurrently, Ring(2) now receives the title FirstRing. The new slope difference is calculated and compared  RING-BUFFER (1)  A  B  B  = LastRing-Ftretfling >=-1.25  B  B  E  B  B ..  Rlngl (FirstfHng)  RING -BUFFER (2)  t t t f t t t f t t t f t t t  z Differvies  Pto  1  2  3  4  5  6  7  8  9  10  11  12  13  14  15  Figure 3.6 Illustration of Unear Ring-Buffer Concept  ORP IstOiffPts 1 2  3  LastRing - Firstfllng >• 4  SLOPE  DIFFERENCES  ORP  —1.25 (Knee is Trapped)  5  AVERAGES OF 1ST  istompts  /\  Into Ring  Ring  Number  Title  Firstfllr  PTS(1-5)  Rlngl  PTS (2-6)  Rlng2  PTS (3-7)  Rlng3  PTS(4-8)  Ring4  PTS (5-9)  RlngS  LastRIn  Figure 3.7 Illustration of BREAKPT Capture of Nitrate Knee  to DELTA and again, if it is less (i.e. more positive), the Ring-Buffer continues to move in sequence. In this way, the Ring-Buffer functions as a moving window across the ORP profile until the knee is trapped by a difference in slope greater than DELTA (Figure 3.7). It should be noted that there is a requirement that only two of the three probes detect a knee in order for control to be initiated. This serves as a protective measure should one probe  suddenly  become  inoperative.  It  also  permits  the  withdrawal (and disconnection from the amplifier) of one probe for cleaning purposes. Experience has shown that it is best to withdraw the probe during the aerobic portion of the cycle, since the computer during this time is merely recording values, rather than actively searching for a control-based feature. Moreover,  reinsertion  allows  some  time  for  the  probe  to  acclimate to reactor conditions before measurements again become critical for control purposes. The program also utilizes global variables in an INCLUDE file, so that both the size of the ring (RINGSIZE, currently set to 5) , the width of the Ring-Buffer (NUMRINGS, currently  set  to  5)  and  the  individual  knee  constraints  (DELTA2A, DELTA2b, and DELTA2C, currently all set to -1.25) can be varied as a function of the operator experience with the ORP probes and the type of waste. Finally, should the knee not be detected for whatever reason (ex. all probes foul (become less responsive) to the point where the knee constraint becomes too severe) some intelligence in terms of a time-base is built into  61 the program to initiate air resupply (in the AASD experiments) or to initiate acetate additions (in the Bio-P experiments), in order to keep the process respiring. 3.3  Raw Feed Collection Procedures During the AASD set of experiments, the SBRs were operated  in a semi-continuous mode, in the sense that they manually received feed in a batch manner (once/day). Thus, activated sludge was wasted diurnally from the pilot-plant aeration basin, by routing it to the sludge thickener, where after 20-30 minutes of gravity settling, the sludge blanket interface, (initially at a level of 100-110 litres  (a function of the system SRT))  usually reached the 40-50 litre mark. The sludge was then drawn off by means of a control valve or pump and collected in a 4 litre milk container for transport to the UBC lab. Once there, it was allowed to gravity settle a second time where a visual inspection  of  the  sludge  consistency  and  settling  characteristics, usually meant that about half the clarified supernatant would be decanted off and disposed of down the drain. By systematically adhering to this two stage thickening process,  the  raw  feed  sludge  consistently  had  a  MLSS  concentration roughly 3 times the aerobic basin of the pilot plant. Furthermore, for the most part, the feed MLSS was greater than  that  in  the  laboratory  reactors.  After  wasting  an  appropriate amount from the reactors (Section 3.4.1) the feed sludge was then added (after shaking to ensure a uniform MLSS concentration)  into the top of the reactor to maintain a  62 constant reactor volume. The  remaining  feed  sludge  was  stored  in  a  Bell-Par  Industries environment chamber held at a constant temperature of 4 °C. For the most part this volume was stored purely for contingency purposes should fresh feed from the pilot plant suddenly become unavailable. In the Biological Phosphorus (Bio-P) Removal experiments, raw sewage was obtained directly from the external equalization tanks  located  outside  the  pilot  plant  facility.  After  collection, it was transported in carboys to the lab to be stored at 4 °C, for up to a maximum of 12 days. 3.4  Operating Control Strategies 3.4.1  Aerobic-Anoxic Sludge Digestion *1 (AASD#1) As mentioned in Section 1.2, the main objective of  this research was to demonstrate the potential ORP has to control sequencing batch reactor wastewater treatment systems. Thus, operating strategies were formulated both to demonstrate control and to evaluate the effectiveness of ORP as a process control parameter. The first such strategy  involved  aerobic-anoxic  digestion of waste activated sludge. It was structured such that the Control Reactor (RCTR#1) was known as the Fixed-Time Control (FT) reactor, since the ON/OFF sequence was "fixed" at 3 hours of air-on and 3 hours of air-off. The ratio of air-on to air-off was arbitrary and other reasonable ratios consistent with the literature review comments (Section 2.3) could have been used. In contrast, the Experimental Reactor (RCTR*2) was  63 labelled as the Real-Time Control (RT) reactor, since the on/off sequence consisted of a 3 hour air-on period (as before) but a variable length of time for air-off, contingent upon detection of  the nitrate  breakpoint. Reactor *2  exhibited  Real-Time  behaviour in the sense that it operated in an instantaneous online self-adjusting fashion. The rationale for adopting this control strategy is that theoretically, the Real-Time Control reactor should provide better treatment  (in terms of solids  degradation) since the bacteria are always ensured a ready supply of highly efficient electron acceptors (be they oxygen or nitrate). Thus, the different sequences of the reactor allow for effective organic carbon removal, and alternating nitrification and denitrification. Both digesters were controlled on the basis of solids retention time (SRT), as this was convenient to use, has significant merits (Smith 1978), and can be related to solids loadings when variations in feed and digester TVSS are recorded as part of the daily solids inventory. Since the reactor volumes are constant (4.8 litres) and there is no recycle, the SRT equals the hydraulic retention time (HRT). The SRT chosen for the AASD#1 experimental runs (10 days) was admittedly on the low end of the scale (Metcalf and Eddy, (1979) recommends 10-20 days); however, a shorter SRT translates to a larger volume wasted according to the equation below. SRT = volume of digester volume wasted per day  (3.1)  On track-study sampling days, larger volumes were  necessary in order to accurately track parameters (such as N0X and NH3) which theoretically range from 0 to 100 % of their full value,  throughout  the  course  of  one  aerobic-anoxic  cycle  (assuming complete nitrification-denitrification). Thus, with a 4.8 litre liquid volume and a 10 day SRT, 480 mL of sludge was wasted on a daily basis and in due compensation, 480 mL of feed sludge was added to keep the reactor volume constant. Other  operational  nuances  included  occasional  scraping of the digester walls to return biomass accumulations to the system. Distilled water was also added on a sporadic basis to compensate for evaporative losses. Evaporation was not perceived to be a problem, as there was seldom an observable discrepancy between the liquid level in the reactors and the 4.8 litre reference mark on the cylinder walls. Prior to start-up, the digester solids concentration was increased significantly by wasting (after a brief settling period), a clarified volume of supernatant (low MLSS) equal to that required to keep a constant SRT. The feed sludge (with a relatively high MLSS) was then added to artificially increase the solids level in the reactors, in an attempt to more closely simulate field digester conditions (> 30,000 mg/L). Before  each  run,  the  reactors  thoroughly cleaned and some of the tubing  were  drained,  (most often the  sampling ports and air supply lines) was replaced. The diffusing stones were also acid washed to remove accumulated microbial growth tending to blind off the air pores. The ORP probes were also cleaned as will be described in Section 3.5.4. The sludge  from  both  reactors  was  then  mixed,  split  into  two, and  reintroduced into the reactors, so that both reactors ostensibly had  identical  starting  conditions  in  terms  of  biomass  characteristics and concentrations. Both reactors were then operated on a Fixed-Time basis for at least two days. If the ORP profile with time consistently produced the characteristic features described in Section 4.2.2. (i.e. In both reactors nitrate knees were present and dissolved oxygen levels during the plateau region of the ORP curve were between 2-4 mg/L  (and roughly equivalent) ) , the  decision to switch to Real-Time control of Reactor implemented.  It must  be noted  however, that  #  2 was  if the user  requested real-time control, it was not until the next anoxic cycle that the computer switched over to this form of control. This circumvented the possibility that the user request could come during an anoxic sequence, in which the knee had already occurred. In order to assess the ability of ORP to effectively maintain control under duress, and to evaluate ORP as a process control parameter, perturbations to the operating strategies were investigated. The first and most natural disturbance to the system involved interrupting the daily wastage and feed pattern, simulating a breakdown in supply (i.e. the waste pumps from the aeration basin). As available carbon for the denitrification reaction  was  exhausted,  the  time  necessary  to  complete  denitrification became elongated; thus, this strategy sought to demonstrate the flexibility of control based upon actual rather  66 than fixed denitrification times. Other aggravations  included  additions of strong  oxidants (hydrogen peroxide and sodium nitrate), and ammonia chloride spikes, all designed to observe the stability of ORP under transient influent conditions. After each disturbance a recovery  time period  was  allotted  to  allow  conditions to  normalize. 3.4.2  Aerobic-Anoxic sludge Digestion *2 (AASD*2) Much of the preceding discussion is applicable to  the second sludge digestion experiment. It should be noted however that AASD#2 was operated at an SRT of 20 days. The control reactor again operated in a Fixed-Time fashion (3 hours air-on, 3 hours air-off), a practice which can also be described as operating in a 50/50 air on/off manner. In contrast to AASD#1, the Real-Time reactor also operated in a 50/50 fashion, by matching its length of aeration period to the previous time for denitrification. In otherwords, the preceding cycle's total time to eliminate the nitrates (as calculated from the moment the air supply terminated, to the nitrate breakpoint  (assuming near  instantaneous disappearance of D.O.)) was recalled from memory and allocated to be the length for the following  cycle's  aeration period. In this way a 50/50 strategy was maintained. As mentioned in Chapter 1, it was suspected that an ORP-driven,  50/50  strategy  might  prove  stressful  for  the  organisms; in the sense that the strategy might collapse in on itself, with very rapid air on/off periods. However, if the bacteria seemed to readily accommodate this strategy, it might  provide grounds for further investigating a control strategy which alternated extremely rapidly between denitrification and nitrification, as determined by the features on the ORP-time curve (Section 4.1). Such a strategy might induce considerably savings, through the discontinuing of overaeration during the nitrification portion of the curve. 3.4.3  Biological Phosphorus (Bio-F) Removal In Bio-P removal , the SBRs model in time the plug-  flow treatment of a waste subjected to the right mix and sequence  of  aerobic, anoxic  and  anaerobic  conditions. The  operation of the two reactors differed in one aspect, that being, the timing for the addition to the reactor of volatile fatty acids (in this research acetate). The Fixed-Time reactor had the addition scheduled at 1 hour and 25 minutes (modelled after Comeau, 1989) into the anoxic period, while the Real-Time reactor had its timing triggered by the nitrate breakpoint. The SBR operation during the Bio-P experiments was somewhat more complex and thus commercially-purchased Chrontrol timers were used to initiate and control most of the sequences during the cycle. For both reactors, the period lengths (Table 3.3) were modelled after Comeau (1989), with each cycle having a total length of 8 hours. During the FILL phase (10 minutes), raw wastewater was pumped from an influent feed bucket to the reactor, where it underwent the first REACT (unaerated) period for 2 hours and 50 minutes. As indicated, approximately in the middle of the unaerated REACT period (after anoxic conditions had ended) acetate (30 mg per litre of raw influent) was pumped  68  Table 3.3 Timing of Phases in a Bio-P SBR SBR PHASE  CONTROL ACTION TIME ON (Hrs:Min)  FILL Period  Feed Pump (0:10)  I  ,— 0:00  REACT (Unaerated)  (2:50)  t  o: iu  Anoxic Period Anaerobic Period  TIME DIAGRAM  (1:25) Acetate Pump (0:06) (1:19)  i •r  *?-nn o.uu  REACT (Aerated) Air Solenoids (4:00) 1  Waste Pump (0:10)  T •  1  / ,uu SETTLE Period  (1:00) Wastewater Mixers (Off)  DRAW/IDLE Period  Effluent Solenoids (0:10)  i 1 •  f  — 7:50 8:00  69 for 6 minutes into the reactors. Subsequently, the following REACT  (aerated) period lasted for 4 hours while the SETTLE  period lasted for 1 hour and included a 10 minute DRAW/IDLE period. Wasting normally occurs during the DRAW period, however, since the sludge settled well below the half-way decanting port, it was not possible to waste at this time. Thus, once/day, in the middle of the REACT (aerated) period, mixed liquor was wasted to control the sludge retention time at 20 days  (a typical  SRT for Bio-P plants) .  The practice of  decanting one half of the reactor contents every 8 hours (i.e. clarified effluent only) made for a 16 hour hydraulic retention time. 3.5  Analytical and Sampling Techniques 3.5.1  General Procedures As mentioned previously, the volume for a particular  test was deducted from the total volume wasted. In all cases before extracting a sample, the sampling port was opened and allowed to run briefly, clearing the line of residual material not fully exposed to REACT conditions. This volume was returned to  the  reactor  before  reopening  the  port  to  obtain  a  representative sample. In addition, an appropriate volume of feed sludge or sewage was set-aside and reserved for later analysis. Sampling, handling and preservation time before analysis was kept to a minimum, with the majority of tests conducted in accordance with Standard Methods, 15th Edition  70 (A.P.H.A. et al., 1980). Exceptions and non-standard testing procedures are discussed in the following sections. 3.5.2  Suspended Solids Measurements Due to the elevated  concentration  of suspended  solids in both the AASD digesters and feed sludge (>5000 mg/L), the Gooch crucible method of solids determination was deemed impractical, as discussed by Anderson (1989). Instead, daily solids were determined by taking duplicate 25 mL aliquots of well mixed sludge or feed (measured in a graduated cylinder) and transferring them to 50 mL centrifuge tubes. These were then spun down at 2500 rpm in an IEC Clinical Centrifuge until solids capture was judged complete (about 10 minutes). The supernatant fraction was vacuum-filtered through a previously tare-weighted, Whatman 934AH glass microfibre filter (5.5 cm diameter), which had been removed from its aluminium storage dish. The sludge residual at the bottom of the centrifuge tube was then scraped out and washed on to the filter paper. The aluminium dish (with the filter paper replaced inside) was then transferred to a Fisher Isotemp forced draft oven (Model 350) , operating at a constant temperature of 104 °C, where it was left to dry overnight. Reweighing with a Mettler AC 100-S2 balance allowed calculation of the Total Suspended Solids (TSS) concentrations, with an average of the duplicate samples assumed to be representative. Total Volatile Suspended Solids (TVSS) was determined by weighing the cooled residue remaining after igniting the dish to 550 °C (for one hour) in a Lindberg muffle furnace (Type 51828).  71  3.5.3  pH, Alkalinity, Dissolved Oxygen and Temperature All pH measurements used a Beckman $ 44 pH meter  with automatic temperature compensation (ATC). Several different probes were used throughout the research; however, the meter was routinely calibrated using twin standard buffers (4.0 and 7.0 or 7.0 and 10.0) before being placed into 25 mL of unfiltered reactor and feed samples. Temperature measurements were made with a mercury thermometer. When dissolved oxygen readings were of interest a Yellow Springs Instrument (YSI) DO meter (model 54ARC) was used in combination with a YSI 5739 submersible probe. The membrane was changed on a regular basis to ensure effective D.O. transfer across the membrane. Samples for total alkalinity were titrated to an end point of pH of 4.5 with 0.02 N H2S04 acid. 3.5.4  ORP Measurements In keeping with the focus of this research, ORP  measurements  were  recorded  continuously  using  the  probes  described in Section 3.2.1. Probe responsiveness was tested prior to each run by immersion in a quinhydrone solution. Quinhydrone, an organic acid, sets up a well-defined equilibrium potential particular to a given pH and temperature. Accordingly, 2 grams of quinhydrone were dissolved into 200 mL of pH = 4 and pH = 7 buffer solutions (ASTM (1983)) and each probe in turn was inserted into the solution. At a pH =  4  (T = 18 °C) , an ORP probe  (with a Ag/AgCl reference  electrode) is expected to yield an ORP measurement of 270  72 millivolts. The corresponding value for a pH = 7 solution is 92 millivolts. In all cases, the ORP probes responded to within 5 to 20 millivolts of the expected value, although with varying degrees of speed (usually 2-15 minutes). During this research it was seldom necessary to resort to some of the harsher cleaning methods described in the American Society for Testing Materials  (ASTM) handbook. The  relatively clean waste and the frequency of aerobic conditions seemed to prohibit the build-up of slime films on the platinum ring which sometimes impede the rate of electron transfer across the surface. Normally all that was necessary was a distilled water rinse followed by a perfunctory wipe with a kleenex tissue. If visual discoloration of the noble metal persisted, the probes were dipped into either a dilute HCl or chromic acid ( 1 g K2Cr207 in 100 mL of concentrated H2S04) cleaning solution, as recommended by the ASTM. In  some  probes  there  was  a  slow  movement  of  microbial growth (resembling a wetting front) up the ceramic porous plug which could have possibly reduced the ion transfer necessary to maintain electroneutrality. As this plug could not be physically accessed for cleaning, no remedial action was taken. 3.5.5  Nitrogen Analysis Nitrate and ammonia samples were first filtered  through Whatman No. 4 filters prior to analysis. Nitrate was analyzed in triplicate by the colorimetric automated cadmium reduction  method  (A.P.H.A.,  1980),  using  a  Technicon  AutoAnalyzer II Continuous Flow Analytical System (Industrial Method No. 100-70W). The cadmium granules advocated in this method were replaced with a cadmium wire. The strip chart recorder peak heights were compared with the heights from a series of standards of known concentrations. Ammonia Nitrogen was measured using the automated phenate method, with the intensity of the colour complex formed, determined by Industrial Method No. 98-70W on the AutoAnalyzer II. Total  Kjeldahl  Nitrogen  (TKN)  (in  the  AASD  experiments) was determined by digesting 2 mL of the sample (and an appropriate volume of the standard) on a BD-40 block digester (in the presence of concentrated H2S04 and K2S04) in order to liberate all organically bound nitrogen. Samples and standards were  then  analyzed  AutoAnalyzer  II  colorimetrically  (Technicon  in  triplicate  Industrial Method  on  the  No. 376-75W).  Percent N in the Bio-P experiments was measured exactly the same way except, instead of a liquid sample, approximately .025 grams of dried solids sample was used. 3.5.6  Phosphorus Analysis Ortho-phosphate (in the form of PO^,"3* was determined  on filtered samples using the automated ascorbic acid reduction method  (Technicon  Industrial Method  No. 327-74W).  In this  method, ammonium molybdate and potassium antimonyl tartrate react with orthophosphate, to form an antimony-phosphomolybdate complex which  yields  an  intense blue  colour  suitable  for  photometric measurement after reduction with ascorbic acid. Samples for total Phosphorus (TP) and/or % P were  74 prepared and measured in the same way as TKN, with digestion on the block liberating all organically bound phosphorus. During the process, liberated phosphorus is oxidized to orthophosphate, the concentration of which can be determined by comparison to peak heights of known standards in the automated ascorbic acid reduction method described above. 3.5.7  Estimates of Carbon Content In order to characterize the sludge (i.e. determine  a  C:N:P: ratio) particulate  samples for COD analysis were  analyzed using the dichromate reflux method outlined in Standard Methods (A.P.H.A., 1980). Fifty mL of the sludge was diluted to 500 mL (i.e. a 1/10 dilution) with 10 mL duplicate volumes withdrawn by wide mouth pipette and transferred to the reflux flasks. Total Organic Carbon  (TOC) was performed on the  soluble fraction of the sludge using a 10 mL sample volume. The samples were run automatically on a Shimadzu Total Organic Carbon Analyzer (Model TOC-500) using a series of low and high standards. Combustion of the sample resulted in the production of a quantity of C02 proportionately equal to the amount of carbon in the sample. 3.6. Sample Preservation and Storage Techniques Whenever possible, samples were analyzed promptly after collection  and  preparation.  Table  3.4  summarizes  sample  preservation and storage techniques when expediency dictated later analysis.  75  Table 3.4 Sample Preservation, Analysis and Detection Limits Chemical Parameter  Sample Volume Preservative Storage Period  Analyzed by  Dichromate Reflux Method  COD  50 mL Frozen Indefinite  TOC  10 mL Frozen Indefinite  NOx-N  3 mL Phenol Mercuric Acetate 3 weeks @ 4°C  Autoanalyzer Colorimetric Automated Cadmium Reduction  3 mL Cone. H 2 S0 4 3 weeks @ 4°C  Autoanalyzer Colorimetric Method  TKN %N  3 mL (TKN) 0.025 g (%N) Cone. H2S04 3 weeks @ 4°C  Autoanalyzer Colorimetric Method  TP %P  3 mL (TP) 0.025 g (%P) Cone. H2S04 3 weeks @ 4°C  Autoanalyzer Colorimetric Method  3 mL Phenol Mercuric Acetate 3 weeks @ 4°C  Autoanalyzer Colorimetric Ascorbic Acid Reduction  NH3-N  Ortho-P  Shimadzu TOC-500  76  3.7  Statistical Techniques Averages, standard deviations, maximum and minimum values  were calculated using the software program Symphony (release 1.2) of Lotus Development Corporation (Cambridge MA).  77 CHAPTER 4 AEROBIC-ANOXIC SLUDGE DIGESTION EXPERIMENTS 4.1  Review of Special Features of ORP Curves Before highlighting some of the mechanical and biological  nuances particular to this research, it is necessary to describe in greater detail, the expected shape of an ORP-time profile, generated when activated sludge is subjected to alternating aerobic-anoxic conditions. Although the main feature of interest is the nitrate breakpoint  (or knee  (which it superficially  resembles)), several other distinctive features exist, some of which may offer potential for control in later research. Since other investigators (Peddie et al., 1988, Jenkins and Mavinic, 1989b) have described these features in detail, only a brief review is presented here. Figure 4.1 displays the classical form of an ORP-time curve produced from an AASD reactor experiencing Fixed-Time conditions (3 hours of air-on, 3 hours of air-off). It can be seen that the ORP probe responds to the influx of oxygen by rising rapidly (as air is supplied to the reactor), even though the dissolved oxygen curve (the dotted line) shows no measurable response. During this initial period it is presumed that oxygen is being consumed  (as soon as it becomes available) by nitrifiers,  oxidizing the ammonia built-up from the previous anoxic portion of the cycle. This is shown by a decrease in NH3 (diamond marker) and  an  attendant  increase  in  the  nitrate  concentration  (triangular marker). Once the majority of this reserve has been transformed to  ORP Plateau  MLVSS/MLSS = 5188/6500 = 0.80; pH = 6.86  _2 a \ Dissolved Oxygen "Breakpoint" ^ (Point of D.O. Breakthrough) Elbow" 3 Hours of Air On ORP1b(mV/30) NOx-N (mg/L) TKN (mg/L) NH3-N (mg/L) D.O. (mg/L)  Nitrate "Breakpoint" "Knee"  3 Hours of Air Off i  15  17  Time (Hours) Figure 4.1 Fixed-Time ORP Profile Under AASD Conditions  nitrates, the oxygen "breaks through" and becomes residual oxygen, measurable by a dissolved oxygen probe (the sudden jump in the dashed (D.O.) line). The ORP-time curve follows suit, making  a sudden bend which due to  its angular  shape, is  colloquially known as the "elbow" since it is reminiscent of the human equivalent. It is not yet clear whether this inflection point/elbow actually corresponds to a concentration of zero NH3 or rather a point where the oxidation of NH3 by 02 is at equilibrium  (in balance with) the production of NH3 through  hydrolysis of organic nitrogen. The latter explanation seems more likely since the NH3 seems to be "levelling out" at some minimum  (plateau) value, which may mean  that beyond  this  inflection point, as fast as it is produced by hydrolysis, it is being converted into nitrates. It can be seen that the nitrate concentration continues to increase beyond this point for the remainder of the aeration period. Eventually the ORP probe mimics the D.O. response, by reaching a plateau value, seemingly a function of numerous variables such as probe sensitivity, the rate of airflow and the biological  dynamics  involved.  This  plateau  reflects  an  equilibrium relationship between the rate of air supply and the rate of air utilization by the biomass; again however, the specifics are not well understood at the present time. Upon cessation of air and as free oxygen is quickly exhausted  from the system, there comes a time when those  bacteria whom are able to, switch over and use nitrates as a terminal electron acceptor in the electron transport chain. Some  80 of the researchers mentioned previously have documented an inflection  point  related  to  the  disappearance  of  oxygen;  however, this has never been definitively observed during this research. As  nitrate  respiration  continues  and  the  nitrate  concentration declines, eventually the point of zero nitrate concentration (the inflection point in the ORP-time curve) is reached. As mentioned this point is known as the "nitrate knee" and it is this feature which is the focus of this research. Beyond this, as more negative potentials are established, a corresponding  "anaerobic  plateau"  begins  to  develop  and  presumably it is here that less efficient solids degradation processes (such as sulfate reduction, methane production and fermentation) predominate. Sampling at the very limit of anaerobiosis however (2 hours and 45 minutes of air off) yielded no production of sulfides. Moreover, even in the feed sludge which may have been stored for up to 8 hours, no measurable sulfides (detection limit of 0.1 ppm) were detected. It would seem that insufficient time is available for any anaerobic organisms (that managed to survive the aerobic phase of the cycle), to develop into a significant population. Thus, after the nitrate breakpoint, in theory, very little if any solids degradation is occurring because of the lack of highly efficient electron acceptors and the failure of other organisms to establish a significant presence. For comparative purposes, Figure 4.2 portrays an ORP-time profile indigenous to the Real-Time Control (RT) reactor (3  81  D)  E  5  MLVSS/MLSS = 4980/6328 = 0.79 Air Off after 3 hrs of Aeration pH = 6.88  Feed  4 -  x O  3  «  -  2 1  O* CO  ORP2c (mV/30) -1 -  >  E,  a. rr  -2 -  o + A  Nitrate Breakpoint as Nitrate Concentration Reaches Zero - Air On  NH3-N (mg/L) TKN (mg/L) NOx-N (mg/L)  O  10  12  14  16  Time (Hrs) Figure 4.2 Real-Time ORP Profile Under AASD*1 Conditions  82 hours of air-on, a variable length of time for the air-off) . Again, clearly evident is the intersection between the ORP knee and the point of zero nitrate concentration. Consistent with the objectives of the Real-Time operating strategy, the profile does not proceed beyond this point; instead, it rises rapidly, as the ORP probe responds to  the presence  of  oxygen  immediately  available after the computer detects the breakpoint and reinitiates the air supply. Figure  4.2  shows a sharp drop  in the ORP value  (at  approximately 2:30 pm) corresponding to the input of daily feed. Due to the daily mechanics involved  in sludge collection,  transport, and routine laboratory analyses, the feed sludge was frequently in a highly reduced state, at the time of feeding, as compared  to  circumstances  the reactor was  contents. Thus,  equivalent  to  feeding  suddenly  in these  increasing  the  concentration of reductants in the reactor, (an increase in the concentration of the reduced form of NAD*) . Depending upon the relative difference between the feed and reactor ORPs, an ORP drop of up to 100 mV (depending upon the probe sensitivity) could occur. Of course, as the feed experienced oxidization, the ORP would begin to return to its prior value. Since the addition of feed created the potential for a false knee to be induced in the Real-Time (RT) reactor curve, the practice of feeding the Real-Time reactor approximately half-way through the aeration cycle (after the D.O. measurement) was adopted. However, the reactors would frequently be out of phase; therefore, it was quite possible that the Fixed-Time (FT)  84 160  Feed to RT Reactor (Decrease In ORP)  Feed to FT Reactor (Increase In ORP)  a. O  Time (Hrs)  Figure 4.3 Effect of Relatively Fresh Feed on Reactor ORP Curves : Air-On Discontinuity  First-Difference Curve  D.O. Breakpoint  > E. Q. DC  O  ' Air-Off Discontinuity Nitrate Breakpoint  Fixed-Time ORP Profile "T"  8  10  12  Time (Hrs)  Figure 4.4 Overlay of First-Difference and ORP-Time Profiles  Activated Sludge  ORP Probes  Amplifier  Acclimitization of Biomass to Air Supply and Solids Loading  Discolouration of and Deposits on the Platinum Ring Fouling/Plugging of the Porous Junction Induced Currents in the Connecting Wires Unshielded Wire Inside the Amplifier Floating/Differential Input Connectors Amps Blown by High Voltage Surges  _I_ Junction Box And Electrical Connecting Cables r Computer Hardware  Connecting Pins Wired to the Wrong Ground Ground Loops Formed by Electrical Wires  Faulty Harddrive and Power Supply Faulty Chips on Three Different MotherBoards Faulty Relay Control Board  1  Computer Software  Routine Debugging of Control Programs Incompatibilities with Quickbasic Version and Custom Built Relay Board under Extended Running Conditions  •  Accessories  Faulty Air Solenoid Connectors between Mixing Shafts and Motors Ill-Designed Loose Ground Pin in Remote Power Bar  Figure 4.5 Linear Diagram of Components Identifying Problem Areas  86 Many of the mechanical problems were isolated and remedied in a diagnostic fashion, by sequentially disconnecting the system elements and linking them in various and tandem combinations until identification of the offending component(s). It  is worthwhile  to mention that a  large portion  of the  difficulty was surmounted, when the experiment was redesigned with adequate knowledge of proper grounding techniques. For example, during  one phase, all electrical  components were  connected (and apparently functioning properly); however, the ORP probes behaved erratically when immersed in the reactor solutions, despite near perfect readings when submerged in quinhydrone test solutions. An oscilloscope detected a stray current travelling down the motor armature, through the mixing shafts and into the reactor solutions, thereby swamping any biologically-induced signals. To remedy this problem, teflon connecters were designed in order to isolate the motors from the mixing shafts/biological liquids. The existence of ground loops further complicated matters by producing an interaction effect between the two reactors, surfacing primarily when one reactor switched on (or off) an air solenoid. The effect manifested itself in the form of a sudden spike in the ORP profile of one reactor, when the air to the other reactor clicked on or off (and vice versa) . This became critical in the Real-Time control reactor, since if the spike conformed to a sudden drop in the ORP profile, it quite realistically simulated a nitrate breakpoint, thus causing the computer to prematurely initiate air resupply. Figure 4.6  87  Interaction Effect Air On or Off to One Solenoid Causes a Spike In the Other ORP Curve  -100 •120 -140  -160 -180  -  -200  -  -220  ORP1a ORP2C ~r 4  I  8  12  16  20  24  Time (Hrs)  Figure 4.6 Reactor Interaction Effects Due to Improper Grounding  88 illustrates a typical example of the interaction effect between the two reactors. Many of the problems were trivial in nature but quite time consuming to detect. For example, a loose ground pin in an electrical socket on a remote power bar, produced an intermittent problem whereby the curve form would be smooth for a period of time (Figure 4.7) and then suddenly degenerate into electrical noise. Eventually this problem worsened to the point where the ORP curves resembled a seismograph waveform (Figure 4.8) . An suspected Quickbasic  even  existence 4.5  more of  language  time  an  consuming  interaction  itself  and  problem  effect  was  the  between  the  the custom-built  relay  control board originally installed in the computer. In this case, the computer would run perfectly, from anywhere from 2 to 9 days, before suddenly "locking up" to the extent of requiring a  power-down/  condition  of  power-up the  reboot  computer  of  usually  the  system.  meant  that  The  locked  one reactor  received air overnight while the other reactor went unaerated, a condition presumed to be highly detrimental to bacterial cultures having a life-span of 20-30 minutes. Moreover, after such a disturbance, any serious comparison between the two reactors was highly questionable. The purchase of a commercial relay-control board solved this problem. Despite many such difficulties, only a few of which have been recounted here, it can be concluded that, provided sufficient attention to detail is observed, a robust design will  89 260  Solenoid Clicks Off  > E. floe O  —  0RP2a 8  10  Time (Hrs)  Figure 4.7 ORP Profile Affected by Intermittent Electrical Noise 270  260 H  210 -\  200 H  ORP2b 190  ~i 4  r  "i  i 12  i  i 16  i  1 20  r  Time (Hrs)  Figure 4.8 Complete Deterioration of ORP Profile  24  eventually prevail. This attention to detail would be paramount in full-scale applications, where numerous electrical and other similar interferences would be commonplace readily negating any meaningful data monitoring and process control. 4.2.2  Experimental Pre-Run Conditions Once the hardware and software irregularities were  eliminated,  attention  could  be  focused  on  the  biological  conditions in the reactor. "Adequate running conditions" could be obtained by harmonizing readily adjustable parameters, such as air supply and solids concentrations. In certain cases, this would take several days as the biological elements within the reactor became accustomed to the dynamic interplay between solids levels and air supply. Experimenting, until the right combination of these two  parameters  was  achieved,  led  to  the  development  of  conditions deemed suitable for the commencement of an AASD run. These conditions consisted of "equivalency" in terms of ... (i)  Both reactors operating on a Fixed-Time basis,  (ii) The consistent occurrence of the characteristic curve shape of the ORP profile under Fixed-Time conditions (with all attendant features); (iii) A good range (at least -200 mV to +200 mV) between the minimum and maximum ORP values; and (iv) A D.O. measurement during the plateau portion of the cycle between 2 and 4 mg/L. Figures 4.9 and 4.10 consist of extreme examples of curves obtained during sporadic periods when the experiment  91  I a. en  o  Time (Hrs)  Figure 4.9 Unusual Response Pattern: No Nitrate Breakpoint 40 30  -  20  -  No ORP Plateau  No D.O Breakpoint  10  > E, 0.  No Nitrate Breakpoint  <r O  ORP2b  Time (Hrs)  Figure 4.10 Unusual Response Pattern: No Diss. Oxygen Breakpoint  seemed to be mechanically sound but experiencing difficulties, as biological conditions inside the reactor adjusted to the balance between air supply and solids level. In the majority of cases, curves much less extreme were observed; however, whenever the micro-organisms were acclimating to pre-run conditions, the ORP curves took a few days to consistently arrive at all of the distinctive features of the "classic" ORP-time curve indigenous to Fixed-Time AASD conditions (Figure 4.1). Once "equivalency" was achieved, the command to "switch over" to Real-Time control was issued (Figure 4.11). From then on the air was activated in the Real-Time reactor by the breakpoint occurring in the anoxic cycle. 4.3  Behavioral Trends: AASD*1 Experimental Conditions 4.3.1  Operating Characteristics and ORP Profiles Several general observations can be made regarding  the pattern of ORP curves generated during the first set of AASD experiments.  Under  this  operating  strategy,  at  least  4  cycles/day of aerobic-anoxic sequences (6 hours total for the air-on, air- off time period) occurred  in the  Fixed-Time  reactor. The Real-Time reactor however would frequently be into its 5th cycle, since denitrification often occurred within 3 hours, making the total cycle length of the Real-Time reactor less than 6 hours. Over the course of a 24 hour period however, all probes in both reactors showed a remarkable consistency in the curve shape, from cycle to cycle as illustrated in Figure 4.12. As mentioned earlier, critics of ORP often decry the  93  160  Fixed-time  Real-Time  120 -  80  -  40  -  -40  -  -80  -  >  o  Drop in ORP Resulting From Feed  -120  ORP2c -160  i  12  16  20  Time (Hrs)  Figure 4.11 "Switch Over Day": FT to RT Control - AASD#1  24  94  180  24  Time (Hrs)  Figure 4.12 Temporal Reproducibility of ORP Curves in RT Reactor  fact that ORP probes in the same sewage, frequently yield widely divergent  results. This  research, however,  emphasized  the  relative change in ORP with time, with Figure 4.13 illustrating that all 3 probes in the same reactor simultaneously detected the breakpoints, despite widely diverging absolute values. Minor discrepancies in detection times are ascribed to differences in the individual probe sensitivities. Moreover, the particular example selected is an extreme example of differences in the absolute ORP values and is presented solely for clarity of illustration  with  regard  to  detection  times. In the vast  majority of cases, the actual absolute difference between probes in the same reactor was less than 20 millivolts. The most  distinctive  characteristic  evident  in  reactors operating under Real-Time AASD conditions, is the selfadjusting ability of the reactor to dynamically meet zeronitrate effluent guidelines. This is due to the reactor's ability to delay switching on the air until denitrification is complete. On a 24 hour basis (after feeding which raises the carbon level in the reactor), the overall available carbon level decreases, necessitating longer and longer denitrif ication times (i.e. There is an increase in the total elapsed time between the cessation of air and the nitrate breakpoint). The advent of feeding  on  the  following  day  immediately  shortens  the  denitrification time and the sequence repeats itself. Operating the  reactors  in  this  way  generates  the  cyclical  pattern  illustrated in Figure 4.14 and 4.15, with the length of the anoxic zone a reflection of the amount of carbon available in  96  180  I Q.  o  Time (Hrs)  Figure 4.13 Spatial Reproducibility of 3 ORP Electrodes in Same Reactor  97 3.2  Point of Feed Addition  3 -i 2.8 2.6 g" X  2.4 2.2  •a  o  H  2  CD  a.  1.8  x o c  1.6  <  1.4  -  o c o  1.2  -  OB  1 -  i_  a  0.8 0.6 0.4  H  0.2  0  Nov/Dec  24  25  27  26  28  29  30  Date  Figure 4.14 Anoxic-Zone-Length: Cyclical Pattern Due to Daily Feed  J2 •o o 'u.  CD 0_  o 'x o c <  "5 c o  o  July  14  15  16  17  18  19  20  21  22  23  Date  Figure 4.15 Anoxic Periods Greater Than the 3 Hour Fixed-Time Limit  the system. Further to this, Figure 4.15 illustrates the power of this approach since, in this snapshot, many of the anoxic periods extend beyond the 3 hour anoxic-limit constraint (time available for denitrification) arbitrarily imposed upon the Fixed-Time reactor. Especially noticeable are the two days in which the feeding process was omitted. On these days, the dearth of  carbon  available  for  denitrification  would  result  (if  decanting had occurred) in a release to the environment (from the Fixed-Time reactor) of an effluent containing nitrates. Again, if a water body had as a priority a ban on nitrates, these instances would represent periods of non-compliance with the stated objectives. In contrast, it can be seen that the Real-Time reactor ensured that all the nitrates were eliminated before release of the effluent. 4.3.2  General Observations: Chemical Parameters Table  4.1  summarizes  some  selected  chemical  statistics of daily measurements performed on the Feed, FixedTime, and Real-Time reactors during AASD#1. A complete listing of chemical data for the entire 60 day run can be found in Appendix E. Since no effort was made to regulate the solids loading to the digesters (other than maintaining a reasonably consistent sludge collection procedure), the daily variation in feed solids concentrations was quite large and is reflected in the large standard deviation (Table 4.1) relative to the means (i.e Std. Dev. approximately 20 % of the mean value) of the TSS  99  Table 4.1  Selected List of Chemical Statistics: AASD#1 Statistic  FEED  Fixed-Time Reactor  Real-Time Reactor  TSS (mg/L)  Maximum Mean Minimum Std.Dev.  13550 7841 5188 1626  7472 6569 5336 600  7404 6511 5288 610  VSS (mg/L)  Maximum Mean Minimum Std.Dev.  10794 6174 4158 1306  5812 5080 4154 442  5712 5005 4116 432  TKN (mg/L)  Maximum Mean Minimum Std.Dev.  953 546 331 111  493 436 265 47  500 428 323 44  NOX-N (mg/L)  Maximum Mean Minimum Std.Dev.  7.68 1.89 0.13 2.05  4.66 1.64 0.08 0.86  4.18 1.80 0.04 0.73  NH3-N (mg/L)  Maximum Mean Minimum . Std.Dev.  16.60 3.00 0.06 4.27  0.99 0.23 0.04 0.29  0.92 0.16 0.07 0.18  TP (mg/L)  Maximum Mean Minimum Std.Dev.  472 306 164 64  385 300 164 49  385 302 199 53  Ortho-P (mg/L)  Maximum Mean Minimum Std.Dev.  31.70 8.40 0.00 9.27  61.54 45.85 23.82 7.59  56.23 42.39 25.00 6.79  5.30 3.20 1.40 0.93  5.20 3.31 1.40 0.88  7.36 6.76 6.37 0.22  7.39 6.77 6.39 0.21  Chemical Parameter  Dissolved Oxygen (mg.L)  pH  Maximum Mean Minimum Std.Dev. Maximum Mean Minimum Std.Dev. -  7.30 6.79 6.37 0.20  and VSS feed solids. It can also be seen that the feed solids concentration (both TSS and VSS) was approximately 1000 mg/L greater  on  average  than  the  reactor  solids  levels. Less  variation was expected in the reactor solids concentrations (Std. Dev. approximately 9 % of the mean). The different extent of these variations are shown in Figure 4.16. It is noted that full-scale  digesters  operate  at  much  greater  solids  concentrations (approx. 3 % solids). The pilot plant facility however, is not able to produce this level of solids as influent feed to the laboratory digesters. The average ratios of VSS/TSS were 0.79, 0.77, and 0.77 for the Feed, FT, and RT reactors, respectively. The relatively constant nature of all of these ratios is illustrated by parallel plots of VSS and TSS for the feed sludge only (Figure 4.17). The speciation of nitrogen forms (TKN, NH3, and N0X) is very much a function of the sampling time (i.e whether the air is on or off); thus, the standard deviations (Table 4.1) for both the NH3 and N0X are quite large. Since the TKN parameter is almost all organic nitrogen, its variation is much less. Figures 4.18 and 4.19 show the profiles with time of total nitrogen and total phosphorus. The feed nitrogen content fluctuated in accordance with the influent solids concentration; however,  inside the reactors, the total nitrogen  remained  relatively constant. As nitrogen was removed from the system, it should have showed a gradual decrease over the course of digestion. It is suspected that experimental error masked this trend and therefore more precise laboratory techniques (such as  101 14 Feed Solids Concentration  13  Ommission of Daily  Feed (2 Days)  12 11 10 9  J S" 8 ™S E.S 7 ^  3  5 4  •  FT and RT Solids Concentrations  3 2  -  1  -  Feed  4- FT Reactor 0 RT Reactor r«-  0  20  40  60  Time (Days)  Figure 4.16 Daily Variation in Feed and Reactor TSS: AASD#1 Ommission of Daily Feed (2 Days)  a» 20  ~r~ 40  60  Time (Days)  Figure 4.17 Parallel Plot: Feed Sludge AASD#1 TSS/VSS Ratio  102 1000  900 -  E. O  •  Feed  +  Rxed-Time  o  Real-Time  2 Days Missed Feed  800  700  -  600 -  t  c  <D  O)  500  -  o _  2 o I-  400  300  200  0  20  40  60  Time (Days)  Figure 4.18 Fluctuations in Total Nitrogen Content: AASD#1 480 460  Feed  440 -j +  Rxed-Time  420 -  Real-Time  400 -  E. ST b. tn  380 360 340  w  320 H  sz a.  300  o  280 -  O  co  sz a. "ja  o  260 240 -  2 Days Missed Feed  220 200 180 -\ 160  - T —  20  40  60  Time (Days)  Figure 4.19 Fluctuations in Total Phosphorus Content: AASD#1  pipetted dilutions) were implemented for subsequent runs. The total phosphorus experienced an increase during the first half of the run, while subsequently levelling off during the latter portion of the run. It is not known why this occurred but it is suspected that the initial rising trend in the influent TP values slowly forced the reactor TP levels to follow suit (since the reactor values represent a trade-off between  the  relative  difference  between  feed  and  wastage  values). With regards to soluble phosphorus, the variation in influent ortho-P was directly related to the freshness of feed. If routine operations dictated that the sludge be stored for several hours before being utilized as feed, then anaerobic conditions would prevail, releasing phosphorus into the bulk liquid. Thus, the standard deviation for the influent ortho-P was greater than 100% of the mean. On a cyclical basis, however, inside the reactor, the alternating aerobic-anoxic conditions would have caused an uptake followed by a release of phosphorus to the liquid. Due to an oversight, this trend was not verified. Total CODs were done on all sludges for the first 20 days. When coupled with daily TKN (minus the ammonia) and TP (minus the ortho-P) measurements, average C:N:P ratios for the sludges  could  be  estimated.  They  were  calculated  to  be  100:5.1:2.7, 100:5.4:3.4, and 100:5.3:3.4 for the Feed, FT and RT sludges, respectively. In all cases, the ratios were slightly larger than the conventional ratio (100:5:1, Metcalf and Eddy (1979)), especially for the nitrogen to phosphorus proportion.  104 This is consistent with the pilot plant's operation as a bionutrient removal plant, as the sludges were expected to have a higher proportion of nutrients, especially phosphorus. Sporadic measurements of soluble COD in the reactors revealed averages of 50 mg/L for the FT reactor, and 46 mg/L for the RT reactor, respectively. Both reactors had an average TOC concentration of 14 mg/L. The values for both these measurements are consistent with the sludge digestion process, as little soluble carbon was expected to be available, since the reactors operate with the primary source of carbon generated through endogenous metabolism. Carbon that does become available through cell lysis is immediately consumed by other bacteria. From the outset of this research, dissolved oxygen measurements were considered less important than ORP, due to reactor dynamics at the lab scale. In other words, it was quickly evident that providing identical airflow rates to the two reactors, often produced different D.O. levels in the bulk liquids. Several possible reasons include; (i)  Irregular pore sizes in the diffusing stones;  (ii)  Disparate fouling rates of these pores;  (iii) Possible slight discrepancies in the internal diameters of the air tubing; and (iv)  Variations in the solids levels between the reactors.  The above visually-discernable  factors  acted  differences  in concert  to produce  (in terms of bubble size)  between the reactors. This translates directly  into oxygen  transfer efficiency. Furthermore, since bubble size control was beyond simple modifications to the experiment, it mitigated against using equal air flow rates to control air supply. Instead, air control was based upon preserving a relatively stable D.O. liquid level in the reactor (usually between 2 and 4 mg/L during the D.O. plateau portion of the cycle). As can be seen from Table 4.1, the relatively low standard deviation means that the majority of D.O. measurements fell within the required range. Routine pH monitoring was incorporated as a matter of principle since pH (acting as a "master variable") often provides the first indication of critical disturbances to a system. In AASD research, pH is especially important, since a prime reason  for  favouring  aerobic-anoxic  over continuous-  aeration methods of treating sludge, is the fact that the consumption of approximately 7.2 mg/L of alkalinity (as CaC03) (Barnes and Bliss, (1983)), during the endogenous-respiration nitrification reaction ... C5H7N02 + 502 ==> 5C02 + NH3 + 2H20 2NH3 + 302 ==>  2N03" + 6H+  H+ + HC03" ==> H2C03  (4.1) (4.2) (4.3)  is balanced by alkalinity generated through denitrification reactions and reactions involving ammonification of organic nitrogen to NH3 (Warner et al., (1985)). Table 4.1 indicates that the pH of both reactors maintained a pH in and around the neutral range of 6.5 to 7.5. This is further shown by a plot of the daily variation in pH for  the  FT  (Figure  4.20)  and  RT  (Figure  4.21)  reactors,  respectively. There does seem to be a slight decrease with time in the pH of both reactors; however, the fairly small amount of fluctuations  in the pH  level indicate that the alkalinity  produced during the anoxic portion of the cycle, was generally sufficient to balance the alkalinity consumed during the aerated portion of the cycle. As mentioned (Section 2.3), the absence of chemical additives to buffer pH is one of the more attractive cost-related  features for considering aerobic-anoxic  sludge  digestion. If, however, the pH continued to decline, perhaps periodic chemical adjustments could be instituted. In this research, all experiments were conducted at a relatively constant room temperature of 22 °C + 1 °C. The impetus for this originates from the Nernst equation, which includes temperature in the denominator of the term preceding the logarithm. If temperature is held relatively constant, then in theory, a measurable change in the ORP potential can be directly attributed to a specific alteration in the ratio of oxidized to reduced species, rather than to a fluctuation in temperature. In practice, the feed sludge was usually slightly cooler  than  the  reactor  sludges;  however,  there  was  no  discernable temperature drop. Thus a decrease in ORP could be ascribed definitively to a change in the ratio of the oxidized to reduced species (in this case the addition of the reducing feed).  107 7.4 7.3 7.2 7.1 7 X Q.  6.9 6.8 6.7 6.6 6.5 -  • Feed + FTRCTR  6.4 6.3  i  40  20  60  Time (Days)  Figure 4.20 Fixed-Time Reactor: pH vs. Time for AASD#1  x Q.  0  20  40  60  Time (Days)  Figure 4.21 Real-Time Reactor: pH vs. Time for AASD#1  4.3.3  Mass Balances: Solids, Nitrogen and Phosphorus One method of comparing the performance of the two  reactors is from a mass balance perspective (Figure 4.22). Both reactors were designed to reduce solids; therefore, since TSS and VSS measurements were made on a daily basis  (for both  digesters plus feed) any missing solids can be presumed to be degraded by bacterial processes. Similarly, nitrogen (TKN, N0X, NH3) was measured daily (with the nitrogen forms both expressed as nitrogen) ; thus, TKN and N0X were directly additive and were equal to the total nitrogen entering and exiting the system. Since the pH remained in the neutral range, it is assumed that no stripping of NH3 occurred and any missing nitrogen is lost solely as nitrogen gas. Phosphorus  (TP, Ortho-P) was also  measured daily; however, phosphorous should theoretically be conserved  since  there  is no biological mechanism  for its  removal. Tables 4.2 and 4.3 summarize the results for each reactor based upon mass balances performed in two distinct manners. The actual calculations have been included in Appendix F. In the tables, the column entitled "Overall Mass Balance" refers to a summation period incorporating days 1 through 60, while the column entitled "Moving Average Balance" involves averaging  the results  from multiple  balance periods, each  equivalent in length to one 10-day SRT period (i.e. First SRT Days 1-10, Second SRT - Days 2-11, etc.). As is evident in both tables, the two methods yield  similar  results  for  solids  degradation (in terms of TSS and VSS) and nitrogen removal. The  Cp = Concentration of Parameter in Feed Sludge Vp = Daily Volume of Feed Sludge Cg = Concentration of Parameter in Reactor V R = Volume of Reactor C = Concentration of Parameter in Waste V = Volume Wasted per Day A(C xV3= Change in Reactor Parameter Over Sampling Period (+) —> Increase ; (-) —> Decrease  Feed  Waste  cF vF  % Reduction =  C  W  V  W  X100  I[(CF)(VF)]  Figure 4.22 General Case of Mass-Balance Around Reactor (Adapted from Koers, (1979))  110  Table 4.2 Mass Balances for Fixed-Time Reactor: AASD#1 Mass Balance Parameter Percent Reduced  Moving Average Balance Wareham (1991)  Moving Average Balance Jenkins et al. (1989a)  Overall Mass Balance Wareham (1991)  Overall Mass Balance Jenkins et al. (1989a)  TSS  14.7 %  12.5 %  15.8 %  VSS  16.8 %  14.0 %  17.7 %  14.6 %  Total N  17.5 %  17.9 %  12.5 %  Total P  -6.5 %  -6.2 %  1.4 %  Table 4.3 Mass Balances for Real-Time Reactor: AASD#1 Mass Balance Parameter Percent Reduced  Moving Average Balance Wareham (1991)  Moving Average Balance Jenkins et al. (1989a)  Overall Mass Balance Wareham (1991)  TSS  15.2 %  15.7 %  VSS  18.0 %  18.3 %  Total N  19.5 %  Total P  -6.9 %  21.1 % -5.8 %  Overall Mass Balance Jenkins et al. (1989a)  relatively low percentage removals for both solids and nitrogen were not unexpected, since the reactors were operated at such a short SRT. For comparative purposes, the work of Jenkins and Mavinic (1989a) is also presented. In their study (comparing continuously aerated versus aerobic-anoxic digestion), one of the reactors was operated in a Fixed-Time fashion (albeit with a cycle partition of 2.5 hours air-on/3.5 hours air-off). The values quoted in Table 4.2 are those reported for the same SRT (10 days) and an equivalent temperature (2 0 °C) . It is apparent that the removals obtained for both solids and nitrogen in the AASD*1 experiments, compare well with the study by Jenkins and Mavinic (1989a), being a few percentage points higher for both solids and nitrogen. The phosphorus mass balance for this experiment recorded  an apparent  increase of  6 percent. The order of  magnitude of this error is typical of the TP digestion technique used; since other researchers, (Jenkins (1988), Elefsiniotis (1992)) have reported similar difficulties with closing the phosphorus loop. It should be noted that the relatively small closing error that Jenkins and Mavinic phosphorus, results.  As  is more they  singular than  acknowledge,  all  (1989a) report for  characteristic the  phosphorus  of their can  be  accounted for within experimental error, with a recovery range of 77-99 %. Thus, although one reactor closed within 1 % (coincidentally it is the aerobic-anoxic reactor considered in this comparison), the range quoted also means that one reactor closed  112 within 23 percent. In fact, of the 18 phosphorus mass balances presented in the original research (Jenkins 1988), only seven (40 %) closed with less than 6 percent. Thus, an average of all phosphorus mass balances presented in their work reveals a phosphorus closing error of 8.6 percent. This latter number more closely aligns itself with the order-of-magnitude phosphorus error arrived at in this study. A Control  comparison  reactors  between  indicates  that  Fixed-Time both  and  Real-Time  reactors  performed  essentially the same in terms of solids degradation (both TSS and VSS). Superficially, it seems that the Real-Time reactor performed slightly better in relation to nitrogen removal (up to 3  % using the overall mass balance method); however, the  difference is not thought to be substantial enough to form any non-debatable conclusive statements. Thus,  as  a  criteria  to  evaluate  the  overall  performance of the two reactors, the mass balances associated with solids, nitrogen and phosphorous do not convincingly reveal a distinguishable difference between the two reactors. Instead, this method indicates that both reactors were comparable in terms of their removal efficiencies, with the Real-Time Control reactor perhaps  (but not definitely) performing marginally  better in terms of nitrogen removal. 4.3.4  Evaluation: Unsteady Process Input Conditions The second method of comparing the performance of  the two reactors is to investigate the probe behaviour, when the reactor contents are subjected to transitory stresses. This  113 concurrently evaluates the suitability of the ORP probe as a control parameter. Accordingly, the reactors received (on a mass basis) "low" and "high" spikes of sodium nitrate, ammonium chloride and hydrogen peroxide in order to simulate unsteady process input conditions. Tables 4.4, 4.5 and 4.6 outline the timing and concentrations of the various spikes. Note that a "high" spike is defined as having 3 times the mass of chemical added as the "low" spike. Samples were removed from the reactors prior to, and immediately following the spikes, after allowing two to five minutes for adequate mixing and dispersion of the chemicals. Figures 4.23 through 4.28 show selected vignettes of the ORP response to the various spikes with some of the more pertinent statistics recorded on each figure. These figures can best be explained by tabulating for each reactor, the number of deviations (over the entire run) from the ideal curve shapes indigenous to the Fixed-Time (Figure 4.1) and Real-Time (Figure 4.2) control operating strategies. Deviations from the "norm" can then be classified as "failures", since in the majority of instances, they represent a failure to complete a biological reaction. For example, in this run, 3 major categories of failures exist, most of which can be linked to chemical spikes. The first class refers to "Incomplete Denitrification" and occurs when there is no discernable nitrate breakpoint in the ORP-time profile. No nitrate breakpoint means that insufficient time existed for the micro-organisms to fully eliminate the  114  Table 4.4  Particulars of Sodium Nitrate Spikes: AASD*1 FT July/11/90 23  RT July/11/90 23  FT Aug/6/90 49  RT Aug/6/90 49  3:10 pm 2:05 2.02 mg/L  5:10 pm 1:30 1.50 mg/L  1:20 pm 1:35 1.68 mg/L  10:00 am 1:30 2.34 mg/L  Time of Spike Amount 2  3:25 pm 43.2 mg  5:10 pm 43.2 mg  1:20 pm 129.6 mg  10:10 am 129.6 mg  Sampling Time Concentration 1  3:30 pm 4.09 mg/L  5:15 pm 3.46 mg/L  1:25 pm 7.02 mg/L  10:15 am 8.09 mg/L  Reactor Date Day Number Sampled Nitrate Air On (Hr:Min) Concentration  'Concentration i s measured as N03-N mg/L Amount i s on a weight b a s i s as Sodium N i t r a t e  2  Table 4.5  Particulars of Ammonium Chloride Spikes: AASD#1 FT July/13/90 25  RT July/13/90 25  FT Aug/9/90 52  RT Aug/9/90 52  5:20 pm 0:55 0.41 mg/L  2:55 pm 0:55 0.39 mg/L  4:35 pm 1:25 0.59 mg/L  2:40 pm 1:25 0.56 mg/L  Time of Spike Amount 2  5:25 pm 43.2 mg  3:00 pm 43.2 mg  4:40 pm 129.6 mg  2:45 pm 129.6 mg  Sampling Time Concentration 1  5:30 pm 1.37 mg/L  3:05 pm 1.27 mg/L  4:45 pm 6.68 mg/L  2:50 pm 6.43 mg/L  Reactor Date Day Number Sampled Ammonia Air Off(Hr:Minl Concentration  C o n c e n t r a t i o n i s measured as NH3-N mg/L Amount i s on a weight b a s i s as Ammonium Chloride  z  Table 4.6  Particulars of Hydrogen Peroxide Spikes: AASD*1 FT Aug/12/90 55  RT Aug/12/90 55  FT Aug/15/90 58  RT Aug/15/90 58  2:00 pm 1:30 1.60 mg/L  3:10 pm 1:30 1.40 mg/L  2:15 pm 1:30 2.70 mg/L  3:10 pm 1:30 3.75 mg/L  2:50 pm  3:40 pm  2:25 pm  3:15 pm  3:15 pm 2:45 0.75 mg/L  3:55 pm 2:15 0.80 mg/L  2:45 pm 2:00 1.50 mg/L  3:35 pm 1:55 2.20 mg/L  Time of Spike Amount 2  3:15 pm 1 mL  3:55 pm 1 mL  Sampling Time Concentration 1  3:17 pm 3.80 mg/L  3:57 pm 3.70 mg/L  Reactor Date Day Number Sampled D.O. Air On(Hr:Mini Concentration 1 Feed Sampled D.O. Air 0n(Hr:Min) Concentration'  2:45 pm 3 mL 2:47 pm 10.6 mg/L  Concentration measured as Dissolved Oxygen (mg/L) Amount is based on a volume of 3% weight/volume H202  2  3:35 pm 3 mL 3:37 pm 10.8 mg/L  115 200  Fed @ 1:30 pm  150  100 50 -  o_  o  -50  -100  -150  Spiked @ 1:20 pm: NQ-N Concentration Increased from 1.68 mg/L to 7.02 mg/L  -200  A Failures - Incomplete Denitrification  -250  40  20  Time (Hrs)  Figure 4.23 High Spike of Sodium Nitrate to FT Reactor: AASD#1  5? E,  a. rr O  -30 H  •40  * Spiked @ 10:10 am; NCk-N Concentration Increased from 2.34 mgA to 8.09 mg/L A Failures - Incomplete Denitrification 20  40  Time (Hrs)  Figure 4.24 High Spike of Sodium Nitrate to RT Reactor: AASD#1  116 200  Fed @ 1:30 pm  150 100 50 -  E. Q_  o  -50 -100  -150 -200 -  * Spiked @ 5:25 pm; NK-N Concentration Increased from 0.41 mg/L to 1.37 mg/L • Failures - Incomplete Oenrtrification  -250 0  20  40  Time (Hrs)  Figure 4.25 Low Spike of Ammonium Chloride to FT Reactor: AASD#1  E,  a. •c  O  Time (Hrs)  Figure 4.26 Low Spike of Ammonium Chloride to RT Reactor: AASD*1  117 250  s  D.O. prior to Feed = 2.70 mg/L Fed @ 2:25 pm.  200  -  150  -  100  -  50  a. rr  O  -50  -  -100  -  -150  * -200  Spiked @ 2:45 pm; Dissolved Oxygen increased from 1.50 mg/L to 10.60 mg/L 12  20  16  24  Time (Hrs)  Figure 4.27 High Spike of Hydrogen Peroxide to FT Reactor: AASD#1 200  D.O. prior to Feed = 3.75 mg/L Fed® 3:15 pm  * -40  Spiked @ 3:35 pm; Dissolved Oxygen Increased from 2.20 mg/L to 10.80 mg/L T 12  -r-  -r-  16  20  24  Time (Hrs)  Figure 4.28 High Spike of Hydrogen Peroxide to RT Reactor: AASD*1  118 nitrates.  These  failures  are  characterized  by  the  solid,  triangular marks noted on the previous six figures. In Figures 4.23 and 4.24, the failures result from an elevated level of nitrate caused by the disassociation of sodium nitrate. In Figure  4.25,  denitrifiers  they to  are  caused  eliminate  by  the  the  inability  nitrates  of  the  generated  by  nitrification of ammonia originally in the form of ammonium chloride. Note that the addition of a particular spike may cause failures in a number of subsequent cycles, as the reactor seeks to recover from the effect of the stress. The second category of failure is the converse of the above and is associated with "Incomplete Nitrification" as depicted in Figure 4.29 (solid rectangular mark). This failure, caused by elevated levels of ammonia in the system, is reflected in the absence of the dissolved oxygen breakpoint in the ORPtime  curve. There  is no  "breakthrough"  of  oxygen  because  insufficient time exists for the nitrifiers to reduce the ammonia to a low enough level to allow free residual oxygen to become present. The  final  failure  category  (Figure  4.30),  is  particular to the Real-Time reactor alone and is a failure in the more conventional sense, since the software "failed" by detecting a false nitrate knee (Figure 4.30, solid circular mark). Daily fluctuations in the air supply rate and solids loading, sometimes resulted in excess air entering the system relative to the mass of solids present in the reactor.  The  resulting over-oxidation of the sludge was reflected in the slow  119 200  Fed @ 2:20 pm  F e d ® 1:50 pm *  150 -  Diss. Ox. Breakpoint "Qbow"asD.O. Breaks Through  100 -  50  -  -50  -  E Q_  rr O  * Spiked @ 4:40 pm; NHg-N Concentration Increased From 0.59 mg/L to 6.68 mg/L  -100 -  -150  •  Failure - Incomplete Nitrification  A  Failure - Incomplete Denitrification FT Reactor: "High* Ammonia Spike  -200  20  40  Time (Hrs)  Figure 4.29 Typical "Incomplete Nitrification Failure" Fed @ 10:30 am  E CL  rr O  •  Failure - Detection of False Breakpoint "Knee* Initiates Air Supply Prematurely  12  Time (Hrs)  Figure 4.30 "False-Knee" Failure In Real-Time ORP Profile  rate at which the ORP value declined, after the air supply was halted. If the rate was excessively slow, the MAXAVOID window (the variable used to delay the search for the breakpoint until air had bled from the line and stability had been achieved) was in essence, prematurely "used up" by little, if any, changes in the ORP value with time. This was especially common if the probe was dirty and/or unresponsive. Thus, by the time the true decline began, the RingBuffer was often partially filled with horizontal  (i.e. zero ORP slope change) values. The sudden  change, as the true descent commenced (i.e the reactor truly entered anoxic conditions), sometimes was sufficiently steep enough to exceed the DELTA limit, (registering a knee-like feature) and triggering the air solenoid. It is evident that there are several ways to remedy this problem, most notably the mechanical methods such as cleaning the probes, attempting to better match the air supply to  the  solids  loading  (reduce  the  air/solids  ratio)  or  deliberately thickening the feed sludge so that the ORP curve declines  more  rapidly  (increasing  the  solids/air  ratio).  Controlling the air supply is at the best of times difficult at the lab scale, while increasing the solids loading is somewhat artificial and may not always be possible. Thus, these two methods were not seriously considered. Furthermore, cleaning the probes produced intermittent success depending on how much the fouling actually contributed to the lack of decline in the ORP curve. The other two ways of reducing these types of  failures were software-based and involved tightening the knee constraint and/or expanding the window capacity of the variable MAXAVOID. Of the two options, expanding MAXAVOID represented a more  certain means  of  success, since tightening  the knee  constraint would ideally involve some experimental trials, being a reactive rather than a proactive method of eliminating the problem. Currently, the program interactively  shorten  the  length  is not flexible enough to of  the  MAXAVOID  window;  however, the program was quickly recompiled (after the window was expanded from 16 to 30 minutes) and this eliminated the problem. Regardless of the solution chosen, it is clear that these types of failures could be reduced or even circumvented with more sophisticated programming techniques and/or better detection algorithms. In terms of some general comments, it is noted that "Incomplete Denitrification" was by far the most common failure. It is also evident that the hydrogen peroxide spikes produced no failures of any kind. Other stresses included the addition of "stale" feed which referred to a period of two consecutive days in which the same sludge was used to feed the reactors thus allowing NH3 in the feed to build-up through hydrolysis of organic nitrogen. With regards to the period in which the feeding process was omitted (already alluded to in Figure 4.15), Figures 4.31 and 4.32 show the FT and RT reactor responses to this  type  "Incomplete  of  stress.  The  Denitrification"  Fixed-Time  reactor  failures, while  logged  the  four  Real-Time  200  150  122  -  100 -  50  -  > Q.  o  -50  -100  -  -150  -  •200 0  20  July/19/90  40  Juiy/20/90  60  July/22/90  Time (hrs)  Figure 4.31 Fixed-Time Reactor Response to Missed Feed: AASD#1 180  0RP2C  Feed  Missed Feed - July/19-21/90 RT Profile -60 0  20  July/19/90  40  July/20/90  60  July/21/90  Time (hrs)  Figure 4.32 Real-Time Reactor Response to Missed Feed: AASD#1  reactor because of its flexibility, easily accommodated this disturbance. Tables  4.7  and  4.8  summarize  the  number  of  occurrences, over the 60 day period, of each of the three categories of failures. The total number of cycles during the run was 231 for the Fixed-Time and 246 for the Real-Time Control reactors respectively. Thus, using the data from Tables 4.7 and 4.8, the Fixed-Time reactor failed 9.5  % of the time (22  failures) while the Real-Time reactor failed only 5.3 % of the time (13 failures). Furthermore as mentioned, many of the RealTime reactor failures were software-based and could have been circumvented with more sophisticated detection algorithms. Thus, "failures"  a  criteria,  comparative indicates  evaluation that  the  based  Real-Time  upon  a  reactor  outperformed the Fixed-Time reactor during AASD#1 by more readily accommodating and recovering from the stresses considered in this research. 4.4  Behaviourial Trends: AASD#2 Experimental Conditions 4.4.1  Operating Characteristics and ORP Profiles As mentioned  in Section 3.4.2, the second AASD  operating strategy consisted of comparing two reactors, both operating in a 50/50 air-on/air-off fashion. The Fixed-Time reactor retained its original ratio for each segment (i.e 3 hours for air-on, 3 hours for air-off); thus, there was a total of four, 6 hour cycles/day. Its characteristic profile was identical to that generated under AASD*1 operating conditions (i.e. Figure 4.1).  Failures Associated with FT Reactor Operation: AASD#1  Table 4.7  Type of Stress  Incomplete Denitrification Failure  Incomplete Nitrification Failure  False Nitrate Breakpoint Failure  Total Number  3  1  0  4  Sodium Nitrate Spikes  4  0  0  4  Ammonia Chloride Spikes  7  1  0  3  Hydrogen Peroxide Soikes  0  0  0  0  Ommission of Daily Feed  4  0  0  4  Addition of Stale Feed  2  0  0  2  20  2  0  22  Normal Operation  Total Number of Failures  Table 4.8  Failures Associated with RT Reactor Operation: AASD#1  Type of Stress  Normal Operation  Incomplete Denitrification Failure  Incomplete Nitrification Failure  False Nitrate Breakpoint Failure  Total Number  2  0  5  7  Sodium Nitrate Spikes  2  0  0  2  Ammonia Chloride Spikes  3  1  0  4  Hydrogen Peroxide Spikes  0  0  0  0  Ommission of Daily Feed  0  0  0  0  Addition of Stale Feed  0  0  0  0  Total Number of Failures  7  i  1  13 5  1  The  Real-Time  reactor's  operation  consisted  of  matching the time for aeration to the previous anoxic period length, as determined by the detection of the nitrate knee. Figure 4.33 portrays the "switch-over" day from Fixed-Time to Real-Time conditions, and depicts the rapid development of a distinctive pattern, reflecting the tendency of the Real-Time reactor to "collapse" in on itself, with very short on/off times for both the aerated and non-aerated portions of the cycle. Consequently, as Figure 4.34 illustrates, the characteristic profile associated with AASD#2 Real-Time conditions, consists of a vastly reduced total cycle time, (very brief air-on and airoff sequences), with the shortest sequence immediately after feeding, followed by a gradual lengthening throughout the day. The fluctuations in the cycle length are better illustrated in Figures 4.35 and 4.36. These figures track the cycle over two days in which the feeding process was omitted. Figure 4.35 has 13 complete cycles, while the next day (Figure 4.36), is comprised of only 7 cycles. The expansion in the cycle length over the course of a day is directly attributable to a depletion  in  readily  available  carbon  in  the  system.  Concurrently, there is a gradual rise in the peak absolute ORP value associated with each cycle, and this is also due to exhaustion of carbon from the system. The short cycle time made it difficult to accurately distinguish the "classic" features of the ORP-time curve, thus some  interpretation has been necessary  Moreover, the brevity  of  for  the cycle time  this analysis. (after  feeding),  240  Feed  0RP2b  -20 -i -40  Fixed-Time  -#> -  " Real-Time  •so -I -100  -i  1  1  r 8  i  12  16  i 20  r 24  Time (Hrs)  Figure 4.33 "Switch Over Day": FT to RT Control - AASD#2  127  Time (Hrs)  Figure 4.34 Real-Time ORP Profile Under AASD#2 Conditions  128  70  Missed Feed Day Nov/11/90 -50  T 4  8  12  ORP2a 16  20  24  Time (Hrs)  Figure 4.35 RT Profile AASD#2 - Missed Feed Day Nov/11/90  >  a. O  Missed Feed Day - Nov/12/90  0RP2a  •40  12  16  20  24  Time(hrs)  Figure 4.36 RT Profile AASD#2 - Missed Feed Day Nov/12/90  129 eventually led to a new software-based "failure" category, in which the program "failed" to locate the breakpoint, by actually physically "missing" the nitrate knee (Figure 4.37). This stands in contradistinction to the AASD#1 "False-Knee" failure in which the  computer  "failed"  by  detecting  a  non-existent  knee,  attributable to the excessively slow decline in the ORP-time curve. As Figure 4.37 illustrates, during the 6th cycle of the day, the steep gradient of the ORP-time curve means that the knee occurred almost immediately upon cessation of air . The computer therefore "missed" the knee entirely and the reactor proceeded into truly anaerobic conditions. After 4 hours, the "intelligence" built  into the program  reactivated  the air  supply, since the computer "assumed" the knee had been missed. Consequently, the next aeration period was also 4 hours as the computer adhered to its 50/50 operating strategy. Subsequent to this, the cycle lengths shortened once again, and eventually, a daily recursive pattern developed revolving around one "MissedKnee" failure a day, with the occasional two such failures in a single day (Figure 4.38). The rationale for this failure is the reverse of that proposed for the "False-Knee" failures of AASD#1. The rapid decline in the ORP curve means that the MAXAVOID variable, (which ordinarily is used to delay the search for the knee), is in reality, comprised of points which should be entering the Ring-Buffer for purposes of detecting the nitrate breakpoint. By the time the Ring-Buffer actually starts filling, the breakpoint  130  - "Missed Knee Failure'  Shortened Cycles  ORP2b Oct/10/90 i  I  12  16  Time (Hrs)  Figure 4.37 "Missed-Knee" Failure in Real-Time ORP Profile  131  Failure  Missed Knee" Failure -200  12  16  20  24  Time (Hrs)  Figure 4.38 Two "Missed-Knee" Failures During Single Day  has already  occurred  and consequently  the  computer  cannot  capture the knee. In order to reduce the number of "Missed-Knee" failures, the variable MAXAVOID was shortened from 30 minutes to 10 minutes (instead of lengthening it, as was done in AASD*1) . This remedy, however, was not entirely successful in eliminating all  of  the  failures  of  this  kind,  since  occasionally  denitrification occurred extremely rapidly after cessation of air. Clearly evident however, from both figures, is the ability of the Real-Time reactor to rapidly  recover from this kind of  failure, in the sense of again developing the short-cycle pattern. 4.4.2  General Observations: Chemical Parameters The chemical parameters measured during AASD*1 were  also recorded for AASD*2 and the data has been relegated to Appendix E with a summary table depicted in Table 4.9. It should be noted that the reactors were spiked with potassium cyanide (56 mg/L) on the third last day of the run (after sampling) ; thus, the reactor statistics (Table 4.9) do not include the final and penultimate days, since certain variables were unduly influenced by the KCN spike. For example, for both reactors, the ortho-P suddenly increased by approximately  20 mg/L as the  cells  level  lysed,  while  the  dissolved  oxygen  rose  by  approximately 3 mg/L, as the demand for oxygen declined. The majority of observations made about the AASD#1 chemical data set are equally applicable to the data obtained from AASD*2. For example, the stochastic nature of the influent feed TSS and VSS solids (as compared to the relatively stable  Table 4.9 Selected List of Chemical Statistics: AASD*2 Fixed-Time Reactor  Real-Time Reactor  10610 6547 4040 1372  6772 6039 4904 362  6820 5931 4942 470  Maximum Mean Minimum Std.Dev.  8466 5376 3362 1109  5350 4826 4122 281  5442 4748 3954 367  TKN (mg/L)  Maximum Mean Minimum Std.Dev.  734 480 294 92  528 441 352 38  530 430 336 41  NOx-N (mg/L)  Maximum Mean Minimum Std.Dev.  6.74 1.29 0.07 1.55  4.05 1.25 0.09 0.77  5.05 0.73 0.14 0.74  NH3-N (mg/L)  Maximum Mean Minimum Std.Dev.  11.20 1.14 0.04 2.52  0.71 0.26 0.00 0.23  0.89 0.16 0.02 0.15  TP (mg/L)  Maximum Mean Minimum Std.Dev.  425 215 116 50  306 260 216 25  317 258 212 27  Ortho-P (mg/L)  Maximum Mean Minimum Std.Dev.  22.26 3.07 0.06 4.54  73.09 60.15 48.41 4.63  75.94 63.56 47.71 4.38  Dissolved Oxygen (mg.L)  Maximum Mean Minimum Std.Dev.  5.30 3.12 0.70 0.93  4.60 2.49 1.00 0.82  Alkalinity (mg/L) (as CaC03)  Maximum Mean Minimum Std.Dev.  256 185 128 28  176 146 120 15  180 146 110 15  Maximum Mean Minimum Std.Dev.  7.37 6.89 6.57 0.18  6.78 6.56 6.36 0.11  6.88 6.54 6.28 0.12  Statistic  FEED  TSS (mg/L)  Maximum Mean Minimum Std.Dev.  VSS (mg/L)  Chemical Parameter  PH  reactor values  (Figure 4.39  and  4.40)),  the  constant and  parallel nature of the VSS/TSS ratio (averages of 0.82, 0.79, and 0.80, for the Feed, Fixed-Time, and Real-Time reactors were calculated), and the speciation and behaviour of the nitrogen forms  (as a function of the air being on or off) were all  similar in nature to the AASD*1 run. The C:N:P ratios for the Feed, Fixed-Time  and Real-Time sludges were 100:5.66:2.41,  100:5.69:2.50, and 100:5.61:2.48, and again the comments made in discussing the results from AASD*1 are equally valid here. Figures 4.41 and 4.42 show the profiles with time of total nitrogen, and total phosphorus. Inside the reactors, both parameters (nitrogen and phosphorus) show a decrease with time over the course of the digestion period. The TSS (and VSS by implication of its constant ratio) also exhibited this trend. The decline of the reactor solids and total nitrogen levels is logical in that there are biological mechanisms for removal of both parameters. Moreover, it is readily apparent from Figures 4.39 to 4.41 that the feed values for both solids and nitrogen are on the average consistently larger than the reactor values. This is also shown by the mean values quoted in Table 4.9. The relative difference between the means (i.e. the feed mean is greater than the reactor mean) is reflected by positive removals being calculated for both parameters (solids and nitrogen). Conversely, as Figure 4.42 indicates, the phosphorus feed levels are consistently lower than the reactor values (on average)  (also indicated  in Table 4.9). Thus, although no  biological mechanism for total phosphorus removal exists, Figure  135 11  2 Days Missed Feed  Time (Days)  Figure 4.39 Daily Variation in Feed and Reactor TSS: AASD#2  8  -  7  -  5  -  4  -  E, (0  2 Days Missed Feed  5 o (0 3  (0 « « O  >  + Fixed-Time o Real-Time - J —  T  20  -r40  60  Time (Days)  Figure 4.40 Daily Variation in Feed and Reactor VSS: AASD#2  136 750  2 Days Missed Feed  + Fixed-Time o Real-Time 250  i  T  40  20  60  Time (Days)  Figure 4.41 Fluctuations in Total Nitrogen Content: AASD#2  440 420  •  400  + Fixed-Time o Real-Time  380 ^mm  -J  o>  E ^m^  a. t  360 340 320 300  3  280  j2  260 H  S  -  O JC  Feed  240 220  a. "5! o  200 180  CD  160 140 120 100  20  40  60  Time (Days)  Figure 4.42 Fluctuations in Total Phosphorus Content: AASD#2  4.42 predicts that the mass balance calculation (Section 4.4.3) will yield a negative removal (i.e. an increase in phosphorus) similar in manner to the increase observed in AASD#1. Figures 4.43 and 4.44 show profiles of the change in pH and alkalinity with time. The pH profile appears to show a slight increase with time; however, the vagaries inherent in the pH measuring apparatus can account for this and it is unlikely that any meaningful trend exists. It is visually discernable however that the feed alkalinity is (on the average) larger than the reactor value. This is also verified in Table 4.9. It is predicted therefore that a mass balance for alkalinity (Section 4.4.3) will  show  a  net removal,  despite  hopes  that the  consumption of alkalinity during nitrification would be offset by the production of alkalinity during denitrification. 4.4.3  Mass Balance Perspective As before, mass balances for solids (TSS and VSS),  nitrogen (TKN + NOx), and phosphorus (TP) were performed around each reactor and these data have been compiled in Appendix F. Due to the KCN spike however, only 58 days of data (rather than the full 60) were used in the calculations. In addition, daily alkalinity measurements allowed a mass balance to be performed for this parameter as well. Tables 4.10 and 4.11 represent a collation of the results, while for comparative purposes, the results from AASD*1 are also presented. As shown  (Table 4.10), the Fixed-Time  reactor removed essentially the same levels (TSS, VSS, nitrogen and phosphorus) for AASD*2 as for AASD*1. This was unexpected,  138  7.4 -i 7.3  2 Days Missed Feed —  -  7.2 7.1  -  7  -  Feed Fixed-Time o Real-Time &2 20  40  60  Time (Days)  Figure 4.43 Daily Variation in Feed and Reactor pH: AASD*2  260 250 240 230  o u O  • Feed +• Fixed-Time © Real-Time  2 Days Missed Feed  220 210  CO  200  a  190 180 170  *5  160  <  150  140 130 120 110 60  Time (Days)  Figure 4.44 Daily Variation in Alkalinity: AASD*2  Table 4.10 Mass Balances for Fixed-Time Reactor: AASD#2 Overall Mass Balance AASD*1 10 Day SRT  Overall Mass Balance AASD*2 20 Day SRT  Mass Balance Parameter Percent Reduced  Moving Average Balance AASD*1 10 Day SRT  Moving Average Balance AASD*2 20 Day SRT  TSS  14.7 %  14.1 %  15.8 %  14.8 %  VSS  16.8 %  16.1 %  17.7 %  16.7 %  Total N  17.5 %  17.7 %  17.9 %  19.4 %  Total P  -6.5 %  -7.5 %  -6.2 %  -9.8 %  Alkalinity  15.5 %  13.8 %  Table 4.11 Mass Balances for Real-Time Reactor: AASD#2 Mass Balance Parameter Percent Reduced  Moving Average Balance AASD*1 10 Day SRT  Moving Average Balance AASD*2 20 Day SRT  TSS  15.2 %  18.5 %  15.7 %  19.9 %  VSS  18.0 %  20.2 %  18.3 %  21.5 %  Total N .  19.5 %  20.6 %  21.1 %  25.9.%  Total P  -6.9 %  -5.0 %  -5.8 %  -5.3 %  Alkalinity  13.4 %  Overall Mass Balance AASD*1 10 Day SRT  J  Overall Mass Balance AASD*2 20 Day SRT  16.2 %  since AASD*2 operated at a 20 day SRT and the longer retention time was expected to produce significantly greater removals. No reason for this poor performance is readily apparent. The Real-Time reactor  (Table 4.11)  did  show a  marginal increase (2 to 4 percentage points, depending upon the mass balance method used) in TSS, VSS, and nitrogen; however, again this removal level is surprisingly low for the long SRT used. Jenkins and Mavinic (1989a) reported overall mass balance removal levels of 21.9 % for TSS, 23.9 % for VSS, 22.7 % for nitrogen and 7.35 % for phosphorus, for an aerobic-anoxic run at a 20 day SRT (20 °C) . As predicted from Figure 4.44, the alkalinity mass balance showed a net removal of alkalinity, even though the pH remained in the neutral range. It is suspected, therefore, that if the run had been extended, periodic adjustments would have become necessary to buffer the pH. Alternatively, the aerated to non-aerated  fraction  (incorporating  of  the  longer non-aerated  cycle  could  be  altered  periods) to produce more  alkalinity to offset any pH drop that occurred. Due to the increase (relative to AASD*1) in the RealTime reactor removals, small differences (up to 6 % depending upon the parameter and mass balance method used) exist in the performance of the two reactors. Again, it is not conclusive, but from a mass balance perspective, the Real-Time reactor may be removing (marginally) more than the Fixed-Time reactor (of the TSS, VSS and nitrogen). The lack of replication prevents a rigourous statement as to the statistical significance of these  differences. 4.4.4  Evaluation: Unsteady Process Input Conditions During this run, the reactors were subjected to one  spike each of sodium nitrate, ammonium chloride and hydrogen peroxide. All spikes were at a level equivalent to the "high" spikes detailed in AASD*1. The pertinent statistics are recorded in Tables 4.12, 4.13 and 4.14, while Figures 4.45 through 4.50 show vignettes of the reactor responses to each spike. The different failure categories are again highlighted figure.  Both  "Incomplete  Denitrification"  and  on each  "Incomplete  Nitrification" failures were observed, as well as the "MissedKnee" failure described earlier. Figures 4.45 and 4.46 reveal that the Real-Time reactor accommodated the sodium nitrate stress better than the Fixed-Time reactor, producing no failures directly attributable to the spike. Figures 4.47 and 4.48 indicate that both reactors had trouble assimilating the ammonium chloride spike, while Figures 4.49 and 4.50 indicate that the hydrogen peroxide spike created problems only for the Fixed-Time reactor. This latter failure is contrasted to run AASD*1 in which the hydrogen peroxide spikes produced no failures of any kind in either reactor. Tables 4.15 and 4.16 tabulate the number of failures for each reactor according to both the type of stress and category of failure. From the data, it is evident that the Fixed-Time reactor failed 11 times, while the Real-Time reactor failed 32 times. These values, however, must be normalized (for  Table 4.12 Particulars of Sodium Nitrate Spike: AASD#2 Reactor Date Day Number Sampled Nitrate Air On (Hr:Min) Concentration  FT Oct/30/90 29  RT Oct/30/90 29  4:00 pm 4:25 pm 1:05 2:00 1.64 mg/L 0.81 mg/L  Time of Spike Amount2  4:25 pm 129.6 mg  4:00 pm 129.6 mg  Sampling Time Concentration1  4:30 pm 6.16 mg/L  4:05 pm 5.34 mg/L  C o n c e n t r a t i o n i s measured a s N03-N mg/L Amount i s b a s e d on a w e i g h t of Sodium N i t r a t e  z  Table 4.13 Particulars of Ammonium Chloride Spike: AASD#2 Reactor Date Day Number Sampled Ammonia Air Off(Hr:Min) Concentration'  FT Nov/5/90 35  RT Nov/5/90 35  3:00 pm 2:40 pm 0:45 0:30 0.61 mg/L 0.17 mg/L  Time of Spike Amount2  3:00 pm 129.6 mg  2:40 pm 129.6 mg  Sampling Time Concentration1  3:05 pm 6.79 mg/L  2:45 pm 6.43 mg/L  C o n c e n t r a t i o n i s measured a s NH3-N mg/L Amount i s b a s e d on a w e i g h t of Ammonium C h l o r i d e  2  Table 4.14 Particulars of Hydrogen Peroxide Spike: AASD # 2 Reactor Date Day Number  FT Nov/20/90 50  RT Nov/20/90 50  9:45 am 2:30 2.75 mg/L  12:15 pm 1:00 3.20 mg/L  Time of Spike Amount2  9:45 am 3 mL  12:15 pm 3 mL  Sampling Time Concentration1  9:47 am 10.9 mg/L  12:17 pm 11.2 mg/L  Sampled D.O. Air On(Hr:Min) Concentration1  C o n c e n t r a t i o n i s measured a s D i s s o l v e d Oxygen (mg/L) Amount i s on a volume b a s i s of 3 % w e i g h t / v o l u m e H202  2  143 100  80  60 40 20 0  -20  > E, QOC  O  -40 -60 -80  Spiked @ 4:25 pm; NQj-N Concentration Increased From 1.64 mg/L to 6.16 mg/L  -100 -120 -140  -160  0RP1b  -180  A Failures - Incomplete Denitrification  -200 -220  40  20  Time (Hrs)  Figure 4.45 Spike of Sodium Nitrate to FT Reactor: AASD#2 100  80  60 40 20 0  -20  >  a. cc O  -40 -60 -80 -100 -120  * Spiked @ 4:00 pm; NQj-N Concentration Increased from 0.81 mg/L to 5.34 mg/L ORP2a  -140 -160 -180 -200  •  Failure - Missed Knee  -220  20  40  Time (Hrs)  Figure 4.46 Spike of Sodium Nitrate to RT Reactor: AASD#2  144 100  *Spiked @ 3:00 pm; Nhfe-N Cone. Increased from 0.61 ^ to 6.79 mg/L  80  60 40 20 0  >  -20 -40  CC  -60  o  -80 -100  -120 -140 -160 -180  •Failures - Incomplete Nitrification  0RP1c  -200  40  20  Time (Hrs)  Figure 4.47 Spike of Ammonium Chloride to FT Reactor: AASD#2  > E,  a. cc O  -20 -40 -60 -80  -  -100  -  -120  -  * Spiked @ 2:40 pm; NHj-N Concentration Increased from 0.17 mg/L to 6.43 mg/L 0RP2b  Failures Incomplete Nitrification  -140 -160 -180 H  Failure Missed Knee  -200  0  20  40  Time (Hrs)  Figure 4.48 Spike of Ammonium Chloride to RT Reactor: AASD#2  145 140 120 100 80 60 40 20  > Q. EC  o  0 •20  -120  * Spiked @ 9:45 am; Dissolved Oxygen Concentration Increased from 2.75 mg/L to 10.9 mg/L  -140  ORP1c  -40 -60 •80 -100  -160  A Failure - Incomplete Denitiification  -180  12  16  Time (Hrs)  Figure 4.49 Spike of Hydrogen Peroxide to FT Reactor: AASD#2 180 170 160 150 140 130 120 110  > CL  tr  o  100 90 80 70 60 50 40 30 20 10  0  ORP2a  Spiked @ 12:15 pm; D.O. Increased from 3.20 to 11.2 mg/L T  12  —f—  l  16  20  24  Time (Hrs)  Figure 4.50 Spike of Hydrogen Peroxide to RT Reactor: AASD # 2  Table 4.15 Failures Associated with FT Reactor Operation: AASD#2 Type of Stress  Incomplete Denitrification Failure  Incomplete Nitrification Failure  Missed Nitrate Breakpoint Failure  Total Number  1  1  0  2  Sodium Nitrate Spike  3  0  0  3  Ammonia Chloride Spike  0  4  0  4  Hydrogen Peroxide Spike  1  0  0  1  Ommission of Daily Feed  1  0  0  1  Total Number of Failures  6  5  0  11  Normal Operation  Table 4.16 Failures Associated with RT Reactor Operation: AASD#2 Type of Stress  Normal Operation  Incomplete Denitrification Failure  Incomplete Nitrification Failure  Missed Nitrate Breakpoint Failure  Total Number  0  1  25  26  Sodium Nitrate Spike  0  0  0  0  Ammonia Chloride Spike  0  4  0  4  Hydrogen Peroxide Spike  0  0  0  0  Ommission of Daily Feed  2  0  0  2  Total Number of Failures  2  5  25  32  each reactor) against the total number of cycles during the run. For example, the Real-Time reactor with its short cycle length had many more opportunities than the Fixed-Time reactor to fail. Accordingly, the Fixed-Time reactor sustained 217 cycles (a failure rate of 5.1 %) , while the Real-Time reactor underwent 525 cycles (a failure rate of 6.1 %) . Thus, from a "failures" perspective, both reactors performed essentially the same. Since the majority of the Real-Time failures were software-based, more sophisticated programming techniques may be able to reduce or even eliminate the "Missed-Knee" category of failure. If this occurs, there may be grounds for stating that the Real-Time AASD#2 operating strategy holds more promise of being better able to control the system; especially since it may have performed better than the Fixed-Time reactor in the mass balance category. Finally, Figures 4.51 and 4.52 show the response of each reactor to the spike of 56 mg/L (0.5 millimoles/litre of potassium  cyanide).  This  concentration  is  one  half  that  suggested by the microbiological department at UBC, however it is clear that the KCN immediately affected the micro-organisms. Cyanide prevents the reaction of oxygen in the overall energyproducing process by binding with ferricytochrome oxidase, the last cytochrome in the oxidative phosphorylation pathway. In both reactors, the ORP gradually rose again as the concentration of dissolved oxygen increased in the reactor (to over 7 mg/L), due to the lack of bacterial demand for an electron acceptor.  148  Spiked with KCN 56 mg/L @ 2:30 pm > E. Q. CC  o  Time (Hrs)  Figure 4.51 Spike of Potassium Cyanide to FT Reactor: AASD # 2  200  150  -  100  -  * Spiked with KCN 56 mg/L @ 2:20 pm  50  ">*  £  0  Q. CC  o  -50 -  -100 -  -150  -  -200  Time (Hrs)  Figure 4.52 Spike of Potassium Cyanide to RT Reactor: AASD # 2  CHAPTER 5 BIOLOGICAL PHOSPHORUS REMOVAL (BIO-P) EXPERIMENTS 5.l  Operating Characteristics and ORP Profiles The  biological  phosphorus  removal  experiment  was  partitioned into two runs (Bio-P*l and Bio-P*2) , with each run being 2 SRTs segmentation  (40 days) in length. The rationale for this was  somewhat  artificial,  in  that  a  solenoid  malfunction drained one-half of the Real-Time reactor contents down the sink at the 40 day mark. It was felt however that the period was of sufficient length to extract useful data, and thus the second run was halted after a similar period of time. During Bio-P#l, the raw feed was supplemented with inorganic phosphorus (Na2HP04) to approximately a concentration of 7 mg/L ortho-P (calculated in Appendix G) . However, the reactors failed to remove phosphorus during this run; therefore, this practice was discontinued when the reactors were restarted. Thus, during Bio-P#2, the feed to the reactors contained whatever ortho-P concentration naturally occurred in the pilot plant influent (usually around 2 mg/L). During both runs, the pilot plant strategy of adding alkalinity (NaHC03) to the raw sewage was continued in order to maintain the pH in the neutral range. The reactors were operated at a 20 day SRT, since that reduced the need for acclimation time between the pilot plant and the reactor conditions. In theory, with a 20 day SRT, 240 mL of liquid should have been wasted on a daily basis. The solids level, however, declined dramatically over the run (Section 5.2) and therefore wasting was occasionally halted.  The Fixed-Time reactor operated with a scheduled time ( 1 hr 25 min into the anoxic period) , for the addition of 3 0 mg acetate/litre  of  influent  (calculated  in Appendix  G ) . In  contrast, the Real-Time reactor's acetate addition was triggered by the detection of the nitrate breakpoint. Before discussing the performance of the reactors, it is useful to consider the "ideal" ORP curve shape, generated under SBR Bio-P conditions. Unlike the AASD experiments (which had a distinct  "indigenous" curve, particular  to  each  reactor's  operation), the curve shown in Figure 5.1 was not ubiquitous enough to be considered as "characteristic" of normal Bio-P operation. The reasons for this will be explained later. Clearly evident in Figure 5.1 are the three distinct zones of the Bio-P process, with a sharp, pronounced nitrate knee initiating the Real-Time addition of acetate. Figure 5.1 does not, by itself, imply perfect biological conditions for the removal of phosphorus; for even when this curve shape was obtained, the reactors seldom achieved consistent excess removal of phosphorus. As will be discussed at the end of Section 5.2, there is a host of biological and chemical parameters that must be in harmony in order to ensure good P removal. For comparison, Figure 5.2 illustrates a frequent shape of the  ORP  curve,  generated  when  the  reactor  denitrified  immediately after the FILL period had finished. The curve's extremely rapid decline meant that the Real-Time reactor's software could not trap the knee in any of the 3 cycles that day. The major reason for this seems to be that the Bio-P  151  Time (Hrs)  Figure 5.1 "Ideal" ORP Profile Under Bio-P Conditions  -20 Cycle 3  -40 -60 -80 -  Software Cannot Trap Nitrate Knees Because They Occur Too Quickly if At All  -100  Bio-P #2  -120  -  -140  -  Rapid Denitrification immediately After Fill  -160  -  3 Cycles Per Day  -180  -  -200 -220 -240  -r 3 Time (Hrs)  Figure 5.2 Software Failure Due to Rapid Denitrification  process is considered to be a highly-loaded carbon system, as compared to the AASD system which has very little soluble carbon available. Although not always the case in this experiment, in theory, a Bio-P system should have plenty of carbon available for denitrification, especially if relatively fresh feed has just been placed in the feed bucket. Since nitrate reduction is the first sequence in a Bio-P SBR, the denitrifying bacteria have few organisms  competing with them  for access to the  substrate. Thus, they are easily (and apparently rapidly) able to eliminate the nitrates, causing the breakpoint to occur in the first several minutes. A number of attempts were made during both runs to track the phosphorus and nitrate behaviour over the course of one complete cycle. Figures 5.3  and  5.4  show the best curves  obtained during Bio-P*l. In the Fixed-Time reactor (Figure 5.3), the nitrate breakpoint occurs just prior to the addition of acetate,  the  impact  of  which,  triggers  the  classical  release/uptake phenomena necessary for Bio-P removal. As can be seen however, the reactor failed to take up excess phosphorus and thus the effluent was discharged  from the reactor at  essentially the same level at which it entered. Although acetate was measured during this track, it was utilised so quickly that none was detected on the gas chromatograph. Figure 5.4 shows the behaviour of the Real-Time reactor. As has been illustrated earlier and as typified by this example, the  nitrate  disappeared  almost  immediately,  causing  true  anaerobic conditions to develop. This was accompanied by a slow  153 20  REACT(Unaerated) Nitrate Knee Occurs Just Prior To Addition  15  10 -  5  ; REACT(Aerated)  of Acetate  -  BiO-P #1 -5 -  -10  -15  Fixed-Time Reactor Profile ORP1c - March/26/91  -  ORP1c + o  Fixed-Time 1 hr. 25 min.  -  Ortho-P NOx  ORP1e  -20 9  -r13  11  15  Time (Hrs)  Figure 5.3 Fixed-Time Reactor Track Study: Bio-P#1 25 20  Computer Initiated Acetate Addition Just Prior to React (Aerated) —  15 10 NOx  5 ;  -5 H -10 -15  »•?«-  9  REACT (Unaerated)  REACT (Aerated)  No Observable Nitrate Knee Since NOx is Already Zero  Bio-P #1 Real-Time Reactor Profile ORP2b - March 26/91  \  -20  ORP2b -25  —I—  — I —  1-t  13  + o  ORP2b Ortho-P NOx  15  Time (Hrs)  Figure 5.4 Real-Time Reactor Track Study: Bio-P#1  release of phosphorus, further accentuated by the addition of acetate, 2 hours and 40 minutes into the cycle (just prior to aeration). The computer added the acetate as a "fail-safe" measure, since at that time it "assumed" that the breakpoint had been  missed.  Again, whatever  phosphorus  was  released  was  subsequently taken back up during aeration; however, no "excess" removal was observed. Another frequent observation was the addition of acetate actually causing the knee itself, as shown in Figures 5.5 and 5.6. The Fixed-Time reactor  (Figure 5.5)  depicts the knee  occurring at precisely the same time (i.e. 1 hour 25 minutes) into all 3 cycles. Although not directly confirmed by NOx analysis, this implies that acetate is being used as a source of easily oxidizable carbon for denitrification purposes, rather than for carbon storage by Bio-P organisms. Similarly, the RealTime reactor  (Figure 5.6) shows the computer initiating the  acetate addition (since the knee had not been detected) after 2 hours and 40 minutes. This carbon is sufficient to complete the denitrification reaction which causes the nitrate breakpoint just prior to the onset of aeration. The best track studies available for Bio-P#2 also reflect this trend. Figure 5.7 shows the addition of acetate to the Fixed-Time  reactor  causing  a  sharp  drop  in  the  nitrate  concentration, with the breakpoint occurring shortly thereafter. In this particular example, the phosphorus was removed to a very low level; therefore, it appeared that the acetate was being partitioned  between  being  used  for  nitrate  reduction  by  155 60 No Observable 0.0. Breakpoints However 0.0. Is Likely Large  40 20 0 -20 H  VTA Addition Causes Nitrate Knee To Occur 1 hr. 25 min. Into AH 3 Cycles  -40 -60 -80 -100 -  BlC-P#2  -120  Fixed-Time Reactor Profile 91-05-17.FT 0RP1b  -140 -160 -180 -200 -220  Tlme(Hrs)  Figure 5.5 VFA-Caused Breakpoints in Fixed-Time Reactor 120 REACT (Aerated)  100 H 80 60 H 40 20 H 0 -20  Bio-P #2 Real-Time Reactor  -40 -  Profile 91-05-1 aRT -60 -  ORP2c  -80 -100 -120 1  7  3 Time (Hrs)  Figure 5.6 VFA-Caused Breakpoints in Real-Time Reactor  156  REACT (Unaerated)  REACT (Aerated)  BioP #2 Fixed-Time Reactor Praflle 0RP1b May/7/91 — + o  0RP1b Ortho-P NOx  15 Time (Hrs)  Figure 5.7 Fixed-Time Reactor Track Study: Bio-P#2  denitrifiers  and  being  used  for  carbon  storage  by  Bio-P  organisms. The Real-Time reactor's breakpoint (Figure 5.8) was again induced by the addition of acetate, at the last possible minute before aeration. This was followed by a quick release prior to aerated uptake of phosphorus. One recurring phenomena was the way in which the shape of the  ORP  curve  was  influenced  by  the  operation  of  the  experimental system. In particular, a delay in the time of occurrence for the nitrate breakpoint was often observed as the feed sludge weakened with time. As has been mentioned, raw sewage was collected in carboys and stored in the cold room for up to 12 days. Since the feed bucket could hold up to 3 days worth of sewage, every 4th day the bucket was replenished with "fresh/stored" sewage from the cold room. However, not only was there a decline in the carbon content in the raw sewage stored in the cold room (Figure 5.9), but there was also a significant decline in the carbon content during the 3 days in between "fresh/stored" feed (Figure 5.10) (the data used to plot these graphs have been included in Appendix H ) . This latter decline occurred because the feed bucket sewage was continuously mixed (albeit at a very slow rate) in order to keep the solids in suspension. Despite being covered to minimize air entrainment, it is evident that sufficient air must have entered the mixture to allow bacteria to utilize short-chain organic compounds generated from the conversion of complex organics in the raw sewage. The decrease in carbon content was therefore reflected in  158  REACT (Unaerated)  BiO-P # 2 Real-Time Reactor Profile 0RP2b May/7/91 +  ORP2b Ortho-P  0RP2b I  11  13  15  Time (Hrs)  Figure 5.8 Real-Time Reactor Track Study: Bio-P#2  Decline in Carbon Content Raw Sewage Stored in Cold Room o» E,  Soluble COD  O  g o 6" iQ O O o a a 7  9  Time (Days)  Figure 5.9  Decline in Carbon Content: Stored in Cold Room  110  100 -  a E  90  IT-  80 -  o  70  U O I-C  Decline in Carbon Content Raw Sewage Stored in Feed Bucket  Soluble COD  t-  iS  60  \Q O U  50  -  C  o i_ a U  Organic Carbon  1.8  £2  3.4  3.8  Time (Days)  Figure 5.10 Decline in Carbon Content: Stored in Feed Bucket  a delay in the time that the knee occurred in any given cycle. This is illustrated in Figures 5.11 and 5.12. Figure 5.11 tracks the knee over the three cycles of the day and as pictured, there is no "average time" for denitrification, since it is constantly lengthening as a function of the strength of the incoming feed. Figure 5.12  continues Figure 5.11  into the next day, and  illustrates how, during the last cycle before replenishment with fresh feed  (from the cold room), the reactor  "failed" to  completely denitrify, in a manner reminiscent of the AASD set of experiments. The 6th cycle occurred after replenishment and consequently  the  time  taken  to  completely  denitrify  was  considerably  shortened once again. The fact that the knee  associated with cycle 6 occurs slightly later than the knee associated with the first cycle, may be indicative of the gradual decline in the carbon content of the feed stored in the cold room itself. 5.2  Chemical Characteristics of Bio-P Experiments Tables 5.1 and 5.2 detail some selected statistics of the  solids, nitrogen and phosphorus levels measured during both BioP#l and Bio-P*2. The detailed chemical data have been presented in Appendix H. In both experiments, the feed TSS level was approximately 100 mg/L (Figures 5.13 and 5.14). Bio-P*2 however experienced a much larger standard deviation as indicated in Table 5.2. Figure 5.14 illustrates the major cause of this, as occurring between the 3rd and 4th data points on the graph. The first 3 points are from sewage stored in the cold room, but initially collected  161 60 40 H 20  Delay in Time of Nitrate Knee Occurrence, Likely a Function of the Carbon Decay in the Feed Storage Bucket  0 -20 H -40 -60  Bio-P #1  -80  Real-Time Reactor Profile ORP2b March 6/91  -100 -120  Cycle #3  -140  Cycle #2  -160 -180  Cycle #1  -200  1 Time (Hrs)  Figure 5.11 Delay in Time of Nitrate Breakpoint Occurrence  Bio-P #1 Real-Time Reactor Profile March 6-7/91  Denitrification Probably Caused by VFA Addition Just Before REACT (Aerated) Fresh Feed from Cold Room Shortens Denitrification Time Again -200 1 Time (Hrs)  Figure 5.12 Two Day Track of Delayed Nitrate Breakpoint  Table 5.1 Solids, Nitrogen and Phosphorus Chemical Data: Bio-P#1 Fixed-Time RCTR Effl  Real-Time RCTR Effl  121 100 77 15  2376 2124 1620 226  11 4 1 3  2612 2281 1890 205  5 3 1 1  Maximum Mean Minimum Std.Dev.  107 88 68 13  1834 1616 1280 196  11 4 1 3  2012 1727 1392 195  5 3 1 1  TKN - Feed (mg/L)  Maximum Mean Minimum Std.Dev.  30.3 28.4 26.8 1.4  % N - RCTR (%)  Maximum Mean Minimum Std.Dev.  NOx-N (mg/L)  Maximum Mean Minimum Std.Dev.  Statistic  FEED  TSS (mg/L)  Maximum Mean Minimum Std.Dev.  VSS (mg/L)  Chemical Parameter  5.72 5.32 4.81 0.25  5.19 4.90 4.53 0.10  0.35 0.14 0.00 0.09  9.43 7.97 6.31 0.94  12.89 7.70 2.69 2.40  Maximum Mean Minimum Std.Dev.  17.0 13.0 9.8 2.4  0.1 N/D N/D N/D  2.5 0.4 N/D 0.8  TP - Feed (mg/L) %P - RCTR (%P)  Maximum Mean Minimum Std.Dev.  9.7 9.5 9.1 0.4  3.56 3.25 2.92 0.25  4.07 3.20 2.53 0.40  Ortho-P (mg/L)  Maximum Mean Minimum Std.Dev.  7.64 6.44 4.91 0.87  10.70 6.38 3.26 2.17  8.80 5.60 2.51  NHj-N  (mg/L)  |  1.70  J  163  Table 5.2 Solids, Nitrogen and Phosphorus Chemical Data: Bio-P#2 Fixed-Time RCTR Effl  Real-Time RCTR Effl  181 107 65 41  3018 2194 1598 417  10 6 2 2  3026 2159 1630 439  10 6 2 3  Maximum Mean Minimum Std.Dev.  162 97 59 36  2648 1825 1266 410  10 6 2 2  2650 1791 1276 431  10 6 2 3  TKN - Feed (mg/L)  Maximum Mean Minimum Std.Dev.  41.2 31.0 24.0 7.4  % N - RCTR (%)  Maximum Mean Minimum Std.Dev.  NOx-N (mg/L)  Maximum Mean Minimum Std.Dev.  NH 3 -N (mg/L)  Chemical Parameter TSS (mg/L)  vss (mg/L)  Statistic  FEED  Maximum Mean Minimum Std.Dev.  6.82 6.32 5.45 0.36  6.26 5.83 5.53 0.24  0.30 0.16 0.04 0.06  9.71 8.49 7.19 0.65  10.68 9.00 7.40 0.88  Maximum Mean Minimum Std.Dev.  13.8 12.4 11.6 0.6  N/D N/D N/D N/D  N/D N/D N/D N/D  TP - Feed (mg/L) %P - RCTR (%P)  Maximum Mean Minimum Std.Dev.  6.3 4.7 3.7 1.1  3.36 2.50 1.12 0.71  3.52 2.54 1.22 0.71  Ortho-P (mg/L)  Maximum Mean Minimum Std.Dev.  3.18 2.19 1.60 0.36  2.07 0.52 0.00 0.78  1.92 0.52 0.01 0.59  130 120  -  110  -  100  -  90  -  80  -  70  -  60  -  •  FaedTSS  50  -  *  FTEffluentTSS  o  RT Effluent TSS  40  -  30  -  20  -  10  -  FMdTSS  Bio-P #1  FT Effluent TSS RT Effluent TSS  <N— 30  40  Time (Days)  Figure 5.13 Variation in Feed and Effluent TSS: Bio-P#1  190  Bio-P #2  Feed TSS •  Feed TSS  + o  FTEffluentTSS RT Effluent TSS  40 Time (Days)  Figure 5.14 Variation in Feed and Effluent TSS: Bio-P#2  during a relatively dry weather spell. In contrast, subsequent data points are from feed collections made when the sewage had been diluted by the influx of water from several days of rain. This caused a significant drop in the feed TSS as depicted in Figure 5.14. In both figures the reactor effluents for each run were generally less than 10 mg/L. Visual inspection of the sludge settling characteristics revealed a highly clarified effluent, produced by a sludge blanket interface settling well below the decanting solenoid port. The solids variation  inside the reactors  is shown in  Figures 5.15 and 5.16. In the latter experiment especially, the TSS level declined dramatically, with bacterial growth not being sufficient to counterbalance the loss in solids due to wastage. Wasting was halted several times (as reflected in occasional horizontal plateaus in the latter portion of the Bio-P#2 curve); however, it is evident that this was not practiced frequently enough to stem the decline in solids. This will be expanded upon in more detail later, when discussing the F:M ratio. Ultimately though this means that the actual SRT is substantially less than 20 days; a factor having major ramifications for the P removal performance. The VSS/TSS ratio was greater in the Feed (Bio-P#l - 0.88, Bio-P*2 - 0.90) than the Fixed-Time (Bio-P#l - 0.76, Bio-P*2 0.83) and Real-Time (Bio-P#l - 0.76, Bio-P*2 - 0.82) reactors, respectively. In both runs, the few effluent solids that were released as decanted supernatant (generally less than 10 mg/L  166 2.7 Real-Time RCTR  2.6 2.5 2.4 2J  11  2J 2.1  2.0 1.9 1.3  Bio-P #1  1.7  Fixed-Time TSS Real-Time TSS  1.6  -r10  —I  40 Time (Days)  Figure 5.15 Variation in Reactor TSS: Bio-P#1  3.1 3.0  -  2.9  -  2*  -  2.7  -  2.6  -  2J5 -  II  2.4  -  2J  -  Z2  -  2.1  -  2.0  -  1.9  -  13  -  1.7  -  •  Fixed-Time TSS  -  +  Real-Time TSS  1.6  1J 4-  Fixed-Tlme RCTR  Bio-P #2 Real-Time RCTR  i  10  I  20  30  Time (Days)  Figure 5.16 Variation in Reactor TSS: Bio-P#2  -1 40  (Appendix H)) were essentially all volatile solids. The feed sewage TKN was approximately 30 mg/L, with about 40 percent being in the form of ammonia. In almost all cases the ammonia was completely nitrified, with effluent NH3 values below the detectable effluent were  limit of 0.05 between  7 and  mg/L. Nitrate 9 mg/L; these  levels in the could  not be  denitrified, since a single SBR operating under this strategy cannot be optimized to obtain concurrent nitrogen and phosphorus removal. Manning and Irvine (1985), operating a similar system, also reported a highly nitrified effluent (> 27 mg/L NOx). Due to inorganic P additions to the feed during Bio-P*l, well over 68 % of the TP (average value of 9.5 mg/L) was in the form of soluble ortho-P. Bio-P*2 however had 47 % of the TP (average value 4.7 mg/L) in soluble form. Figures 5.17 and 5.18 track the progress of the % N and % P values for both reactors (both runs) and indicate that the second run had a slightly larger average % N value than the first run. This is verified in Tables 5.1 and 5.2. In both runs (especially Bio-P#2) , there was a tendency for the % P to increase with time. In theory, this should occur as phosphorus is removed from the bulk liquid; however, the fact that little ortho-P removal was observed makes this observed trend more fortuitous than certain. In fact, the ortho-P behaviour was less than ideal as illustrated reactor's  in Figures 5.19 and 5.20. In Figure 5.19, the effluent  phosphorus  level  oscillates  around  the  influent feed phosphorus level; thus, on the average, whatever  5.8 5.6 % N FT RCTR  5.4 5.2 5.0 4.8  %NRTHCTR  4.6  Bio-P #1  4.4 4J2 4.0 3.3 3.6  + A  % N FT RCTR % H RT RCTR  • o  % P FT RCTR % P RT RCTR  3.4 %P FT RCTR  12 3.0 2.3 2.6 2.4 10  20  30  40  Time (Days)  Figure 5.17 Reactor Plot of Percent N and P: Bio-P#1 % N FT RCTR  6 -  Bio-P#2 + A • o  % N FT RCTR % N RT RCTR % P FT RCTR % P RT RCTR  % P FT RCTR 2  -  i  l  10  20  30  40  Time (Days)  Figure 5.18 Reactor Plot of Percent N and P: Bio-P#2  169 11 Fixed-Time RCTR  10 -  9 8  -  7  -  6 -  BIo-P #1  4 H 3  -  •  Feed Ortho-P  +  Fixed-Time Ortho-P  o  Real-Time Ortho-P  10  20  30  40  Time (Days)  Figure 5.19 Track of Ortho-P Concentrations: Bio-P#1 12 3.0  -  2.8 2.6 2.4 2.2 2.0  -  1.8 1.6 -  Bio-P #2  - • Feed Ortho-P + Fixed-Time Ortho-P 1.2 o Real-Time Ortho-P 1.0 1.4  0.8 0.6 -  Real-Time RCTR  0.4 0.2 0  Fixed-Time RCTR i  10 Time (Days)  Figure 5.20 Track of Ortho-P Concentrations: Bio-P#2  entered the reactor was also released from the reactor. The parallel behaviour of both reactors (in terms of synchronous high/low oscillations) can be correlated with the decline in the carbon content in the feed bucket as elaborated below. Ortho-P was measured every second day; thus, one sample would be taken relatively close to the day in which fresh sewage had been added to replenish the feed bucket. On such days the feed  would  be  denitrification  relatively  rich  would proceed  in  rapidly  carbon,  and  therefore  (Figure 5.2)  and be  followed by a good release of phosphorus when the acetate was added to the reactor. Subsequently, during the aerated sequence, the microorganisms would take up phosphorus and the effluent level would  be below  average, with  some  "excess" removal  observed. The next samples, however, would be taken just prior to replenishing the feed bucket; thus, they would be furthest from the previous "fresh/stored" feed day. Denitrification would therefore be delayed (perhaps even incomplete) and some (or all) of the acetate added would be used for denitrification purposes, rather than for carbon storage by Bio-P organisms. On such days, relatively large values of effluent P were observed, because aerated P uptake had been preceded by poor P release. This established the alternating high/low effluent ortho-P pattern shown in Figure 5.19. The decline in the carbon content in the feed bucket and the lack of steady-state conditions are advocated as the major causes of the poor P removal observed during this research. This  will be emphasized repeatedly in later sections of the analysis. During Bio-P#2 (Figure 5.20), the raw sewage influent P values were much lower than Bio-P#l, due to the absence of inorganic P supplements. Good P removal was observed only up to where the feed sewage had been subjected to several days of rain. The dilution of the carbon in the sewage (coupled with its subsequent decay), although producing an attendant drop in the influent P value, was evidently enough to push the P values into exhibiting the parallel high/low behaviour, as explained above. Table 5.3 and 5.4 detail the carbon, oxygen, alkalinity and pH statistics for both runs. Figures 5.21 and 5.22 depict the soluble COD behaviour of the feed and reactors during each run. The effluent from both reactors was generally below 30 mg/L for Bio-P#l and 20 mg/L for Bio-P*2. Using the mean values, this made for soluble COD removals of 81 % and 83 % for the FT and RT reactors (Bio-P#l) and 75 % and 79 % for the FT and RT reactors (Bio-P#2) . As  indicated  however,  significant  removal  was  occurring inside the feed bucket, during the days in between replenishment. Figure 5.22 (Bio-P*2) reveals the sharp drop in feed COD from the dry spell to the wet period, commencing after the 3rd data point. Pilot plant data showed a drop in the influent total COD from over 400 mg/L to 230 mg/L, for these collection dates. Figures 5.23 and 5.24 show carbon plots for the feed from both runs. During Bio-P*l (Figure 5.23), both the inorganic and organic carbon comprise roughly equal amounts of the total carbon. This is substantiated in Table 5.3. During run Bio-P#2  Table 5.3 Carbon, Oxygen, Alkalinity and pH Data: Bio-P#1 Chemical Parameter  Statistic TC  Carbon (mg/L)  Maximum Mean Minimum Std.Dev.  COD (mg/L)  Maximum Mean Minimum Std.Dev.  Dissolved Oxygen (mg.L)  Alkalinity  pH  FEED IC TOC  114 95 79 11  66 48 31 10  60 47 38 6  Fixed-Time TC IC TOC  Real-Time TC IC TOC  63 45 31 11  63 45 31 10  52 37 25 10  53 38 25 9  29 27 20 3  28 25 15 4  7.00 4.60 0.70 2.07  6.90 2.90 0.70 2.37  155 143 118 13  Maximum Mean Minimum Std.Dev.  11 8 6 1  Maximum Mean Minimum Std.Dev.  320 237 164 47  310 254 192 37  312 253 178 36  Maximum Mean Minimum Std.Dev.  7.56 7.28 6.81 0.21  7.37 7.12 6.64 0.18  7.38 7.15 6.97  10 7 6 1  J  0.14  Table 5.4 Carbon, Oxygen, Alkalinity and phi Data: Bio-P#2 Chemical Parameter  Statistic TC  Carbon (mg/L)  Maximum Mean Minimum Std.Dev.  COD (mg/L)  Maximum Mean Minimum Std.Dev.  129 93 74 15  FEED IC TOC 79 56 42 11 72 53 42 11  50 37 28 8  Fixed-Time TC IC TOC  Real-Time TC IC TOC  78 55 38 13  78 56 35 14  64 47 31 12  14 8 6 2  66 47 28 13  20 13 10 3  18 11 4 3  8.00 6.65 1.20 1.36  8.00 7.26 4.20 0.84  Dissolved Oxygen (mg.L)  Maximum Mean Minimum Std.Dev.  Alkalinity  Maximum Mean Minimum Std.Dev.  360 265 210 46  392 277 172 66  390 282 170 69  Maximum Mean Minimum Std.Dev.  7.59 7.38 7.09 0.16  7.86 7.54 7.11 0.19  7.97 7.66 7.34 0.19  pH  13 8 6 2  173 160 150 140 -  Feed COO  130 120 110 100 -  Bio-P #1  90 80  + o  70 -  Feed COO Fixed-Time COD Real-Time COO  60 50 -  Fixed-Time COO  40 30 20 H  Real-Time COD  10  T  10  30  20  40  Time (Days)  Figure 5.21 Variation in Feed and Reactor COD: Bio-P#1  80  Bio-P#2 70 -  Feed COD  + o  Feed COD Fixed-Time COD Real-Time COD  60  50 -  40  30 Fixed-Time COD 20 -  10  -  10  20  30  40  Time (Days)  Figure 5.22 Variation in Feed and Reactor COD: Bio-P#2  174 120 110 100 90 80 70 60 50 40 30 -  BiO-P # 1 • FeedTC + Feed IC o Feed TOC  Feed TOC  20 10  20  10  30  40  Time (Days)  Figure 5.23 Carbon (TC, IC, TOC) Plots for Feed: Bio-P#1 130  Bio-P#2 •  FeedTC  Feed TOC - J —  10  T-  20  30  40  Time (Days)  Figure 5.24 Carbon (TC, IC, TOC) Plots for Feed: Bio-P#2  however, the percentage of inorganic carbon is larger than the organic carbon,  another indication of the generally "weaker"  sewage used during this run. The decline in feed TOC from the 3rd to 4th data points (Bio-P#2) is not as marked as it was in the COD profile; however, it is still sufficiently pronounced, to be suggested as a partial reason for the sudden change in the P behaviour from generally stable low values to the fluctuating behaviour described earlier. Figures 5.25  and  5.2 6 illustrate  (for both runs) the  behaviour of the carbon in the Fixed-Time reactor. As can be seen, the TOC was very low (< 10 mg/L) and fairly constant as indicated by the horizontal nature of the TOC plot and the relatively even distance separating the IC from the TC profile. The Real-Time reactor, if plotted, would show a similar trend. The large standard deviations (Tables 5.3 and 5.4) for the reactor dissolved oxygen concentrations, are indicative of the lack of control achievable at the lab scale. Small adjustments to the needle flow control valves produced wide swings in the D.O measurement in the bulk liquid. A plot of these values would be essentially stochastic and of little value, especially since, in the Real-Time reactor (Bio-P*l) , the standard deviation was almost as large as the mean. In run Bio-P#2 no attempt was made to control the oxygen supply and thus the D.O. level was often at a maximum, usually around 7 mg/L. The  alkalinity  values  were  also  random  in  nature,  reflecting the casual manner in which two scoops of sodium bicarbonate were tossed into the feed bucket, every time it was  176  120  Bio-P #1  110 a x 7  100 90 -  Fixed-Time TC Fixed-Time IC Fixed-Time TOC  80 70 -  Fixed-Time TC  60 50 40 30 20 10 H 0  i  20  10  30  40  Time (Days)  5.25 Carbon (TC, IC, TOC) Plots for FT RCTR: Bio-P#1  Bio-P #2 A Fixed-Time TC x Fixed-Time IC v Fixed-Time TOC  40  Figure 5.26 Carbon (TC, IC, TOC) Plots for FT RCTR: Bio-P#2  filled. Plots of the variation in pH with time are shown in Figures 5.27 and 5.28; since all pH measurements fall within the neutral range, it is clear that the alkalinity additions were more  than  sufficient  to  supply  the  consumptive  needs  of  nitrification. Some unduly large pH values were recorded, and it is suspected that some C02 was being stripped from solution due to excessive aeration. When all of the preceding observations are considered, it is evident that several key biological and chemical parameters must be in balance in order to consistently achieve good P removal. One such relationship is the TKN/COD ratio, which in effect quantifies the denitrification capacity of the influent sewage. Researchers have long recognized the importance of this ratio. For example, Ekama et al., (1984) critiqued the Modified Bardenpho (Phoredox) process and predicted it would experience complete nitrification/denitrification, only when the influent sewage possessed a TKN/COD ratio less than 0.07. (i.e. a COD/TKN ratio of greater than 14:1). TKN/COD ratios larger than 0.07 seemed  to have  difficulty  in providing  enough  carbon for  denitrification. The need to accommodate lower strength sewages was one reason (among others) behind the development of the UCT process, reported to be able to cope with TKN/COD ratios of up to 0.14 (i.e. COD/TKN ratios as low as 7:1). Working within these ratios, Ekama et al., (1984) were able to guarantee enough carbon available (in most instances) to ensure that nitrates did not bleed through to the anaerobic reactor.  6.8 -\  0  |  1  10  1  ;  20  1  1  30  a  1  j  40  Time (Days)  Figure 5.27 Variation in pH Feed, FT and RT RCTRS: Bio-P#1  0  10  20  30  40  Time (Days)  Figure 5.28 Variation in pH Feed, FT and RT RCTRS: Bio-P#2  Barnard et al. (1985), however, showed that the Kelowna B.C., Bio-P process was able to achieve good P removal with ratios between 7:1 and 10:1, despite predictions that it would need a COD/TKN ratio of at least 14:1 in order to function effectively, The pilot plant's TKN/COD ratio is usually between 0.06 and 0.08 (Comeau (1989)). Unfortunately, in this research, total COD values  are  only  available  for  the  feed  collection  days.  Accordingly, the average total CODs for Bio-P*l and Bio-P#2 were 261 mg/L and 292 mg/L, respectively. Using the mean values for TKN (Tables 5.1 and 5.2), a TKN/COD ratio of 0.11 was calculated for both Bio-P*l and BioP*2. As large as this ratio is, it is still lower than the actual ratio present on most days, since the COD values do not consider the decline in COD during the days in between replenishment of the feed bucket. Moreover, in this experiment, the ratio was unusually affected by the vagaries in local weather patterns, since one collection would influence the following 12 days. The fact that the TKN/COD ratio on most days is quite large is somewhat overshadowed by the peculiarity of the SBR treatment method, in that it transposes the traditional (ex. UCT or UBC) order of zones, from anaerobic, anoxic, aerobic, to anoxic, anaerobic, aerobic. This has the effect of accentuating the concern about whether sufficient carbon is available for Bio-P organisms to predominate. To illustrate, in the traditional sequence, the emphasis has not only been to ensure enough carbon enters the first  (anaerobic) zone, but also that it enters in the right form (i.e. as rapidly biodegradable (RBD) carbon (Nicholls and Osborn (1979)). The RBD fraction of the carbon is understood to be that portion  of  the  carbon  cytoplasmic membrane  that  of the  can  easily  cell by  pass  diffusion  through or  the  osmotic  pressure. RBD carbon is usually comprised of short-chain fatty acids (SCFA), such as acetate, propionate, butyrate etc., and much work has been done at UBC on processes designed to enhance the production of these substrates in the incoming sewage (Rabinowitz  et  al.  (1986),  (1987),  Elefsiniotis  (1992)).  Seibritz, Ekama and Marais (1983) have established that there must be at least 25 mg/L of RBD COD available in the anaerobic zone to ensure good P release/carbon storage. Further to this, there must be enough remaining carbon to reduce the nitrates in the second (anoxic) zone, as implied by the earlier comments about the TKN/COD ratio. If insufficient carbon is available, nitrates will bleed through  (via the  recycle line) into the anaerobic zone, inhibiting P release. Current theories suggest that nitrates inhibit P release (as measured by bulk liquid orthophosphate concentrations) by providing an electron acceptor for facultative denitrifiers. Consequently, Bio-P organisms do not have exclusive access to all of the RBD substrate. There is, however, considerable evidence (Hascoet and Florentz (1985), Vlekke (1988) and Comeau (1989)), that at least a fraction of Bio-P bacteria are capable of assimilating polyphosphates in the presence of nitrates. Thus, the reason for poor P release (when nitrates are present  in the anaerobic zone), becomes one of competition between Bio-P organisms (rather than inhibition by other organisms) and is a function of the relative mix of organisms in the wastewater (those releasing P and those accumulating P ) . Although it is likely that a combination of the above reasons is responsible for P release not being as vigourous in the presence of nitrates, this research will explain its results from the first premise (i.e. nitrates provide electron acceptors for bacteria, which in the process of denitrifying, utilize some of the carbon which should have been stored by Bio-P bacteria). The  SBR  trait  however,  of  inverting  the  first  two  sequences, means that all of the carbon in the influent sewage is primarily available for denitrification. This includes all of the RBD COD, although it is appreciated that other than the first (and perhaps a portion of the second) day after fresh sewage has replenished the feed bucket, most of the RBD fraction of the sewage would have disappeared. Upon entering the reactor, unless there is a large amount of carbon (specifically RBD COD) available  in the influent, practically  all of it will be  utilized by denitrifying bacteria and none will be available for storage by Bio-P organisms. Several researchers have suggested different values of COD utilized / mg of nitrate reduced. Ekama et al. (1984) has estimated the amount of RBD in a sewage by assuming that every mg of nitrate reduced by RBD carbon, utilizes 8.6 mg of the carbon for synthesis and energy production (U.S. EPA (1987)). Rabinowitz (1985), in a series of acetate fed batch experiments  derived a rate of 3.60 mg COD / mg N03-N, a value less than one half of the value quoted above. In fact, this value is very close to the theoretical  (stoichiometric) value for acetate  (3.53 mg COD/mg N03-N) as calculated by McCarty et al. (1969). Whichever method is used, it is apparent that a considerable fraction  of  the  influent  carbon  would  be  utilized  for  denitrification just because of the order of sequences in the SBR. At the full-scale level there is much less of a problem, since  fresh  feed  is available  on a  daily  basis. At  the  laboratory scale however, the SBR characteristic of inverting the two unaerated sequences (as it relates to the quantity and partitioning of carbon), can be accommodated in one of several ways. Manning and Irvine (1985) have circumvented the difficulty by using synthetic feed (not seeded with microorganisms and therefore not subject to substantial COD decay), prepared daily at the desired COD/TKN ratio. In their case, using SBRs on a 8 hour cycle, they used a relatively low COD/TKN ratio of 7.5:1, but were still able to reduce the ortho-P from 13 mg/L to 0.5 mg/L. The other method of ensuring enough RBD carbon, is the approach utilized in this research. As demonstrated, it involves artificially adding substrate when the denitrification reaction is suspected (Fixed-Time) or known (Real-Time) to be complete. This procedure operates from the premise that none of the influent carbon will be available for Bio-P carbon storage.  However, as already seen in this analysis, the fluctuation in the carbon content when using real sewage still influences the operation of the SBRs significantly. On days when there is fresh feed available, denitrification happens quickly, often foiling the attempt by the Real-Time reactor to trap the nitrate breakpoint. During subsequent cycles, when the influent carbon content is low, denitrification  likely occurs using carbon  generated through endogenous reactions, much like the AASD set of  experiments. On  breakpoint  these  days,  clashes with the  the  delay  reactor's  in the nitrate  addition  of acetate  (especially the Fixed-Time reactor). In such cases, the acetate is used partially for denitrification and partially for Bio-P carbon storage. Thus, poor P uptake in the aerobic zone is observed and, as mentioned, this often degenerates into an oscillating high/low behaviour exhibited by the effluent P. A second critical parameter that must be in balance is the Food:Microorganism (F:M) ratio in the reactor. Many researchers consider the F:M ratio as having a major influence on the biological nutrient removal process (in terms of its operation and performance  (Krichten et al. (1985), Tracy and Flammino  (1987)). Of the SBR studies reviewed for this research, Manning and Irvine (1985) used an F:M ratio of 0.26 g COD/g VSS/d while Irvine et al. (1985) reported successful full-scale P removal at the Culver Indiana SBR, with F:M ratios of 0.16 and 0.42 kg BOD5/kg MLVSS/d. Maier  et  al.  (1984),  in  a  series  of  pilot  plant  experiments, observed that the rate of phosphorus uptake/unit of  MLVSS decreased by a factor of 2.6, as the F:M ratio declined from 0.2 to 0.1 kg TBOD/kg MLVSS/day. Tracy and Flammino (1985) reported bench-scale results in which the TBOD:TP ratio was held constant at 16:1, while the F:M ratio was decreased from 0.44 to 0.24 TBOD/kg MLVSS/d. They observed that the rate of phosphorus uptake in the aerobic zone decreased by a factor of three. McCartney and Oleszkiewicz (1988) used synthetic feed in lab scale SBRs, but were unable to achieve excess P removal. They hypothesized that, among other reasons, their F:M ratio (not stated in the paper) was too low to get good P removal. The lack of uniformity in both the way of reporting the F:M ratio and in the operation and type of Bio-P systems for which results are available, make comparisons with this research difficult. As evidenced by the preceding discussion however, there is little doubt that the F:M  ratio is an important  parameter and can considerably influence the propensity for P removal in a system. Most wastewater  treatment  systems are designed  to be  operated at steady-state. In this research however, the mass of solids in the reactor declined dramatically over the course of the run. The lack of aeration control may have contributed to an over-oxidized biomass (loss in solids); however, since little solids were lost in the effluent, it is clear that the major cause of this was a lack of bacterial growth inside the reactor. Thus,  insofar  as  the  solids  were  concerned,  steady-state  conditions were not achieved. Comeau (1989) operated SBRs in a similar manner using an  8 hour cycle and a 20 day SRT. His objective was to characterize the addition of various levels of acetate on PHA storage. The results for the 30 mg/1 acetate addition were very similar to the results from this research, in that both release and uptake occurred to about the same levels observed in this study. No excess removal of phosphorus was observed for any of the acetate additions (0, 15, 30, 45 mg/L) and thus the effluent P levels were virtually the same as the influent values. He does comment however, both on the lack of aeration control and the lack of steady-state conditions; however, no time-series solids data is presented. As  is  evident  in  this  research,  the  F:M  ratio  was  constantly changing with time due to fluctuations in both the carbon content in the feed bucket and the decline in the solids in the reactor; thus, no calculations are presented for this analysis. Using the averages for the total COD and the MLVSS is invalid, and it does not reflect the reality of the trends experienced in the reactor. It is suspected however, that the lack of steady-state conditions influencing the F:M ratio, also contributed to the lack of excess phosphorus removal observed during the course of this research. 5.3  Evaluation of Reactors: Breakpoint Categories As is evident from the above analysis, during both runs the  reactors failed to remove, for any reasonable length of time, a level of phosphorus that could be considered as "excess". Thus, the reactors cannot be compared on the basis of successful P removal. Moreover, the characteristic curve shape  (i.e. the  ideal  ORP-time  profile  depicted  in Figure  5.1)  was never  achieved, for either reactor, for any significant period of time. Therefore, a tabulation of deviations from an "indigenous" profile (due to spikes or otherwise) is not possible (as was done for the AASD set of experiments). In fact, no spikes of any kind were performed, due to the general lack of stability (both phosphorus related and ORP related) in the reactor. It  is possible, however, to  outline  a  protocol  for  evaluating the reactors, which could be followed in the event that excess biological phosphorus removal is regularly achieved. This is done by categorizing the nitrate breakpoints into distinct groupings and tabulating the number of occurrences of each kind. For example, since a key criterion for successful Bio-P removal involves the elimination of nitrates from the anaerobic sequence, a reactor operating under Fixed-Time conditions may prematurely implement the addition of VFAs, before all nitrates have been reduced by denitrifying bacteria. Thus, a proportion (or all) of the acetate may be used to reduce nitrates, rather than being sequestered into carbon reserves by Bio-P organisms. This  has  already  been  observed  in  Figures  5.5  and  5.6.  Partitioning of the acetate between denitrifiers and Bio-P microbes represents a "failure" category, since, in essence, the objective of VFA addition has been partially thwarted. Such a category can be recognized by a detailed examination of the time-of-occurrence of the breakpoints. If the nitrate breakpoint occurs either simultaneously with or after the acetate addition  (i.e greater than or equal to), it defeats the purpose of VFA addition since all or a portion of the acetate is being used to reduce nitrates, rendering it unavailable for the exclusive use of micro-organisms capable of excess P removal. Categorizing  the  nitrate  breakpoints  into  different  groupings is illustrated in Figures 5.29 and 5.30. Figure 5.29 shows  a  detailed  snapshot  over  two  days,  itemizing  the  breakpoints into those that occurred before the addition of acetate  (and thus the acetate was used  solely  for carbon  storage), those that were directly attributable to (i.e induced by) the addition of acetate, and those that occurred after VFA addition and thus had a portion of (or all of) the acetate utilized  for  denitrification.  As  implied  in  the  previous  paragraph, the latter two categories can be considered as one category. A longer snapshot in time is presented in Figure 5.30. This plots (over 8 days) the length of time taken to denitrify in the Fixed-Time reactor, as measured by the length of time from the end of the FILL period to the nitrate breakpoint. Similar to the AASD  experiments, a cyclical  pattern  (on a  larger  scale)  develops, this time a function of the carbon content in the feed bucket. The dotted line represents the point of Fixed-Time addition of acetate (i.e. 1 hour and 25 minutes into the anoxic zone). Thus, those cycles which possess denitrification times below the line are operating in true Bio-P fashion, that is, having acetate additions which comply with the stated objective (i.e. used solely for carbon storage). Those cycles greater than  188 60 40 -  Knee < VFA Add  Knee > VFA Add  / ^-—-^^^^  20 0 -  \  ^  -20 -40 -  I  a.  S o  -60  -  -80  -  "  I \  | 1 \  ^  •  ^  ^  ^  Bio-P #1  If// //// lllj  Fbted-TIme Reactor ORP Profile 0RP1b March 18-19/91  III  ^T"" "•  -100 -120 -  Mf  I 5  r—'  ^  s** _^^^^*~  Point of VFA Addition FTRCTR  J\«  lllll  ~4\  \m  2lYT  -140 -160 -  Cycle  Note  /  1  VFAs Used for Bio-P  / I  2  VFAs Probably Cause Oenitrtflcation  3-6  -180 -  VFAs Used for Denitrification  -200 -220 -240 -  i  i  i  Time (Hrs)  Figure 5.29 Breakpoints Classified According to Acetate Use  Figure 5.30 Nine Day Track of Denitrification Time  or equal to the line are "failing" insofar as the purpose of acetate addition is concerned, since the acetate is not being exclusively stored in carbon reserves. As can be seen, in this particular period, for a full 44 % of the time, the acetate was not used solely for carbon storage. Other  breakpoint  categories  involve  the  Incomplete  Denitrification failure previously shown in Figure 5.12. There did not seem to be a corresponding Incomplete Nitrification failure, as measured by the NH3 level in the effluent. This is due to the large D.O. values observed during reactor aeration. One  further  "failure"  category  is  the  "Rapid  Denitrification" pattern previously documented in Figure 5.2 and which occurs when denitrification happens immediately after the FILL period has ended. This category is a "failure" insofar as the Real-Time reactor is concerned, since it is unable to detect the  breakpoint,  upon  which  proper  acetate  addition  is  contingent. It is not a "failure" from the Fixed-Time reactor perspective, however, since the acetate is added regardless of when the knee occurs. Another "failure" particular to Real-Time control is "Curve Distortion" which makes the true knee impossible to ascertain. Since Real-Time control hinges upon clean reproducible curves, any time there is distortion, the software has difficulty in detecting the breakpoint. For example, Figure 5.31 depicts the curve generated when the decanting solenoid failed, by remaining open after the DRAW/IDLE period had terminated. Thus, during the next FILL period, the incoming sewage mixed with the settled  190  200 Third Cycle 5:00pm - 1:00am 150  -  100 50  -50 -100  Bio-P #1 Real-Time Reactor Profile Saturday March/30/91 Profile ORP2c  -  -150 - Nitrate Breakpoint -200 First Cycle 1:00am • 9:00am -250  Second Cycle 9:00am - 5:00pm Solenoid Fails and Decants One Half the Solids  Time (Hrs)  Figure 5.31 Disruption of Reactor Due to Solenoid Failure  reactor  contents  and  then  immediately  exited  the reactor,  carrying half the solids with it. Thus, the ORP probes measured the contents of a reactor that was much diluted. In Figure 5.32, the profile is shown which results from a mixer dislodging (allowing the reactor contents to settle). In this particular figure, the ORP probe measured the value obtained  in the  clarified supernatant, rather than from a reactor that was uniformly mixed. The final  breakpoint  categories  can be considered  as  "success" categories, in the sense that the purpose of acetate addition  (to an SBR operating  in Bio-P  fashion) is being  realized. For the Fixed-Time reactor, this translates into the breakpoint occurring well before the addition of acetate (1 hour and 25 minutes). For the Real-Time reactor, it represents a sharp, detectable breakpoint which can be used to trigger the release of acetate to the bulk liquid. Tables 5.5 and 5.6 tabulate the number of occurrences (for both runs) of each type of breakpoint category and tallies those considered to be failures for each reactor. The total number of cycles in each run should theoretically be 120 (i.e. 40 days x 3 cycles/day); however, a few days were disregarded in each run due to power failures (longer than the UPS back-up capability) and days in which the reactor operation was momentarily halted in order to download the data. As  can  percentage  be  seen,  (40-70  %)  the of  tables failures  indicate for  both  a  rather  high  reactors.  No  conclusions about the relative performance of the reactors can  192  Mixer Failure @ 920 am 100 -  Second Cycle 9:00am - 5:00pm  ORP2c Profile Measuring Clarified Liquid ORP Value  50 -  Mixer Reconnected 11:45 am  Bio-P #2 No Observable Nitrate Breakpoint  Real-Time Reactor Profile Sunday April/28/91 Collapse of Mixer  First Cycle 1:00am - 9:00am  Time (Hrs)  Figure 5.32 Disruption of Reactor Due to Mixer Failure  Table 5.5 Breakpoint Classification Categories: Bio-P#1 # of Cycles  % of Cycles  Breakpoint < VFA Addition  51  43 %  Failure - Breakpoint > VFA Addition  56  48 %  Failure - Incomplete Denitrification  7  6 %  Rapid Denitrification - No Breakpoint  4  3 %  118  100 %  69  59 %  7  6 %  Failure - Incomplete Denitrification  11  9 %  Failure - Rapid Denitrification  25  21 %  6  5 %  118  100 %  Breakpoint classification Category Bio-P*l Fixed-Time Reactor  Fixed-Time Failure Percentage = 54 % Real-Time Reactor Sharp Detectable Breakpoint Failure - Breakpoint = VFA Addition  Failure - Curve Distortion Real-Time Failure Percentage  = 41 %  Table 5.6 Breakpoint Classification Categories: Bio-P#2 Breakpoint Classification Category Bio-P*2  # of Cycles  % of Cycles  Fixed-Time Reactor Breakpoint < VFA Addition  7  6 %  Failure - Breakpoint > VFA Addition  67  58 %  Failure - Incomplete Denitrification  3  3 %  38  33 %  115  100 %  Sharp Detectable Breakpoint  33  29 %  Failure - Breakpoint = VFA Addition  35  30 %  Failure - Incomplete Denitrification  4  4 %  37  32 %  6  5 %  115  100 %  Rapid Denitrification - No Breakpoint Fixed-Time Failure Percentage = 61 % Real-Time Reactor  Failure - Rapid Denitrification Failure - Curve Distortion Real-Time Failure Percentage  = 71 %  194 be drawn from these results, since the purpose of this exercise was merely to illustrate one aspect of the protocol that would be followed in evaluating the performance of the reactors. Perhaps the only comment that can be made is a relativistic one, in terms of the difference between Bio-P*l and Bio-P*2. The generally weaker sewage of Bio-P*2 is likely the major reason behind the greater number of failures (30%) in the "Breakpoint = VFA" category, as compared to Bio-P*l (6 %) . In this case it seems reasonable to suggest that weaker sewage directly caused a greater proportion of times that acetate was used to directly induce the breakpoint. To summarize, the above method involves categorizing the breakpoints into distinct groupings based upon whether they assist or hinder the purpose of VFA addition in SBR Bio-P removal. This would be incorporated into a larger protocol for evaluating a system successfully removing phosphorus. That is, the above analysis could be considered in conjunction with measurements of effluent ortho-P (presented as a time-series analysis),  from  a  Graphically  depicting  successfully the  operating  differences  in  Bio-P  system.  effluent  quality  between a functional process (one in which ortho-P levels were consistently low and constant) and a non-functional process (one with either high or erratic P levels) would assist in deciding which  system  was  the  preferred  one  in  terms  of  control  stability. It is hoped, of course, that an ORP-driven system would be recognizable as the better alternative; however, more research is needed to substantiate this.  195  CHAPTER 6 CONCLUSIONS AND RECOMMENDATIONS 6.1  Conclusions Many of the traditional methods of controlling activated  sludge  plants  (ex.  F:M  and  SRT), use  variables  which  are  historical in nature, in the sense that they convey what has historically happened to the biomass. A system at steady-state can be effectively controlled by the proper application of such parameters.  There  exists  a  need  however,  to  continue  to  investigate parameters which can rapidly assess the current status of the biomass, since, during transient conditions, the parameters mentioned above can not be evaluated rapidly enough. This research, therefore, has addressed the need for a process control strategy for biological wastewater treatment systems to be founded on a bacterial vision of the process scheme.  In  particular,  the  bacterial  correlation  with  the  relative change with time in oxidation-reduction potential has been explored. Specific conclusions particular to the operating strategies considered in this research, include the following: 1) There is a clear, distinct breakpoint in the ORP-time curve  which  disappearance  can of  be  definitively  nitrates  and  can  correlated  therefore  be  with  the  assumed  to  represent the point of complete denitrification. 2)  The  nitrate  breakpoint  has  been  observed  to  be  reproducible from cycle to cycle, such that it can be reliably used for control purposes. In the majority of instances, it is sufficiently pronounced to be readily detected by a computer  program,  subject  to  proper  instalment  of  the  necessary  interfacing equipment between the computer and the ORP probe. 3) For the AASD*1 operating strategy (FT - 3 hours air-on/3 hours air-off, RT - 3 hours air-on/nitrate-breakpoint-determined air-off) the reactors performed essentially the same in terms of solids degradation  (15 % - 18 %) , depending upon the mass  balance method used and the solids (TSS or VSS) considered. The Real-Time reactor seemed to perform slightly better (up to 3 %) in relation to nitrogen removal; however, this difference was deemed to be insubstantial with regards to forming conclusions. The phosphorus recorded an apparent increase of 6 %, which was not considered excessive, as other researchers using the same TP digestion  technique  have  encountered  errors  of  the  same  magnitude. 4) For the AASD#1 operating strategy, the reactors were subjected to spikes of hydrogen peroxide, sodium nitrate and ammonium chloride. For each reactor, the number of deviations from the "indigenous" curve shape were tabulated and considered as "failures", since they predominantly represented a failure to complete a biological reaction  (i.e. either nitrification or  denitrification). The Fixed-Time reactor "failed" 9.5 % of the time while the Real-Time reactor failed 5.3 % of the time. Thus, the Real-Time reactor under this strategy was considered to more readily accommodate disturbances to the system. 5) The AASD#2 operating strategy (FT - 3 hours each for airon/air-off, RT - air-on the same time as the air-off (determined by the nitrate breakpoint), seemed to perform marginally better  both  in terms of solids removal  (up to  4 %) and  nitrogen  removal (up to 6 %) . Again, these results are subject to some interpretation since replicate experiments were not performed due to the prohibitive workload involved. 6) The AASD#2 operating strategy was subjected to the same spikes  as  AASD*1;  however,  accommodated  the  stresses  normalization  (in terms  of  in in the  this a  case,  similar  number  of  the  reactors  manner,  cycles  that  when had  potential for failure) was taken into account. 7) Under the Bio-P experimental conditions investigated in this research, excess biological phosphorus removal was not observed for any significant period of time. This was attributed primarily  to  the  lack  of  steady-state  conditions  and  the  declining strength of the influent carbon. 8) A screening protocol was developed which could aid in evaluating a Bio-P SBR should excess P removal be observed. It consists of categorizing the time-of-occurrences of the nitrate breakpoints  according  to whether they hinder  or  assist  the  purpose of acetate addition to reactors operating in a Bio-P SBR fashion. An example of the application of this protocol was demonstrated. 9) In summary, the Fixed-Time and Real-Time  strategies  represent two antithetical management approaches.  Fixed-Time  control strategies are based on rapidly antiguated knowledge of the process dynamics. From the bacterial vantage point, this represents wasted treatment potential and/or inefficient reactor operation. Real-Time control strategies, however, evaluate the  198 process dynamics vicariously, through the bacterial "eyes" of ORP. A process functioning at the micro-organism environmental level, in most cases, should be more versatile in its response to transient influent conditions, since it is operating  more  fully cognizant of the bacterial needs. 6.2  Recommendations The results from this research indicate a number of areas  worthy of consideration for further research. They include the following possibilities. 1) A critical analysis of the current algorithm (Lawrence 1991), reveals that the breakpoint algorithmn can be represented by the following general equation... DELTA = {Xi+9 - Xj+5 - X{+4 - X,.} / 5 where...  (6.1)  Xi - any ORP value (i = 1 to 180).  In some applications, this may not be enough points to detect the knee, and  in such instances attention would have to be  directed to a more robust design. 2) Many post-denitrification strategies use external carbon sources (such as methanol) for denitrification. These are added on a continual basis with no feedback as to whether the carbon is actually needed for that particular cycle. The ORP nitrate breakpoint could be used to trigger the addition of the carbon source on an "as-needed" basis, reflecting the fact that some cycles would have sufficient carbon available generated through endogenous reactions. Considerable savings in terms of the cost of methanol may result from a strategy which always ensured complete elimination of NOx, either through carbon generated  199 internally or carbon added externally. 3) None of the AASD strategies considered in this research examined  vector  reduction.  Most  digesters  are  subject  to  regulations which specify certain log kills (Class A, B, etc.) for pathogenic  organism  control. It would  be worthwhile  to  compare aerobic digestion log kills with ORP controlled AASD log kills to see if there is a comparable reduction in pathogens. 4) As previously noted, the AASD ORP-time curve contains other distinctive features which show potential for control. In particular, the "dissolved oxygen breakpoint" seems to represent the point where the ammonia is reduced to a very low (if not zero) level. Thus, proceeding past this point may in effect be supplying air that is not needed (i.e. overaeration). A strategy could be formulated  in which the air  is cycled  on and off  according to detection of both breakpoints, one on other side of the cycle. A pulsating air strategy such as this may result in considerable  savings  of  air  while  simultaneously  ensuring  nitrification / denitrification. 5) The AASD strategy could be used with different sludges, in particular high rate (short SRT) sludges, mixes of primary and secondary sludges, and industrial sludges to see if ORP control has a broader applicability. 6) Using the Bio-P screening protocol, acetate additions could be added on a sequential basis. If the nitrate breakpoint did not occur in a "reasonable" length of time, the acetate could be added in a two-stage process. The first (smaller) pulse could be used to eliminate any remaining nitrates and the second  200 (larger) addition could be used solely for carbon storage by Bio-P  bacteria.  This  would  always  ensure  maximum  carbon  storage/P release in the anaerobic sequence of the SBR, even when using weaker strength sewages. 7)The Bio-P process should be investigated again, perhaps at a larger scale (pilot scale) and most certainly at steadystate. It is felt that the pilot scale level would reduce the effect of some of the variability that surfaced during the operation of these lab-scale reactors. Most notably, the lack of aeration control might matter less at a larger scale and/or be eliminated  with  a  more  sophisticated  control  apparatus.  Secondly, the declining strength of the influent carbon could be circumvented by direct additions of influent from the sewer line. It  is  appreciated  that  there  would  associated  with  this  latter  difficulties noticeably  a  stronger  sewage  would  be  some  approach.  increase  the  unique Most rapid  denitrification "failures". In this research, the overwhelming majority of such failures occurred at the beginning of the BioP#2 run, when the sewage was the strongest. Unfortunately, the Real-time control software could not detect the breakpoint because it occurred too rapidly after the FILL period. As mentioned, this coincided with the best period of P removal. When  the  sewage  was  diluted  with  rain  however,  better  breakpoints occurred but excess P removal was lost. Thus, a concession must be made between quality of effluent and quality of curves - a compromise that might be difficult to rationalize.  REFERENCES Abufayed, A.A. and E.D. Schroeder, 1986a. "Performance of SBR/ Denitrification with a Primary Sludge Carbon Source". Journal Water Pollution Control Federation. 58(5):387. Abufayed, A.A. and E.D. Schroeder, 1986b. "Kinetics and Stoichiometry of SBR/Denitrification with a Primary Sludge Carbon Source". Journal Water Pollution Control Federation. 58(5):398. Alleman, J.E. and R.L. Irvine, 1980a. "Nitrification in the Sequencing Batch Biological Reactor". Journal Water Pollution Control Federation. 52(11):2747. Alleman, J.E. and R.L. Irvine, 1980b. "Storage-Induced Denitrification using Sequencing Batch Reactor Operation". Water Research. 14:1483. American Public Health Association (A.P.H.A.), 1980. Standard Methods for the Examination of Water and Wastewater. 15th Ed., Washington, D.C., 1134p. American Society for Testing and Materials (A.S.T.M.), 1983. Section 11: Water and Environmental Technology. Volume 11:01, Section D1498 Standard Practice for OxidationReduction Potential of Water, p.233. Anderson, B.C., 1989. "Improvements in the Aerobic Digestion of Waste Activated Sludge through Chemical Control of Mixed Liquor pH: Pilot - Scale Investigations". Ph.D. Thesis, University of British Columbia, Vancouver, B.C. 418p. Armiger, W.B., Lee, G., Bordacs, K. and K.D. Tracy, 1990. "Automated On-Line Control Strategy for the Optimization of Nutrient Removal Processes". Instrumentation. Control and Automation of Water and Wastewater Treatment and Transport Systems, In Proceedings of the 5th IAWPRC Workshop. 2 6 July-3 August, Yokohama and Kyoto, Japan, p. 187. Arora, M.L., Barth, E.F. and M.B. Umphries, 1985. "Technology Evaluation of Sequencing Batch Reactors". Journal Water Pollution Control Federation. 57.(8) :867. Barnard, J.L.., 1976. "A Review of Biological Phosphorus Removal in the Activated Sludge Process". Water S.A., 2(3):136. Barnard, J.L., Stevens, G.M. and P.J. Leslie, 1985. "Design Strategies for Nutrient Removal Plants". IAWPRC, Paris. Water Science Technology, 17:233.  202 Benefield, L.D., Judkins, J.F. and B.L. Weand, 1982. Process Chemistry for Water and Wastewater Treatment. Prentice Hall Inc., Englewood Cliffs, N.J., 510p. Blanc, F.C. and A.H. Molof, 1973. "Electrode Potential Monitoring and Electrolytic Control in Anaerobic Digestion". Journal Water Pollution Control Federation. 45(4):655. Bockris, J. O'M. (ed.), 1972. Electrochemistry of Cleaner Environments. Plenum Press, New York, N.Y., 296p. Boyd, R.F., 1984. General Microbiology. Times Mirror/Mosby College Publishing, 807p. Burbank, N.C. Jr., 1981. "ORP - A Tool for Process Control?". In Application of On-Line Analytical Instrumentation to Process Control R.M. Arthur (ed.), p. 65. Charpentier, J., Florentz, M. and G. David, 1987. "Oxidation Reduction Potential (ORP) Regulation: A Way to Optimize Pollution Removal and Energy Savings in the Low Load Activated Sludge Process". IAWPRC, Rio, Water Science Technology. 19:645. Charpentier, J., Godart, H., Martin, G. and Y. Mogno, 1989. "Oxidation-Reduction Potential (ORP) Regulation as a Way to Optimize Aeration and C, N, and P Removal: Experimental Basis and Various Full-Scale Examples". IAWPRC, Brighton, Water Science Technology. 21:1209. Comeau, Y., Rabinowitz, B., Hall, K.J. and W.K. Oldham, 1987a. Phosphate Release and Uptake in Enhanced Biological Phosphorus Removal from Wastewater". Journal Water Pollution Control Federation. 59(7) :707. Comeau, Y., Oldham, W.K. and K.J. Hall, 1987b. "Dynamics of Carbon Reserves in Biological Dephosphatation of Wastewaters". In Advances in Water Pollution Control IAWPRC International Conference. Rome, Italy, Sept. 28-30, p. 39. Comeau, Y., 1989. "The Role of Carbon Storage in Biological Phosphate Removal from Wastewater". Ph.D Thesis, University of British Columbia, Vancouver, B.C., 194p. Dahod, S.K., 1982. "Redox Potential as a Better Substitute for Dissolved Oxygen in Fermentation Process Control". In Biotechnology and Bioengineering. 9, Gaden, E.L. Jr.(ed.), John Wiley and Sons Inc., p. 2123. DataTranslation Inc., 1988. Users Manual for DT2814 Document UM-05198-B, 70p.  203 De la Menardiere, M., Charpentier, J., Vachon, A. and G. Martin, 1991. "ORP as a Control Parameter in a Single Sludge Biological Nitrogen and Phosphorus Removal Activated Sludge System". Water S.A.. 17(2):123. Dickinson, D., 1969. "Redox Measurement of Treatability by the Activated Sludge Process". Water Research. 3.:955. Dold, P.L., Ekama, G.A. and G.v.R. Marais, 1980. "A General Model for the Activated Sludge Process". Progress In Water Technology. 12:47. Dyson, R.D., 1974. Cell Biology: A Molecular Approach. Allyn and Bacon Inc., Boston, 701p. Eckenfelder, W.W. Jr. and J.W. Hood, 1951. "The Application of Oxidation-Reduction Potential to Biological Waste Treatment Process Control". In Proceedings of the 6th Purdue Industrial Waste Conference. Feb. 21-23 1951, Purdue University, West Lafayette, Indiana, p. 221. Eckenfelder, W.W. Jr., 1958. "A Discussion - Redox Potentials in the Laboratory". Sewage and Industrial Wastes. 30(4):501. Eilbeck, W.J., 1984. "Redox Control in Breakpoint Chlorination of Ammonia and Metal Ammine Complexes". Water Research. 18(1):21. Eilbeck, W.J., and G. Mattock, 1987. Chemical Processes in Wastewater Treatment. John Wiley and Sons, Ellis Horwood Ltd., Chichester, England, 331p. Ekama, G.A., Marais, G.v.R. and I.P. Siebritz, 1984. "Chapter 7: Biological Excess Phosphorus Removal". In Theory. Design and Operation of Nutrient Removal Activated Sludge Processes. Water Research Commission, P.O. Box 824, Pretoria, 0001 Elefsiniotis, P., 1992. "The Acid-Phase Fermentation in the Biological Phosphorus Removal Process". Ph.D. Thesis, University of British Columbia, Vancouver, B.C. Evans, B. and D. Filman, 1988. "Solids Handling Costs at Large Sewage Treatment Plants". In Proceedings of Joint ASCE/ CSCE Environmental Engineering Conference. July 12-19, Vancouver, B.C., p.590. Grune, W.N. and Chun-Fei Chueh, 1958. "Redox Potentials in Waste Treatment - Laboratory Experiences and Applications". Sewage and Industrial Wastes. 30(4):479.  Harrison, D.E.F., 1972. "Physiological Effects of Dissolved Oxygen Tension and Redox Potential on Growing Populations of Microorganisms". Journal of Applied Chemistry and Biotechnology. 22:417. Hascoet, M.C. and M. Florentz, 1985. "Influence of Nitrates on Biological Phosphorus Removal". Water S.A. 11(1);1. Hashimoto, S., Fujita, M. and K. Terai, 1982. "Stabilization of Waste Activated Sludge through the Anoxic-Aerobic Digestion Process". Biotechnology and Bioenaineerina. 24:1789. Heduit, A. and D.R. Thevenot, 1989. "Relation Between Redox Potential and Oxygen Levels in Activated-Sludge Reactors". IAWPRC, Brighton, Water Science Technology. 21:947. Hood, J.W., 1948. "Measurement and Control of Sewage Treatment Process Efficiency by Oxidation-Reduction Potential". Sewage Works Journal, 20(4):640. Hoover, S.R., Jasewicz L. and N. Porges, 1952. "Biochemical Oxidation of Dairy Wastes. IV. Endogenous Respiration and Stability of Aerated Dairy Sludge". Sewage and Industrial Wastes. 24(9):1144. Ip, S.Y., Bridger, J.S. and N.F. Mills, 1987. "Effect of Alternating Aerobic and Anaerobic Conditions on the Economics of the Activated Sludge System". IAWPRC. Rio de Janerio. Water Science Technology. 19:911. Irvine, R.L. and A.W. Busch, 1979. "Sequencing Batch Biological Reactors - An Overview". Journal Water Pollution Control Federation,, 51(2) :235. Irvine, R.L., Ketchum, L.H. Jr., Breyfogle, R. and E.F. Barth, 1983."Municipal Application of Sequencing Batch Treatment". Journal Water Pollution Control Federation. 55(5):484. Irvine, R.L., Ketchum, L.H. Jr., Arora, M.L. and E.F. Barth, 1985. "An Organic Loading Study of Full-Scale Sequencing Batch Reactors". Journal Water Pollution Control Federation. 57(8):847. Irvine, R.L., Murthy, D.V.S., Arora, M.L., Copeman, J.L. and J.A. Heidman, 1987. "Analysis of Full-Scale SBR Operation at Grundy Centre, Iowa". Journal Water Pollution Control Federation. 59(3):132.  205 Jenkins, C.J., 1988. "Anoxic-Aerobic Digestion of Waste Activated Sludge: A Lab Scale Comparison to Aerobic Digestion With and Without Lime Addition". M.A.Sc. Thesis, University of British Columbia, Vancouver, B.C., 223p. Jenkins, C.J. and D.S. Mavinic, 1989a. "Anoxic-Aerobic Digestion of Waste Activated Sludge: Part I - Solids Reduction and Digested Sludge Characteristics". Environmental Technology Letters. 10:355. Jenkins, C.J. and D.S. Mavinic, 1989b. "Anoxic-Aerobic Digestion of Waste Activated Sludge: Part II Supernatant Characteristics, ORP Monitoring Results and Overall Rating System". Environmental Technology Letters. 10:371. Ketchum, L.H. Jr., and Ping-Chau Liao, 1979. "Tertiary Chemical Treatment for Phosphorus Reduction Using Sequencing Batch Reactors". Journal Water Pollution Control Federation. 51(2):298. Ketchum, L.H. Jr., Irvine, R.L., Breyfogle, R.E. and J.F. Manning Jr., 1987. "A Comparison of Biological and Chemical Phosphorus Removals in Continuous and Sequencing Batch Reactors". Journal Water Pollution Control Federation, 59(1):13. Kim, M.H. and O.J. Hao, 1990. "Comparison of Activated Sludge Stabilization under Aerobic or Anoxic Conditions". Research Journal of the Water Pollution Control Federation,62(2):160. Kjaergaard, L., 1976. "Influence of Redox Potential on the Glucose Catabolism of Chemostat Grown Bacillus licheniformis". European Journal of Applied Microbiology. 2:215. Kjaergaard, L., 1977. "The Redox Potential: Its Use and Control in Biotechnology". In Advances in Biochemical Engineering. 2 Ghose, T.K., Fiechter, A. and N. Blakebrough (eds.), Springer - Verlag, Berlin, p. 131. Kjaergaard, L. and B.B. Joergensen, 1979. "Redox Potential as a State Variable in Fermentation Systems". In Computer Applications in Fermentation Technology. Arminger, W.B. (ed.), Biotechnology and Bioengineering Symposium No. 9 p. 85. Kjaergaard, L. and B.B. Joergensen, 1981. "The Redox Potential, A Hitherto Seldom Used Parameter in Fermentation Systems". In Advances in Biotechnology Vol I - Scientific and Engineering Principles. M. Moo-Young (ed.), Pergamon Press, p. 371.  206 Koch, F.A. and W.K. Oldham, 1985. "Oxidation - Reduction Potential- A Tool for Monitoring, Control and Optimization of Biological Nutrient Removal Systems". IAWPRC, Paris. Water Science Technology. 17:259. Koch, F.A., Oldham, W.K. and H.Z. Wang, 1988. "ORP as a Tool for Monitoring and Control in Bio-Nutrient Removal Systems". In Proceedings of Joint ASCE/CSCE Environmental Engineering Conference. July 12-19, Vancouver, B.C., p.162. Koers, D.A., 1979. "Studies of the Control and Operation of the Aerobic Digestion Process Applied to Waste Activated Sludges at Low Temperatures". Ph.D. Thesis, University of British Columbia, Vancouver, B.C., 288p. Krichten, D.J., Hong, S.N. and K.D. Tracy, 1985. "Applied Biological Phosphorus Removal Technologies for Municipal Wastewater Treatment by the A/0 Process". In Management Strategies for Phosphorus in the Environment. R.Perry and M. Schmidtke (eds.). Selper Ltd. London, pg. 399 Lawrence, P.D., 1991. Personal Communications Lohmann, J., 1985. "State of Automation of Wastewater Treatment Plants in the F.G.R.". Instrumentation and Control of Water and Wastewater Treatment and Transport Systems. In Proceedings 4th IAWPRC Workshop. 27 April - 4 May, Houston and Denver, USA, p.9. Maier, W. et al., 1984. "Pilot Scale Studies on Enhanced Phosphorus Removal In a Single Sludge Activated Sludge Plant". In Enhanced Biological Phosphorus Removal from Wastewater. Vol (II), IAWPRC Post Conference Seminar, Paris, France, pg.51. Manning, J.F. and R.L. Irvine, 1985. "The Biological Removal of Phosphorus in a Sequencing Batch Reactor". Journal Water Pollution Control Federation. 57(1):87. Matsuda, A., Ide, T., and S. Fujii, 1988. "Behaviour of Nitrogen and Phosphorus During Batch Aerobic Digestion of Waste Activated Sludge - Continuous Aeration and Intermittent Aeration by Control of D.O.". Water Research. 22.(12) :1495. McCartney, D.M. and J.A. Oleszkiewicz, 1988. "Removal of C, N and P in a SBR at Low Temperatures". In Proceedings of Joint ASCE/CSCE Environmental Engineering Conference. July 12-19, Vancouver, B.C., p.320. McCartney, D.M. and J.A. Oleszkiewicz, 1990. "Carbon and Nutrient Removal in a Sequencing Batch Reactor at Low Temperatures". Environmental Technology Letters, 11:99.  McCarty,P.L., Beck, L. and P.St.Amat, 1969. "Biological Denitrification of Wastewaters by Addition of Organic Materials". Proceedings of 24th Industrial Waste Conference, Purdue University, West Lafayette, Indiana. Melcer, H., Bedford, W.K., Topnik, B.H. and N.W. Schmidtke. 1987. "Conversion of Small Municipal Wastewater Treatment Plants To Sequencing Batch Reactors". Journal Water Pollution Control Federation. 59(2):79. Metcalf and Eddy Inc., 1979. Wastewater Engineering : Treatment Disposal, Reuse. Second Ed., McGraw-Hill Co., N.Y., 920p. MetraByte Corporation, 1989. Data Acquisition and Control Catalogue, 21, p78. Microsoft Corporation, 1987a. Microsoft QUICKBASIC 4.0: Learning and Using Microsoft Ouickbasic. 386p. Microsoft Corporation, 1987b. Microsoft QUICKBASIC 4.0: Programming in Basic - Selected Topics. 322p. Microsoft Corporation, 1987c. Microsoft QUICKBASIC 4.0: BASIC Language Reference. 530p. Midgley D. and K. Torrence, 1978. Potentiometric Water Analysis. John Wiley and Sons Inc., 409p. Milligan, P.A.T., 1989. Personal Communications. Minister of Supply and Services Canada, 1981. National Inventory of Municipal Waterworks and Wastewater Systems in Canada. Ottawa, Ontario, Canada. Morris, J.C. and W. Stumm, 1967. "Redox Equilibria and Measurements of Potentials in the Aquatic Environment". Advances Chemistry Series. No. 67, Article 13, p. 270. Nicholls H.A. and D.W. Osborn, 1979. "Bacterial Stress: A Prerequisite for Biological Removal of Phosphorus". Journal Water Pollution Control Federation. 51(3):557. Nussberger, F.E., 1953. "Applications of Oxidation-Reduction Potentials to the Control of Sewage Treatment Processes". Sewage and Industrial Wastes. 25(9):1003. Oleszkiewicz, J.A. and S.A. Berquist, 1988. "Low Temperature Nitrogen Removal in Sequencing Batch Reactors". Water Research, 22.(9) : 1163 .  208 O'Rourke, J.T., Tomlinson, H.D. and N.C. Burbank, Jr., 1963. "Variation of ORP in An Activated Sludge Plant with Industrial Waste Load". Industrial Water and Wastes. 8(6):15. Palis, J.C. and R.L. Irvine, 1985. "Nitrogen Removal in a Low Loaded Single Tank Sequencing Batch Reactor". Journal Water Pollution Control Federation. 57(1):82. Peddie. C.C. and D.S. Mavinic, 1988. "Preliminary Results of a Pilot Scale Evaluation of Aerobic/Anoxic Sludge Digestion".In Proceedings Canadian Society of Civil Engineering Annual Conference. 25-27 May 1988, Calgary, Alberta, p. 461. Peddie, C . C , Koch, F.A., Jenkins, C.J. and D.S. Mavinic, 1988. "ORP as a Tool for Monitoring and Control of SBR Systems for Aerobic Sludge Digestion". In Proceedings of Joint ASCE/CSCE Environmental Engineering Conference, July 12-19, Vancouver, B.C., p.171. Petersen, G.K., 1966. "Redox Measurements: Their Theory and Technique". Radiometer A/S Emdrupvei72 DK 2400 Manual8. Copenhagen, Denmark, 3 Op. Poduska, R.A. and B.D. Anderson, 1981. "Successful Storage Lagoon Odour Control". Journal Water Pollution Control Federation. 53(3):299. Rabinowitz, B., 1985. "The Role of Specific Substrates in Excess Biological Phosphorus Removal". Ph.D. Thesis, University of British Columbia, Vancouver, B.C. Rabinowitz, B. and W.K. Oldham, 1986. "Excess Biological Phosphorus Removal in the Activated Sludge Process Using Primary Sludge Fermentation". Canadian Journal of Civil Engineering. 13:345. Rabinowitz, B., Koch, F.A., Vassos, T.D. and W.K. Oldham, 1987. "A Novel Operational Model for a Primary Sludge Fermenter for Use with the Enhanced Biological Phosphorus Removal Process". In Proceedings of the IAWPRC Specialized Conference on Biological Phosphorus Removal from Wastewater. Rome, pg. 349. Radjai M., Hatch R.T. and T.W. Cadman, 1984. "Optimization of Amino Acid Production by Automatic Self-tuning Digital control of Redox Potential". Biotechnology and Bioengineering Symposium No. 14. John Wiley and Sons, p. 657.  209 Randall, C.W., Marshall, D.W. and P.H. King, 1970. "Phosphate Release in Activated Sludge Process". Journal of the Sanitary Engineering Division. In Proceedings of the American Society of Civil Engineers. SA 2, p.395. Rich, L.G., 1982. "A Cost-Effective System for the Aerobic Stabilization and Disposal of Waste Activated Sludge Solids". Water Research. 16:535. Rimkus, R.R., Ziols, R. and A. Shaikh, 1985. "Computer Control of Raw Sewage Chlorination for Odour Control". Instrumentation and Control in Water and Wastewater Treatment and Transport Systems. In Proceeding 4th IAWPRC Workshop. 27 April-4 May, Houston and Denver, USA., p. 297. Roberts, F.W. and D.A. Rudd, 1963. "Applications of Oxidation Reduction Potential to Sewage Purification". Journal of Instrumentation and Sewage Purification, p. 227. Rohlich, G.A., 1948. "Measurement and Control of Sewage Treatment Process Efficiency by Oxidation-Reduction Potential - A Discussion". Sewage Works Journal. 20(4):650. Rudd, D.A., Roberts, F.W. and D.E. Brooks, 1961. "Oxidation Reduction Potential Measurements in Sewage Purification". Instrument Engineer. 2(3):61. Sekine, T., Iwahorik, K., Fujimoto, E. and Y. Inamori, 1985. "Advanced Control Strategies for the Activated Sludge Process". Instrumentation and Control of Water and Wastewater Treatment and Transport Systems. In Proceedings 4th IAWPRC Workshop. 27 April - 4 May, Houston and Denver, USA., p269. Shammas, N.M., 1988. "The BASIC Revival". BYTE Magazine, 13(9):295. Shapiro, J., Levin, G.V. and Z.G. Humberto, 1967. "Anoxically Induced Release of Phosphate in Wastewater Treatment". Journal Water Pollution Control Federation. 39(11):1810. Shibai H., Ishizaki A., Kobayashi, K. and Y. Hirose, 1974. "Simultaneous Measurement of Dissolved Oxygen and Oxidation Reduction Potentials in the Aerobic Culture". Journal of Agricultural and Biological Chemistry. 38(12):2407. Siebritz, I.P., Ekama, G.A. and G.v.R. Marais, 1983. " A Parametric Model for Biological Excess Phosphorus Removal". IAWPRC, Capetown, Water Science Technology. 15:127.  Silverstein, J. and E.D. Schroeder, 1983. "Performance of SBR Activated Sludge Processes with Nitrification Denitrification". Journal Water Pollution Control Federation. 55(4):377. Smith, D., 1978. "Wastage Rates Determined by SRT Method". Water and Sewage Works. 125(9);68. Snoeyink, V.L. and D. Jenkins, 1980. Water Chemistry.. John Wiley and Sons Inc., New York, N.Y., 463p. Stumm, W. 1966. "Redox Potential as an Environmental Parameter: Conceptual Significance and Operational Limitation". Advances in Water Pollution Research. Vol. 1, In, Proceedings of 3rd International Conference of Int. Ass, on Water Pollution Research.. Munich, Germany, p. 283. Tortora, G.J., Funke, B.R. and C.L. Case, 1982. Microbiology: An Introduction. (2nd Ed.), Benjamin/Cummings Pub. Co. Inc. 772p. Tracy, K.D. and A. Flammino, 1985. "Kinetics of Biological Phosphorus Removal". Presented at the 58th Annual Water Pollution Control Federation Conference, Kansas City, Missouri. Tracy, K.D. and A. Flammino, 1987. "Biochemistry and Energetics of Biological Phosphorus Removal". In Advances in Water Pollution Control. R. Ramadori (ed.), Pergamon Press, London, pg. 15. U.S. Environmental Protection Agency, 1986. "Summary Report: Sequencing Batch Reactors". Report No. EPA-625-8-86-011, Office of Technology Transfer, Cincinatti, Ohio, 23p. U.S. Environmental Protection Agency, 1987. "Design Manual: Phosphorus Removal". Report No. EPA-625-1-87-001, Office of Technology Transfer, Cincinatti, Ohio, 116p. Vaccari, D.A., Cooper, A. and C. Christodoulatos, 1988. "Feedback Control of Activated Sludge Waste Rate". Journal Water Pollution Control Federation. 60(11):1979. Van Haandel, A.C., Ekama, G.A. and G.v.R. Marais, 1981. "The Activated Sludge Process Part 3 - Single Sludge Denitrification". Water Research. 15:1135. Vlekke, G.J.F.M., Comeau, Y. and W.K. Oldham, 1988. "Biological Phosphate Removal from Wastewater with Oxygen or Nitrate in Sequencing Batch Reactors". Environmental Technology Letters. 9(8):791.  Wang, N.S. and G.M. Stephanopoulos, 1987. "Computer Applications to Fermentation Processes". In CRC Critical Reviews in Biotechnology. 2.(1), p.30. Warner, A.P.C., Ekama, G.A. and G.v.R. Marais, 1985. "The Activated Sludge Process: Part 4 - Application of the the General Kinetic Model to Anoxic-Aerobic Digestion of Waste Activated Sludge". IAWPRC, Paris, Water Science Technology. 17(8):1475. Watanabe, S., Baba, K. and S. Nogita, 1985. "Basic Studies of an ORP/External Carbon Source Control System for the Biological Denitrification Process". Instrumentation and Control of Water and Wastewater Treatment and Transport Systems. In Proceedings 4th IAWPRC Workshop. 27 April - 4 May, Houston and Denver, USA, p. 641. Weber, L.J. and D.I. McLean, 1979. Electrical Measurement Systems for Biological and Physical Scientists. Addison -Wesley Publishing Company, 399p. Westcott, C.C., 1976. "Oxidation-Reduction Potential with Beckman Metallic Electrodes". Technical Information Bulletin. No. 952-EC-76-GT, Scientific Instruments Division, Irvine, California 92713, p. 13. Whitfield, M., 1969. "Eh as an Operational Parameter in Estuarine Studies". Limnology and Oceanography, 14(4):547. Williams, D.S., Burgarino, A.E. and J.R. Fernandez, 1986. "Process Control and Management Information Processing at a Municipal Wastewater Treatment Plant". Journal Water Pollution Control Federation. 58(10):949. Wimpenny, J.W.T., 1969. "The Effect of Eh on Regulatory Processes in Facultative Anaerobes". Biotechnology and Bioengineerinq, 11(4):623. Wimpenny, J.W.T. and D.K. Necklen, 1971. "The Redox Environment and Microbial Physiology: The Transition from Anaerobiosis to Aerobiosis in Continuous Cultures of Facultative Anaerobes". Biochimica et Biophysica Acta. 253:352. Zhou, J., 1991. "Applicability Study of ORP Probes in the Biological Phosphorus Removal Process". M.A.Sc. Thesis University of British Columbia, Vancouver, B.C.  212  APPENDIX A Page Derivation of the Nernst Equation  213  APPENDIX A Derivation of the Nernst Equation For the general reaction..  aA  +  bB  <=>  cC  dD  The Van't Hoff Equation. . A G = A G ° + RT logr"{C}c{D}d~l  Q^CBpJ  Thus for the equation  ox + ne" <=> r e d  (1) (2) (3)  The V a n ' t Hoff E q u a t i o n . . AG = A G ° + RT l o d {red}  (4)  |_{ox} Now... "The reduction of one mole of oxidant to its reduced form requires the passage of nF coulombs of electricity against a potential difference of E volts, so the electrical work done by the system at constant temperature and pressure is nEF joules. This is equal to the decrease in free energy of the system" (Eilbeck and Mattock, (1987)). The Gibbs Free Energy Equation A G = -nEF  (5)  at Standard State  (6)  A G ° = -nE°F  Substituting (5) and (6) into (4) Gives.... Or. .  -nEF = -nE°F + RT log| {red} {ox}  (?)  - RT log {red} nF {ox}  (8)  E  =  which is the Nernst Equation.  214  APPENDIX B Page  Intracellular Redox and Energy Calculation  215  APPENDIX B Intracellular Redox and Energy Calculation A Oxygen as a Terminal Electron Acceptor Consider the oxygen terminal electron acceptor with E° adjusted to an E value associated with a pH of 7.0, T = 25°C) . °2(aq) +  4H+ + 4 e  @ pH = 7  < = > 2H  2° E ° = + 1 - 2 7 (Snoeyink & Jenkins, 1980)  E = E° + .0592 log {H + } 4 n E = 1.27 + .0592 log {10"7}4 4 E = 1.27 + (-.42) = 0.85 volts  when coupled with... (Dyson, 1974, T = 25°C) NAD+ + H+ + 2e" <=> NADH  E° = -0.32 § pH = 7  gives the equation 1/2 02(aq) + H + + NADH <=> NAD+ + H20 and since A G = -nEF A G = -2(23000 calories)[(-0.32)-(0.85)] volts volts A G = -46000 x (-1.17) = -53,820 cal/mole = -53.8 kcal/mole B ATP The Free energy of hydrolysis of ATP is approximately - 7000 cal/mole and there are 3 ATP molecules generated in one pass of the ETC with oxygen as the terminal electron acceptor. Thus... Efficiency = (3)(7000) 53820  x 100 %  = 39 % capture.  C Oxidative Phosphorylation Generates 38 ATP and with potential glucose oxidation of 686,000 cal/mole. Efficiency =  (38)(7000) x 100 % = 39 % efficiency 686000  APPENDIX C SOFTWARE FLOWCHARTS - AASD AND BIO-P Figure  Page  C.l  AASD START-UP AND INITIALIZATION MODULE  217  C. 2  AASD SCAN AND PLOTTING MODULE  217  C. 3 AASD INTERACTIVE MODULE  218  C.4  AASD RESET MODULE - 1A - BOTH RCTRS FT - AIR ON  219  C.5  AASD RESET MODULE - IB - BOTH RCTRS FT - AIR OFF  219  C.6  AASD RESET MODULE - 2A(i) - RT CONTROL - AIR ON FT... 220  C.7  AASD RESET MODULE - 2A(ii) - RT CONTROL - AIR OFF FT. 220  C.8  AASD RESET MODULE - 2B(i) - RT CONTROL - AIR ON RT... 221  C.9  AASD RESET MODULE - 2B(ii) - RT CONTROL - AIR OFF RT. 221  C. 10 AASD CLOSURE STATEMENTS  222  C. 11 AASD READPROBE MODULE  222  C. 12 BIO-P START-UP AND INITIALIZATION MODULE  223  C. 13 BIO-P SCAN AND PLOTTING MODULE  223  C. 14 BIO-P INTERACTIVE MODULE  224  C.15 BIO-P VFA ADDITION TO REAL-TIME REACTOR MODULE  224  C.16 BREAKPOINT SUBROUTINE - MODULE 1  225  C.17 BREAKPOINT SUBROUTINE - MODULE 2  225  C.18 BREAKPOINT SUBROUTINE - MODULE 3  226  C.19 BREAKPOINT SUBROUTINE - MODULE 4  226  (STARTY  INCLUDE: GLOBAL AEHOBIC-ANOXIC SLUDGE DIGESTION START-UP AND iNmAUZATraN MODULE  Initializing Block SCAN - 0 ; SCANTIME - SCAN.TIME STARTUP - 0 ; FLAGLOOP - T FLAGDIFF - T; REALTIME - F FLAG.RT - F ; NrTHATE - F FLAGSCRN - F; RENEW - F STARTPT - 1 ; ENDPT - 180 PT - 1 : INITIALIZE A/D BOARD  CALL (AIR ON) 'RELAYSWfTCH (FIXED TIME) RELAYSWITCH (REALTIME)  RECORD AIR ON TIME AIRON.FT - T  OPEN COMMENT FILE FOR STORING MESSAGES  SCAN AND PLOTTING MODULE  FIGURE C.1 AASD START-UP AND INITIALIZATION MODULE READPROBE MODULE  IF SCAN NUMSCANS FLAGLOOP -FELSE FLAGLOOP = T  FIGURE C.2 AASD SCAN AND PLOTTING MODULE  TEST KEYBOARD BUFFER FOR INPUT KCODE - JINKEY (Function)  AASD INTERACTIVE MODULE  FIGURE C.3 AASD INTERACTIVE MODULE  219 RESET MODULE 2A (!)  AASD RESET MODULE 1B  RESET MODULE PART1A BOTH REACTORS FIXED TIME AIR-ON  CALL (AIR OFF) 'RELAYSWTTCH(FT) RELAVSWrrCH (HT)  CLOSURE STATEMENTS  AIRON.FT - F RECORD TIME OF AIR OFF FT  FLAG.RT > F AIRON.RT = F  SCAN AND  RECORD TIME OF AIR OFF RT  PLOTTING MODULE  FIGURE C.4 AASD RESET MODULE - 1A - BOTH RCTRS FT - AIR ON /  INTERACTIVE MODULE  ^-"1F\^J  /  RESET " MODULE 2A(i)  * ^^FLAG.HTZ>  s^  n^^ ^ ^ IF ^ \ ' •"^AJHONJ-T^9  F  l  ( pni i TiMra  i  AASD RESET  / I F \ / A OFF FT \ \>-3HRS /  MODULE PART1B BOTH REACTORS  RESET MODULE 1A  ^  F  ti  CLOSURE STATEMENTS  FIXED TIME AIR-OFF  /  / CALL \ / (AIR ON) \ ^ /^RELAYSWTTCH (FT) N. RELAYSVWTCH (RT)  1  AIRON.FT - T RECORD TIME OF AIR ON FT  \  '1 SCAN AND PLOTTING MODULE  FIGURE C.5 AASD RESET MODULE - 1B - BOTH RCTRS FT - AIR OFF  220  SCAN AND PLOTTING MODULE  FIGURE C.6 AASD RESET MODULE - 2A(i) - RT CONTROL - AIR ON FT /  INTERACTIVE  F  ^-^1F^-\  y  MODULE  *  ^ F L A G . H I ^  | 1  RESET MODULE 18  J  RESET MODULE 2A(I)  ^1  yS  F ^ - \ T N.l-l^-' f  \  ( POLL TIMER  )  AASD RESET  /  I F  / " ^ A C H =FFT  MODULE  \  V > - 3 HRS  PART2A0I) 1RCTRFT 1RCTRRT AIR-OFF FTRCTR  F  \ /  i  CLOSURE STATEMENTS  /  / /  CALL \. (AIR ON) \ RELAYSWTTCH (FT) \ ^  '' AIRON.FT - T RECORD TIME OF AIR ON FT  '' SCAN AND PLOTTING MODULE  FIGURE C.7 AASD RESET MODULE - 2A(ii) - RT CONTROL - AIR OFF FT  RESET MOCXILE1A  AASD RESET MODULE PART2B(I) 1RCTRFT 1RCTRRT AIR-ON RTRCTR  RESET MODULE 28(10  \>-UMTT  * / ~  CLOSURE STATEMENTS  i  Nots: AASO#1 • Umit - 3 hours AASD#2-UmitCalculated Time for Anoxic Period  M /  /  CALL N. (AIR OFF) \ REUYSWrrCH (RT) \  I  I  AIRON.RT - F RECORD TIME OF AIR OFF RT  SCAN AND PLOTTING MODULE  FIGURE C.8 AASD RESET MODULE - 2B(i) - RT CONTROL - AIR ON RT RESET MODULE 1B  AASD RESET MODULE PART2B(ii) 1 RCTRFT 1 RCTRRT AIR-OFF RTRCTR  Note: MAXANOX Umit - 4 hours T  RESET MODULE CALL (AIR ON) RELAYSWrrCH (RT)  2B(1)  AIRON.RT - T RECORD TIME OF AIR ON RT CALL (AIR ON) RELAYSWrTCH (RT)  AIRON.RT - J RECORD TIME OF AIR ON RT RENEW- F  NITRATE-F SCAN AND PLOTTING  CLOSURE STATEMENTS  MODULE  FIGURE C.9 AASD RESET MODULE - 2B(ii) - RT CONTROL - AIR OFF RT  222  RESET  \ )  RON  MODULE  •  FLAGLCOP - T  AASD  '  CLOSURE  F T - FT + 1  STATEMENTS  t ^ ^  F  ^ \  F  \ ^ FT-181 T[ PT-1  I  T ^-""CALL / ^ AXES  \ .  ' SCAN AND PLOTTING MODULE  FIGURE C.10 AASD CLOSURE STATEMENTS SCAN AND  *  PLOTTING  SCAN-SCAN + 1  MODULE PRODUCE DATA ARRAY ADDRESSES SEGMENT - VARSEG(MVOLTS(0,SCAN)) OFFSET - VARPTR(MVOLTS(0,SCAN))  -H  AASD READPROBE MODULE FLAGLOOP - F  SCAN-0  FIGURE C.11 AASD READPROBE MODULE  STOP  223 INCLUDE: GLOBAL BIOLOGICAL PHOSPHORUS REMOVAL v START-UP AND \ INITIALIZATION \ MODULE  Initializing Block SCAN = 0 ; SCANTIME = SCAN.TIME STARTUP = 0 ; FLAGLOOP = T FLAGDIFF « T; VFAPass = 0 VFAPump = F ; NITRATE = F FLAGSCRN = F ; RENEW » F FT = 1;STARTPT = 1;ENDPT= 180 Acetate = F; INITIALIZE A/D BOARD  CHECK TIME FOR START OF ANOXIC PERIODS @ 1:10 am @ 9:10 am @ 5:10 pm  RECORD TIME ANOXIC PERIOD STARTS OPEN COMMENT FILE FOR STORING MESSAGES  SCAN AND PLOTTING MODULE  FIGURE C.12 BIO-P START-UP AND INITIALIZATION MODULE START-UP AND INITIALIZATION MODULE  READPROBE MODULE  •(TIMER ON/INCR  IF SCAN = NUMSCANS FLAGLOOP = F ELSE FLAGLOOP =T  BIO-P SCAN AND PLOTTING MODULE  VFA ADDITION MODULE [CLOSURE] FLAGLOOP =T  CALL PLOT INTERACTIVE MODULE  FIGURE C.13 BIO-P SCAN AND PLOTTING MODULE  224 SCAN AND  TEST KEYBOARD BUFFER FOR INPUT  PLOTTING  KCODE = JINKEY (Function)  BIO-P INTERACTIVE  MODULE  ESC  MODULE  NONSENSE  IF \ _ KCODE SELECT |  INPUT F  GRAPHICS OFF FLAGSCRN = F  VFA ADDITION MODULE  FIGURE C.14 BIO-P INTERACTIVE MODULE  Note: LIMIT = 2 hours 42 minutes T  VFAPASS = VFAPASS + 1 x  CALL ACETATE ON RELAYSWrTCH (RT)  VFAPUMP = T RECORD TIME OF PUMP ON  RENEW = T  VFAPUMP = F VFAPASS = 0 ACETATE = T SCAN AND I PLOTTING  CALL ACETATE OFF RELAYSWITCH (RT)  CLOSURE STATEMENTS  I MODULE  FIGURE C.15 BIO-P VFA ADDITION TO REAL-TIME REACTOR MODULE  225 AASD  RESET MODULE 2B (ii) OR BIO-P VFA ADDITION MODULE  BREAKPOINT SUBROUTINE MODULE 4 BREAKPOINT SUBROUTINE MODULE 2  BREAKPOINT SUBROUTINE MODULE 3  FIGURE C.16 BREAKPOINT SUBROUTINE - MODULE 1 BREAKPOINT SUBROUTINE MODULE 1  BREAKPOINT SUBROUTINE MODULE 2  AASD RESET MODULE 2B(ii) OR BIO-P VFA ADDITION MODULE  RINGNUM = 1  RING(RINGNUM) = SUM/RINGSIZE  RRSTRING = RING(RINGNUM)  FIGURE C.17 BREAKPOINT SUBROUTINE - MODULE 2  RINGNUM = RINGNUM + 1 SUM = SUM - DORP(LOWBOUND) + DORP(PT) RING(RINGNUM) = SUM/RINGSIZE  BREAKPOINT SUBROUTINE MODULE 1  BREAKPOINT  AASD RESET MODULE 2B(ii)  SUBROUTINE MODULE 3  OR BIO-P VFA ADDITION MODULE  SEARCH = T LASTRING = RING(RINGNUM) DIFFRING = LASTRING-FIRSTRING  KNEEA,BORC = T KNEECOUNT = KNEECOUNT + 1  FIGURE C.18 BREAKPOINT SUBROUTINE - MODULE 3 BREAKPOINT SUBROUTINE MODULE 1  RINGNUM = RINGNUM + 1 SUM = SUM - DORP(LOWBOUND) + DORP(PT) RING(RINGNUM) = SUM/RINGSIZE FIRSTRING = RING(RINGNUM - RINGSIZE + 1) LASTRING = RING(RINGNUM) DIFFRING = LASTRING - FIRSTRING  AASD RESET MODULE 2B(ii) OR BIO-P VFA ADDITION MODULE  NITRATE = T  BREAKPOINT SUBROUTINE MODULE 4  KNEEA,BORC = T KNEECOUNT = KNEECOUNT + 1  FIGURE C.19 BREAKPOINT SUBROUTINE - MODULE 4  APPENDIX D SOFTWARE CODE - AASD'l, AASD*2 AND BIO-P Program Name GLOBAL. BI - AASD # 1, AASD*2, BIO-P  Page 228  AEROBIC-ANOXIC SLUDGE DIGESTION - Main Program Start-Up and Initialization Module 229 Scan and Plotting Module 230 Readprobe Module 230 Interactive Module 231 Reset Module: Parti - Both RCTRS FT 232 Reset Module: Part2 - 1 RCTR FT/ 1 RCTR RT -AASD*1 233 Reset Module: Part2 - 1 RCTR FT/ 1 RCTR RT - AASD#2. . . 235 BIOLOGICAL PHOSPHORUS REMOVAL - Main Program Start-Up and Initialization Module Scan and Plotting Module Interactive Module VFA Addition to RT RCTR Module ReadprobeModule INFORM.BAS AASD#1 AASD#2 BIOP FILENAME. BAS REFRESH. BAS INITREL.BAS RELAY. BAS AXES. BAS PAXIS.BAS SCANS. BAS DIFF.BAS AASD#1/AASD#2 BIO-P ORPSCRN.BAS WRITING. BAS TRANSFER. BAS PLOT. BAS LAYOUT.BAS AASD#1/AASD#2 BIO-P UPDATE.BAS TYPROBE.BAS JINKEY.BAS BREAKPT.BAS AASD*1/AASD # 2 BIO-P  237 238 239 240 241 242 242 242 243 243 244 244 245 245 246 247 247 248 248 249 249 250 250 251 251 251 252 255  / GLOBAL.Bl DEFINT A-Z ' Declaration of SubroutinesDECLARE SUB INFORM () DECLARE SUB RELAYSWITCH (Relaynum%) DECLARE SUB INITRELAYS () DECLARE SUB FILENAME (FTout$, RTout$, Commout$, FTnum, RTnum, Commnum) DECLARE SUB REFRESH (Probe$) DECLARE SUB ORPSCRN () DECLARE SUB AXES () DECLARE SUB PAXIS () DECLARE SUB SCANS (SCAN, Ft) DECLARE SUB DIFF (Flagdiff, Pt) DECLARE SUB WRITING (Pt, FToutS, RTout$, FTnum, RTnum) DECLARE SUB TRANSFER (ProbeID$, Pt) DECLARE SUB PLOT (Pt) DECLARE SUB BREAKPT (Commnum, Pt, Nitrate, Renew) DECLARE SUB LAYOUT () DECLARE SUB UPDATE (Pt) ' Declaration of Functions DECLARE FUNCTION TYPROBE$ (Probe$) DECLARE FUNCTION jinkey% () DECLARE FUNCTION getscanl% (iobase%, first%, last%, BYVAL segaddr%, BYVAL offaddr*) ' Declaration of Constants CONST SCAN.TIME = 2 'The scanning time is 2 seconds. CONST NUM.CHANNELS = 1 6 'The number of channels to be scanned. CONST NUM.SCANS = 60 'Number of scans in two minute interval. CONST NUM.PTS = 1 8 1 'For dimensioning purposes. CONST MAX.ANOX = 14400 'Currently a Four Hours Maximum Anoxic Limit CONST KY.LY = SH79 'For <Yes> decision in selecting other probes. CONST KY.LN = &H6E 'For <No> decision finished viewing probes. CONST KY.ESC = SH1B 'For escaping from program. CONST chan0% = 0 'The first channel - lower bound. CONST chanl5% = 15 'The last channel - upper bound. CONST baseaddr% = &H220 'The base address of the A/D board. CONST ioaddr% = &H300 'The base address of the relay board. CONST FALSE = 0 'Mostly used for flag settings. CONST TRUE = 1 'Mostly used for flag settings. CONST RINGSIZE 5 'The Width of the Ring. CONST NUMRINGS 5 'The number of Rings in the Buffer. CONST DELTA2A1 -1. 25 'The difference in slope between the first and last CONST DELTA2B! -1. 25 'rings of the Ringbuffer for the Real Time CONST DELTA2C! -1. 25 'ORP Probes. CONST MAXAVOID 15 'Safety Factor to allow stability after air ceases. ' Dimensioning of Arrays DIM MVolts(NUM.CHANNELS, NUM.SCANS) DIM ORPla(NUM.PTS) AS SINGLE, ORPlb(NUM.PTS) AS SINGLE DIM ORPlc(NUM.PTS) AS SINGLE, 0RP2a(NUM.PTS) AS SINGLE DIM 0RP2b(NUM.PTS) AS SINGLE, 0RP2c(NUM.PTS) AS SINGLE DIM DOxl(NUM.PTS) AS SINGLE, DOx2(NUM.PTS) AS SINGLE DIM ORP(NUM.PTS) DIM ~ "" DORPla(NUM.PTS) AS SINGLE, DORPlb(NUM.PTS) AS SINGLE DIM DORPlc(NUM.PTS) AS SINGLE, DORP2a(NUM.PTS) AS SINGLE DIM DORP2b(NUM.PTS) AS SINGLE, DORP2c(NUM.PTS) AS SINGLE DIM RING2a(NUM.PTS) AS SINGLE, RING2b(NUM.PTS) AS SINGLE DIM RING2c(NUM.PTS) AS SINGLE -Variables shared between Modules COMMON SHARED 0RPla() AS SINGLE, 0RPlb() AS SINGLE, 0RPlC() AS SINGLE COMMON SHARED 0RP2a() AS SINGLE, ORP2b() AS SINGLE, 0RP2c() AS SINGLE COMMON SHARED DOxl() AS SINGLE, D0x2() AS SINGLE COMMON SHARED 0RP(), MVolts() COMMON SHARED DORPla() AS SINGLE, DORPlb() AS SINGLE, DORPlCf) AS SINGLE COMMON SHARED DORP2a() AS SINGLE, DORP2b() AS SINGLE, DORP2c() AS SINGLE COMMON SHARED RING2a() AS SINGLE, RING2b() AS SINGLE, RING2c() AS SINGLE COMMON SHARED Startpt, Endpt, ONOFFmap&, DigitOl, Digit02, Digit21, Digit22 COMMON SHARED Digit41, Digit42, Digit61, Digit52, Digit3, Digit4  AASD1BAS and AASD2.BAS DEFINT A-Z STARTUP AND INITIALIZATION MODULE 'This module introduces the user to the mechanics of the program, initializes 'some parameters, and declares global parameters. '$INCLUDE: 'GLOBAL.BI' CLS CALL INFORM  'Call the information for the program mechanics.  CALL FILENAME(FTout$, RTout$, CommoutS, FTnum, RTnum, Commnum)'Set disk Files Runprompt: LOCATE 21, 15: INPUT ; "Do you want to run the program? (Y/N) RAns$ = UCASE$(RAns$) IF RAns$ = "Y" THEN GOTO Initialize ELSEIF RAns$ = "N" THEN GOTO Theend ELSE GOTO Runprompt END IF  ", RAns$  Initialize: SCAN = 0 Scantime = SCAN.TIME OUT baseaddr%, &H0 FOR x = 1 TO 100: NEXT x i = INP(baseaddr% + 1) i = INP(baseaddr% + 1)  'Set the Scan counter to zero to start the scans. 'The Scan time is currently every 2 seconds. 'Initialize the DT2814 A/D Board 'as per the DT2814 manual on pg. 5-9  CALL INITRELAYS  'Initialize the relay board - set all relays off.  Startup = 0 Flagloop = TRUE Flagdiff = TRUE Realtime = FALSE Flag.RT = FALSE Nitrate = FALSE Renew = FALSE Flagscrn = FALSE  'Used to control the Scanning Loop 'Flag for breaking out of and into Scanning Loop. 'Flag to signify no preceeding point in Diff Sub. 'Initially no Real Time Control of Reactor # 2 'Real-time indicated - wait for anoxic cycle 'No Nitrate Breakpoint Detected as of yet. 'Flag used to clear/reset Breakpt Sub variables. 'Flag indicating whether graphics is invoked  Pt = 1 Startpt = 1 Endpt =180 CALL LAYOUT CALL AXES  'Assign initial point of the start of cycle. 'Storage of initial Pt value. 'There are 180 points in a Six Hour Cycle. 'Layout the Text mode information. 'Calculate the relevant time axis.  'Air on for 3 hours of Aeration Relaynum% = 0: CALL RELAYSWITCH(Relaynum%) 'Air.FT is switched on Relaynum% = 1: CALL RELAYSWITCH(Relaynum%) 'Air.RT is switched on StartAer.FTS = TIMER 'Poll the TIMER Function AirOn.FT = TRUE OPEN CommoutS FOR APPEND AS #Commnum PRINT #Commnum, "AirFT On at "; TIMES PRINT #Commnum, "AirRT On at "; TIMES  'Write to the comment file  230 SCAN AND PLOTTING MODULE This module scans the ORP probes every 2 seconds and then every 2 minutes an average for each probe is calculated and plotted if graphics is invoked else an update is written to the screen in text mode. Scanning: ON TIMER(Scantime) GOSUB Readprobe TIMER ON DO  'Every 2 sec. go to the Readprobe Module  'Enable On Timer event-handling trapping routine 'Loop enclosing the entire program - to exit press <Escape>  IF Flagloop = FALSE THEN  'Break out of the Scanning Loop  TIMER STOP CALL DIFF(Flagdiff, Pt)  'Calculate the First Difference  Flagdiff = FALSE  'Now Preceeding Pts are available  Datecheck = VAL(MIDS(DATES, 4, 2)) 'Perform Date check on the Data IF Datecheck <> FTnum THEN 'If past midnight (ie. new day) CLOSE fCommnum 'Close comment file - ooen data CALL FILENAME(FTout$, RToutS, Commout$, FTnum, RTnum, Commnumj 'file OPEN CommoutS FOR APPEND AS #Commnum 'Open new comment file END IF CALL WRITING(Pt, FToutS, RTout$, FTnum, RTnum)  'Write data to disk  IF Flagscrn = FALSE THEN CALL UPDATE(Pt) 'Update the information screen IF Flagscrn =» TRUE THEN  CALL TRANSFER(ProbelDS, Pt) CALL PLOT(Pt) END IF  'Transfer the array of points 'Plot history of points to present  READPROBE MODULE 'This module does the actual reading of the probes by calling the SCAN Sub Readprobe: SCAN - SCAN + 1  'Increment the SCAN Counter  LOCATE 23, 42: PRINT USING "###"; SCAN segment% = VARSEG(MVolts(0, SCAN)) offset% - VARPTR(MVolts(0, SCAN))  'Produce the requisite FAR 'Pointer to the data array  'Call the function returning an error code errnum% = getscanl%(baseaddr%, chan0%, chanl5%, segment%, offset%) IF errnum% <> 0 THEN PRINT #Commnum, "Getscan returned an error code at "; TIMES GOTO Theend END IF CALL SCANS(SCAN, Pt) 'Call the SCAN Subroutine IF SCAN =• NUM.SCANS THEN SCAN = 0 Flagloop =* FALSE END IF RETURN  '60 Scans (2 min) elapsed 'Break out of scanning loop  INTERACTIVE MODULE This module allows the user to interact with the process allowing him to select any of the probes which he desires to observe on a real-time basis. kcode = jinkey%  'Test for Keystroke in the Keyboard buffer.  IF kcode THEN  'Determine what the keystroke is.  SELECT CASE kcode CASE KY.ESC EXIT DO CASE KY.LY GOTO Whichprobe  'Which probe has been selected.  Whichprobe: LOCATE 23, 48: INPUT "Which Probe? (Letter)"; Probe$ Probe$ = UCASE$(Probe$) IF Probe$ = "A" OR Probe$ = "B" OR Probe$ = "C" THEN GOTO RTprompt IF Probe$ = "D" OR Probe$ = "E" OR Probe$ = "F" THEN GOTO RTprompt ELSE GOTO Whichprobe END IF RTprompt: IF Realtime = FALSE THEN 'Interested in Real Time Control? LOCATE 23, 48: INPUT "Real-time control RCTR 2? (Y)"; Ans.RTS Ans.RT$ = UCASE$(Ans.RT$) IF Ans.RT$ = "Y" THEN Realtime = TRUE END IF SCREEN 3  'For Hercules Graphics capabilities  Flagscrn = TRUE  'Do not overlay text mode on graphics  CALL REFRESH(Probe$) ProbeID$ - TYPROBE$(Probe$) CALL TRANSFER(ProbeID$, Pt) CALL PLOT(Pt) LOCATE 23, 27: PRINT "Scan Number -  'Refresh the screen 'Identify the Selected probe 'Transfer the array of points 'Plot history of points to present "  CASE KY.LN SCREEN 0  'Turn off Hercules Graphics  Flagscrn = FALSE  'Invoke Text mode again  CALL LAYOUT  'Layout the text information  CALL UPDATE(Pt)  'Update the screen information  CASE ELSE END SELECT END IF  'Do nothing 'Closes Select Case kcode Structure. 'Closes IF kcode Decision Block.  RESET MODULE: Part 1 - Both Reactors Fixed time This module resets some flags to break out of loops at the appropriate times. 'Real time not implemented yet.  IF Flag.RT = FALSE THEN  — Part la Air On IF AirOn.FT = TRUE THEN  'Check for finish of 3 hr aeration  FinishAer.FTS = TIMER  period  'Poll the TIMER Function  'Check if 3 hr air on period overlaps into next day IF FinishAer.FTS < 10920 AND StartAer.FTS >= 75480 THEN FinishAer.FTS = FinishAer.FTS + 86400 END IF IF (FinishAer.FTS - StartAer.FTS) >= 10800 THEN Relaynum% = 0: CALL RELAYSWITCH(Relaynum%) Relaynum% = 1: CALL RELAYSWITCH(Relaynum%) StartAnox.FTS = TIMER AirOn.FT = FALSE PRINT ICommnum, "AirFT Off at "; TIME$ PRINT #Commnum, "AirRT Off at "; TIME$  'Aerated for 3 hours 'Air.FT is switched off 'Air.RT is switched off 'Poll the TIMER Function 'Write to the comment file  IF Realtime = TRUE THEN 'User wants Realtime control 'Avoid Part 1 - no Real Time Flag.RT = TRUE 'Poll the TIMER Function StartAnox.RTS = TIMER AirOn.RT = FALSE PRINT #Commnum, "Real-Time started at "; TIME$ END IF END IF  'Closes 3 Hour Aeration Block  END IF  'Closes If AirOn.FT = TRUE Part la Decision Block  '  Part lb Air Off  IF AirOn.FT = FALSE THEN FinishAnox.FTS = TIMER  'Check for Finish of 3 hours air off period 'Poll the TIMER Function  'Check if 3 hour air off period overlaps into next day IF FinishAnox.FTS < 10920 AND StartAnox.FTS >= 75480 THEN FinishAnox.FTS = FinishAnox.FTS + 86400 END IF IF (FinishAnox.FTS - StartAnox.FTS) >= 10800 THEN 'Anoxic for 3 hours Relaynum% = 0: CALL RELAYSWITCH(Relaynum%) 'Air.FT is switched on Relaynum% = 1: CALL RELAYSWITCH(Relaynum%) 'Air.RT is switched on StartAer.FTS = TIMER 'Poll the TIMER Function AirOn.FT = TRUE PRINT #Commnum, "AirFT On at "; TIME$ 'Write to the comment file PRINT #Commnum, "AirRT On at "; TIMES END IF 'Closes 3 hour Air Off Decision Block END IF  'Closes If AirOn.FT = FALSE Part lb Decision Block  •Note: This is for the AASD#1 Program RESET MODULE: Part 2 - 1  RCTR Fixed Time / 1 RCTR Real time  ELSEIF Flag.RT = TRUE THEN 'Real Time Control Implemented •  Part 2a(i) - Fixed Time Air On  IF AirOn.FT = TRUE THEN FinishAer.FTS = TIMER  'Check for Finish of 3 hour aeration period 'Poll the TIMER Function  'Check if 3 hr air on period overlaps into next day IF FinishAer.FTS < 10920 AND StartAer.FTS >= 75480 THEN FinishAer.FTS = FinishAer.FTS + 86400 END IF IF (FinishAer.FTS - StartAer.FTS) >= 10800 THEN Relaynum% = 0: CALL RELAYSWITCH(Relaynum%) StartAnox.FTS = TIMER AirOn.FT = FALSE PRINT Kommnum, "AirFT Off at "; TIMES END IF  'Aerated for 3 hours 'Air.FT is switched off. 'Poll the TIMER Function 'Write to the comment file  END IF  'Closes If AirOn.FT = TRUE Part 2a(i) Decision Block  '  Part 2a (ii) - Fixed Time Air Off  IF AirOn.FT = FALSE THEN FinishAnox.FTS = TIMER  'Check for finish of 3 hr air off period 'Poll the TIMER Function  'Check if 3 hour air off period overlaps into next day IF FinishAnox.FTS < 10920 AND StartAnox.FTS >= 75480 THEN FinishAnox.FTS = FinishAnox.FTS + 86400 END IF IF (FinishAnox.FTS - StartAnox.FTS) >= 10800 THEN Relaynum% = 0: CALL RELAYSWITCH(Relaynum%) StartAer.FTS = TIMER AirOn.FT => TRUE PRINT #Commnum, "AirFT On at "; TIMES END IF END IF ' IF AirOn.RT = TRUE THEN FinishAer.RTS = TIMER  'Anoxic for 3 hours 'Air.FT is switched on. 'Poll the TIMER Function 'Write to the comment file  'Closes If AirOn.FT = FALSE Part 2a(ii) Decision Block Part 2b (i) - Real Time Air On 'Check for finish of 3 hour air on period 'Poll the TIMER Function  'Check if 3 hour air on period overlaps into next day IF FinishAer.RTS < 10920 AND StartAer.RTS >= 75480 THEN FinishAer.RTS = FinishAer.RTS + 86400 END IF IF (FinishAer.RTS - StartAer.RTS) >= 10800 THEN Relaynum% - 1: CALL RELAYSWITCH(Relaynum%) StartAnox.RTS = TIMER AirOn.RT =» FALSE PRINT #Commnum, "AirRT Off at •*; TIME$ END IF END IF  'Aerated for 3 hours 'Air.RT is switched off. 'Poll the TIMER Function 'Write to the comment file  'Closes If AirOn.RT = TRUE Part 2b(i) Decision Block  /  Part 2b (ii) - Real Time Air Off  IF AirOn.RT = FALSE THEN  'Check for Finish of Air Off Period  FinishAnox.RTS = TIMER  'Poll the TIMER Function  'Check if Maximum Anoxic limit overlaps into next day IF FinishAnox.RTS < MAX.ANOX AND StartAnox.RTS >= (86400 - MAX.ANOX) THEN FinishAnox.RTS = FinishAnox.RTS + 86400 END IF IF (FinishAnox.RTS - StartAnox.RTS) >= MAX.ANOX THEN 'Anoxic limit exceeded Relaynum% = 1: CALL RELAYSWITCH(Relaynum%) 'Air.RT is switched on. StartAer.RTS = TIMER 'Poll the TIMER Function AirOn.RT = TRUE PRINT #Commnum, "Nitrate knee NOT detected on "; DATE$; PRINT #Commnum, " AirRT activated at "; TIME$ Renew = TRUE 'Reset Breakpoint Subroutine CALL BREAKPT(Commnum, Pt, Nitrate, Renew) Renew = FALSE ELSE  'Search for Nitrate Breakpt CALL BREAKPT(Commnum, Pt, Nitrate, Renew) IF Nitrate = TRUE THEN Relaynum% = 1: CALL RELAYSWITCH(Relaynum%) 'Air.RT switched on. StartAer.RTS = TIMER 'Poll the TIMER Function AirOn.RT = TRUE PRINT #Commnum, "Nitrate knee detected on "; DATES; PRINT #Commnum, " AirRT activated at "; TIME$ Nitrate = FALSE Renew = TRUE 'Reset Breakpoint Subroutine CALL BREAKPT(Commnum, Pt, Nitrate, Renew) Renew = FALSE END IF 'Closes If Nitrate = TRUE Decision Block  END IF  'Closes If Anoxic limit is > MAX.ANOX Decision Block  END IF  'Closes If AirOn.RT = FALSE Part 2b(ii) Decision Block  END IF  'Closes IF Flag.RT = FALSE Block - RESET MODULE  '  Closure Statements TIMER ON  'Enable the On Timer trapping  Flagloop = TRUE  'Break back into the Scanning Loop.  Pt = Pt + 1  'Increment point.  IF Pt = 181 THEN Pt = 1 CALL AXES END IF  'Start of next 6 Hour Cycle 'Reset Pt to one 'Calculate the new time Axis 'Closes IF Pt = 181 Decision Block.  END IF  event-handling subroutine.  'Closes IF Flagloop = FALSE Block Scanning Loop  LOOP WHILE Startup < 2  'Closes DO LOOP Structure.  Theend: CLOSE #Commnum ONOFFmaps = SHFFFF OUT (ioaddr%), ONOFFmapS OUT (ioaddr% + 1), ONOFFmapS CLS END  'Close the Comment File 'When exiting the program 'turn off all the relay 'switches at both ports A and B  235  'Note: This is for the AASD#2 Program '  RESET MODULE: Part 2 - 1 RCTR Fixed Time / 1 RCTR Real time  ELSEIF Flag.RT = TRUE THEN 'Real Time Control Implemented '  Part 2a (i) - Fixed Time Air On  IF AirOn.FT = TRUE THEN  'Check for Finish of 3 hour aeration period  FinishAer.FTS = TIMER  'Poll the TIMER Function  'Check if 3 hr air on period overlaps into next day IF FinishAer.FTS < 10920 AND StartAer.FTS >= 75480 THEN FinishAer.FTS = FinishAer.FTS + 86400 END IF IF (FinishAer.FTS - StartAer.FTS) >= 10800 THEN Relaynum% = 0: CALL RELAYSWITCH(Relaynum%) StartAnox.FTS = TIMER AirOn.FT = FALSE PRINT #Commnum, "AirFT Off at "; TIMES END IF  'Aerated for 3 hours 'Air.FT is switched off. 'Poll the TIMER Function 'Write to the comment file  END IF  'Closes If AirOn.FT = TRUE Part 2a(i) Decision Block  '-  Part 2a (ii) - Fixed Time Air Off  IF AirOn.FT = FALSE THEN FinishAnox.FTS = TIMER  'Check for finish of 3 hr air off period 'Poll the TIMER Function  'Check if 3 hour air off period overlaps into next day IF FinishAnox.FTS < 10920 AND StartAnox.FTS >= 75480 THEN FinishAnox.FTS = FinishAnox.FTS + 86400 END IF IF (FinishAnox.FTS - StartAnox.FTS) >= 10800 THEN Relaynum% = 0: CALL RELAYSWITCH(Relaynum%) StartAer.FTS = TIMER AirOn.FT = TRUE PRINT #Commnum, "AirFT On at '*; TIMES END IF END IF ' IF AirOn.RT = TRUE THEN FinishAer.RTS = TIMER  'Anoxic for 3 hours 'Air.FT is switched on. 'Poll the TIMER Function 'Write to the comment file  'Closes If AirOn.FT = FALSE Part 2a(ii) Decision Block Part 2b(i) - Real Time Air On 'Check for finish of aeration period 'Poll the TIMER Function  'Check if aeration period overlaps into next day IF FinishAer.RTS < 10920 AND StartAer.RTS >= 75480 THEN FinishAer.RTS = FinishAer.RTS + 86400 END IF AerPeriod.RTS = FinishAer.RTS - StartAer.RTS  'Calculate Aeration Period  IF (AerPeriod.RTS) >= AerLength.RTS THEN 'Aerated for anoxic period Relaynum% = 1: CALL RELAYSWITCH(Relaynum%) 'Air.RT is switched off. StartAnox.RTS = TIMER 'Poll the TIMER Function AirOn RT — FALSE PRINT #Commnum, "AirRT Off at "; TIMES 'Write to the comment file PRINT #Commnum, "RT Aeration Period for "; AerPeriod.RTS END IF END IF  'Closes If AirOn.RT = TRUE Part 2b(i) Decision Block  /  Part 2b(ii) - Real Time Air Off  IF AirOn.RT = FALSE THEN  'Check for Finish of Air Off Period  FinishAnox.RTS = TIMER  'Poll the TIMER Function  'Check if Maximum Anoxic limit overlaps into next day IF FinishAnox.RTS < MAX.ANOX AND StartAnox.RTS >= (86400 - MAX.ANOX) THEN FinishAnox.RTS = FinishAnox.RTS + 86400 END IF AnoxPeriod.RTS = FinishAnox.RTS - StartAnox.RTS  'Air off length of time  IF (AnoxPeriod.RTS) >= MAX.ANOX THEN Relaynum% = 1: CALL RELAYSWITCH(Relaynum%) StartAer.RTS = TIMER AirOn.RT = TRUE AerLength.RTS = AnoxPeriod.RTS PRINT icommnum, "Nitrate knee NOT detected on PRINT #Commnum, " AirRT activated at "; TIME$  'Anoxic limit exceeded 'Air.RT is switched on. 'Poll the TIMER Function 'Assign aeration time DATE$;  Renew = TRUE 'Reset Breakpoint Subroutine CALL BREAKPT(Commnum, Pt, Nitrate, Renew) Renew = FALSE ELSE  'Search for Nitrate Breakpt CALL BREAKPT(Commnum, Pt, Nitrate, Renew) IF Nitrate = TRUE THEN Relaynum% = 1: CALL RELAYSWITCH(Relaynum%) 'Air.RT switched on. StartAer.RTS = TIMER 'Poll the TIMER Function AirOn.RT = TRUE AerLength.RTS = AnoxPeriod.RTS 'Assign aeration time PRINT icommnum, "Nitrate knee detected on "; DATES; PRINT #Commnum, " AirRT activated at "; TIME$ Nitrate = FALSE Renew = TRUE 'Reset Breakpoint Subroutine CALL BREAKPT(Commnum, Pt, Nitrate, Renew) Renew = FALSE END IF 'Closes If Nitrate = TRUE Decision Block 'Closes If Anoxic limit is > MAX.ANOX Decision Block  END IF END IF  'Closes If AirOn.RT = FALSE Part 2b(ii) Decision Block  END IF  'Closes IF Flag.RT = FALSE Block - RESET MODULE Closure Statements  TIMER ON  'Enable the On Timer trapping  Flagloop = TRUE  'Break back into the Scanning Loop.  Pt = Pt + 1  'Increment point.  IF Pt = 181 THEN Pt = 1 CALL AXES END IF  'Start of next 6 Hour Cycle 'Reset Pt to one 'Calculate the new time Axis 'Closes IF Pt = 181 Decision Block.  END IF  event-handling subroutine.  'Closes IF Flagloop = FALSE Block Scanning Loop  LOOP WHILE Startup < 2  'Closes DO LOOP Structure.  Theend: CLOSE #Commnum ONOFFmapS = SHFFFF OUT (ioaddr%), ONOFFmapS OUT (ioaddr% + 1), ONOFFmapS CLS END  'Close the Comment File 'When exiting the program 'turn off all the relay 'switches at both ports A and B  BIOP.BAS DEFINT A-Z STARTUP AND INITIALIZATION MODULE This module introduces the user to the mechanics of the program, initializes some parameters, and declares global parameters. '$INCLUDE: 'GLOBAL.BI' CLS CALL INFORM  'Display the information for the program mechanics.  CALL FILENAME(FToutS, RTout$, Commout$, FTnum, RTnum, Commnum)'Set disk Files Runprompt: LOCATE 23, 15:  INPUT  "Do you want to run the program? (Y/N) RAns$ = UCASE$(RAns$)  RAns$  IF RAns$ = "Y" THEN GOTO Setscreen ELSEIF RAns$ = "N" THEN GOTO Theend ELSE GOTO Runprompt END IF Setscreen: CLS LOCATE 10, 14: PRINT "The reactors are not in an anoxic mode." LOCATE 11, 14: PRINT "Anoxic Sequence Starting Times are the" LOCATE 12, 14: PRINT "following ... 1:10 am, 9:10 am and 5:10 pm. Initialize: FOR x = 1 TO 5000 FOR y = 1 TO 100: NEXT y NEXT X  'Delay to slow down the timer loop  Checktimefi = TIMER  'Poll the timer function  SCAN = 0 Scantime = SCAN.TIME Startup = 0 Flagloop = TRUE Flagdiff = TRUE Nitrate - FALSE Renew = FALSE Flagscrn = FALSE  'Set the Scan counter to zero to start the scans. 'The Scan time is currently every 2 seconds. 'Used to control the Scanning Loop 'Flag for breaking out of and into Scanning Loop. 'Flag to signify no preceeding point in Diff Sub. 'No Nitrate Breakpoint Detected as of yet. 'Flag used to clear/reset Breakpt Sub variables. 'Flag indicating whether graphics is invoked  VFAPass = 0 VFAPump = FALSE Acetate = FALSE  'The VFA counter to time the pump operation. 'The RT Acetate Pump is off 'Acetate not added to the RT reactor yet  Pt = 1 Startpt = l Endpt = 1 8 0  'Assign initial point of the start of graph. 'Storage of initial Pt value. 'There are 180 points in a Six Hour Graph.  IF ChecktimeS > 0 THEN AnoxStartS = 4200 'Time: 1:10 am Datecheck = VAL(MID$(DATE$, 4, 2)) 'Perform Date check on the Data IF Datecheck <> FTnum THEN 'If past midnight (ie. new day) CALL FILENAME(FTout$, RTout$, Commout$, FTnum, RTnum, Commnum) 'file END IF IF ChecktimeS > 4200 THEN AnoxStartS = 33000 IF ChecktimeS > 33000 THEN AnoxStartS = 61800 IF ChecktimeS > 61800 THEN GOTO Initialize  ' Time: 9:10 am ' Time: 5:10 pm  SamplingTime: PolltimeS = TIMER  'Poll the timer function  IF PolltimeS > AnoxStartS THEN GOTO StartRecording ELSE GOTO SamplingTime END IF  'The anoxic cycle commences 'Start Recording the ORP values 'Return and poll the timer function again  StartRecording: OUT baseaddr%, SH0 FOR x = 1 TO 100: NEXT X i = INP(baseaddr% + 1) i = INP(baseaddr% + 1)  'Initialize the DT2814 A/D Board 'as per the DT2814 manual on pg. 5-9 /  CALL INITRELAYS  'Initialize the relay board - set all relays off.  OPEN Commout$ FOR APPEND AS #Commnum PRINT #Commnum, "Anoxic Period Started at StartAnoxS = PolltimeS Oper$ = "Acetate not added yet" CLS CALL LAYOUT CALL AXES  TIME$  'Write to the 'comment file  'Layout the text information. 'Calculate the relevant time axis. SCAN AND PLOTTING MODULE  This module scans the ORP probes every 2 seconds and then every 2 minutes an average for each probe is calculated and plotted if graphics is invoked else an update is written to the screen in text mode. Scanning: ON TIMER(Scantime) GOSUB Readprobe TIMER ON DO  'Every 2 sec. go to the Readprobe Module  'Enable On Timer event-handling trapping routine 'Loop enclosing the entire program - to exit press <Escape>  IF Flagloop = FALSE THEN  'Break out of the Scanning Loop  TIMER STOP CALL DIFF(Flagdiff, Pt) Flagdiff = FALSE  'Calculate the First Difference 'Now Preceeding Pts are available  CALL WRITING(Pt, FTout$, RTout$, FTnum, RTnum) IF Flagscrn = FALSE THEN CALL UPDATE(Pt) LOCATE 14, 46: PRINT Oper$ END IF IF Flagscrn = TRUE THEN CALL TRANSFER(ProbeID$, Pt) CALL PLOT(Pt) END IF  'Write data to disk  'Update the information screen  'Transfer the array of points 'Plot history of points to present  INTERACTIVE MODULE This module allows the user to interact with the process allowing him to select any of the probes which he desires to observe on a real-time basis. kcode = jinkey%  'Test for Keystroke in the Keyboard buffer.  IF kcode THEN  'Determine what the keystroke is.  SELECT CASE kcode CASE KY.ESC EXIT DO  'Exit from the program  CASE KY.LY GOTO Whichprobe  'Which probe has been selected.  Whichprobe: LOCATE 23, 48: INPUT "Which Probe? (Letter)1*; Probe$ Probe$ = UCASES(Probe$) IF Probe$ = "A" OR Probe$ = "B" OR Probe$ = "C" THEN GOTO Startplot IF Probe$ = "D" OR Probe$ = "E" OR ProbeS = "F" THEN GOTO Startplot ELSE GOTO Whichprobe END IF Startplot: SCREEN 3  'For Hercules Graphics capabilities  Flagscrn = TRUE  'Do not overlay text mode on graphics  CALL REFRESH(Probe$) ProbeID$ = TYPROBE$(Probe$) CALL TRANSFER(ProbelDS, Pt) CALL PLOT(Pt) LOCATE 23, 27: PRINT "Scan Number -  'Refresh the screen 'Identify the Selected probe 'Transfer the array of points 'Plot history of points to present "  CASE KY.LN SCREEN 0  'Turn off Hercules Graphics  Flagscrn = FALSE  'Invoke Text mode again  CALL LAYOUT LOCATE 14, 46: PRINT Oper$ CALL UPDATE(Pt)  'Layout the text information  CASE ELSE END SELECT END IF  'Update the screen information 'Do nothing 'Closes Select Case kcode Structure. 'Closes IF kcode Decision Block.  VFA ADDITION TO REAL-TIME REACTOR MODULE IF Acetate = FALSE THEN  'Acetate not added as of yet  VFAddtimeS = TIMER  'Poll the TIMER Function  IF VFAPump = FALSE THEN  'The pump is not currently on  'If nitrate knee was not detected - Acetate added after 2 hr 42 minutes '(ie. 6 minutes (3 passes) plus 2 minutes spare) prior to commencement 'of aeration period IF (VFAddtimeS - StartAnoxS) >= 9720 THEN 'Time is > than 2 hr 42 min. Relaynum% = 0 CALL RELAYSWITCH(Relaynum%) 'Acetate added to RT Reactor VFAPump = TRUE 'VFA RT pump is on PRINT #Commnum, "No Nitrate knee detected on "; DATES PRINT #Commnum, "Acetate pumped to RT reactor starting at "; TIME$ Oper$ = "Acetate RT Feed Pump On" IF Flagscrn = FALSE THEN LOCATE 14, 46: PRINT Oper$ Renew = TRUE 'Clear/Reset Breakpoint Sub CALL BREAKPT(Commnum, Pt, Nitrate, Renew) Renew = FALSE ELSE  'Search for nitrate breakpoint  CALL BREAKPT(Commnum, Pt, Nitrate, Renew) IF Nitrate = TRUE THEN Relaynum% = 0 CALL RELAYSWITCH(Relaynum%) 'Acetate added to RT Reactor VFAPump = TRUE 'VFA RT pump is on PRINT #Commnum, "Nitrate knee detected at "; TIME$ PRINT #Commnum, "Acetate started to RT reactor at "; TIME$ OperS = "Acetate RT Feed Pump On" IF Flagscrn = FALSE THEN LOCATE 14, 46: PRINT Oper$ Renew = TRUE 'Clear/Reset the Breakpt Sub CALL BREAKPT(Commnum, Pt, Nitrate, Renew) Renew = FALSE END IF END IF  'Closes IF Nitrate = TRUE Decision Block  'Closes Real Time Acetate Addition Decision Block  ELSE 'Since RT Acetate Pump is on VFAPass = VFAPass + 1 'Increment Pass Counter by 1 IF VFAPass > 2 THEN '6 min (3 passes) have elapsed Relaynum% = 0 CALL RELAYSWlTCH(Relaynum%) 'Turn off RT Acetate pump VFAPump = FALSE 'Reset Pump Variable VFAPass = 0 'Reset Pass Counter Acetate = TRUE 'Reset Acetate Variable PRINT #Commnum, "Acetate finished to RT reactor at "; TIME$ Oper$ = "RT Acetate has finished pumping" IF Flagscrn = FALSE THEN LOCATE 14, 46: PRINT OperS END IF END IF 'Closes IF VFAPump = FALSE Decision Block END IF  'Closes IF Acetate = FALSE Decision Block  /  Closure Statements TIMER ON  'Enable the On Timer trapping  Flagloop = TRUE  'Break back into the Scanning Loop.  Pt = Pt + 1  'Increment point.  END IF  event-handling subroutine.  'Closes IF Flagloop = FALSE Block Scanning Loop  IF Pt = 181 THEN Startup = 3  'Breakout of the Loop  LOOP WHILE Startup < 2  'Closes DO LOOP Structure.  Theend: TIMER OFF CLOSE fCommnum ONOFFmapfi = &HFFFF OUT (ioaddr%), ONOFFmapS OUT (ioaddr% + 1 ) , ONOFFmapfi CLS IF Startup = 3 THEN GOTO Setscreen  'Close the Comment File 'When exiting the program 'turn off all the relay 'switches at both ports A and B  END /  "  —  • • ; : : ; : • •urrrrssTs^ssss-ssTKTnx-s  '  •  =—~-~—=—*  ;  J g  a-  —  ••,,..,  READPROBE MODULE  'This module does the actual reading of the probes by calling the SCAN Sub Readprobe: SCAN = SCAN + 1  'Increment the SCAN Counter  LOCATE 23, 42: PRINT USING '»###"; SCAN segmentt = VARSEG(MVolts(0, SCAN)) 'Produce the requisite FAR offset% = VARPTR(MVolts(0, SCAN)) 'Pointer to the data array 'Call the function returning an error code errnum% = getscanl%(baseaddr%, chanO%, chanl5%, segment%, offset%) IF errnum% <> 0 THEN PRINT #Commnum, "Getscan returned an error code at "; TIMES GOTO Theend END IF CALL SCANS (SCAN, Pt) IF SCAN = NUM. SCANS THEN SCAN = 0 Flagloop = FALSE END IF RETURN  'Call the SCAN Subroutine '60 Scans (2 min) elapsed 'Break out of scanning loop  i INFORM.BAS 'SINCLUDE: 'GLOBAL.BI' 'Note: This is for the AASD#1 Program THIS SUBROUTINE DETAILS THE MECHANICS OF THE PROGRAM SUB INFORM STATIC 2, 23: PRINT "COMPUTER CONTROLLED SLUDGE DIGESTION " 3, 23: PRINT "USING OXIDATION-REDUCTION POTENTIAL" 5, 20: PRINT "This program allows the user to select and watch" 6, 15: PRINT "each of the individual ORP probes associated with " 7, 15: PRINT "both the Fixed-Time (#1) (3 hr air on / 3 hr air off) " 8, 15: PRINT "and the Real-Time (#2) (3 hr air on / variable time air" 9, 15: PRINT " off - depending upon nitrate breakpoint) Reactors. " 10, 20:: PRINT "Each probe has been assigned a capital letter and " 11, 15:: PRINT "for distinguishing purposes the ORP probes have been " 12, 15: PRINT "given the appendages a, b, and c to denote the front," 13, 15: PRINT "side and back probes respectively" 0RP2a - D " 15, 27: PRINT "ORPla - A 0RP2b - E " 16, 27: PRINT "ORPlb - B 0RP2C - F " 17, 27: PRINT "ORPlC - C  LOCATE LOCATE LOCATE LOCATE LOCATE LOCATE LOCATE LOCATE LOCATE LOCATE LOCATE LOCATE LOCATE LOCATE END SUB  ' INFORM.BAS '$INCLUDE: 'GLOBAL.BI' 'Note: This is for the AASD#2 Program THIS SUBROUTINE DETAILS THE MECHANICS OF THE PROGRAM SUB INFORM STATIC 2, 23: PRINT "COMPUTER CONTROLLED SLUDGE DIGESTION " 3, 23: PRINT "USING OXIDATION-REDUCTION POTENTIAL" 5, 20: PRINT "This program allows the user to select and watch" 6, 15: PRINT "each of the individual ORP probes associated with " 7, 15: PRINT "both the Fixed- (#1) (3 hr air on / 3 hr air off) and ' 8, 15: PRINT "Real-Time (#2) (50/50 variable times of air on and" 9, 15: PRINT " off, depending upon the nitrate breakpoint) Reactors. 10,, 20:: PRINT "Each probe has been assigned a capital letter and " 11,, 15:; PRINT "for distinguishing purposes the ORP probes have been ' 1 12,, 15:: PRINT "given the appendages a, b, and c to denote the front, 13, 15:: PRINT "side and back probes respectively" 0RP2a - D " 15, 27:: PRINT "ORPla - A ORP2b - E " 16, 27: PRINT "ORPlb - B ORP2C - F " 17, 27: PRINT "ORPlC - C  LOCATE LOCATE LOCATE LOCATE LOCATE LOCATE LOCATE LOCATE LOCATE LOCATE LOCATE LOCATE LOCATE LOCATE END SUB  i INFORM.BAS '$INCLUDE: •GLOBAL.BI• 'Note: This is for the BIO-P Program THIS SUBROUTINE DETAILS THE MECHANICS OF THE PROGRAM SUB INFORM STATIC LOCATE LOCATE LOCATE LOCATE LOCATE LOCATE LOCATE LOCATE LOCATE LOCATE LOCATE LOCATE LOCATE LOCATE LOCATE LOCATE LOCATE LOCATE  1, 22: PRINT "EXCESS BIOLOGICAL PHOSPHORUS REMOVAL USING" 2, 22: PRINT "OXIDATION REDUCTION POTENTIAL DETECTION OF" 3, 27: PRINT "THE DISSAPPEARANCE OF NITRATES" 5, 16: PRINT "This program demonstrates the use of ORP as a control" 6, 14: PRINT "parameter for bio-p processes in a sequencing batch " 7, 14: PRINT "reactor. Sodium Acetate is added to the Fixed Time " 8, 14: PRINT "Reactor (nr. rt.) at a preset time during the anoxic" 9, 14: PRINT "sequence, while the addition of VFAs to the Real Time" 10, 14: PRINT "Reactor (far.rt,) is governed by the detection of the" 11, 14: PRINT "ORP breakpt. corresponding to nitrate dissappearance." 13, 16: PRINT "The user can select and watch any probe in the " 14, 14: PRINT "FT (#1) or RT(#2) reactors where each probe has been" 15, 14: PRINT "assigned a capitol letter and for distinguishing" 16, 14: PRINT "purposes an appendage a, b, or c to denote the front," 17, 14: PRINT "side and back probes respectively" ORP2a - D" 19, 27: PRINT "ORPla - A ORP2b - E" 20, 27: PRINT "ORPlb - B 0RP2c - F" 21, 27: PRINT "ORPlc - C  END SUB  242  FILENAME.BAS '$INCLUDE: 'GLOBAL.BI' •Note: This is for ALL Programs •  A SUBROUTINE WHICH GENERATES THE FILENAMES FOR THE DATA FILES  • —  i  —  •  ..,  ,  .  —  —  —  —  —  —  SUB FILENAME (FToutS, RTout$, CommoutS, FTnum, RTnmn, Commnum) Temp$ = DATE$ YearS = RIGHT$(Temp$, 2) Month$ = LEFTS(Temp$, 2) Day$ = MIDS(Temp$, 4, 2) Composite$ = Year$ + "-" + Months + "-" + Day$ FTout$ =• CompositeS + ».FT«I RToutS = CompositeS + ".RT" CommoutS = CompositeS + ".msg  'Fixed Time Filename 'Real Time Filename 'The Comments Filename"  FTnum = VAL(DayS) RTnum = FTnum + 100 Commnum =» FTnum + 200  'Arbitrary numbering system 'Arbitrary numbering system 'Arbitrary numbering system  OPEN FTOUtS FOR PRINT #FTnum, PRINT #FTnum, PRINT #FTnum, CLOSE #FTnum  APPEND AS #FTnum •Print out file headings " TIME Seconds ORPla ORPlb ORPlc " ,DOxl DORPla DORPlb DORPlc" •"  OPEN RTOUtS FOR PRINT #RTnum, PRINT #RTnum, PRINT #RTnum, CLOSE #RTnum  APPEND AS #RTnum " TIME Seconds " DOX2 DORP2a ""  'Print out file headings ORP2a ORP2b ORP2C DORP2b DORP2C"  END SUB  'SINCLUDE: 'GLOBAL.BI' 'Note: This is for ALL Programs  REFRESH.BAS  THIS SUBROUTINE REFRESHES THE SCREEN FOR THE NEXT PROBE'S PLOTS SUB REFRESH (ProbeS) STATIC 'Refresh the Screen with CALL ORPSCRN 'ORP Graph cooridinates ProbelDS - TYPROBE$(Probe$) LOCATE 23, 2: PRINT "Showing Probe - "; ProbelDS LOCATE 23, 48: PRINT "Select Another ? (Y/N)"' END SUB  244 INITREL.BAS $INCLUDE: 'GLOBAL.BI' Note: This is for ALL Programs A SUBROUTINE WHICH INITIALIZES THE SOLID STATE RELAY CONTROL 10 BOARD This subroutine is designed to output 16 bits state relays that are connected to Metrabyte's the IBM PC. Port A Relays: 0 - 7 Relay Control Bits: 1 Port B Relays: 8 - 1 5 0  of data to control the solid PIO-12 I/O Board for the = OFF = ON  Note: In setting up the port configuration it initializes all relays of ports A and B to OFF. To do this it leaves the global variable ONOFFmapS = SHFFFF with all 32 bits set to 1. The global constant ioaddr% is also used. SUB INITRELAYS STATIC OUT (ioaddrt + 3 ) , &H80 ONOFFmapS = SHFFFF OUT (ioaddr%), ONOFFmapS OUT (ioaddr% + 1), ONOFFmapS  'Sets up all ports (A,B,C) as output 'ports. Note: OUT (ioaddr% + 3 ) , SH89 'would be used for inputs to port C 'Set global variables for all relays off 'Set all port A relays off 'Set all port B relays off  END SUB RELAY.BAS '$INCLUDE: 'GLO BAL.BI• 'Note: This is for ALL Programs ' A SUBROUTINE WHICH FLIPS THE BIT TO CHANGE THE RELAY SWITCH STATUS * Note: The subroutine scans the global variable ONOFFmapS which indicates ' the present relay status and uses it to turn Relaynum% ON if OFF, or ' OFF if ON. Again the Relay control bits are 1 = OFF and 0 = ON. •  SUB RELAYSWITCH (Relaynum%) SmaskS = 0 RmaskS = ONOFFmapS SmaskS = SmaskS OR (2  Relaynum%)  IF (ONOFFmapS AND SmaskS) <> 0 THEN SmaskS = SmaskS XOR SHFFFF Rmasks = Rmasks AND SmaskS ELSE Rmasks = Rmasks OR SmaskS  •Get the present relay status •Set relay bit Relaynum% = 1 'Relay Relaynum% is OFF 'Flip the lower 16 bits 'Transfer the ON bit into the 'Present Relay Status Word 'Relay Relaynum% is ON 'Transfer the OFF bit into the 'Present Relay status Word  END IF 'Update the global relay status variable IF RmaskS = IF RmaskS = ONOFFmapS = 'Output the  -65535 THEN RmaskS = 0 65535 THEN RmaskS = SHFFFF Rmasks Updated relay status word to I/O ports A and B  OUT (ioaddr%), RmaskS Bmask% = RmaskS IF Bmask% Bmask% Bmask% Bmask% ELSE Bmask% END IF  < = = =  0 THEN Bmask% XOR SHFFFF (Bmask% \ SH100) Bmask% XOR SHFFFF  •Flip the bits •Shift Hi-byte Pattern into the Low-byte 'Flip the bits back again  = (Bmask% \ SH100)  OUT (ioaddr% + 1), Bmask% END SUB  'The lower byte to Port A  'The higher byte to port B  245  AXES.BAS '$INCLUDE: 'GLOBAL.BI' •Note: This is for ALL Programs A SUBROUTINE WHICH CALCULATES  THE RELEVANT TIME SCALE AXIS  SUB AXES STATIC Seconds* = TIMER HourO = Seconds* \ 3600 DigitOl = HourO \ 10 Hourrem! = Seconds* / 3600 Digitreml! =• HourO / 10 Digit02 = ((Digitreml! - DigitOl) * 10) Mintrunc! = (Hourrem! - HourO) * 60 Digit3 = Mintrunc! \ 10 Digitrem2! = Mintrunc! / 10 Digit4 = ((Digitrem2! - Digit3) * 10) \ 1 Hour2 = HourO + 2 Hour4 = HourO + 4 Hour6 = HourO + 6 IF Hour2 > 24 THEN Hour2 = Hour2 IF Hour4 > 24 THEN Hour4 = Hour4 IF Hour6 > 24 THEN Hour6 = Hour6 Digit21 = Hour2 \ 10 Digit41 = Hour4 \ 10 Digitei = Hour6 \ 10 Digit22 = ((Hour2 / 10) - Digit21) Digit42 = ((Hour4 / 10) - Digit41) Digit62 = ((Hour6 / 10) - Digitei)  24 24 24  * 10 * 10 * 10  'Calculate the first two •digits of the starting time. 'First digit 0 hour •Second digit 0 hour 'Calc. third & fourth digits 'Third digit 0, 2, 4, 6 hours •Fourth digit 0, 2, 4, 6 hours  •Check if time scale extends 'into the next day. 'First digit 2 hour 'First digit 4 hour 'First digit 6 hour 'Second digit 2 hour 'Second digit 4 hour 'Second digit 6 hour  END SUB  PAXIS.BAS '$INCLUDE: 'GLOBAL.BI' 'Note: This is for ALL Programs A SUBROUTINE WHICH PRINTS OUT THE RELEVANT TIME SCALE AXIS SUB PAXIS STATIC LOCATE LOCATE LOCATE LOCATE LOCATE LOCATE LOCATE LOCATE LOCATE LOCATE LOCATE LOCATE END SUB  21, 21, 21, 21, 21, 21, 21, 21, 21, 21, 21, 21,  17: 19: 20: 31: 33: 34: 44: 46: 47: 58: 60: 61:  PRINT PRINT PRINT PRINT PRINT PRINT PRINT PRINT PRINT PRINT PRINT PRINT  USING "#"; DigitOl; Digit02 i t . ti  USING USING n.n USING USING  " # " ; Digit3; Digit4 " # " ; Digit21;r Digit22 " # " ; Digit3; Digit4 " # " ; Digit41;: Digit42  it. n  U S I N G " # " ; Digit3; Digit4 U S I N G " I " ; Digit61 ; Digit62 n•n U S I N G " # " ; Digit3; Digit4  SCANS.BAS '$INCLUDE: 'GLOBAL.BI' 'Note: This is for all Programs THIS SUBROUTINE SUMS AND AVERAGES THE PROBE READINGS SUB SCANS (SCAN, Pt) STATIC 'Sum the Scans MVoltslaS = MVoltslaS MVoltslbS = MVoltslbS MVoltslcS = MVoltslcS MVolts2aS = MVolts2aS MVolts2b& = MVolts2bS MVolts2cS = MVolts2cS MVoltDOlS = MVoltDOlS MVoltD02S = MVoltD02S  + + + + + + + +  MVolts(0, MVolts(1, MVolts(2, MVolts(3, MVolts(4, MVolts(5, MVolts(6, MVolts(7,  SCAN) SCAN) SCAN) SCAN) SCAN) SCAN) SCAN) SCAN)  IF SCAN = NUM.SCANS THEN •60 Scans therefore calculate 2 minute avg. reading for each probe ORPla(Pt) = MVoltslaS / SCAN ORPlb(Pt) = MVoltslbS / SCAN ORPlc(Pt) = MVoltslcS / SCAN 0RP2a(Pt) = MVolts2aS / SCAN 0RP2b(Pt) = MVolts2bS / SCAN 0RP2c(Pt) = MVolts2cS / SCAN DOxl(Pt) = MVoltDOlS / SCAN D0x2(Pt) = MVoltD02S / SCAN •Convert digital numbers to millivoltages ORPla(Pt) ORPlb(Pt) ORPlc(Pt) 0RP2a(Pt) 0RP2b(Pt) ORP2c(Pt) DOXl(Pt) > DOx2(Pt) = DOxl(Pt) = DOx2(Pt) >  = ((ORPla(Pt) - 2048) = ((ORPlb(Pt) - 2048) = ((ORPlc(Pt) - 2048) • ((ORP2a(Pt) - 2048) = ((0RP2b(Pt) - 2048) = ((ORP2c(Pt) - 2048) ((DOxl(Pt) - 2048) / ((DOx2(Pt) - 2048) / .082317 * (DOxl(Pt)) " .082317 * (DOx2(Pt))  500 / 2048) 500 / 2048) 500 / 2048) 500 / 2048) 500 / 2048) 500 / 2048) 2048) * 500 2048) * 500 + .251 + .251  'Reset the millivoltage sum to zero MVoltslaS = 0: MVoltslbS = 0: MVoltslcS MVolts2aS = 0: MVolts2bS = 0: MVolts2cS MVoltDOlS = 0: MVoltD02& = 0: END IF END SUB  247  i DIFF.BAS '$INCLUDE: 'GLOBAL.BI' •Note: This is for AASD#1 and AASD#2 Programs A SUBROUTINE WHICH CALCULATES THE FIRST DIFFERENCE OF THE ORP PROFILES SUB DIFF (Flagdiff, Pt) Precpt = Pt - 1 IF Flagdiff = TRUE THEN ORPla(Precpt) ORPlb(Precpt) ORPlc(Precpt) ORP2a(Precpt) ORP2b(Precpt) ORP2c(Precpt)  = = = = =  ORPla(Pt) ORPlb(Pt) ORPlc(Pt) ORP2a(Pt) ORP2b(Pt) ORP2c(Pt)  •At start up of program the initial 'first difference point will be set 'equal to zero since there is no •preceeding point.  END IF IF Flagdiff = FALSE AND Pt = Startpt THEN ORPla(Endpt) ORPlb(Endpt) ORPlc(EndDt) 0RP2a(Endpt) 0RP2b(Endpt) ORP2c(Endpt)  ORPla(Precpt) ORPlb(Precpt) ORPlc(Precpt) 0RP2a(Precpt) 0RP2b(Precpt) 0RP2c(Precpt) END IF •Calculate the First DORPla(Pt) DORPlb(Pt) DORPlc(Pt) DORP2a(Pt) DORP2b(Pt) DORP2c(Pt)  'Store last point so it becomes •first point of the next cycle.  Difference of the ORP (2 minute intervals) (ORPla(Pt) ORPla(Precpt)) / 2 (ORPlb(Pt) ORPlb(Precpt)) / 2 (ORPlc(Pt) ORPlc(Precpt)) / 2 (ORP2a(Pt) ORP2a(Precpt)) / 2 (ORP2b(Pt) 0RP2b(Precpt)) / 2 (ORP2c(Pt) ORP2c(Precpt)) / 2  END SUB i DIFF.BAS '$INCLUDE: 'GLOBAL.BI' 'Note: This is for the BIO-P Program A SUBROUTINE WHICH CALCULATES THE FIRST DIFFERENCE OF THE ORP PROFILES SUB DIFF (Flagdiff, Pt) Precpt = Pt - 1 IF Flagdiff = TRUE THEN ORPla(Precpt) ORPlb(Precpt) ORPlc(Precpt) ORP2a(Precpt) ORP2b(Precpt) ORP2c(Precpt)  = = = = = =  ORPla(Pt) ORPlb(Pt) ORPlc(Pt) ORP2a(Pt) ORP2b(Pt) ORP2c(Pt)  'At start up of program the initial 'first difference point will be set 'equal to zero since there is no 'preceeding point.  END IF 'Calculate the First DORPla(Pt) DORPlb(Pt) DORPlc(Pt) DORP2a(Pt) DORP2b(Pt) DORP2c(Pt) END SUB  Difference of the ORP (2 minute intervals) (ORPla(Pt) ORPla(Precpt)) / 2 (ORPlb(Pt) ORPlb(Precpt)) / 2 (ORPlc(Pt) ORPlc(Precpt)) / 2 (ORP2a(Pt) ORP2a(Precpt)) / 2 (ORP2b(Pt) 0RP2b(Precpt)) / 2 (ORP2c(Pt) ORP2c(Precpt)) / 2  ORPSCRN.BAS •$INCLUDE: 'GLOBAL.BI• 'Note: This is for ALL Programs A SUBROUTINE WHICH SETS UP THE ORP GRAPHING CO-ORDINATES SUB ORPSCRN STATIC CLS 'Set up the Initial Boxes and Graph Dimensions LINE (0, 0)-(719, 335), , B LINE (110, 10)-(590, 270), , B LINE (110, 160)-(590, 160) •Put in the tick marks for the Time scale axis Pixtime = 110 FOR i = 1 TO 9 PSET (Pixtime, 271) PSET (Pixtime, 272) Pixtime = Pixtime + 60 NEXT i 'Put in the tick marks for the ORP scale axis Pixorp = 10 FOR j = 1 TO 11 PSET (109, Pixorp) PSET (108, Pixorp) Pixorp = Pixorp + 25 NEXT j 'Print out the Time Scale Axis CALL PAXIS LOCATE 22, 35: PRINT "Time (hrs)" 'Print out LOCATE LOCATE LOCATE LOCATE LOCATE LOCATE LOCATE LOCATE LOCATE LOCATE  the ORP Scale Axis 2, 9: PRINT "300" 5, 9: PRINT "200" 8, 9: PRINT "100" 12, 9: PRINT " 0" 16, 8: PRINT "-100" 19, 8: PRINT "-200" 6, 2: PRINT " O" 7, 2: PRINT " R" 8, 2: PRINT " P" 10, 2: PRINT " (mv)'  END SUB WRITING.BAS • $INCLUDE: •GLOBAL.BI' 'Note: This is for ALL Programs •  THIS SUBROUTINE WRITES THE DATA TO THE DISK FILE  SUB WRITING (Pt, FTout$, RTout$, FTnum, RTnum) STATIC 'Write to the Fixed-Time Disk File OPEN FTout$ FOR APPEND AS FTnum PRINT #FTnum, TIME$; " "; PRINT #FTnum, USING "#####.## "; TIMER; PRINT #FTnum, USING "+###.## "; ORPla(Pt); ORPlb(Pt); ORPlc(Pt); PRINT #FTnum, USING " #.# "; DOxl(Pt); PRINT #FTnum, USING "+###.## "; DORPla(Pt); DORPlb(Pt); DORPlc(Pt) CLOSE #FTnum •Write to the Real-Time Disk file OPEN RTout$ FOR PRINT #RTnum, PRINT #RTnum, PRINT #RTnum, PRINT #RTnum, PRINT #RTnum, CLOSE #RTnum END SUB  APPEND AS RTnum TIME$; " "; USING "#####.## "; TIMER; USING "+###.## "; ORP2a(Pt); ORP2b(Pt); 0RP2c(Pt); USING " #.# "; DOx2(Pt); USING "+###.## "; D0RP2a(Pt); DORP2b(Pt); DORP2c(Pt)  i TRANSFER.BAS '$INCLUDE: 'GLOBAL.BI• 'Note: This is for ALL Programs ' '  A SUBROUTINE WHICH TRANSFERS THE PROBE READINGS TO A GENERAL ARRAY READY FOR PLOTTING  I  I - — — — — — — — — — — — — — — —  =  =  —  =  -  =L=m  as——-33;—=——=  LUlt  , ^  =  — — _ — — — • — -  SUB TRANSFER (ProbeID$, Pt) SELECT CASE ProbeID$ CASE "ORPla" FOR i = startpt TO Pt ORP(i) = ORPla(i) NEXT i CASE "ORPlb" FOR i = startpt TO Pt ORP(i) = ORPlb(i) NEXT i CASE "ORPlc" FOR i = startpt TO Pt ORP(i) = ORPlo(i) NEXT i CASE "ORP2a" FOR i = Startpt TO Pt ORP(i) = ORP2a(i) NEXT i CASE "ORP2b" FOR i = Startpt TO Pt ORP(i) = ORP2b(i) NEXT i CASE "ORP2C" FOR i = Startpt TO Pt ORP(i) = ORP2c(i) NEXT i END SELECT END SUB  i '$INCLUDE: •GLOBAL.BI• 'Note: This is for ALL Programs '  PLOT.BAS  A SUBROUTINE WHICH PLOTS THE PROBE READINGS UP TO THE PRESENT POINT  SUB PLOT (Pt) FOR j = Startpt TO Pt 'Proportion to transform ORP values to pixels Markl = (ORP(j) / 50) * 25 Pixel1 - 160 - Markl 'Plot the point PSET (168 + 2 * j, Pixell) NEXT j END SUB  . LAYOUT.BAS — •$INCLUDE: 'GLOBAL.BI• 'Note: This is for AASD#1 and AASD#2 Programs THIS SUBROUTINE LAYS OUT THE TEXT INFORMATION SCREEN SUB LAYOUT STATIC CLS LOCATE 2, 23: PRINT "COMPUTER CONTROLLED SLUDGE DIGESTION " LOCATE 3, 23: PRINT "USING OXIDATION-REDUCTION POTENTIAL " LOCATE 5, 13: PRINT "RCTR #1 - FIXED TIME" LOCATE 5, 46: PRINT "RCTR #2 - REAL TIME" - " LOCATE 7, 13: PRINT "ORPla - " LOCATE 7, 46: PRINT "ORP2a - " LOCATE 9, 13: PRINT "ORPlb - " LOCATE 9, 46: PRINT "ORP2b - " LOCATE 11, 13: PRINT "ORPlc - " LOCATE 11, 46: PRINT "ORP2C LOCATE 13, 13: PRINT "Time of Last Update - " LOCATE 13, 46: PRINT "Point Number - " LOCATE 15, 13: PRINT "Note: Hit <Y> - Yes - if desire to see ORP plots" LOCATE 16, 23: PRINT "<N> - No - when finished viewing plots" LOCATE 17, 23: PRINT "<ESC> - Escape - to exit program" LOCATE 19, 13: PRINT "Note: Time is updated every two minutes" LOCATE 20, 19: PRINT "There are 60 scans (at 2 sec intervals) in 2 min" LOCATE 21, 19: PRINT "There are 180 pts ( 2 min intervals) in a 6 hr cycle" LOCATE 23, 30: PRINT "Scan number - " END SUB  • LAYOUT.BAS '$INCLUDE: 'GLOBAL.BI' •Note: This is for the BIO-P Program THIS SUBROUTINE LAYS OUT THE TEXT INFORMATION SCREEN SUB LAYOUT STATIC CLS LOCATE LOCATE LOCATE LOCATE LOCATE LOCATE LOCATE LOCATE LOCATE LOCATE LOCATE LOCATE LOCATE LOCATE LOCATE LOCATE LOCATE LOCATE LOCATE LOCATE  END SUB  2, 15: PRINT "COMPUTER CONTROLLED ADDITION OF A VFA CARBON SOURCE" 3, 17: PRINT "BASED ON THE ORP-TIME VARIATION IN A BIO-P PROCESS " 5, 13: PRINT "RCTR #1 - FIXED TIME" 5, 46: PRINT "RCTR #2 - REAL TIME" - " 7, 13: PRINT "ORPla - " 7, 46: PRINT "ORP2a - " 9, 13: PRINT "ORPlb - " 9, 46: PRINT "ORP2b - " 11, 13: PRINT "ORPlc - " 11, 46: PRINT "ORP2C 13, 13: PRINT "Time of Last Update - " 13, 46: PRINT "Point Number - " 14, 13: PRINT "Acetate Addition Status Report - " 16, 13: PRINT "Note: Hit <Y> - Yes - if desire to see ORP plots" 17, 23: PRINT "<N> - No - when finished viewing plots" 18, 23: PRINT "<ESC> - Escape - to exit program" 19, 13: PRINT "Note: Time is updated every two minutes" 20, 19: PRINT "There are 60 scans (at 2 sec intervals) in 2 min" 21, 19: PRINT "There are 180 pts ( 2 min intervals) in a 6 hr cycle" 23, 30: PRINT "Scan number - "  i '$INCLUDE: 'GLOBAL.BI' 'Note: This is for ALL Programs '  UPDATE.BAS  THIS SUBROUTINE UPDATES THE SCREEN LAYOUT EVERY TWO MINUTES  I  _ —  _  ————.m^^._-====a=========m;  SUB UPDATE (Pt) STATIC LOCATE 7, 25: PRINT USING "+###.#"; ORPla(Pt) LOCATE 7, 57: PRINT USING "+###.#"; ORP2a(Pt) LOCATE 9, 25: PRINT USING "+###.#"; ORPlb(Pt) LOCATE 9, 57: PRINT USING "+###.#"; ORP2b(Pt) LOCATE 11, 25: PRINT USING "+###.#"; ORPlc(Pt) LOCATE 11, 57: PRINT USING "+###.#"; ORP2c(Pt) LOCATE 13, 35: PRINT TIME$ LOCATE 13, 62: PRINT USING "###"; Pt END SUB  • '$INCLUDE: * GLOBAL.BI' 'Note: This is for ALL Programs  TYPROBE.BAS  A FUNCTION WHICH IDENTIFIES THE SELECTED PROBE FUNCTION TYPROBE$ (Probe$) STATIC SELECT CASE Probe$ CASE "A" TYPROBE$ CASE »B" TYPROBE$ CASE n^n TYPROBE$ CASE IIQlt TYPROBES CASE "E" TYPROBE$ CASE u p ii TYPROBES CASE " G" TYPROBE$ CASE "H" TYPROBES CASE ELSE TYPROBES  a>  "ORPla"  = "ORPlb" = "ORPlc" = "ORP2a" = "ORP2b" ss  "ORP2C"  Si  "D.O.#l"  = "D.O.#2" = "No such probe"  END SELECT END FUNCTION  JINKEY FUNCTION 'This function tests for a key stroke in the keyboard buffer. FUNCTION jinkey% a$ = INKEYS IF a$ = "" THEN jinkey% = 0: EXIT FUNCTION 'Nothing there - exit IF LEN(a$) = 2 THEN 'Something there - obtain jinkey% = ASC(MID$(a$, 2, 1)) + &H100 'ASCII Code ELSE jinkey% = ASC(a$) END IF END FUNCTION  > BREAKPT.BAS '$INCLUDE: 'GLOBAL.BI' 'Note: This is for AASD#1 and AASD#2 Programs '  THIS SUBROUTINE FINDS THE NITRATE BREAKPOINT (KNEE)  SUB BREAKPT (Commnum, Pt, Nitrate, Renew) STATIC IF Renew = FALSE THEN Avoid = Avoid + 1  'Drop through Subroutine instead of resetting 'Increment ORP stability counter after feeding  IF Avoid > MAXAVOID THEN  'ORP should have stabilized by now  Count = Count + 1  'Increment internal Ring counter  IF Pt <= RINGSIZE THEN LowBound = Pt + 180 - RINGSIZE ELSE LowBound = Pt - RINGSIZE END IF IF Count <= RINGSIZE THEN  'In Subsequent cycles the Ring 'Buffer may straddle two cycles  SumA! «• SumA! + DORP2a(Pt) SumB! = SumB! + DORP2b(Pt) SumC! = SumC! + DORP2c(Pt)  'Ring is not full 'Sum the First Difference values  IF Count = RINGSIZE THEN  'The Ring is full  Ringnum = 1  'Assign Ring Number  RING2a(Ringnum) = SumA! / RINGSIZE RING2b(Ringnum) = SumB! / RINGSIZE RING2c(Ringnum) = SumC! / RINGSIZE  'Calculate the average 'Slope for the Ring  FirstRingA! = RING2a(Ringnum) FirstRingB! = RING2b(Ringnum) FirstRingC! = RING2c(Ringnum)  'This becomes the first 'Ring of the Ring Buffer  END IF ELSEIF Count > RINGSIZE AND Search = FALSE THEN 'Start filling next ring Ringnum = Ringnum + 1  'Increment Ring Number  SumA! = SumA! - DORP2a(LowBound) + DORP2a(Pt) 'Kick out First SumB! = SumB! - DORP2b(LowBound) + DORP2b(Pt) 'value and add in SumC! = SumC! - DORP2C(LowBound) + DORP2c(Pt) 'latest First Diff RING2a(Ringnum) = SumA! / RINGSIZE RING2b(Ringnum) = SumB! / RINGSIZE RING2C(Ringnum) = SumC! / RINGSIZE IF Ringnum = NUMRINGS THEN  'Calculate avg 'First Diff of 'this new Ring 'The Ring Buffer is Full  Search = TRUE  'Enable Search for Breakpoint  LastRingA! = RING2a(Ringnum) LastRingB! = RING2b(Ringnum) LastRingC! = RING2c(Ringnum)  'The most recently calculated 'Ring becomes the last Ring 'in the Buffer  DiffRingA! = LastRingA! - FirstRingA! DiffRingB! = LastRingB! - FirstRingB! DiffRingC! = LastRingC! - FirstRingC! END IF  'Take the Diff between 'the first and last 'Rings in the Buffer  END IF IF Search = TRUE THEN  'Search for the Nitrate Breakpoint  IF KneeA = FALSE THEN 'Knee 0RP2a not detected as of yet IF DiffRingA! <= DELTA2A! THEN 'Arbitrary Constraint KneeA = TRUE KneeCount = KneeCount + 1 PRINT #Commnum, "Nitrate KneeA detected on "; DATES; PRINT Icommnum, " at approximately "; TIME$ END IF END IF IF KneeB = FALSE THEN 'Knee 0RP2b not detected as of yet IF DiffRingB! <= DELTA2B! THEN KneeB = TRUE KneeCount = KneeCount + 1 PRINT #Commnum, "Nitrate KneeB detected on "; DATES; PRINT #Commnum, " at approximately "; TIME$ END IF END IF IF KneeC = FALSE THEN 'Knee 0RP2C not detected as of yet IF DiffRingC! <= DELTA2CJ THEN KneeC = TRUE KneeCount = KneeCount + 1 PRINT #Commnum, "Nitrate KneeC detected on '•; DATES; PRINT #Commnum, " at approximately "; TIMES END IF END IF IF KneeCount >= 2 THEN Nitrate = TRUE '>= Two knees detected END IF  'Closes If Search = TRUE Decision Block  ELSEIF Count > RINGSIZE AND Search = TRUE THEN Ringnum = Ringnum + l  'Ring Buffer moves along 'Increment Ring Number  SumA! = SumAi - DORP2a(LowBound) + DORP2a(Pt) 'Kick out First SumB! = SumB! - D0RP2b(LowBound) + DORP2b(Pt) 'value and add in SumC! = SumC! - D0RP2c(LowBound) + D0RP2c(Pt) 'latest First Diff RING2a(Ringnum) = SumAi / RINGSIZE RING2b(Ringnum) = SumB! / RINGSIZE RING2c(Ringnum) => SumC! / RINGSIZE  'Calculate the 'average slope 'for the Ring  FirstRingA! = RING2a(Ringnum - RINGSIZE + 1) FirstRingB! = RING2b(Ringnum - RINGSIZE + 1) FirstRingC! = RING2C(Ringnum - RINGSIZE + 1)  'Assign the 'First Ring of 'the new Buffer  LastRingA! = RING2a(Ringnum) LastRingB! = RING2b(Ringnum) LastRingC! = RING2c(Ringnum)  'The latest Ring 'becomes the last 'Ring of Buffer  DiffRingA! = LastRingA! - FirstRingA! DiffRingB! = LastRingB! - FirstRingB! DiffRingC! = LastRingC! - FirstRingC!  'Calculate Diff 'between first 'and last Rings  IF KneeA = FALSE THEN 'Knee 0RP2a not detected as of yet IF DiffRingA! <= DELTA2A! THEN KneeA = TRUE KneeCount = KneeCount + 1 PRINT #Commnum, "Nitrate KneeA detected on "; DATES; PRINT #Commnum, " at approximately "; TIMES END IF END IF  IF KneeB = FALSE THEN 'Knee 0RP2b not detected as of yet IF DiffRingB! <= DELTA2B! THEN KneeB = TRUE KneeCount = KneeCount + 1 PRINT #Commnum, "Nitrate KneeB detected on "; DATE$; PRINT fCommnum, " at approximately "; TIME$ END IF END IF IF KneeC = FALSE THEN 'Knee ORP2c not detected as of yet IF DiffRingC! <= DELTA2C! THEN KneeC = TRUE KneeCount = KneeCount + 1 PRINT fCommnum, "Nitrate KneeC detected on "; DATE$; PRINT #Commnum, " at approximately "; TIME$ END IF END IF IF KneeCount >= 2 THEN Nitrate = TRUE '>= Two knees detected END IF END IF  'Closes If Count <= Ringsize Decision Block 'Closes If Avoid > MaxAvoid Decision Block  ELSE KneeA = FALSE KneeB => FALSE KneeC = FALSE Avoid = 0 Count = 0 SumA! = 0 SumB! = 0 SumC! = 0 Search = FALSE KneeCount = 0 END IF END SUB  'Clear and Reset all the Variables for next Cycle  'Closes Renew = FALSE Decision Block  / BREAKPT.BAS '$INCLUDE: 'GLOBAL.BI' 'Note: This is for the BIO-P Program '  THIS SUBROUTINE FINDS THE NITRATE BREAKPOINT (KNEE)  SUB BREAKPT (Commnum, Pt, Nitrate, Renew) STATIC IF Renew = FALSE THEN Avoid = Avoid + 1  'Drop through Subroutine instead of resetting 'Increment ORP stability counter after feeding  IF Avoid > HAXAVOID THEN  'ORP should have stabilized by now  Count = Count + l  'Increment internal Ring counter  LowBound = Pt - RINGSIZE  'Calculate lower bound of the Ring  IF Count <= RINGSIZE THEN  'Ring is not full  SumA! - SumA! + DORP2a(Pt) SumB! - SumB! + DORP2b(Pt) SumC! = SumC! + DORP2c(Pt)  'Sum the First Difference values  'The Ring is full  IF Count = RINGSIZE THEN Ringnum = 1  'Assign Ring Number  RING2a(Ringnum) = SumA! / RINGSIZE RING2b(Ringnum) = SumB! / RINGSIZE RING2C(Ringnum) = SumC! / RINGSIZE  'Calculate the average 'Slope for the Ring  FirstRingA! = RING2a(Ringnum) FirstRingB! = RING2b(Ringnum) FirstRingC! = RING2C(Ringnum)  'This becomes the first 'Ring of the Ring Buffer  END IF ELSEIF Count > RINGSIZE AND Search = FALSE THEN 'Start filling next ring Ringnum = Ringnum + 1  'Increment Ring Number  SumA! = SumA! - D0RP2a(LowBound) + DORP2a(Pt) 'Kick out First SumB! = SumB! - DORP2b(LowBound) + DORP2b(Pt) 'value and. add in SumC! = SumC! - DORP2C(LowBound) + DORP2c(Pt) 'latest First Diff RING2a(Ringnum) = SumA! / RINGSIZE RING2b(Ringnum) = SumB! / RINGSIZE RING2c(Ringnum) = SumC! / RINGSIZE IF Ringnum = NUMRINGS THEN  'Calculate avg 'First Diff of 'this new Ring 'The Ring Buffer is Full  Search = TRUE  'Enable Search for Breakpoint  LastRingA! = RING2a(Ringnum) LastRingB! = RING2b(Ringnum) LastRingC! = RING2c(Ringnum)  'The most recently calculated 'Ring becomes the last Ring 'in the Buffer  DiffRingA! = LastRingA! - FirstRingA! DiffRingB! = LastRingB! - FirstRingB! DiffRingC! = LastRingC! - FirstRingC! END IF  'Take the Diff between 'the first and last 'Rings in the Buffer  256  IF Search = TRUE THEN  'Search for the Nitrate Breakpoint  IF KneeA = FALSE THEN 'Knee 0RP2a not detected as of yet IF DiffRingA! <= DELTA2A! THEN 'Arbitrary Constraint KneeA = TRUE KneeCount = KneeCount + 1 PRINT #Commnum, "Nitrate KneeA detected on "; DATES; PRINT ICommnum, " at approximately "; TIMES END IF END IF IF KneeB = FALSE THEN 'Knee 0RP2b not detected as of yet IF DiffRingB! <= DELTA2B! THEN KneeB = TRUE KneeCount = KneeCount + 1 PRINT ICommnum, "Nitrate KneeB detected on "; DATES; PRINT #Commnum, " at approximately "; TIMES END IF END IF IF KneeC = FALSE THEN 'Knee 0RP2c not detected as of yet IF DiffRingC! <= DELTA2C! THEN KneeC = TRUE KneeCount = KneeCount + l PRINT #Commnum, "Nitrate KneeC detected on "; DATES; PRINT #Commnum, " at approximately "; TIMES END IF END IF IF KneeCount >= 2 THEN Nitrate = TRUE '>= Two knees detected END IF  'Closes If Search = TRUE Decision Block  ELSEIF Count > RINGSIZE AND Search = TRUE THEN Ringnum = Ringnum + 1  'Ring Buffer moves along 'Increment Ring Number  SumAi = SumA! - DORP2a(LowBound) + DORP2a(Pt) 'Kick out First SumB! = SuraB! - DORP2b(LowBound) + D0RP2b(Pt) 'value and add in SumC! = SumC! - DORP2c(LowBound) + DORP2c(Pt) 'latest First Diff RING2a(Ringnum) = SumA! / RINGSIZE RING2b(Ringnum) = SumB! / RINGSIZE RING2C(Ringnum) = SumC! / RINGSIZE  'Calculate the 'average slope 'for the Ring  FirstRingA! = RING2a(Ringnum - RINGSIZE + 1) FirstRingB! = RING2b(Ringnum - RINGSIZE + 1) FirstRingC! = RING2c(Ringnum - RINGSIZE + 1)  'Assign the 'First Ring of 'the new Buffer  LastRingA! = RING2a(Ringnum) LastRingB! = RING2b(Ringnum) LastRingC! = RING2C(Ringnum)  'The latest Ring 'becomes the last 'Ring of Buffer  DiffRingA! DiffRingB! DiffRingC!  'Calculate Diff 'between first 'and last Rings  LastRingA! - FirstRingA! LastRingB! - FirstRingB! LastRingC! - FirstRingC!  IF KneeA = FALSE THEN 'Knee 0RP2a not detected as of yet IF DiffRingA! <= DELTA2A! THEN KneeA = TRUE KneeCount = KneeCount + 1 PRINT #Commnum, "Nitrate KneeA detected on "; DATES; PRINT #Commnum, " at approximately "; TIMES END IF END IF  IF KneeB = FALSE THEN 'Knee 0RP2b not detected as of yet IF DiffRingB! <= DELTA2B! THEN KneeB = TRUE KneeCount = KneeCount + 1 PRINT #Commnum, "Nitrate KneeB detected on "; DATES; PRINT #Commnum, " at approximately "; TIMES END IF END IF IF KneeC = FALSE THEN 'Knee 0RP2c not detected as of yet IF DiffRingC! <= DELTA2C! THEN KneeC =» TRUE KneeCount = KneeCount + 1 PRINT fCommnum, "Nitrate KneeC detected on "; DATE$; PRINT fCommnum, " at approximately "; TIMES END IF END IF IF KneeCount >= 2 THEN Nitrate = TRUE '>= Two knees detected END IF  END IF  'Closes If Count <= Ringsize Decision Block 'Closes If Avoid > MaxAvoid Decision Block  ELSE KneeA = FALSE KneeB = FALSE KneeC = FALSE Avoid = 0 Count = 0 SumA! =» 0 SumB! = 0 SumC! = 0 Search = FALSE KneeCount = 0 END IF END SUB  'Clear and Reset all the Variables for next Cycle  'Closes Renew = FALSE Decision Block  APPENDIX E CHEMICAL DATA - AASD#1 Chemical Parameter Suspended Solids (TSS and VSS) Feed (AASD#1 and AASD*2) Fixed-Time Reactor (AASD#1 and AASD#2) Real-Time Reactor (AASD#1 and AASD*2) Nitrogen (TKN, NOx and NH3) Feed (AASD#1 and AASD#2) Fixed-Time Reactor (AASD#1 and AASD*2) Real-Time Reactor (AASD#1 and AASD#2) Phosphorus (TP and Ortho-P) Feed (AASD*1 and AASD#2) Fixed-Time Reactor (AASD*1 and AASD#2) Real-Time Reactor (AASD*1 and AASD#2) Dissolved Oxygen Fixed-Time Reactor (AASD*1) Real-Time Reactor (AASD#1) Fixed-Time Reactor (AASD*2) Real-Time Reactor (AASD*2) pH, Temperature and Alkalinity Feed (AASD#1 and AASD#2) Fixed-Time Reactor (AASD*1 and AASD#2) Real-Time Reactor (AASD#1 and AASD*2) Chemical Oxygen Demand Feed (AASD#1 and AASD*2) Fixed-Time Reactor (AASD#1 and AASD#2) Real-Time Reactor (AASD*1 and AASD*2)  Page 259 260 2 61 262 263 264 265 2 65 265 266 266 2 67 267 268 2 68 268 269 269 2 69  <J\  o Irt  <  CO  (-N  •Q00NN«0N«rJNOvt-0C0-0NOOrvJfNJ1OC0f\J'O-0>0Ot0vfO0)C0vtOOOe0O^t0C0 *OT-'Or\irorotnC>^^co^cXf\ieorviin^ooor\|r-h-fo^^MS-0'vth-in^<><>r\Jin*or^-r\i concN^«JOO-*ino^cOM(Mt-r-^^(\jor\ji-^oinoa)ioCMn«-ino»-oo*o>0(MO NM»J^sf^,OCoK^^N«1jin'jN'04in>OiA»oiriin'^'fli/i>l>o»niri^io>Oininin«*-J  < » / -> J X ^ £  x  ooeoooooeocooooocoeoooeocooocooo" o o o o o o o o o o o o o o o o o o  o o o o o o o o o o o o o o o o o o o o o o o o o o o o o o o o o o o o o o o o  O^IOOCJ'OOOOOJ'JOON^O'OW M M ' - M N ' * o g o S M M N O O O i n M O ^ ^0>jO>'-(>>j00»nins»vjOvjsjif>O''O"-  a  IO(\J(\JO<0(MrviONNC000 0 4 io^KtinroeorJ^O^*coc>^>h>.h> N- eg •— o* ~ T tn tn  oo>*•^/^mu^•o^-ot>'•0^»•0•ln•  I  t OO'O^'OIMOCOstOONNstvOONtOtO t eo-oof\JO^ON»,o>»'OOjn-1fw>NM'» •o<o>0'©*Om'Oinmtn*o>Otnu"tin^»»4'*0  i *o r\j o » K >0 O ' M Kl •I in ro »-  O N O N «- >* ** N>Ou> o n o *o >* «-  ft) ft)  r  QOArara&raQra4TOra&raraQ^B^u4(9<3^iQra&n3raffl^n<9reranrai?iT}i  ? »o•- ro o  c * su o X  t/>  t_  •—  <  i  rtJBfflrS3u.S<9roroQroCLrororo(63  X  4) U 3C 3 (0 O U  O*oeoo>o*-0"eoo*-o«--  (OOi-Ot-C^N'-OOOOO  1  •O«-OO00O0*OO»-«~r-r-  o.oeooT-r\jooooo*-T-o«-o«—  o  .- c — x ra C 10 *l • XXXV  »-NMN»in>ONeoOkO'  • "O w )  SS888RRRSRRRRfcl5RI2RS8RRSRSRRRRR oooooooooooooooooooooooooooooo' *0 5 e O N 0 8 0 W [ M ' | ' * » O O s } * Q * Q f i O ( M ' 0 ^ * J ' O N ^ ' 0 « W ( M O t O v O N M ^ ^ N ^ M N T - N O i n O t - n S ^ i n s j N N ^ ^ f s . p ^ M ' - n n ^'0**'*'st»ONini/iS'Oin«nininv*«ON(>DininiOir>'Oin,OineoK0'0 5'OCO>tN'*OOCO a pON re^O°N^>^* t 5O O N* 0i n0!Jog«0 cOinNN-OM'OOOininro  o i n f f l O f O O « * Wf N N n i r t i cn or i, n o N  *- 00 *- T- O r- f\J N N in >Oinoo o  R  •*- w 5 Q § E o -g ° V ••" C  i  >o(>N.r*>o^ONO^ooot>r-r nK-NN.S.r«-'OoO'Ooo  o o o o o o o o o o o o o o o o o o o o o o o o o o o o • • ^«00NOWslNje000C0Nst^^00rj(0C0C0CM'0NO^N*Ov0 > i MinrjN*rj^co^^r4rnrnfnfNJKi'>oo>N.o*-ininrg<>o»r-.sjf\j • • <0(>inininNS<00<0,0<oK'<OinNin4'ON^st^in>f'ONnn  t  ON**«J00^M0000^NNO«|O,00J^«*vtNO<t'Or\J'0,Oe0  i » t i  oootnoo>Qinococoooo<4p<chS->ot-(ONir<{>Nt>0'<tp>S>cg oo<->o«,2oohN(OcoDOO>soi>N>osooinins<dsin<o  i  S§i4aalSQ.aSaaSSSSSa.iiSS§SQ.Q.SaS  ! ! S a S a a a s S aS ! !  __  i t  __  __  > ro o o o o i ooooeooorsjrvfMeorsJNaor>jf\jeoeoeocoeorMO>eococaeocorNJr\jOtoeo  i«*  t-Nrost  in>oK»t>Oi-rji  invOMoo>o»-Ni  ** "•Nino £.. «~ r- Kl o  o *- eg «o in %T oo rsj in co «- O nNin'-  SSaaSSSSSsSSSSSS  i t • or\joor\i(\jnjeo(>->or<-  « B N N C > e o t - o o e o o S K o o { O S  lr-NK|'*in,ON  c — • m C T3  260  AAS0#1  DAY  FIXED TIME REACTOR SUSPENDED SOLID CONCENTRATIONS DATE  1 Jun/19/90 2 20 3 21 4 22 5 23 6 24 7 25 8 26 9 27 10 28 11 29 12 30 13  Jul/01/90  14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30  02 03 04 05 06 07 08 09 10 11 12 13 14 15 16 17 18  31  Jul/19/90  32 33 34 35 36 37 38 39 40 41 42 43  20 21 22 23 24 25 26 27 28 29 30 31  44  Aug/01/90  45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 Maximum Mean Minimum Std. Dev.  02 03 04 OS 06 07 08 09 10 11 12 13 14 15 16 17  Sailing Time (Hr:Min)  MLSS (mg/L)  MLVSS (mg/L)  SOLIDS RATIO  12:00 pm 10:35 am 10:15 am 1:30 pm 6:00 pm 5:30 pm 1:20 pm 11:10 am 1:50 pm 2:00 pm 2:15 pm 3:00 pm 6:15 pm 3:50 pm 10:00 am 9:10 am 10:15 am 11:50 am 3:50 pm 3:40 pm 2:20 pm 10:40 am 3:10 pm 9:35 am 1:15 pm 2:40 pm 3:05 pm 10:15 am 12:35 pm 3:15 pm 1:15 pm 3:15 pm 12:45 pm 4:00 pm 12:15 pm 1:10 pm 5:15 pm 3:55 pm 10:30 am 1:15 pm 7:45 pm 11:25 pm 1:40 pm 12:35 pm 4:50 pm 4:00 pm 1:30 pm 10:50 pm 1:20 pm 1:30 pm 1:30 pm 1:45 pm 1:25 pm 1:55 pm 2:15 pm 8:15 am 1:30 pm 2:20 pm 9:30 am 8:30 am  5716 5598 5790 5524 5436 5336 5376 5924 5866 5712 5938 5826 6100 5854 5826 5852 5878 5970 6278 6724 6980 6818 6774 6752 6666 6702 6568 6530 6604 6960 6980 6800 6856 6956 7416 7172 7006 6954 7028 7370 7472 7322 7084 7140 6792 7052 7252 7088 7456 7216 6904 6826 7082 7278 6960 6756 6628 6516 6646 6270  4496 4412 4552 4358 4252 4154 4216 4728 4632 4454 4606 4510 4704 4506 4490 4508 4522 4602 4864 5204 5416 5298 5272 5236 5192 5202 5088 5046 5084 5400 5388 5240 5284 5370 5718 5428 5406 5380 5424 5702 5812 5692 5468 5498 5228 5452 5566 5418 5732 5538 5274 5266 5456 5584 5330 5152 5058 4994 5090 4818  0.79 0.79 0.79 0.79 0.78 0.78 0.78 0.80 0.79 0.78 0.78 0.77 0.77 0.77 0.77 0.77 0.77 0.77 0.77 0.77 0.76 0.78 0.78 0.78 0.78 0.78 0.77 0.77 0.77 0.78 0.77 0.77 0.77 0.77 0.77 0.76 0.77 0.77 0.77 0.77 0.78 0.77 0.77 0.77 0.77 0.77 0.77 0.76 0.77 0.77 0.76 0.77 0.77 0.77 0.77 0.76 0.76 0.77 0.77 0.77  7472 6569 5336  5812 5080 4154  600  442  AASD#2 FIXED TIME REACTOR SUSPENDED SOLID CONC:ENTRATIONS  DAY  1  DATE  Oct/02/90  2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31  03 04 05 06 07 08 09 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 Nov/01/90  32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 Maximum Mean Minimum Std. Dev.  02 03 04 05 06 07 08 09 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30  Sampling Time Hr:Min 2:00 pm 10:20 am 2:05 pm 2:00 pm 2:40 pm 2:15 pm 12:55 pm 11:25 am 1:30 pm 2:40 pm 3:00 pm 4:25 pm 2:30 pm 11:45 am 3:05 pm 12:55 pm 1:05 pm 3:20 pm 11:05 am 3:20 pm 2:20 pm 1:30 pm 3:30 pm 1:35 pm 2:55 pm 1:20 pm 6:10 pm 1:10 pm 2:05 pm 1:10 pm 4:45 pm 7:40 pm 4:40 pm 5:50 pm 2:50 pm 1:05 pm 1:55 pm 2:10 pm 12:45 pm 1:10 pm 10:30 am 1:15 pm 4:50 pm 2:00 pm 1:20 pm 6:55 pm 1:15 pm 4:05 pm 1:20 pm 3:15 pm 1:30 pm 2:05 pm 9:30 pm 3:45 pm 3:30 pm 1:45 pm 12:25 pm 12:10 pm 12:15 pm 11:05 am  MLSS (mg/L)  MLVSS (mg/L)  SOLIDS RATIO  6332 6678 6772 6468 6554 6340 6324 6242 6266 6374 6654 6382 6470 6502 6366 6394 6148 6046 6248 6196 6168 6194 6254 6154 6146 6212 5988 6066 6064 6034 6006 6104 5972 5916 5856 5970 5916 6078 6038 5890 5932 5946 5830 6026 5984 5814 5842 5650 5738 5760 5760 5588 5288 5330 5368 5196 5208 5248 5036 4904  5032 5316 5350 5148 5204 5032 4966 4912 4930 5060 5268 5096 5162 5176 5092 5132 4934 4830 4978 4952 4956 4982 5018 4954 4906 4988 4784 4852 4850 4846 4802 4910 4772 4722 4676 4802 4760 4864 4850 4716 4762 4764 4680 4834 4796 4664 4682 4562 4581 4624 4612 4492 4238 4266 4284 4122 4146 4208 4074 4042  0.79 0.80 0.80 0.80 0.79 0.79 0.79 0.79 0.79 0.79 0.79 0.80 0.80 0.80 0.80 0.80 0.80 0.80 0.80 0.80 0.80 0.30 0.80 0.81 0.80 0.80 0.30 0.80 0.80 0.80 0.80 0.30 0.80 0.80 0.80 0.80 0.30 0.80 0.80 0.30 0.80 0.80 0.80 0.80 0.80 0.80 0.80 0.81 0.80 0.80 0.80 0.80 0.80 0.80 0.80 0.79 0.80 0.80 0.81 0.82  6772 6039 4904  5350 4826 4122  362  281  p s 0 O 0 p - O 0 p » ^ 0 0 O 0 0 O O O O O 0 0 r - T - 0 0 O 0 O O O 0 O O 0 O O O 0 0 0 0 O 0 0 r \ ) r - O 0 O O O 0 0 0 O 0 O 0 ' - r \ J Ncoa}o)ScoooSN-(oeooo<oootOflOcoco(OcO(Oeooo(Ocaeoa)a)cncoeocaa}oo(ooooocQeocoeo(0(Ooooocoa}ion O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O  N N N C 0 ' * N O ^ ^ N O a O v » r y v 0 O C 0 ^ O N ^ ^ N ' 0 N ^ i n O O O C 0 ^ N f ' 0 » N < 0 C 0 N C 0 ^ N t ' 0 e 0 N O N N s * O C 0 C 0 ' *0 0 '•-*J *^* O o -4- co o - ' - - - ~ i n r\j r\j — ~ _. - j r - ^ K » ^ ^ i > o o o ' 6 ' 0 0 0 ' N N ' 0 ' o K * o S N K N ' 0 ' 0 > o N ' 0 » n i n < M ^ i n i n ^ n n v J M M O r - r - o o o o o ro -t m  ~ . - ~ ~ i ~ . _ ~ m tn in m  J oooo mo - ^r^f vf\jj r M^N—ONeo0^r vr^j 0fJMNn c^ g4 N> *O ^4 M^ NO N0 0N On ON ^» N- cj or Jo ^> ^c so t( N0 <0 l» Ne ^o 0( >0 rOavot -Oo^>«SNoO3 ec 0o Oo O5 NN e^ 0^ *^ »- O* i «n- i *n* »Novi Of lOs 't *sNt fi nC >0 *f v\ Jj ON '0 -0' C- o0 oN (' >O0( ' \ Nl  *0 *0 *0 "O •© *0 * 0 *0 ""O  rg ^ ^ in  oo sf r*. -*  >t Nin *o o m  K»  O r - N O  rg m ^  S  S ino >*o -sj  &§&&&&£§&S.&S.&!l&&a&!5&&&g.S.&&£&&&&&&5.&&&5.S.&§S.S.S.g.g.&&&&&&&8.&&&&S.§ N o r \ ) N N N » - » - t - r \ i M N r N r - n r - r - n » - M r s j T - K t ' - K i T - - o p - r o » - ^ N f o i ^ N r - r - ( \ j t - f - 0 ' - i n N « - N » - r o * - r O ' - N ( > i  i «- r\j rvj  C\J  o  > r - { \ J M ^ l f l ' O S e O O O « - N M ^ i n » O N e O O ' 0 * - » - N M > n n ' O N C O « > O i - ( M l i - f f f - T - i - T - ( M N N ( V N N N N ( M N M M O O O O O O O O O r r » - >  «-r\jM»*in«or^tooo«-fMi  o  o  o  o  o  o  o  o  o  o  o  o  1 ^ i/>>0 S C O  o  o  o  o  o  o  o  o  o  o  o  o  o  o  o  o  o  o  o  o  o  o  o  o  o  a  o  o  o  o  o  o  o  o  o  o  o  o  o  o  o  o  o  o  o  o  o o  o  X <!J C TO <o at — *-<  o  O ( O ( 0 ^ O 0 0 N < 0 O N O ( M O N ^ ( 0 O < O ( 0 O , O•ON «M e Q CO Q O ** - ^ f > j r * - 0 ( M O S - M O - » * r - - ^ T - ( > O i n O r M O O O " CM " " *CO CO « N- CO - d , . . .r-* - o _1 - O C M i n- l'_M_- ^ . _r O K I ^ f M M c\j _ K I i n «- o O .__. -_ -. •_ , - m  SS2  P J i n >0 CM * - o * - ro r - o • - •** m m * *  - * CM *o fM o ^ o o o e o ( g p < o < o o o o < 4 ( o « i ) > t s t ( O No o^ <o «oo^oo' ^4 t0 os et (o ot eo oo (>oooeoocooNo ON co oc oo oe «a o v i> }t ^^ ^e eo a%^ t<^oy«) r j N O N c o > o 4 < < { < o ^ N « o ^ c o » n O T - « O s * i n ^ N N s | v t ^ M C O O f O f v i S N o w N o e o 4 c o ^ ( > » - i n w ' O O N i n ' O S s m g i l n * o ^ K » f ^ J f o ^ . ^ w | n ^ ^ Q Q '*Vo *^ o c*V o y'** ) ' "V 0 «•"" - • «2 o «> t o ^ K i n g - M i n » o N ( > ^ N r - o g K < > ^ n f > l o 3 ^ c 9 p p ^ N e D ( > a ^ [ N i c o ^ NS . «" o I-- o •o wo m < n i n i n i n i n i n i A i n m i n > o < O in r •Ominin >o " « N ^ « > 0 ^ y ) « > 0 ^ 4 N < l ^ « N N v ^ ^ S S > h * ' o S , 0 N S > 0 S ' 4 t 0 ' 0 N r * x ) , 0 , 0  O «~ CO «s j in N ^)  lTKOO'OO ° "* St 'N»O sr CK N i n j *  > * n ^ n ' - » - n i f i i f t n * .* y j >o  l O ^ ^ w o o o e O ' O i  j ^ t o i o N ' - ^ M N ' - N o a e o *  3  S  o o i n o o i n o i n o i n i n o o i n o i n i n i n i n o i n i n o o o o i n o i n i n o i n o i n i n o o i n i n i n o o o m i n i n i n i n o i n o t n i n o i n o o i n o o t - i n N o o - * M v » i o o o g ^ a r - i n N ^ N O N r \ i « - w i n N K i n r - > t o N O ^ ^ i n o ^ o ^ i n N K i o o » - ' i o o n * " O i n n ' N i M M ' - N r > J  r\ioonjKu^»-or\i«--*r\i*o^oeoo«~Mr>jrsioinO'f>jf>Jrjfvc>jr\jf\jro^ror-r^  o  p  «- CM K» *tf i n «0 I  o  o  i ^ i n > O N e o o o » - N n > » i n ' O K e o o < 0 ' - N i  i>f m < O N ( 0  0>0  X CO C "O ffl « ' r - M X X X CO  0 0 0 © 0 0 0 0 0 0 0 0 0 « - 0 0 0 0 0 0 © 0 0 0 « ~ 0 i  o o o o o o o o o o * - o o o o i n i n * *  o o o o o o o o o o o o o  rMfomf\jo»r»'0^» ^oeor-rviro^rofvJMfM o o o o r o c 3 > * O K > » - o o r o » - o o o o  o * - o r \ J o m i \ i o » - o o « ~ * - o < M - * r \ i o r o o o o » - f \ i o * o o o » - o o o o o o o o o ' 0 » -  v» O v j OJ  _. •tndvt»-r\iinoinoinrMrjnMN(vJinin»-1-(Ooir» i-«*M,0»n*t**i/i^i/itn^stiniA'j,Oin**N*s*inir«in>jM'*  R i i  m»-'Oin'On>tMnKi'OSN«oin(Nj^«nrororOfOin»oeoininstMM,o«-'OiOinMr  « - r - O N  cooo  m u " i U " » m o O i r t o m o o » / > o o o i n t / > t n v » r - Q O ' - O O M ' - i n O - * M M O ' - f V J ( M  Nsr m a N < o n i n i i N j - i M ^ f M ^ t - r y * - * -  K «  N O f ^ O O O O O O O O O O O O O O ( \ l m S ( D « - 0 « ( V j K ' 0 « ) N C 0  o» «o co ru eo ro • r \ i N O r o N * o o o o o o « - r \ i r u * - o c M O o o o o o o o o o o o  v» *o »o I !tC t r » m m * - f \ i h - * ^ » • N N O i n m o O K ) ^ ' l«rj*Ji »-*-MOOO»-ror»joo'0*-omN.i l O O O O O O O O O O O O O  NNKiminKiCM/itoinrsjfNjfOuK ooo«-oomor-f\ioooooomc\i«j,or«JH>rj»/*r>oh-NO  Kfc;  C T>  ro NO *- *m ^t fO »-  m o i n i r t i n o o o o u i o o i n o o o i r t m o u t o o m m m o o o i n o innon-*(OroMOrjo^NnininOfvjooK>0'-Minnin'-inn K I N C N i m ^ i A » - N N » - ' 0 0 ' * S " r - O N K ) > * i n i / 1 f V l N r - > * N I \ J n r y " 0  ii-rsiro>tin^}^coo<o^rsiro^in^N-oo(>o^Nro^in^^ooo>Or-rJK>^in^^oo(>o^^rvJrosru^<>^ I N N N N N r \ I N W ( \ I M O O O O O O O O O ' - » - i - r - i - r - t - » * ^ r « N O J N N f g N N N ( \ l ( \ J M f O O O O O O O O O O r - t - ^ r - r - ^ f - r  i-^irtNON-eooo'-iMi  K 10 C D  (D 4» •— *-*  i - ^ r - r - ^ o ^ r J ^ e o N S « ( y ^ O « o > t O N i n i - c o o o ^ N M ^ n f v J > * ^ S N » - 0 » i n e o » - ^ N y ) * 0 ^ $ i n S ^ C h N ^ i n O t - 5 N i n M 0  0  0  0  0  0  0  0  0  0  0  0  0  0  0  0  0  0  0  0  0  0  0  0  0  0  0  0  0  0  0  0  0  0  0  0  0  0  0  0  0  0  0  0  0  0  0  0  0  0  0  0  0  0  0  0  0  0  >  »  0  o  n i n M O O ' O c o ^ ^ N T - o ^ o * - i f t c o « ^ « M N t O N f N t ' - c > o o M ^ N S ' 0 ^ t f i 4 0 ( > N ^ u i m i n o ^ i n » o o ^ ( > w n ^ - 4 S i ' i n * o o c o ^ r j ^ r s J O ^ ^ ^ o ^ e o ^ ^ ^ ^ t ^ c o ^ r o r g r o o ^ ^ r O ' - o i n ^ ^ r v j ^ ^ ^ n ^ N O O o e o ^ c o ^ ^ r * 0 » - » - « - O 0 r - O 0 t - O r - O * - O 0 ' - ' - ' - 0 O r O « - 0 t - O 0 N ' - O r - t - O > t r f - t - ( \ I O r M f ( M ' - r * ' - N O » - O N « - ' - r - O ' - N 0 0  i n i n i n i n i n >i •  S  H-  C C C C *•- H- **- C H - *•- C **- * •  ( V O ( M » - f y O « - f - N [ M ^ r - ^ ^ N N O 0 O N f \ J N » - ( M N i - 0 0 O 0 '  K>or\jfvj«— o  o  o  ^* * - o  o  CO «- fM CO CM - * i n fo  • > t > t s t > * - * ^ ^ ^ > t N * ^ ^ N * s t > f s t s t N j ^ ^ > t > * N t > f ^ s t » * N * > f ^ ^ ^ > * f o ^ > » s t * * n K ) M r o M n r o M i  r - ^ r - r - N r - N O N O O f M N M O O O N "  o  * - *— • - r*i  C C C **- C C H - C *+- C H - <•- »»- •*- **- C "*- C C "•-*•- s - *•- C C **- C M - C C C C C C C *•-«+-**- *•- «•- C H - H - H -  o o o o o o o o o o o o o o o o o o o o o o o o o o o o o o o o o o o o o o o o o o o o o o o o o o o o o o o o o o o  C  istin^ONCOOO«-i>ji  « - r N * M ^ i n ^ ^ e o o * o ^ W K i ^ i n * o h ^ a » o * o ^ r v j r o ^ u ^ ^ K c o o » o ^ r > j r o s f i n * O N - c o < > > o « - - r \ j i  ' ^ r m i n m m m t n m m i n t n ' < o  ^ e o c o o ^ o » T - K « - o o o K o o o o * - o o o r \ j o o c > o o o ^ o ^ . » - f o O ' - f o o r ^ ' - o o o o o e o i n o ( > o o o o « ~ o o o o o o o o  o  o  o  o  o  o  o  o  o  o  o  o  o  o  o  o  o  o  o  o  o  o  o  o  o  o  o  o  o  o  o  o  o  o  o  o  o  o  o  o  o  o  o  o  o  o  o  o  o  o  o  o  o  o  o  o  o  o  o  l O N N i n r m i « - O O ( M f - O f - 0 N N N N O N r M i  o  o  o  o  *o »* CO *o < 0 > o o a  • r g N O C N ) » - « - O t - 0 « - r - r - i - r ' » - 0 » - N r O T - f y r - O t - N O ' - < \ » « - » - « # N r M r g « - T - f N J » -  i n vn co  S5SSSR3iaasS5SS§SS55B333933333S55355^555555553*S52HSS33323  SSS5S5S55S5S5S5SSSg5S555555S55S5SS55SSS6SS5SS5glsSS5SS55SSSS i • - rsj tn -* in *o r*  i-rvjn^iA^osoo^OT-Nn>*in'ONcoO'Oi-NM^in'ONeoO'Ot-pjn*tin»oscoo>0'-pJMN»inM3N(0(>-0'-NM^iA-oNooo>o  %r «- o o Kl -o m N. •J- * * (M  264  AAS0#1  DAY  REAL TIME REACTOR NITROGEN CONCENTRATIONS DATE  1  Jun/19/90  2 3 4 5 6 7 8 9 10 11 12  20 21 22 23 24 25 26 27 28 29 30  13  Jul/01/90  14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31  02 03 04 05 06 07 08 09 10 11 12 13 14 15 16 17 18 Jul/19/90  20 21 22 23 24 25 26 27 28 29 30 31  32 33 34 35 36 37 38 39 40 41 42 43 44  Aug/01/90  45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 Maximum Mean Minimum Std. Oev.  02 03 04 05 06 07 08 09 10 11 12 13 14 15 16 17  EIapsed Time Since Air ON or OFF (Hr:Min)  On On Off On On Off On On On On On On On On On On On On On On On On On On On On On On On On Off Off On On On On On Off On On On On On On On On On On On On On On On On On On On On On On  1:25 0:20 0:45 2:45 1:05 2:55 2:15 1:35 1:30 1:35 1:30 2:10 1:30 0:20 1:45 2:00 1:40 2:00 0:35 1:50 1:40 1:40 1:30 1:50 1:50 1:40 2:35 1:45 1:55 1:30 0:40 2:15 1:15 1:20 2:00 2:25 1:05 3:00 2:05 1:50 1:35 1:30 1:30 1:40 1:15 1:40 1:20 1:20 1:30 1:40 2:00 1:50 1:35 1:40 2:55 1:40 1:05 1:35 2:30 1:35  TKN <mg/L)  NOx (mg/L)  NH3 (mg/L)  359 368 401 323 351 348 350 368 358 402 402 387 403 414 414 376 346 338 394 429 466 438 473 460 440 424 451 425 408 439 450 489 447 445 476 474 422 457 471 500 491 462 434 450 464 473 483 475 464 472 430 449 440 495 448 449 432 448 432 391  1.74 0.83 1.55 0.14 1.74 0.22 2.27 1.80 2.00 2.11 1.88 2.38 1.78 1.12 1.85 2.03 2.59 3.65 2.03 f.38 1.50 1.50 1.50 1.74 1.68 1.45 1.78 1.30 1.43 1.15 1.59 0.76 1.22 1.12 2.17 4.18 1.81 0.17 1.77 2.18 2.03 2.01 2.00 2.12 1.59 0.04 1.60 1.98 2.34 2.22 2.39 2.31 3.20 2.54 2.36 2.32 1.75 1.91 2.55 1.90  0.08 0.22 0.49 0.92 0.10 0.90 0.13 0.13 0.14 0.08 0.10 0.07 0.10 0.13 0.10 0.11 0.11 0.07 0.07 0.07 0.10 0.08 0.10 0.09 0.10 0.11 0.13 0.10 0.09 0.08 0.20 0.74 0.08 0.10 0.09 0.09 0.09 0.61 0.10 0.10 0.10 0.10 0.09 0.10 0.11 0.10 0.11 0.11 0.11 0.12 0.11 0.11 0.11 0.12 0.12 0.16 0.11 0.10 0.11 0.10  500 428 323 44  4.18 1.80 0.04 0.73  0.92 0.16 0.07 0.18  AASD#2 DAY  REAL TIME REACTOR NITROGEN CONCEN [•RATIONS  DATE  1 Oct/02/90 2 03 3 04 4 05 5 06 6 07 7 08 8 09 9 10 10 11 11 12 12 13 13 14 14 15 15 16 16 17 17 18 18 19 19 20 20 21 21 22 22 23 23 24 24 25 25 26 26 27 27 28 28 29 29 30 30 31 31 Nov/01/90 32 02 33 03 34 04 35 05 36 06 37 07 38 08 39 09 40 10 41 11 42 12 43 13 44 14 45 15 46 16 47 17 48 18 49 19 50 20 51 21 52 22 53 23 54 24 55 25 56 26 57 27 58 28 59 29 60 30  Maximum Mean Minimum Std. Dev.  EIapsed Time Since Air ON or OFF (Hr:Min> On 1:55 Off 1:35 Off 0:30 Off 0:45 On 1:25 Off 1:15 On 1:55 On 0:25 Off 1:15 Off 1:30 Off 0:55 On 0:35 On 0:35 On 1:20 On 0:45 On 3:55 On 0:25 On 1:30 On 0:10 On 0:35 On 2:15 On 0:05 On 1:05 Off 0:20 Off 1:00 On 0:30 On 1:00 Off 0:50 Off 0:45 On 1:35 On 0:30 On 0:05 On 0:55 On 0:05 Off 0:30 On 1:35 On 0:10 Off 0:35 On 0:05 On 0:05 On 0:15 On 0:15 On 0:05 On 1:40 Off 0:50 On 0:15 On 0:05 On 0:10 On 0:05 On 0:10 Off 3:00 Off 0:30 Off 0:30 Off 0:55 On 1:15 On 0:25 On 0:10 On 0:15 On 0:35 Off 4:00  TKN (mg/L)  NOx (mg/L)  NH3 (mg/L)  525 473 530 498 472 462 478 456 455 467 479 461 470 475 463 470 432 441 435 455 437 444 446 446 437 439 452 438 427 407 446 442 429 429 425 418 439 404 430 408 414 401 395 409 402 376 411 402 396 391 385 386 354 369 358 350 364 336 345 354  2.01 0.19 0.51 0.19 0.91 0.16 0.37 0.44 0.19 5.05 1.04 0.61 0.44 0.96 0.56 0.60 0.37 1.06 0.47 0.57 1.32 0.28 0.37 0.47 0.35 0.57 0.94 0.59 0.30 1.08 0.50 0.28 0.75 0.31 0.66 2.69 0.47 0.42 0.14 0.26 0.67 0.61 0.99 1.74 0.25 0.81 0.34 0.38 0.27 0.57 0.15 0.60 0.68 0.69 1.28 0.96 0.49 1.28 0.15 0.30  0.05 0.35 0.09 0.29 0.05 0.26 0.10 0.07 0.24 0.35 0.19 0.03 0.03 0.03 0.02 0.04 0.02 0.02 0.09 0.04 0.04 0.12 0.04 0.09 0.27 0.06 0.08 0.15 0.17 0.06 0.05 0.19 0.05 0.10 0.10 0.34 0.10 0.17 0.21 0.30 0.09 0.27 0.89 0.07 0.23 0.08 0.16 0.23 0.32 0.32 0.57 0.15 0.16 0.20 0.07 0.32 0.22 0.07 4.99 10.58  530 430 336 41  5.05 0.73 0.14 0.74  0.89 0.16 0.02 0.15  265  AASD#2  AASOHM PHOSPHORUS MEASUREMENTS  DAY  1 2 3 4 5 6 7  a  9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60  FEED  OATE  Jun/19/90  20 21 22 23 24 25 26 27 28 29 30 Jul/01/90 02 03 04 05 06 07 08 09 10 11 12 13 14 15 16 17 18 Jul/19/90 20 21 22 23 24 25 26 27 28 29 30 31 Aug/01/90 02 03 04 05 06 07 08 09 10 11 12 13 14 15 16 17  Max i nun Mean Minimun S t d . Oev.  FIXED TIME  REAL TIME  REACTOR  REACTOR  TP  3rtho-P  TP  Ortho-P  TP  Ortho-P  220 241 164 214 205 271 307 250 216 352 294 279 259 246 259 246 308 354 410 472 252 262 261 276 292 263 301 246 413 366  8.47 0.20 0.53 5.60 8.76 18.78 6.26 0.20 6.94 1.76 12.46 0.45 19.23 11.64 0.28 0.28 0.45 5.07 27.18 30.85 18.94 0.45 25.13 0.36 17.96 7.45 1.77 2.11 2.03 18.76  23.82 28.43 39.46 35.90 43.88 46.38 47.38 47.38 50.73 52.18 53.38 54.33 55.18 54.33 50.73 50.00 48.53 47.23 48.90 48.53 46-40 45.55 49.13 48.05 46.27 44.59 44.90 43.33 43.22 40.70 42.80 45.74 53.84 46.69 41.58 40.53 40.11 38.75 35.07 35.38 36.01 33.49 34.22 32.96 44.53 43.65 41.91 47.36 44.53 44.31 47.47 49.21 50.21 53.93 55.04 53.93 60.43 59.50 57.55 61.54  199 205 225 199 216 215 219 231 230 256 251 247 264 254 258 275 255 252 254 265 289 279 298 293 280 274 288 271 326 341 346 370 373 359 369 361 331 351 350 376 385 320 309 320 334 338 338 351 341 350 328 343 333 364 349 349 363 361 348 333  25.00 28.80 33.02 46.18 45.40 46.32 48.30 49.68 54.08 54.68 56.23 51.08 55.10 53.30 51.58 51.93 48.78 49.38 48.65 46.40 45.08 44.00 48.90 46.28 44.06 44.27 41.96 39.75 37.23 36.28 36.60 43.01 42.17 46.48 36.64 35.07 36.96 51.68 40.11 38.85 38.54 37.38 37.48 37.48 37.77 37.66 36.14 39.52 35.48 33.96 36.90 35.16 35.53 36.18 39.25 39.34 40.83 42.68 42.68 44.08  61.54 45.85 23.82 7.59  385 302 199 53  56.23 42.39 25.00 6.79  325 445 261 271 279 385 429 330 345 320 340 344 399 361 301 332 332 276 347 415 323 265 250 364 294 375 253 295  15.48 31.70 10.45 0.00 4.14 4.06 0.00 0.00 0.00 4.48 16.26 23.40 23.04 12.19 0.64 27.88 0.38 0.00 0.64 3.78 18.37 0.00 11.50 0.00 6.59 11.94 0.00 0.00  186 218 211 210 226 164 216 234 230 261 265 259 277 260 258 263 269 270 259 277 297 292 292 286 309 287 289 292 311 341 326 354 346 342 385 344 344 334 343 353 358 321 325 329 329 333 323 328 347 328 329 332 348 359 355 339 344 332 346 338  472 306 164 64  31.70 8.40 0.00 9.27  385 300 164 49  — —  DAY  DATE  1 Oct/02/90 03 2 3 04 4 05 5 06 6 07 7 08 8 09 9 10 10 11 11 12 12 13 13 14 14 15 15 16 16 17 17 18 18 19 19 20 20 21 21 22 22 23 23 24 24 25 25 26 26 27 27 28 28 29 29 30 30 31 31 Mov/01/90 32 02 33 03 34 04 35 05 36 06 37 07 38 08 39 09 40 10 41 11 42 12 43 13 44 14 45 15 46 16 47 17 48 18 49 19 50 20 51 21 52 22 53 23 54 24 55 25 56 26 57 27 58 28 59 29 60 30  Maximum Mean Minimum Std. Dev.  PHOSPHORUS MEASUREMENTS FEED  FIXED TIME  R EAL TIME  REACTOR  REACTOR  TP  Ortho-P  TP  287 322 237 191 177 175 199 134 330 42! 20 24! 30 165 203 151 264 243 184 206 225 193 242 222 202 185 256 242 198 297 241 210 186 202 238 223 221 210 169 193  7.40 0.22 18.14 2.58 0.31 0.07 2.41 0.81 2.19 0.16 1.13 9.64 0.17 8.88 4.82 0.92 5.45 7.79 0.07 0.48 0.18 0.19 8.91 4.29 3.82 0.07 8.25 0.25 0.14 0.07 2.83 8.07 1.84 8.04 8.04 0.09 0.08 2.75 0.09 0.09  48.41 51.02 49.89 52.24 52.51 51.72 53.38 54.25 53.81 53.38 60.21 57.40 59.55 58.23 60.78 59.63 59.13 61.03 59.79 60.21 59.88 61.61 62.10 59.96 60.95 61.21 63.20 60.26 61.47 61.13 60.87 60.61 61.47 60.87 62.34 59.92 57.50 59.97 59.35 59.44 58.10 63.99 73.09 65.86 61.22 63.10 60.87 62.56 61.58 61.22 64.97 64.17 68.40 64.62 66.41 65.28 66.70 65.75 78.30 88.68  306 286 317 304 293 292 298 280 283 288 291 283 286 287 283 285 271 273 268 274 269 267 273 272 267 273 274 270 267 267 230 229 222 222 226 218 226 215 223 212 242 241 245 244 237 228 238 237 237 235 249 245 235 239 237 232 240 231 227 222  47.71 52.51 56.26 58.18 59.74 60.97 58.61 58.96 60.79 59.48 60.45 61.36 60.62 61.44 61.35 61.85 62.76 62.93 61.44 63.83 63.59 63.09 63.83 63.50 62.16 62.16 64.84 63.20 64.93 64.06 64.93 64.24 64.50 63.98 65.71 63.20 63.37 60.96 62.47 62.92 62.38 68.81 75.94 70.87 68.63 65.77 65.06 64.97 67.91 65.95 67.65 67.74 67.08 66.70 69.81 70.28 70.76 67.17 79.34 90.76  73.09 60.15 48.41 4.63  317 258 212 27  75.94 63.56 47.71 4.38  224 222 200 208 204 185 201 180 198 187 237 223 205 196 185 134 116 152  9.53 0.35 0.12 8.18 0.08 0.07 0.06 0.99 0.10 0.10 22.26 1.03 0.08 0.12 0.09 2.49 0.31 0.57  297 301 306 306 297 287 290 289 279 292 278 281 289 278 296 273 273 287 279 274 267 270 275 281 267 271 271 263 274 272 216 230 227 220 226 228 231 223 218 223 248 244 245 254 242 244 240 240 245 245 248 246 248 241 245 243 235 243 231 231  425 215 116 50  22.26 3.07 0.06 4.54  306 260 216 25  ... —  Ortho-P  TP  Ortho-P  266  DISSOLVED OXYGEN MEASUREMENTS 'AAS001I FIXED TIME REACTOR DAY  1 2 3 4 5 6 7  a  9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60  DATE  Jun/19/90 20 21 22 23 24 25 26 27 28 29 30 Ju1/01/90 02 03 04 05 06 07 08 09 10 11 12 13 14 15 16 17 18 Jul/19/90 20 21 22 23 24 25 26 27 28 29 30 31 Aug/01/90 02 03 04 05 06 07 08 09 10 11 12 13 14 15 16 17  Max i nun Mean Minimum S t d . Dev.  DISSOLVED OXYGEH MEASUREMENTS AASO#1) REAL TIME REACTOR  Sampling Length Airflow Dissolved Time o f Time of Rate Oxygen (Hr:Min) A e r a t i o n (mL/min) Concentration (Hr:Min) (mg/L) 12:45 1:00 1:05 1:45 7:00 2:35 1:15 1:30 1:40 1:55 2:00 2:50 2:50 10:05 9:55 8:55 10:10 9:55 3:45 3:50 2:15 9:55 10:00 9:25 9:05 2:35 2:35 9:35 9:45 10:15 9:50 10:30 10:30 4:10 10:55 10:30 5:05 11:40 5:50 11:55 6:15 7:40 1:00 12:30 12:45 12:45 12:55 7:45 1:15 1:25 1:30 1:40 1:45 1:50 2:00 8:00 9:00 2:15 9:15 8:30  pm pm pm pm pm pm pm pm pm pm pm pm pm am am am am am pm pm pm am am am am pm pm am am am am am am pm am am pm am pm am pm am pm pm pm pm pm pm pm pm pm pm pm pm pm am am pm am am  2:00 2:00 2:00 2:30 1:30 3:00 1:30 1:30 1:30 1:30 1:30 2:00 1:50 2:50 2:30 1:30 2:00 2:00 1:30 1:30 1:30 3:00 3:00 2:15 2:30 1:00 1:00 1:45 1:45 2:15 1:30 2:00 1:75 1:30 2:00 1:30 1:00 1:30 1:30 1:30 1:30 3:00 2:00 1:30 1:30 1:30 1:30 2:00 1:30 1:30 1:30 1:30 1:30 1:30 1:30 1:30 2:30 1:30 2:20 1:30  154 154 154 161 154 154 151 154 154 151 161 151 161 154 151 151 151 146 146 143 154 146 146 146 143 146 149 144 143 146 146 151 146 149 144 146 154 151 165 151 165 165 151 151 146 154 154 151 158 149 151 151 154 161 154 154 151 154 149 154  2.50 2.00 2.00 2.30 2.60 2.85 2.70 1.75 2.60 3.20 3.85 3.20 4.00 4.20 4.00 4.45 4.90 5.20 4.60 2.80 3.20 3.20 3.10 2.10 3.20 2.80 2.70 4.45 4.10 2.80 1.90 4.05 3.80 2.20 1.40 2.80 4.45 5.30 4.05 3.75 3.80 3.90 4.40 4.40 4.30 3.70 3.05 2.40 2.85 2.70 2.90 3.00 2.90 1.80 1.60 2.15 2.40 2.70 2.70 3.05  5.30 3.20 1.40 0.93  DAY  DATE  1 Jun/19/90 2 20 3 21 4 22 5 23 24 6 7 25 8 26 9 27 10 28 11 29 12 30 13 J u l / 0 1 / 9 0 14 02 15 03 16 04 17 05 18 06 19 07 20 08 09 21 22 10 11 23 24 12 25 13 26 14 27 15 28 16 29 17 30 18 31 J u l / 1 9 / 9 0 32 20 33 21 34 22 35 23 36 24 37 25 38 26 39 27 40 28 41 29 42 30 43 31 44 Aug/01/90 45 02 46 03 47 04 48 05 49 06 07 50 51 08 52 09 53 10 54 11 55 12 56 13 57 14 58 15 59 16 60 17  Maximum Mean Minimum S t d . C ev.  Length Sampling Airflow Dissolved Time of Time of Rate Oxygen (Hr:Min) A e r a t i o n (mL/min) Concentration (Hr:Min) (mg/L) 12:45 pm 12:30 pm 1:45 pm 11:00 am 7:25 pm 2:30 pm 1:15 pm 10:45 am 2:30 pm 1:00 pm 4:00 pm 2:45 pm 6:40 pm 12:35 pm 9:55 am 8:55 am 10:15 am 11:45 am 3:20 pm 1:40 pm 2:15 pm 10:15 am 1:15 pm 9:30 am 1:00 pm 2:15 pm 2:35 pm 12:20 pm 12:05 pm 9:30 am 11:45 am 12:10 pm 1:15 pn 3:55 pn 11:45 am 8:25 an 5:55 pn 11:20 an 9:30 an 7:50 an 7:45 pn 11:20 an 8:15 an 11:55 an 11:10 an 10:15 an 1:55 pm 11:15 pm 10:00 an 12:25 pm 12:40 pm 11:45 an 1:50 pn 11:20 am 3:10 pm 8:20 am 9:00 an 3:10 pm 9:15 am 8:15 am  2:00 2:00 2:00 2:30 1:30 3:00 2:00 1:30 1:30 1:30 1:30 2:15 1:50 2:50 1:30 2:00 1:30 2:00 1:30 1:30 1:30 1:30 3:00 1:30 2:00 1:30 2:30 1:30 1:75 2:15 1:30 2:00 1:30 1:30 2:00 1:30 1:00 1:30 1:30 3:00 1:30 3:00 2:00 1:30 1:30 1:30 1:30 1:30 1:30 1:30 1:30 1:30 1:30 1:30 1:30 1:30 2:45 1:30 2:15 1:30  128 128 128 128 128 127 125 128 125 125 125 121 125 121 122 127 124 121 117 117 121 132 128 125 125 124 128 124 121 121 132 138 128 128 124 121 127 125 121 121 138 125 128 122 121 121 122 125 121 121 121 121 124 125 125 122 122 124 117 119  1.90 2.20 1.80 2.00 2.65 3.10 3.15 3.35 3.00 3.55 3.15 3.80 3.70 3.70 4.20 4.50 4.45 5.20 4.45 3.80 2.30 3.30 60 00 15 70 90 10 3.95 85 45 90 50 80 30 35 35 50 75 05 55 30 95 35 4.30 70 50 90 75 40 70 60 00 70 40 15 30 75 85 05  5.20 3.31 1.40 0.88  267  DISSOLVED OXYGEN MEASUREMENTS  DISSOLVED OXYGEN MEASUREMENTS  REAL TIME REACTOR - AAS0#2  FIXED TIME REACTOR - AAS0#2  DAY  DATE  1  Oct/02/90  2 3  03 04 05 06 07 08 09 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31  4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31  Nov/01/90  32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60  02 03 04 05 06 07 08 09 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30  Maximum Mean Minimum Std. Oev.  DAY Dissolved SampIing Length Airflo M Oxygen Time of Time of Rate (Hr:Min> Aeration (mL/min) Concentration (Hr:Min) <mg/L) 1:45 pm 8:15 am 2:45 pm 12:20 pm 2:30 pm 2:45 pm 9:30 am 10:00 am 9:15 am 10:00 am 12:35 pm 6:25 pm 2:00 pm 2:40 pm 9:00 am 9:10 am 1:30 pm 2:40 pm 9:55 am 3:30 pm 10:00 am 9:30 am 10:00 am 3:30 pm 4:15 pm 4:40 pm 4:40 pm 10:25 am 4:25 pm 10:50 am 11:35 am 10:55 am 4:45 pm 5:40 pm 11:15 am 12:00 pm 11:35 am 12:00 pm 12:10 pm 12:00 pm 1:10 pm 1:25 pm 1:35 pm 1:55 pm 1:35 pm 2:30 pm 8:55 am 2:40 pra 9:35 am 9:45 am 9:50 am 12:45 pm 1:15 pm 12:30 pm 1:50 pm 3:45 pm 9:45 am 10:20 am 11:00 am 10:05 am  1:30 2:15 2:15 1:00 1:30 1:30 2:10 2:30 1:15 1:50 1:30 1:00 2:15 3:00 3:00 3:00 1:00 2:00 3:00 2:15 2:30 1:45 2:00 1:30 2:00 2:00 2:45 2:15 2:00 2:20 2:45 1:50 1:25 2:00 1:30 2:00 1:30 1:30 1:30 1:00 2:00 2:00 2:00 2:00 1:30 2:10 2:30 1:50 2:35 2:30 2:20 2:30 2:50 1:45 2:50 2:15 2:05 2:30 2:45 1:30  37 38 38 45 40 38 35 37 36 35 36 33 30 33 30 28 28 26 30 25 30 30 28 28 25 30 25 25 30 25 20 30 30 33 33 30 26 25 30 30 30 27 30 28 28 30 33 28 25 25 30 30 30 30 28 34 33 30 33 30  1.90 5.30 1.70 4.70 3.00 3.35 3.60 3.80 3.40 3.30 2.95 3.00 3.15 2.75 3.10 3.00 1.00 1.25 4.40 3.45 3.70 4.00 3.30 2.30 2.60 3.15 3.70 2.75 2.55 2.40 2.00 2.50 2.00 3.50 2.50 0.70 3.10 2.50 3.00 2.15 3.20 3.25 4.30 3.40 2.70 2.20 3.10 2.30 3.40 2.75 3.90 4.25 3.80 4.50 3.70 4.20 4.50 5.10 7.20 7.35  5.30 3.12 0.70 0.93  DATE  1 Oct/02/90 03 04 4 05 06 5 6 07 08 7 8 09 9 10 10 11 11 12 13 12 14 13 14 15 15 16 16 17 17 18 18 19 19 20 20 21 21 22 22 23 23 24 24 25 25 26 26 27 27 28 28 29 29 30 30 31 31 Nov/01/90 32 02 33 03 34 04 35 05 36 06 37 07 38 08 39 09 40 10 41 11 42 12 43 13 44 14 45 15 46 16 47 17 48 18 49 19 50 20 51 21 52 22 53 23 54 24 55 25 56 26 57 27 58 28 59 29 60 30  2 3  Maximum Mean Minimum Std. D ev.  Sampling Length Airflow Dissolved Time o f Time of Rate Oxygen (Hr:Min) Aeration (mL/min) Concentration (Hr:Min) (mg/L) 1:50 8:15 1:35 1:50 2:30 3:25 10:00 10:00 9:15 10:00 12:35 4:55 2:45 1:30 9:45 10:05 1:30  pm am pm pm pm pm am am am am pm pm pm pm am am pm  3:55 pm 12:00 pra 3:35 pm 2:40 pra 12:40 pm 10:15 am 2:50 pm 4:15 pm 1:40 pm 5:45 pm 10:20 am 2:15 pm 1:00 pm 3:15 pm 12:15 pm 4:00 pm 4:30 pm 10:20 am 12:55 pm 12:30 pm 12:00 pm 10:25 am 12:00 pm 11:05 am 2:15 pm 11:30 am 1:55 pm 12:25 pm 2:30 pm 10:45 am 4:30 pm 11:30 am 12:15 pm 10:15 am 10:35 pm 9:05 pm 2:35 pm 2:55 pm 3:45 pm 9:35 am 12:15 pm 12:00 pm 10:00 am  1:30 1:15 0:50 1:00 1:00 1:00 0:50 1:00 1:00 3:00 1:30 1:00 0:45 3:00 1:15 1:00 0:45 2:00 1:00 0:45 2:30 0:50 1:00 0:50 1:00 0:45 0:45 1:00 0:45 1:30 0:50 0:45 1:00 0:50 0:45 1:30 0:45 0:45 0:45 1:00 0:45 1:05 2:30 1:30 0:40 1:50 0:40 0:45 0:50 1:00 1:15 0:45 0:45 1:00 0:45 2:15 0:50 1:30 1:30 3:10  56 43 38 37 40 34 32 33 31 31 32 35 30 30 32 35 31 30 30 28 28 35 33 33 32 36 30 30 30 30 30 25 34 33 30 33 30 30 28 30 30 30 30 28 30 28 35 36 35 34 37 30 27 32 33 37 33 35 35 35  4.60 4.00 2.75 1.75 4.20 2.80 2.00 2.40 2.75 3.30 1.40 2.25 1.60 1.70 2.20 3.05 1.90 1.90 2.05 1.60 1.50 2.35 2.70 2.30 2.60 3.00 2.50 2.60 2.10 3.00 2.30 1.20 3.40 2.50 2.20 1.00 2.40 2.00 1.60 3.00 2.20 2.30 3.80 2.40 1.20 1.60 1.75 2.55 3.30 3.20 3.75 2.00 1.30 3.10 2.40 3.90 2.60 4.40 6.50 7.10  4.60 2.49 1.00 0.82  268  AAS0#l| TEMPERATURE ANO DH MEASUREMENT S  OAT  DATE  FEED  FIXED TIME REACTOR  pH Temp pH •C 20 20 20 24 23 22 22 21 21 21 21 20 13 Jul/01/90 22 14 02 21 03 20 15 16 04 19 17 05 19 18 06 19 19 07 20 20 08 20 21 09 21 22 10 21 23 11 23 24 12 23 25 13 22 26 14 21 27 15 22 28 16 20 17 20 29 30 18 20 31 Jul/19/90 -32 20 -6.77 33 21 23 6.55 25 34 22 6.66 22 35 23 6.70 21 36 24 6.82 22 37 25 6.76 21 38 26 6.88 20 39 27 6.71 21 40 28 6.37 23 41 29 6.41 22 42 30 31 6.40 6 43 44 Aug/01/90 6.64 6 6.62 22 45 02 6.44 22 46 03 6.47 22 47 04 6.46 26 48 05 6.54 22 49 06 6.95 24 50 07 6.65 23 51 08 6.79 23 52 09 6.65 24 53 10 6.68 24 54 11 6.90 26 55 12 6.81 24 56 13 6.69 23 57 14 6.69 22 58 15 6.73 21 59 16 6.72 20 60 17 1  Jun/19/90  2 3 4 5 6 7 8 9 10 11 12  Maximum Mean Minimum Std. Dev .  20 21 22 23 24 25 26 27 28 29 30  Temp  REAl TIMI: REACTOR pH  °C 22 22 22 24 23 22 22 22 22 22 22 22 22 22 22 21 21 20 20 20 21 22 23 24 22 21 22 20 21 20 21 24 24 25 23 22 22 22 20 22 23 23 24 22 22 22 23 26 22 24 24 23 24 24 26 24 23 22 23 22  6.86 7.12 7.19 7.05 6.71 6.84 6.84 6.80 7.13 7.30 7.02 6.61 6.78 6.81 6.65 6.94 7.03 6.95 6.77 6.82 6.66 7.03 6.79 7.03 6.89 6.90 6.88 6.99 7.01 6.70  7.02 7.13 7.12 7.13 6.91 7.04 6.84 6.83 7.07 7.36 7.08 6.61 6.90 6.90 6.66 6.90 6.97 6.94 6.91 6.91 6.80 6.90 6.90 6.90 6.91 6.88 6.86 6.90 6.88 6.82 6.77 6.62 6.55 6.57 6.59 6.60 6.83 6.81 6.89 6.87 6.59 6.59 6.56 6.76 6.70 6.53 6.49 6.53 6.65 6.55 6.65 6.62 6.37 6.44 6.40 6.44 6.42 6.46 6.41 6.47  7.30 26 6.79 21 6.37 6 0.20 3.3  7.36 26 6.76 22 6.37 20 0.22 1.4  AASD#2 DAY  TEMPERATURE. pH AND ALKALINITY MEASUREMENTS )ATE  22 22 22 24 23 22 22 22 22 22 22 22 22 22 22 21 21 20 "20 20 21 22 23 24 22 21 22 20 21 20 21 24 24 25 23 22 22 22 20 22 23 23 24 22 22 22 23 26 22 24 24 23 24 24 26 24 23 22 23 22  7.39 26 6.77 22 6.39 20 0.21 1.4  FIXED TIME REACTOR  REAL T IME REACTOR  pH Temp Alk . pH Temp Alk . pH Temp Aik °C °C *C  Temp  °C 7.03 7.13 7.10 7.13 6.87 7.02 6.84 6.86 7.05 7.39 7.00 6.62 6.88 6.90 6.63 6.90 6.96 6.92 6.88 6.89 6.81 6.91 6.89 6.90 6.92 6.88 6.92 6.88 6.90 6.84 6.78 6.69 6.62 6.60 6.62 6.59 6.84 6.86 6.88 6.85 6.59 6.60 6.58 6.74 6.67 6.55 6.51 6.56 6.62 6.54 6.64 6.64 6.42 6.47 6.39 6.41 6.48 6.52 6.44 6.45  FEED  20 18 20 18 18 16 15 18 18 18 20 20 15 18 19 18 18 18 14 18 18 15 18 18 20 16 19 17 17 17 31 Nov/01/90 16 32 02 16 33 03 18 04 34 18 14 35 05 36 06 16 07 37 18 38 08 16 09 39 16 40 10 15 41 -11 42 -12 43 13 6.93 18 44 14 7.01 16 45 15 7.02 16 46 16 6.98 17 47 17 7.02 18 48 18 7.15 14 49 19 7.04 12 50 20 7.07 15 51 21 7.05 15 52 22 7.18 14 53 6.81 16 23 54 24 7.21 14 55 7.37 12 25 56 26 7.12 15 57 27 7.27 13 58 28 6.95 14 59 29 6.99 13 60 50 6.96 12 1  Oct/02/90  2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30  Maximum Mean Minimum Std. Dev.  03 04 05 06 07 08 09 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31  6.83 6.94 6.75 6.65 6.89 6.84 6.72 6.64 6.72 6.81 6.85 6.77 6.93 6.86 7.01 6.89 6.83 6.67 6.83 6.69 6.64 6.57 6.75 6.74 6.68 6.75 6.59 6.79 6.78 6.76 6.76 6.64 6.74 6.80 7.17 7.01 7.05 7.06 7.07 7.12  7.37 6.89 6.57 0.18  204 194 188 150 180 178 165 136 172 164 180 190 208 220 178 162 220 190 166 152 152 128 160 154 150 138 168 164 148 182 186 192 152 170 256 204 248 220 176 200 — ... 180 190 196 208 188 192 184 196 186 190 232 218 220 220 238 166 160 218  6.54 6.62 6.60 6.69 6.61 6.65 6.62 6.44 6.43 6.42 6.36 6.41 6.43 6.44 6.40 6.42 6.44 6.46 6.45 6.46 6.46 6.46 6.45 6.45 6.40 6.43 6.42 6.41 6.44 6.45 6.48 6.68 6.55 6.53 6.72 6.54 6.58 6.59 6.65 6.66 6.70 6.65 6.59 6.62 6.65 6.61 6.66 6.63 6.62 6.66 6.63 6.78 6.67 6.68 6.69 6.72 6.71 6.73 6.98 6.98  20 256 6.78 17 185 6.56 12 128 6.36 2 28 0.11  20 20 20 20 21 20 20 20 20 20 20 20 20 20 20 20 20 20 19 20 20 20 20 20 20 20 20 20 20 20 20 20 20 20 20 20 20 20 20 20 20 21 20 20 20 20 20 20 19 19 18 20 20 18 18 19 19 18 20 18  136 144 166 176 145 155 140 124 124 124 120 134 128 132 142 138 130 128 142 138 140 134 136 128 126 134 124 124 134 138 152 176 154 148 170 144 148 154 154 164 166 166 158 152 158 152 156 156 150 164 152 154 152 160 158 164 164 164 206 226  6.55 6.44 6.53 6.61 6.50 6.52 6.48 6.45 6.40 6.28 6.38 6.41 6.40 6.46 6.41 6.41 6.45 6.37 6.47 6.46 6.48 6.44 6.46 6.43 6.39 6.73 6.38 6.42 6.40 6.41 6.42 6.88 6.56 6.51 6.65 6.54 6.54 6.56 6.63 6.59 6.64 6.62 6.56 6.61 6.60 6.61 6.63 6.60 6.62 6.61 6.63 6.75 6.62 6.67 6.72 6.69 6.72 6.73 6.94 6.98  21 176 6.88 20 146 6.54 18 120 6.28 1 15 0.12  20 20 20 20 21 20 20 20 20 20 20 20 20 20 20 20 20 20 19 20 20 20 20 20 20 20 20 20 20 20 20 20 20 20 20 20 20 20 20 20 20 21 20 20 20 20 20 20 19 19 18 20 20 18 18 19 19 18 20 18  140 140 174 166 142 138 140 124 124 110 126 128 130 128 130 136 134 132 138 142 142 134 134 130 128 128 128 128 132 140 142 176 156 148 180 148 148 150 160 158 150 168 144 150 156 164 156 160 152 160 154 158 162 162 158 162 170 166 218 222  21 180 20 146 18 110 1 15  AASDUM DAY  TOTAL COO MEASUREMENTS  DATE FEED  1 Jun/19/90 2 20 3 21 4 22 5 23 6 24 7 25 8 26 9 27 10 28 11 29 12 30 13 Jul/01/90 14 02 15 03 16 04 17 05 18 06 19 .07 20 08 21 09 22 10 23 11 24 12 25 13 26 14 27 15 28 16 29 17 30 18  Maximum Mean Minimum Std. Dev .  Total COD (mg/L) RT RCTR FT RCT  6630 6704 3370 7444 7074 5963 10555 7132 7585 9585 9650 9172 8914 12597 13775 10019 18269 18343 19374 14917 N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A  3148 4704 4417 3000 5222 4481 5888 7585 6642 7359 8321 8620 12500 8918 4776 7948 9888 9179 8097 9888 N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A  3963 4280 4481 3074 3000 6333 5815 6113 7699 7397 12044 7628 5365 7518 9234 5037 8029 10949 10402 13029 N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A  19374 10354 3370 4373  12500 7029 3000 2458  13029 7070 3000 2826  AASD02 Chemical Oxygen Demand Measurents (mg/L)  DATE  FEED  FT#1  RT#2  Oct/12/90  8176  8257  8457  Nov/9/90  7425  7176  7984  Nov/23/90  8530  6882  6093  APPENDIX F MASS BALANCES - AASD#1 and AASD#2 Chemical Parameter AASD#1 - Fixed-Time Reactor TSS VSS Nitrogen Phosphorus - Real-Time Reactor TSS VSS Nitrogen Phosphorus AASD*2 - Fixed-Time Reactor TSS VSS Nitrogen Phosphorus Alkalinity - Real-Time Reactor TSS VSS Nitrogen Phosphorus Alkalinity  Page 271 272 273 274 275 276 277 278 279 280 281 282 283 284 285 286 287 288  AASD#1 TOTAL SUSPENDED SOLIDS MASS BALANCE - FIXED-T1HE REACTOR DAY  FEED RCTR#1 SUMFEED SUMRCT1 (SUMFD- DELTA RCT SOLIDS X SOLIDS MLSS MLSS Day 1-9 Day 2-10 SUHFT) (Day10-1) RED REDUCED (mg/L) (mg/L) X 0.48 X 0.48 *4.8 ColF-G ColH*100 ColD  1 2  7108 7852 5188 6198 5936 8104 9244 7284 6370 9122 7638 7052 6454 6698 6850 6106 8228 9568 11866 13550 7216 7286 7656 7308 7624 6902 8034 6530 10540 9318  3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 0 32 0 33 8070 34 11872 35 6514 36 6858 37 6618 38 9594 39 10068 40 7818 41 7818 42 8014 43 8042 44 8072 45 9430 46 7964 47 6940 48 9736 49 7642 50 6114 51 7814 52 9264 53 9592 54 5950 55 5464 56 7696 57 6482 58 7936 59 5726 60 6848  5716 5598 Moving Average Mass Balance X Removed = 5790 Overall Mass Balance X Removed = 5524 Solids 5436 Day 1-59 Day 2-60 FD-FT Day 60-1 Reduced 2659 35472 5336 224582 186451 38131 5376 5924 5866 30376 -19 6126 5712 24270 6107 31343 1632 5278 5938 24433 6910 5826 31240 24450 6790 173 6617 2765 4644 6100 32135 24727 7408 5854 32258 24927 2006 5324 7331 32624 2352 5109 5826 25163 7461 2285 32022 25391 6631 4346 5852 30516 -221 5367 5878 25369 5147 499 5970 30969 25419 5550 5051 2717 32504 25691 4096 6278 6813 6724 33821 26068 3773 3980 7753 36659 5539 6980 26622 10037 4498 36737 6818 26966 9771 3446 6324 6774 37137 27408 4416 9729 5313 6752 37596 27852 9744 4445 5299 6666 37816 28243 3907 5666 9573 38545 28639 9906 3955 5951 6702 37908 28926 2870 6568 8983 6112 37172 6530 29047 1210 6916 8125 6604 -576 34611 28989 6198 5622 6960 33166 28980 4187 -96 4283 6980 34175 29057 778 4340 5118 6800 30678 29070 1608 125 1483 27003 29120 499 6856 -2117 -2616 31242 6956 29259 1392 591 1983 38980 3427 7416 29602 9378 5951 2899 38794 29892 7172 8902 6003 7006 38229 30120 8109 2285 5824 6954 38271 1680 30288 7983 6303 37817 326 7028 30321 7497 7170 7370 38177 30508 1872 5797 7669 41930 3226 7874 7472 30830 11100 45683 2237 12392 7322 31054 14628 614 10052 7084 41782 31116 10667 34245 -1325 4587 7140 30983 3262 -1824 6792 34993 30801 4192 6016 5184 7052 36228 30823 221 5405 36874 1430 4477 7252 30966 5908 7088 35600 288 4317 30995 4605 7456 35440 413 31036 4404 3992 7216 35356 -1229 30913 4443 5672 6904 34538 30712 -2006 3826 5832 34442 -1238 6826 30588 3853 5092 7082 35028 30561 4468 -278 4746 35758 30794 4964 2333 7278 2631 6960 34088 30750 -442 3780 3338 6756 32888 30512 2376 -2381 4757 6628 30291 -2208 5168 33251 2960 6516 31689 29840 -4512 6361 1849 6646 31830 29566 2264 -2736 5000 31644 29262 6270 2382 -3043 5425  14.70 15.79  20.2 16.8 21.2 14.5 16.5 15.7 13.6 17.6 16.3 12.6 11.8 12.3 17.2 14.3 14.1 15.0 15.4 16.1 18.6 17.9 12.9 12.7  4.8 -9.7  1.9 15.3 15.5 15.2 16.5 19.0 15.2 18.8 27.1 24.1 13.4 17.2 14.3 12.1 12.1 11.3 16.0 16.9 14.8 13.5  7.4 11.1 14.5 15.5 20.1 15.7 17.1  272  AASD#1 VOLATILE SUSPENDED SOLIDS MASS BALANCE - FIXED-TIME REACTOR DAY  FEED RCTR#1 SUHFEED SUHRCT1 (SUMFD- DELTA RCT SOLIDS X SOLIDS MLVSS MLVSS Day 1-9 Day 2-10 SUHFT) <Day10-1) RED REDUCED (mg/L) (mg/L) X 0.48 X 0.48 *4.8 ColF-G ColH*100 ColD  1 5716 2 6308 3 4158 4 4982 5 4740 6 6438 7 7318 8 5772 9 5104 10 7214 11 6056 12 5550 13 5084 14 5186 15 5366 16 4798 17 6442 18 7516 19 9486 20 10794 21 5736 22 5772 23 6144 24 5756 25 6078 26 5472 27 6342 28 5170 29 8308 30 7396 0 31 32 0 33 6386 34 9568 35 5228 36 5462 37 5230 38 7602 39 7864 40 6114 41 6168 42 6288 43 6328 44 6372 45 7344 46 6214 47 5384 48 7608 49 5912 50 4728 51 6008 52 7168 53 7512 54 4556 55 4202 56 5910 57 4944 58 6114 59 4400 60 5256  4496 4412 Moving Average Mass Balance X Removed = 4552 Overall Mass Balance % Removed = Solids 4358 4252 Day 1-59 Day 2-60 FD-FT Day 60-1 Reduced 1546 31332 32878 177010 144132 4154 4216 4728 4632 -202 5375 19084 5173 24257 4454 4868 5799 931 24976 19177 4606 -202 5900 19157 5699 24855 4510 4540 1661 25524 6201 19323 4704 1219 4908 6128 25572 19445 4506 4568 6180 1613 25787 19606 4490 4124 5526 1402 25272 19746 4508 5404 -989 19647 4415 24062 4522 -144 4751 4895 24384 19633 4602 1968 3744 19830 5712 4864 25542 2870 3645 20117 6516 5204 26632 8355 4349 4006 28907 20552 5416 5308 20837 8159 2851 28996 5298 3677 4445 21204 8122 29326 5272 3581 4643 8223 29786 21563 5236 4799 3283 21891 8082 29973 5192 3264 5106 22217 8370 30588 5202 7671 5339 22451 2333 5088 30122 6147 7020 874 22538 5046 29558 5006 -576 5582 5084 27487 22480 3821 -77 3898 22473 5400 26293 4574 432 4142 27090 22516 5388 -154 1819 1973 22500 5240 24320 230 -1383 5284 22524 -1153 21371 22609 2129 854 1275 24738 5370 8149 2477 22857 5673 5718 31006 1632 6237 30889 23020 7869 5428 5546 7274 1728 5406 30467 23193 1421 5740 23335 7161 5380 30495 6695 23346 6810 115 5424 30156 1507 5377 23497 6884 30381 5702 9544 6799 23772 2746 5812 33316 10351 23967 12309 1958 5692 36276 24014 470 8679 33164 9150 5468 4164 23909 3108 -1056 5498 27016 -960 4713 5228 27565 23813 3753 4634 221 4413 28469 23835 5452 23924 4124 5566 28941 5017 893 3984 23921 3955 -29 5418 27876 144 3674 27754 23936 3818 5732 23804 3852 -1315 5168 5538 27657 5274 23604 3362 -2006 5368 26965 23507 3324 4294 5266 26831 -970 27234 23486 3748 3949 5456 -202 4124 5584 27781 23657 1709 2415 3430 5330 26443 23599 2844 -586 5152 25477 23400 2077 -1987 4065 5058 25730 23227 2503 -1728 4231 -3542 4994 24451 22873 1578 5121 4041 5090 24548 22658 1890 -2150 4818 24391 22439 1952 -2189 4140  16.79 17.70  22.2 19.5 23.7 17.8 19.2 17.7 16.3 22.5 20.1 14.7 13.7 13.9 18.3 15.2 15.6 16.0 16.7 17.7 20.8 20.3 14.8 15.3  8.1 -6.5  5.2 18.3 20.2 18.2 18.8 22.2 17.7 20.4 28.5 26.2 15.4 17.1 15.5 14.3 14.3 13.2 18.7 19.9 16.0 14.5  8.7 13.0 16.0 16.4 20.9 16.5 17.0  273  AASD41 NITROGEN MASS BALANCE - FI XED-TIME REACTOR DAY  FEED RCTR#1 SUMFEED SUMRCT1 CSUMFD- DELTA-N Nitrogen X N Lost Lost (TKN + (TKN + Day 1-9 Day 2-10 SUMFT) RCTR#1 :olH*100 (Day10-1) N Out NOx) NOx) N In X 4.8 ColF-G (mg/L) (mg/L) X 0.48 X 0.48 ColD  1 478.45 346.72 2 510.75 395.15 Moving Average Mass Balance X Removed = 3 334.05 378.19 Overall Mass Balance X Removed = Nitrogeil 4 445.53 366.92 5 410.45 389.77 Day 1-59 Day 2-60 FD-FT Day 60-1 Removed 2796 12434 3218 6 552.71 265.08 422 15652 7 599.72 358.94 8 486.17 384.60 9 409.54 362.22 1578 451 189 262 10 674.61 386.11 2029 1579 545 9 535 11 541.78 397.09 2123 442 1589 549 107 12 515.24 400.51 2138 224 390 613 1612 13 453.94 413.52 2225 678 1606 623 -55 14 439.24 378.39 2229 584 529 55 1659 15 465.84 375.20 2243 1684 517 249 268 16 445.26 410.81 2201 1695 111 321 432 17 535.46 407.72 2127 1715 436 199 237 2151 18 630.32 403.69 1727 530 121 409 19 807.79 411.31 2257 569 245 324 1752 20 953.35 448.22 2321 1789 729 373 356 21 513.17 478.27 2518 1825 693 355 337 22 525.70 487.54 2517 1867 685 425 259 23 529.29 467.02 2552 1905 690 383 306 24 559.91 455.09 2595 353 1940 700 347 25 570.51 483.14 2640 1968 732 280 452 26 527.58 466.05 2700 702 267 435 1995 27 571.85 459.30 2696 647 260 387 28 497.38 465.57 2668 2021 507 -83 590 2013 29 713.93 430.92 2519 2003 401 -92 493 2404 30 616.13 459.05 467 -165 632 1987 2454 31 0.00 453.21 210 44 166 1991 32 0.00 476.15 2202 -41 -30 -11 1988 1947 33 541.24 448.93 1974 224 -139 363 34 770.23 454.15 2198 681 81 600 2664 1983 35 441.39 482.96 1989 634 63 571 36 442.50 472.40 2623 0 571 1989 572 37 432.55 465.65 2560 527 131 396 2002 38 617.39 458.24 2529 2010 473 397 39 684.93 475.05 2483 77 2020 496 104 392 40 498.58 474.83 2516 2023 732 34 698 41 549.81 483.14 2755 2037 133 849 983 42 547.57 476.67 3019 2049 714 119 595 43 584.22 478.97 2762 2044 260 -49 308 44 589.22 472.82 2303 310 19 2374 2046 329 45 657.31 476.35 2050 41 387 2478 428 46 587.52 474.15 34 465 2053 499 47 494.84 465.26 2552 -614 1115 1992 501 48 691.52 347.13 2493 400 95 49 539.23 494.68 2496 2001 495 1986 530 -152 681 50 446.95 451.55 2516 -101 591 51 560.54 455.71 2466 1976 490 504 577 52 691.56 463.83 2473 1969 -73 430 1980 544 114 53 707.20 496.66 2524 54 435.02 494.19 2581 1989 592 86 506 1990 484 475 55 407.48 476.20 2474 10 1987 425 56 586.68 460.11 2388 400 -25 2041 391 -149 57 464.32 459.61 2432 540 58 600.21 444.75 2323 2017 305 -240 545 59 410.68 450.32 2017 335 -6 341 2352 429 60 483.56 434.72 2335 2007 328 -101  17.47 17.86  12.9 25.2 20.7 17.5 30.4  2.5 12.2 15.1 11.0 18.1 13.9 14.1 13.4 10.2 11.8 13.4 16.7 16.1 14.5 23.4 20.5 25.7  7.6 -0.6 16.5 22.5 21.8 22.3 15.7 16.0 15.6 25.3 28.1 21.5 13.4 13.0 15.6 18.2 44.7 16.0 27.1 24.0 23.3 17.0 19.6 19.2 17.8 -6.1 23.5 14.5 18.4  274  AASD#1 PHOSPHORUS MASS BALANCE - F IXED-TIME REACTOR  DAY  X P RCTR#1 SUHFEED SUMRCT1 CSUMFD- DELTA RCT TOTAL Lost TP Day 1-9 Day 2-10 SUMFT) (Day10-1) P Lost :olF-G ColH*100 Cmg/L) (mg/L) X 0.48 X 0.48 *4.8 FEED  TP  ColD  1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60  220  186  241 164 214  -6.48 218 lovinq Average Mass Balance X Removed = 211 Overall Mass Balance X Removed = -6.18 210 Phosphor us 226 Day 1-59 Day 2-60 F0-FT Day 60-1 Reduced -541 8750 8562 164 189 730  205 271 307 250 216 352 294 279 259 246 259 246 308 354 410 472 252 262 261 276 292 263 301 246 413 366 0 0 325 445 261 271 279 385 429 330 345 320 340 344 399 361 301 332 332 276 347 415 323 265 250 364 294 375 253 295  216 234 230 261 265 259 277 260 258 263 269 270 259 277 297 292 292 286 309 287 289 292 311 341 326 354 346 342 385 344 344 334 343 353 358 321 325 329 329 333 323 328 347 328 329 332 348 359 355 339 344 332 346 338  1002 1066 1091 1146 1168 1188 1182 1152 1180 1247 1274 1360 1347 1348 1356 1364 1386 1364 1339 1260 1232 1286 1161 1035 1215 1502 1501 1487 1502 1489 1519 1678 1843 1685 1421 1461 1522 1561 1521 1475 1476 1442 1455 1491 1481 1417 1364 1394 1376 1396 1385  946 968 991 1023 1040 1085 1107 1124 1143 1142 1148 1166 1174 1189 1202 1224 1233 1242 1258 1274 1296 1312 1342 1370 1386 1433 1460 1485 1496 1497 1510 1512 1500 1491 1464 1457 1452 1447 1440 1437 1422 1426 1429 1439 1453 1464 1471 1479 1472 1480 1485  57 97 100 123 128 103 74 28 37 104 126 193 173 159 153 139 153 122 81 -14 -64 -25 -181 -335 -171  69 41 2 7 -8 10 166 344 193 -44 3 70 115 82 38 53 16 26 53 28 -47 -108  -85 -96 -84 -99  360 226 230 322 163 451 226 168 192 -10 58 182 72 154 134 221 86 91 158 163 211 163 298 288 158 470 264 250 110 10 130 19 -120  -82 -269  -72 -53 -53 -72 -29 -144  38 34 91 144 106 77 77 -71 86 43  -303 -128 -131 -199  -35 -348 -151 -140 -155  114 69 11 101 6 19 -82 66 31 -78 -178 -275 -189 -479 -623 -330 -402 -223 -248 -104  -17 -120  147 464 275 225 75 123 168 154 67 197 -22 -8 -38 -116 -152 -184 -162  -24 -170 -143  -30.3 -12.0 -12.0 -17.3 -3.0 -29.3 -12.8 -12.1 -13.1  9.1 5.4 0.8 7.5 0.4 1.4 -6.0  4.8 2.3 -5.8 -14.1 -22.3 -14.7 -41.2 -60.2 -27.1 -26.7 -14.8 -16.7 -6.9 -1.2 -7.9  8.8 25.2 16.3 15.8  5.2 8.1 10.7 10.1  4.5 13.4 -1.5 -0.5 -2.6 -7.8 -10.7 -13.5 -11.6 -1.7 -12.2 -10.3  275  AASD#1 TOTAL SUSPENDED SOLIDS MASS BALANCE - REAL-TIME REACTOR DAY  FEED RCTR#2 SUMFEED SUMRCT2 (SUMFD- DELTA RCT SOLIDS X SOLIDS MLSS MLSS Day 1-9 Da/ 2-10 SUMRT) (Day10-1) RED REDUCED (mg/L) (mg/L) X 0.48 X 0.48 *4.8 ColF-G ColH*100 ColD  1 2  3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60  7108 7852 5188 6198 5936 8104 9244 7284 6370 9122 7638 7052 6454 6698 6850 6106 8228 9568 11866 13550 7216 7286 7656 7308 7624 6902 8034 6530 10540 9318  0 0 8070 11872 6514 6858 6618 9594 10068 7818 7818 8014 8042 8072 9430 7964 6940 9736 7642 6114 7814 9264 9592 5950 5464 7696 6482 7936 5726 6848  5640 15.18 5574 Moving Average Mass Balance X Removed = 15.74 5678 Overall Mass Balance X Removed = 5470 Solids 5308 Day 1-59 Day 2-60 FD-FT Day 60-1 Reduced 5288 39769 4426 35344 224582 184813 5370 5756 5736 -480 6991 5540 30376 23866 6511 23.0 5700 31343 23926 7417 605 6812 21.7 31240 1834 5297 6060 24109 7131 17.0 6054 32135 2803 15.4 24390 7745 4942 1680 5658 32258 24558 7700 6020 18.7 32624 4159 6028 24913 7711 3552 12.7 5854 2323 32022 25145 6876 4553 14.2 -394 5674 30516 25106 5410 5803 19.0 -374 5658 30969 25068 5900 6275 20.3 2794 32504 6122 25348 7156 4362 13.4 6680 33821 25818 4704 3299 8003 9.8 7054 36659 4771 26295 5592 15.3 10363 6900 36737 26701 4061 10036 5975 16.3 6810 37137 27254 5530 9882 4353 11.7 6664 37596 27560 10037 3053 6984 18.6 6740 37816 5579 27985 9831 4253 14.8 6554 38545 28407 4224 5914 10138 15.3 6448 37908 28787 3792 5330 14.1 9122 6378 37172 28909 1229 7034 8263 18.9 -730 6504 6528 34611 28836 5774 18.8 6849 33166 28738 -984 5412 4428 16.3 7040 34175 28805 5370 672 4698 13.7 6748 30678 28776 1902 -298 2200 7.2 6930 27003 28903 -1900 1277 -3177 -11.8 6682 31242 28875 2367 -278 2645 8.5 7200 38980 29185 9794 3101 6694 17.2 7138 38794 29517 9277 3312 5965 15.4 38229 6828 29733 2160 8496 6336 16.6 6776 38271 29852 8420 1190 7229 18.9 37817 6974 600 29912 7906 7306 19.3 7404 38177 1747 30086 8091 6344 16.6 7328 41930 2784 30365 11565 8781 20.9 45683 7274 30530 13501 15153 1651 29.6 6896 41782 30633 1027 11149 10122 24.2 34245 -67 7186 30626 3619 3686 10.8 34993 6862 30493 4500 -1325 5824 16.6 7182 36228 30663 1699 5564 3865 10.7 36874 7010 30776 1123 6098 4975 13.5 35600 30784 6992 86 4729 4815 13.3 35440 7218 30695 -893 4745 5638 15.9 6856 35356 30468 -2266 4887 7153 20.2 6984 34538 30329 -1392 5601 4209 16.2 6964 34442 30362 4080 326 3754 10.9 7106 35028 30324 -384 5089 4705 14.5 7274 35758 30521 5237 1978 3259 9.1 6852 34088 30363 -1584 5309 3725 15.6 32888 6666 30198 2690 -1651 4341 13.2 6774 30093 33251 3157 -1046 4204 12.6 6482 31689 29740 1949 -3533 5482 17.3 6706 31830 29668 2162 2882 -720 9.1 31644 6562 29465 2178 -2026 4204 13.3  276  AASD#1 VOLATILE SUSPENDED SOLIDS MASS BALANCE - REAL-TIME REACTOR DAY  FEED RCTR#2 SUMFEED SUHRCT2 (SUHFD- DELTA RCT SOLIDS X SOLIDS MLVSS HLVSS Day 1-9 Day 2-10 SUMRT) (Day10-1) RED REDUCED <mg/L) <mg/L) X 0.48 X 0.48 *4.8 ColF-G CotH*100 ColD  1 2  3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60  5716 6308 4158 4982 4740 6438 7318 5772 5104 7214 6056 5550 5084 5186 5366 4798 6442 7516 9486 10794 5736 5772 6144 5756 6078 5472 6342 5170 8308 7396  0 0 6386 9568 5228 5462 5230 7602 7864 6114 6168 6288 6328 6372 7344 6214 5384 7608 5912 4728 6008 7168 7512 4556 4202 5910 4944 6114 4400 5256  4430 4386 Moving Average Mass Balance X Removed 4460 Overall Mass Balance X Removed = Solids 4304 4148 Day 1-59 Day 2-60 FD-RT Day 60-1 Reduced 32466 4116 2525 177010 142019 34991 4390 4526 4528 5938 18809 5448 -490 4328 24257 6156 115 6040 4410 24976 18821 4694 4799 5922 1123 24855 18933 4664 25524 6418 1728 4690 19106 950 25572 6372 5421 4346 19201 25787 2539 3792 4645 19455 6332 5247 25272 19507 5765 518 4498 24062 -749 5379 4370 19432 4631 5860 24384 5035 -826 4356 19349 25542 1978 4017 4740 19547 5995 19911 3638 3083 5168 26632 6721 8640 28907 20267 3562 5078 5436 3264 8402 5138 5344 28996 20593 4368 3928 29326 21030 8296 5256 2434 6079 29786 21274 8512 5152 4782 3562 5240 29973 21630 8343 3120 30588 8646 5526 5020 21942 2947 7885 4938 4970 30122 22236 518 29558 22288 7270 6752 4848 5267 -682 5948 5026 27487 22220 4144 -710 4855 26293 22149 5288 365 4540 5420 27090 22186 4905 -374 2546 24320 22148 2172 5178 749 -1601 -852 5308 21371 22223 -557 5124 24738 22167 2571 3128 2304 6304 5500 31006 22398 8608 5809 30889 8247 2438 5478 22642 30467 7641 1843 5797 5232 22826 816 5196 30495 22908 7588 6772 250 6974 30156 22932 7224 5340 5907 1402 30381 23073 7308 5712 7804 23294 10021 2218 5640 33316 23440 1459 11377 5612 36276 12836 797 33164 23520 9644 8847 5290 10 3486 27016 23521 3495 5502 -1075 5227 5254 27565 23413 4152 1277 28469 23541 3651 5498 4928 595 28941 23601 5340 4745 5320 27876 4292 -163 4455 5306 23584 -1027 27754 23482 5299 5498 4272 5200 27657 23270 -2112 6498 4386 26965 -1373 5205 5326 23133 3832 5282 23129 3702 -38 3740 26831 -547 4707 5388 27234 23075 4160 3091 23221 1469 5560 27781 4560 23064 -1574 4954 5170 26443 3379 4984 25477 22903 -1613 4188 2575 5064 25730 22787 -1162 4105 2943 -3014 4980 4870 24451 22485 1966 5008 22393 -922 3077 24548 2155 3951 4956 24391 22215 -1776 2175  17.99 18.34  24.5 24.2 19.3 18.4 21.2 14.7 20.8 22.4 24.0 15.7 11.6 17.6 17.7 13.4 20.4 16.0 18.1 16.4 22.8 21.6 18.5 16.8 10.5 -7.5 12.6 20.3 18.8 19.0 22.2 23.1 19.4 23.4 31.4 26.7 12.9 19.0 12.8 16.4 16.0 19.1 23.5 19.3 13.9 17.3 11.1 18.7 16.4 16.0 20.4 12.5 16.2  AASD#1 NITROGEN MASS BALANCE - RE AL-TIME REACTOR  . FEED RCTR#2 SUHFEED SUMRCT2 CSUMFD- DELTA-N Nitroger X N (TKN + (TKN + Day 1-9 Day 2-10 SUMRT) RCTR#2 Lost Lost N Out (Day10-1) ColH*10( NOx) NOx) N In X 0.48 X 0.48 X 4.8 ColF-G (mg/L) (mg/L) ColD 1 478.45 360.74 2 510.75 368.83 Moving Average Mass Balance X Removed = 19.51 21.07 3 334.05 402.55 Overall Mass Balance X Removed 4 445.53 323.14 Nitroge« 5 410.45 352.74 Day 1-59 Day 2-60 FD-RT Day 60-1 Removec 6 552.71 348.22 12199 3452 15652 154 3298 7 599.72 352.27 8 486.17 369.80 9 409.54 360.00 10 674.61 404.11 1575 454 246 2029 208 12.1 1592 11 541.78 403.88 531 168 363 17.1 2123 12 515.24 389.38 1586 616 28.8 2138 552 -63 392 208 9.4 13 453.94 404.78 1625 600 2225 1655 574 299 275 14 439.24 415.12 2229 12.3 15 465.84 415.85 1687 556 231 10.3 2243 325 1700 124 16 445.26 378.03 2201 502 378 17.2 25.4 17 535.46 348.59 1689 438 540 2127 -102 18 630.32 341.65 1681 558 26.0 2151 470 -88 19 807.79 396.03 2257 1677 580 -39 619 27.4 20 953.35 430.38 1690 631 504 127 21.7 2321 21 513.17 467.50 1727 791 416 2518 375 16.5 1744 607 24.1 22 525.70 439.50 2517 774 167 23 529.29 474.50 1772 780 495 19.4 2552 285 24 559.91 461.74 1794 801 22.4 220 580 2595 510 25 570.51 441.68 2640 1825 815 306 19.3 26 527.58 425.45 839 369 470 17.4 2700 1862 27 571.85 452.78 248 9.2 2696 1915 781 533 28 497.38 426.30 1930 739 594 2668 145 22.2 29 713.93 409.43 1919 600 -101 700 2519 27.8 30 616.13 440.15 1906 629 2404 498 -131 26.2 484 31 0.00 451.59 2454 1912 542 58 19.7 1919 209 32 0.00 489.76 2202 282 73 9.5 99 33 541.24 448.22 1947 1913 35 -65 5.1 34 770.23 446.12 262 2198 1915 283 21 11.9 35 441.39 478.17 2664 1940 470 723 253 17.7 548 36 442.50 478.18 1953 670 122 20.9 2623 609 37 432.55 423.81 2560 1951 621 24.3 -12 1974 38 617.39 457.17 2529 555 229 326 12.9 39 684.93 472.77 1990 493 157 336 13.5 2483 2014 259 40 498.58 502.18 502 2516 243 10.3 2016 724 41 549.81 493.03 2755 740 16 26.3 42 547.57 464.01 920 3019 2023 996 76 30.5 2019 793 43 534.22 436.00 2762 744 -49 28.7 2006 297 422 44 589.22 452.12 2303 -125 18.3 435 45 657.31 465.59 2374 2000 374 -60 18.3 46 587.52 473.04 2024 454 218 2478 236 8.8 47 494.84 484.60 2552 2037 515 132 383 15.0 48 691.52 476.98 2039 454 434 17.4 2493 20 49 539.23 466.34 647 2496 2022 475 -172 25.9 50 446.95 474.22 2516 2013 -90 593 503 23.6 51 560.54 432.39 1997 2466 469 -152 621 25.2 52 691.56 451.31 394 16.0 2473 2005 468 73 53 707.20 443.20 2524 2000 524 567 22.4 -43 54 435.02 497.54 2581 2016 412 565 153 15.9 55 407.48 450.36 2474 2005 469 -109 578 23.4 56 586.68 451.32 1989 399 2388 -160 558 23.4 57 464.32 433.75 2432 1968 464 -208 671 27.6 58 600.21 449.91 2323 1960 362 -79 441 19.0 59 410.68 434.55 1941 2352 411 -190 601 25.6 60 483.56 392.90 2335 1922 412 -190 602 25.8  DAY  AASD#1 PHOSPHORUS MASS BALANCE • REAL-TIME REACTOR DAY  FEED RCTR#2 SUMFEED SUMRCT2 (SUMFD- DELTA RCT TOTAL XP TP TP Day 1-9 Day 2-10 SUMRT) (Day10-1) P Lost Lost (mg/L) (mg/L) X 0.48 X 0.48 *4.8 ColF-G ColH*100 ColD  1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60  220 241 164 214  205 271 307 250 216 352 294 279 259 246 259 246 308 354 410 472 252 262 261 276 292 263 301 246 413 366 0 0 325 445 261 271 279 385 429 330 345 320 340 344 399 361 301 332 332 276 347 415 323 265 250 364 294 375 253 295  199  -6.90 205 Moving Average Mass Balance X Removed = -5.83 225 Overall Mass Balance X Removed = Phosphor us 199 216 Day 1-59 Day 2-60 FD-RT Day 60-1 Reduced -510 8617 8750 133 643 215  219 231 230 256 251 247 264 254 258 275 255 252 254 265 289 279 298 293 280 274 288 271 326 341 346 370 373 359 369 361 331 351 350 376 385 320 309 320 334 338 338 351 341 350 328 343 333 364 349 349 363 361 348 333  1002 1066 1091 1146 1168 1188 1182 1152 1180 1247 1274 1360 1347 1348 1356 1364 1386 1364 1339 1260 1232 1286 1161 1035 1215 1502 1501 1487 1502 1489 1519 1678 1843 1685 1421 1461 1522 1561 1521 1475 1476 1442 1455 1491 1481 1417 1364 1394 1376 1396 1385  958 980 991 1022 1040 1061 1088 1099 1110 1109 1116 1136 1143 1164 1181 1183 1192 1210 1218 1247 1272 1304 1339 1377 1415 1461 1496 1524 1536 1541 1555 1562 1537 1513 1489 1476 1480 1474 1474 1457 1440 1444 1461 1467 1481 1487 1492 1498 1507 1506 1509  44 85 100 124 128 127 94 53 71 138 159 224 204 184 175 180 193 155 121 13 -40 -18 -178 -342 -200  41 5 -38 -34 -52 -36 115 306 172 -69 -16 42 88 47 17 35 -2 -5 24 0 -70 -128 -104 -132 -110 -123  274 221 106 312 182 206 269 115 106 -10 67 202 72 211 168 24 91 173 82 293 250 322 346 384 379 456 350 288 120 43 144 72 -254 -240 -235 -130  34 -62 5 -168 -168  38 163 62 144 53 53 58 96 -10 24  -229 -135  -5 -188  -55 -80 -175  -62 -35 147 92 23 132 -27 7 156 102 -18 39 -280 -290 -339 -524 -726 -579 -415 -345 -326 -154  -95 -180  43 561 412 167 114 9 150 42 185 203 -40 -168  -38 -144 -122 -181 -161 -228 -100 -147  -22.9 -12.7 -0.5 -16.4 -4.7 -6.7 -14.8 -5.4 -3.0 11.8  7.2 1.7 9.8 -2.0  0.5 11.5  7.4 -1.3  2.9 -22.2 -23.5 -26.4 -45.1 -70.1 -47.7 -27.6 -23.0 -21.9 -10.3 -6.4 -11.8  2.6 30.4 24.4 11.7  7.8 0.6 9.6 2.8 12.6 13.8 -2.8 -11.6 -2.5 -9.7 -8.6 -13.3 -11.6 -16.5 -7.2 -10.6  2fc -»  v*t^f^eoeot^t^>oot>eoeoiO"-^*ocM«»inT-foiof--»-«oo»inS.toin«-o*ocMfo«-f^«-inoc> to^^c\i^^toinin-4r^inin>oinN.fo«-'-tMfocMcofOincMCMCMinfo»-tMiMf>->Of'~co«-o>r-fo  N*  »-*-T-r-.-«-r-«-«-«-.-»-«-»-*-«-T-t-»-»-«-»-  »— r— V) 5 o •o 3u o> fO  II  c  "8  §  *t 0)  o c 01 CO on CO VI ID X  ( M n O f l O O N M S l O » > 0 « ' - ^ O J S i O O * > t l O ' - 4 e O S i n T - 0 - t O > - n * O O M N > » ' O C h ? » < - N N I M N m N i n O I 0 N S N S N 0 > O < 0 i a i M ( > ' S n i < X C 0 S ^ ( M I M M i n 0 > O i n n i M I \ l r - T - » M M ( M O . » S - » O 0 ) S ^ I > S C 0 ' 0 ' - O i n > J > 0 O ' 0 > f C 0 i n 0 J N N . i n ( M M ^ i n O ' 0 C 0 N e 0 M M < )  vtinin^in^^in^^in^st^Njin^roiOM^KiiM  HP  <-Mnn-*K)nMio-t>»>tinininin>0  </l OK  >  ot  r-«-t-r-r-<-v-<-«-T-T-r-CM*-CMIM  II  a>  , «o»»ininf^«-»-»-fo-»ino>0-ocMO~t M n - J S O ' e o o o c g > o i nohy -i -^4> ooicoMi n- c* vM»' -<ion cMot -n*fc^oi ncfo^m t n v t ^ C M C M t o t o ^ >-OoCaOJ fS^ q > fCo M f ^o c oNci M c o i n > » » - c \ i c~"~ > i n r -' >'- o -> c— > t -o i n v t - o a j i n M r - m n m S i nc N CMo*— «-M n N C « ' * o • IiMO« N - «u- n CM- iCM ' tOr^a K (M f lCM o ^• i O N i < I i. N - «>- » « -i *n- i ni o« e - oi o io - . ^> rt -' -T -- o^ cr o - |pO! n N « N )K^l t- -* NK pI i- > > '^  I to CO o in IM in IS  o «••»  et  H 01  a co u.  ~* ID  CO in o • in rvi i n CM  o c ra  <u m c» 10 VI  L. in V <s X  > «*  r» -^ ID c L.  V > o > I o  <os-i'Oaoin<oi'ioor-<toco>tt->oo4a->Ntar-<-'OinM>>oiMin'Oin>}<a<o>»o-t J'Qlfl>»0>li-inO(V>-N«-|0'-C>-»SMM<QIOI>N<\l<MO'-MO>»OinBN^>0>»(MrM>0 MOJointOOtoeorvJui'-OfOininNmoo-i-JO.SOSo.Ni^inoioS.aS^-o.N'iin^vf  1 - *o u. o  MrylNKinMKIMMniMKIKIIMIMIMnWNOINIM  I  «-(MNIM(MNIM^t-t-(M«-^»-r-»-i-  V-*  r- T- r*. ** m *o «— N*  — ~ —. - O S . N N o t^ in to in in in in CM IM CM CM  >-co  ra o  >minr\ir--inr^»tN-coeo»»fOCMO  f>- >o  i n ^* i r^  *- oo  >» ID  o «MC0IMC0«*O>*IM^"*-*rMO«M tor^t>->Oin^(M>t^^incoN-o  to -O r- vj in to to CM CM to <0 to -t in , ..  *o eo co *0 "4" .  -  _  sQ *o *Q »o >o *o ^O *0 *o *0 *0 *0 ^ *0 *0 *0 *o *0  O ^ M O I M CM O O  minuima  0 ' O O v g < N t a D ~ » M ) 0 - J - } I M O O - * - l ' O M > O M N N < t ^ - O O M r j O ' O N M O M ( M O M O < f O O O O - 0 - 0 - g CMoeo-*eoiMc\j>*-oov*oco f ~ ttoo ««-- imn c of~oo»ototococMto>o*-o«T-o-joeOi-Sinint-Nin'OaoNnfM'OMOO'-S'-iSo-jninMCON'O-ico^'OSN f^ -> O ,O C M<o , O - * o - » > 0 - » < g o, i n « * m N . r O « t *Oino(Mooo^ro(Moeoin*-M^>ocoO'4fyrJinint-insrN>0'ioOf-in»-vjoSiOT-o eg <oo oo > CMo oo i n < o i n i n i n > o O i n i A i A ^ ^ O or>^ininin,0Nor>«0K(>in<0stt0Sin«K^N'04inNNint0<c3>0in>0S>0,0«)/iin -o so *o •o «0 '»— - c u M > » i n ' O K »«— c>o»-f\i)<i>»in'ONooc>Oi-Ni<i>»in^N«)0'Or-t\iM-*in<ON«00>0'-r\in-»in<oS«)c»Ot-f>iKi.»in^NeoO'0 >->-<-<-»->-<-'-r-T-wNMriiMNrvirjNr\inminiOMioiOMiOKi^>»>*-*~t>»-»-*-*-*inininininini/nninin>o  S  280  AASD#2 VOLATILE SUSPENDED SOLIDS MASS BALANCE - FIXED-TIME REACTOR Note: Mass Balance has used 58 days of data. DAY  FEED RCTR#1 SUMFEED SUMRCT1 (SUHFD- DELTA RCT SOLIDS X SOLIDS MLVSS MLVSS Day1-19 Day 2-20 SUMFT) (Day20-1) RED REDUCED (mg/L) (mg/L) X 0.24 X 0.24 *4.8 ColF-G ColH*100 ColD  1 2  3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60  8466 7818 3362 4922 4438 4832 4958 6092 8442 7510 4984 6476 7898 4326 5282 4120 7150 6462 4902 5286 6028 5212 6176 5436 5016 4540 6038 5874 4590 6948 5578 5154 4560 5060 6160 5828 5650 5664 4278 4928  0 0 5630 5434 4918 5130 4972 4446 4880 4500 4570 4438 5434 4920 4480 4402 4554 3930 3606 5148  5032 5316 Moving Average Mass> Balance X Removed = 5350 Overall Mass Balance X Removed = 5148 5204 Solids 5032 4966 Day 1-57 Day 2-58 (FD-FT) Day 58-1 Reduced 4912 74452 65968 8484 -3955 12439 4930 5060 5268 5096 5162 5176 5092 5132 4934 4830 4978 -384 4200 26986 23169 3816 4952 -1728 4868 3140 4956 26222 23083 -1766 4565 2798 4982 25793 22994 -624 3274 3898 26237 22963 5018 4954 26538 22903 3635 -1200 4835 4509 3904 -605 4906 26777 22873 3943 3838 4988 22878 26821 106 3874 -614 4488 4784 26721 22848 3879 -374 4254 26708 22829 4852 -1008 4321 3313 4850 26092 22778 2714 -2026 4740 22677 4846 25391 -1411 4667 3256 4802 25862 22607 3101 -1210 4310 4910 25647 22546 2539 -1939 4478 4772 24988 22449 -1776 4460 25044 22360 2684 4722 -2189 4929 2740 4676 24991 22251 -634 3895 3262 4802 25481 22219 25164 22202 -336 3297 4760 2961 2794 -547 3341 4864 24969 22175 -490 3491 3001 4850 25152 22151 3969 2817 -1152 4716 24910 22093 3661 -1056 2605 4762 24646 22040 -1219 2635 4764 1416 23395 21979 -1315 1314 4680 21912 21913 -1 4834 1414 -346 1760 23310 21896 3786 2865 -922 4796 24715 21850 -576 3560 4664 2984 24805 21821 -816 3623 2807 4682 24588 21780 2660 -1382 4042 24371 21711 4562 2689 -1272 3961 4581 24336 21648 -854 3090 4624 23840 21605 2235 -1430 3478 21534 2048 23581 4612 -1344 3319 23441 1975 21466 4492 -2323 4385 2062 4238 23412 21350 -1968 2250 4218 23502 21252 4266 -2486 23204 21127 2077 4563 4284 1906 -3062 4969 20974 4122 22881 -3446 1779 5226 22581 20802 4146 1667 -3082 4748 20648 4208 22315 -3082 4819 20494 1737 4074 22231 1593 -3456 5049 4042 21914 20321  16.08 16.71  15.6 18.6 17.7 14.9 18.2 16.8 14.3 16.8 15.9 16.6 18.7 18.0 16.8 17.9 17.8 19.7 15.3 13.1 13.4 13.9 15.9 14.9 11.3  6.0 7.5 15.3 14.4 14.7 16.6 16.3 13.0 14.8 14.2 18.7 17.9 19.7 21.7 23.1 21.3 21.7 23.0  281  AASD#2 NITROGEN MASS BALANCE - FIXED-TIME REACTOR  Note: M ass Balance has used 58 days of data. X N FEED RCTR#1 SUMFEED SUMRCT1 CSUMFD- DELTA-N Nitrogen RCTR#1 Lost Lost (NOx + (TKN + Dayl-19 Day 2-20 SUMFT) (Day20-1)ColF-G ColH*100 NOx) NOX) N In N Out X 4.8 Cmg/L) (mg/L) X 0.24 X 0.24 ColD 1 652.90 510.83 17.67 2 735.48 503.15 Moving Average Mass Balance X Removed = 19.43 3 536.08 523.23 Overall Mass Balance X Removed = 4 437.18 529.10 5 401.10 513.20 Nitrogen 6 395.92 487.96 7 438.49 482.18 Day 1-57 Day 2-58 (FD-FT) Day 58-1 Removed 1299 8 294.20 487.66 6688 6035 653 -646 9 647.48 461.16 10 713.72 480.82 11 464.09 455.41 12 563.69 448.40 13 688.07 470.66 14 397.14 451.10 15 475.21 496.71 16 355.23 452.85 17 616.35 445.78 18 552.07 468.38 19 408.69 466.24 18.7 20 446.18 454.36 167 -271 438 2346 2179 441 21 511.16 438.93 133 2296 2163 -308 19.2 97 467 22 426.18 446.17 2242 2145 -370 20.8 23 554.24 455.38 89 -354 442 20.0 2216 2127 24 508.10 462.14 374 2244 129 -245 16.7 2115 25 453.41 461.04 2269 2108 161 -129 290 12.8 184 360 26 414.25 445.51 2283 2100 -176 15.7 394 27 559.24 444.69 2277 2089 188 -206 17.3 28 520.34 429.60 2341 259 411 2082 -151 17.5 29 423.16 448.20 2074 237 -157 393 17.0 2311 2241 209 30 631.57 447.13 169 -40 9.3 2072 274 2069 212 -61 31 533.57 435.61 2281 12.0 208 271 32 472.31 457.62 2274 2066 -63 11.9 33 423.23 452.27 156 6 150 6.8 2222 2066 34 450.30 422.66 180 535 2228 2048 -355 24.0 35 556.24 440.09 177 238 10.7 2222 2045 -61 224 204 36 513.26 450.05 2271 2046 20 9.0 37 510.30 452.84 203 278 12.4 2246 2043 -75 337 38 486.30 437.70 2236 200 -137 15.1 2036 2254 39 400.74 425.89 2029 226 -137 362 16.1 40 457.39 438.17 2243 2029 215 -4 218 9.7 41 0.00 430.19 282 2231 2025 206 -77 12.7 366 42 0.00 403.25 2128 2012 116 -250 17.2 261 43 517.22 407.05 1995 1999 -4 -264 13.1 44 510.36 433.15 1992 129 -134 263 12.4 2122 481 45 453.57 402.70 2258 1982 276 -205 21.3 468 46 465.25 408.36 2267 1973 294 -174 20.7 47 470.04 399.45 1966 278 -145 423 18.9 2245 457 48 422.56 410.46 2233 1957 275 -181 20.5 49 456.62 410.70 284 459 20.6 2232 1948 -175 50 402.42 411.99 361 2190 1943 248 16.5 -113 51 436.65 403.09 491 22.7 2159 1930 229 -262 52 408.88 401.48 1917 233 -244 477 2150 22.2 53 509.15 392.33 2147 1910 237 -146 382 17.8 54 475.21 367.24 2161 1893 268 -350 618 28.6 55 436.35 387.64 564 2142 264 1878 -300 26.3 264 624 56 422.65 377.67 2123 1860 -361 29.4 2102 666 57 429.37 353.75 1839 263 -403 31.7 58 333.27 376.23 261 -238 499 2088 1828 23.9 59 316.31 361.19 2072 1809 263 -370 633 30.5 243 -278 60 429.21 372. 28 2038 1795 521 25.6  DAY  282  a  AASD*  PHOSPHORUS MASS BALANCE - FIXED-TIME REACTOR  Note: Mass Balance has used 58 days of data.  DAY  1 2 3 4 5 6 7 S 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60  X P FEED RCTR#1 SUMFEED SUMRCT1 (SUMFD- DELTA-P Total P Lost TP Day1-19 Day 2-20 SUMFT) RCTR#1 Lost TP P In P Out (Day20-1)ColF-G ColH*100 <mg/L) <mg/L) X 0.24 X 0.24 X 4.8 ColD 287 297 301 Moving Average Mass Balance X Removed = -7.50 322 306 Overall Mass Balance X Removed = -9.83 237 191 306 177 297 175 287 Phosphorus 199 290 Day 1-57 Day 2-58 (FD-FT) Day 58-1 Removed -554 -259 -295 2999 3553 134 289 330 279 425 292 201 278 245 281 301 289 165 278 203 296 151 273 264 273 243 287 184 279 -110 -135 1064 1309 -12 206 -245 274 1301 -163 -93 -8 225 1045 -256 267 1292 -173 -98 -9 193 1021 -271 270 1285 -149 -125 -12 242 1011 -274 275 -17.7 1281 -77 -181 222 1023 -258 281 -14 1276 -96 -146 202 1034 -242 267 1272 -91 -140 -13 185 1040 -231 271 1267 -86 -144 -13 256 1037 -230 271 1264 -77 -120 -11 242 1066 -197 263 1259 -86 -128 -12.2 198 1045 -214 274 1258 -29 -238 -24.1 297 991 -267 272 1242 -312 84 8 241 1014 -228 216 1228 -283 68 6 210 1013 -215 230 1216 -245 20 186 991 -225 2 227 1198 -365 163 202 996 -202 16 220 1186 35 238 -191 -226 226 996 3 1176 57 223 -159 -216 228 1017 5 1162 221 -155 -269 114 231 1007 11 1149 210 -147 -269 122 223 1002 12.1 1135 169 -127 -269 141 1008 14.0 218 1125 193 -126 85 999 -211 8 223 1119 0 -128 -106 -23 248 991 -2 1112 0 -167 -149 -18 244 945 -1 1103 224 -216 -173 -44 245 887 -4 1100 222 -159 -62 -97 254 941 -10 1093 200 -94 -139 45 242 999 4 1087 208 -84 -130 46 244 1003 4 1081 204 -90 20 240 991 -110 2 1073 185 -91 240 982 -163 72 7.4 1067 201 -88 42 245 979 -130 4.3 1074 180 -118 -257 245 956 139 -26.9 1078 198 -137 248 941 -223 -23.7 86 1082 187 -144 246 938 -235 -25.1 91 1089 237 -150 -30 248 939 134 -285 1093 223 -146 -23 241 947 72 -218 1097 205 -153 -24 245 -235 943 82 1100 196 -161 -23 243 -218 939 58 1103 185 -169 -24 235 -227 933 58 1109 134 -181 -32 243 -301 927 120 1110 116 -192 -25.1 231 -230 919 38 1106 152 -206 -13.8 231 -125 900 -82  283  AASD#2 ALKALINITY MASS BALANCE - FIXED-TIME REACTOR Note: Mass Balance has used 58 days of data.  DAY  1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60  ALK FEED RCTR#1 SUMFEED SUMRCT1 (SUMFD- DELTA-A RCTR#1 Lost ALK Day1-19 Day 2-20 SUMFT) ALK (Day20-1)ColF-G (mg/L) (mg/L) ALK In ALK Out X 4.8 X 0.24 X 0.24 204 194 188 150 180 178 165 136 172 164 180 190 208 220 178 162 220 190 166 152 152 128 160 154 150 138 168 164 148 182 186 192 152 170 256 204 248 220 176 200 0 0 180 190 196 208 188 192 184 196 186 190 232 218 220 220 238 166 160 218  X ALK Lost ColH*100  ColD 136 13.82 144 Moving Average Mass Balance X Removed 15.49 166 Overall Mass Balance X Removed = 176 145 Alkalini ty 155 140 Day 1-57 Day 2-58 (FD-FT) Day 58-1 Removed 527 134 392 2533 2006 124 124 124 120 134 128 132 142 138 130 128 142 186 196 10 22. 631 827 138 203 25. 184 -19 630 814 140 41. 335 182 -154 623 804 134 46. 369 177 -192 613 790 136 33. 265 183 -82 609 792 128 41. 323 184 -139 602 786 126 26. 208 179 -29 600 779 134 22. 172 172 0 600 773 124 180 23.1 180 0 600 780 124 128 16, 176 48 603 779 134 168 86 81 10. 607 775 138 164 86 77 10. 612 775 152 151 230 -79 -10. 623 774 176 142 106 36 4. 628 770 154 124 29 96 12. 630 754 148 115 154 -39 -5. 637 752 170 134 67 67 8. 641 775 144 125 96 29 3. 646 771 148 136 58 79 10. 648 785 154 145 77 69 8. 652 798 154 145 115 30 3. 658 804 164 149 154 -4 -0. 666 815 166 111 144 -4. 673 -33 784 166 66 144 -10. 680 -78 746 158 109 686 125 -16 -2. 795 152 158 692 115 43 5. 851 158 166 699 134 31 3. 864 152 168 707 154 14 874 1. 156 168 712 880 106 62 7. 156 176 715 890 58 13. 150 118 173 718 891 13. 164 58 116 181 712 893 33. 152 -115 297 180 712 892 20. 154 0 180 188 713 901 152 19 169 18.8 205 710 916 160 -48 253 27.7 193 714 907 158 67 126 13.9 193 718 911 164 77 116 12.8 184 720 904 164 48 136 15.0 186 722 908 164 48 138 15.2 173 732 906 206 202 -28 -3.1 149 747 896 226 288 -139 -15.5  284  AASD#2 TOTAL SUSPENDED SOLIDS MASS BALANCE - REAL-TIME REACTOR Note: Mass Balance has used 58 days of data. DAY  FEED RCTR#2 SUMFEED SUMRCT2 (SUMFD- DELTA RCT SOLIDS X SOLIDS MLSS MLSS Day1-19 Day 2-20 SUMRT) (Day20-1) RED REDUCED Cmg/L) (mg/L) X 0.24 X 0.24 *4.8 ColF-G ColH*100 ColD  1 2  3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60  10610 9596 4040 5986 5384 5914 6078 7454 10356 9210 6074 7854 9562 5190 6380 4924 8634 7826 5962 6436 7298 6292 7512 6574 6114 5586 7400 7242 5632 8450 6836 6182 5522 6160 7442 6982 6798 6868 5170 5974  0 0 6870 6630 6016 6256 6086 5472 6000 5498 5604 5438 6632 6082 5524 5436 5560 4714 4300 6118  6658 6820 Moving Average Mass Balance X Removed = 6768 Overall Mass Balance X Removed = 6580 6558 6374 Solids 6222 Day 1-57 Day 2-58 (FD-RT) Day 58-1 Reduced 6132 90746 9798 -8237 18034 80948 6208 6402 6612 6488 6392 6660 6404 6414 6150 6338 6290 6250 32888 -1958 29295 3593 5552 6204 31886 29147 -2957 2739 5696 6304 31335 29036 2299 -2227 4526 6222 31875 28950 2926 -1718 4644 6136 32242 28848 -2026 3393 5419 5856 32527 28724 3803 -2486 6289 5964 -1238 32575 28662 3913 5151 5832 32457 28590 -1440 5307 3867 5806 32444 28494 -1930 3950 5880 5962 31697 28388 3309 -2112 5421 5824 28199 -3782 30838 2639 6421 5938 3341 -2640 31408 28067 5981 5860 31164 27939 -2554 3225 5778 5934 30353 27765 2588 -3485 6072 5910 27647 -2371 30432 2786 5157 5794 30380 27498 -2976 2882 5858 5818 30984 27418 -1594 3566 5160 30588 27292 5812 3296 -2525 5820 30341 5866 27190 -2035 3151 5186 5768 27074 -2314 30558 3484 5797 5678 30254 26948 3306 -2525 5831 5630 29937 26786 3150 -3235 6385 5592 28427 26635 1791 -3024 4815 5448 26624 26470 154 -3302 3456 5574 28344 1941 -1354 26402 3295 5510 30059 26293 -2179 5944 3765 5651 30162 26250 3912 -869 4781 5514 29887 26180 3707 -1402 5109 5442 29610 26055 -2496 3555 6051 5406 29571 25955 3617 -2006 5623 5530 28983 25857 3126 -1958 5085 5454 28662 25759 -1949 2903 4852 5464 28524 25647 2877 -2256 5133 5068 28503 25445 3059 -4042 7100 5152 28617 25290 3326 -3082 6408 5192 28290 25140 3150 -3005 6155 5068 27940 24962 2979 -3571 6550 5098 27613 24777 2836 -3686 6522 27300 4942 24579 2720 -3965 6685 4976 27190 24411 2779 -3370 6149 4762 26788 24202 -4166 2586 6752  18.49 19.87  16.9 17.9 14.4 14.6 16.8 19.3 15.8 16.4 18.1 17.1 20.8 19.0 18.5 20.0 16.9 19.3 16.7 19.0 17.1 19.0 19.3 21.3 16.9 13.0 11.6 19.8 15.8 17.1 20.4 19.0 17.5 16.9 18.0 24.9 22.4 21.8 23.4 23.6 24.5 22.6 25.2  •o o  N ' 0 0 > « I ^ M « 1 0 ( M M M > 0 > < t n i M O ' O O i n N O > O N S l f l ^ M M I M O N M O S N N ' O O r - N coo>inincoo<or-o>co«-oocMO«-ooooo»-rnoinMON.€OCM«-o>eoooinioroinm<oi»i~» »-r-«-»-T-CM»-"-»-«-CMCM«-CM«-CM«-CM»-CMCMCMCM»-»-«-»-«-CMCM*-»-«-CMCMtMCMCMCMCMCM  *— i n O TCM CM  0>  y  II  ~o  1! > S  II  moo»->*ocMin^oocMOroOK)mm»-«*CMinroo>>»-*oo>o«-o>0'0»-eocMT-~*«-inmt--o n M » - » 0 ' N o - i t - o 9 i n o o » N c o o s n ' O O f l } « ( M o i M n O ' » ' O n < - n i n ' O o n o, o o i M o o»-o«-coininin«-e5in«tf»-ineo-*eo«-r'»r--*eo-OfOCMeocMinio*-in»t»»oinincoc --co«-to  • •*  N O O N N N - f O M ' 0 ' l ^ l V O I » - J ' O r o>0'OiMOin'-(M'*-iioin(ooOin-»o ~t«-^»o-*S.-oKcMinr».oooooointoo «- CM «— * - « - * - I I *— * - CM CM «— CM*— CM * - * -  "85 oo r>i n •o to  ee.  « "8 > u o  >•  •  l  l  l  l  l  i  l  l  l  l  l  l  i  t  l  l  ^ O N O O O ' 0 » ^ ( M ( 0 0 » ' O K | r o i n N O i n i n O oS|0>-(M<jMin»->-KiinS<|iM'-oo'-0'-rO'-N inS-«-S<0'OocMmoo<Ovtin>o»-s»inO"-cMmeo »— «- CM CM CM CM T— «— I » - » - « - « — • — * ~ f O C M C M t O f O t O C M C \ l i  l  l  l  l  l  l  l  I  I  I  I  I  I  I  I  I  I  I  I  I  I  IS  a  u G c 5 a cc mm* is  fi •« u o 3 O  «•*»  o  r. .o e o r v i .r ^ o- .o > o p M 3 __. _ r . - . t»it^T-<orot^N-«-K>-*to»*o.>oc>T-or^inin'r-»-o>co~»ocMoo r o t ^ c M < - c o * - c > c MeoF c- h i o K-S ^ c M « - > g ^ c > K - i n c M C > ^ ^ c > * f O C M i n ^ c > < o o O ( M i n > o c O T - h » r ' ~ * - t o tOCMCMfOfOtOIOfOtOfOCMfOfOCMCMCMIOIOrOIOIOfOCM rMMMMIOMMIMIMNKIIMIMIMIMNIM  i n CM I CM CM 00  «*«-oocM«-inro>0>0-*o>ooooino«-ino>io»-0>oinoooor^MN.<o«-'-incMN.inc><o -*t^cMin>otoovMin»-«-CMr-t^incoo^«-CM«-ooinr-^oeocMio;tr»o>»->o~»'-<oo»»«-r>cM«-«-ooo»eooor-<omv*cM»-ooooeof~-'OJ'iocM«-«- o o < M O S 4 < o > t n i M O O ' S ' 0 4  t- o ne ro • o  »t  Q u.  a 0) <o o 10 c  ^>  is •0 X IB  oo  .^  *i m  *a  ID <0  u 10  IS Q  dl IS  X <>  f - CM in in  o c 10  • «t «- -* t»-  t.  41 > o X o>  >*  I O K l K I | i l N N r v l M N N N N N I M N < - r r - ^ r t - r f - f ^ r - i - 0 0 0 0 0 0 0 0 0 » 0 . » 0 > CMCMCMCMCMCMCMCMCMCMCMCMCMCMCMtMCMCMCMCMCMCMCMCMCMCMfMCMCMCMCMCMCMCMCMCM«-«-«-«-  S( M M S t O K > - < - W f M t - N S e O - t < - < - > * 0 > N O ' O i n i M O i n i n Q r - ^ 0 ' - ' - C M N ^ < - t - i n ' - « »  < n 1 M 0 "o g- » - l8W 0 « ' «00' 0 v a « r (MM CI M >_ n S (S \l_i MN..No O^O0' »>T > < >t o> > > >o 0i ci ni << -- >> i1<0>' »i -- r«-- r<- -Oot o0 jMN0n- <} |0«) )«>f t' '- -OoOo C« 5o to0) rr -- Ki o) T< -.._!. K i e O - 0 0 0 0 > ^ > - 0 - > - 0 > O M O > M M O i n i O M « O i n - J - I l f l l M B i n K l ( M O  0 ' l \ l N N U l N < n N N o n i O > O C > 0 ( > > « > - 0 ' « - 0 > - O M ( > M S C O i n n M C O m ^ - » i n l M < O i n M ( M O > O i O t n > o o > 0 ' 0 > 0 ' 0 « i n i n i n ^ i r v t i n i n ^ i n v t J K i « - M - » ^ - » > i > » i < i n K i M i < i K i ( M r M f M < M r 1 Crvl u Crvl C M C M f M C M C M C M C M C M C M C M• Crvl M Crvl M Crvl M Crvl M Crvl M CMM Crvl M C| \M M Crvi M Crvl M Crvl M Crvl M Crvl M Crvl M Crvl M Cl M M Crvl M Crvl M Crvi M Crvl M Crvl M Crvl M Crvl M Crvi M Crvi M Crvl M Crvl M Crvi M Crvl M  IS Q  N N N n ^ r > i o ^ < t i \ i o a ) 0 4 N < ) o a < ) O N « ^ N ^ N 4 i n o o o a N t ^ < ) a N e o « ) r \ i g a ^ > i < Q t a s o i \ i i \ i > r o « ) q < o ^ < f o > t c o o oOv»c>focMKcMCMOc>vor^otOiMininvOfOC>c>cocMrOoc>r^»ih-ooinofo«-cMr^Ko  ™ O *OiinOiNn < - iin-i|nOi t - n<«-*oi>n O O ^C^Mi>nOiO a ~S»N^>^0^'v t O >K*'^OsK»N> K I>N*'^O*i^ n i >n»^«M*-- J i »n-i*n>^* n n >'»*«l*<> l K *1>0»»>-»>> » - ~O*OrOoO>Ot i i n>i»nIiOnNi ( n i\nIiOnO^>« I *v in ni in n^ j ^S>^r'v0t'v < t^ ^* *^ >t t> M <Q •o «* CO  CO «CO f-  CM -o to tO  CM 00 to O •* -* >t  CM  CM CO to in 00 o -» -tf  CM^>0<0OC0«*OC000vtOOO00O^»C000OOO~»C0OCM%0OOO00^tOOCM-4-O<0C0 i - ^ m ^ ^ K i N a ^ N i n < o v O < o i M i n < O N r M f O t o « - t o r ^ « * e g o h - f o, t o r \ i c o o i n f o O v i inooomOin*-ino*-co*o*ocMO ^•^o*-o^tcoinin«4 >*ONt^tino*o«— ^<om^OminNtin>oinmtn>f^ ininvtin-J-st^^t^t^in^vtv^^totoin  ^ N M ^ m ^ N e o t K O i - i \ i n « t i n « N o j o > o » - N M v f i n * N c o » o » - ( \ i M - * i n ^ N o j o » o ^ c g n ^ u i > o N « o o v o ' - f J n ^ i n ' O N < o < > ' 0 «-«-«-'-«-«-«-'-«-»-cMCMCMCMCMCMCMCMCMiMiOfototoiotofOtototo>*-*>»~*vt-4--*«*-4'~»inininininininininin^  AASD#2 NITROGEN MASS BALANCE - REAL-TIME REACTOR Note: Mass Balance has used 58 days of data. FEED RCTR#2 SUMFEED SUMRCT2 (SUMFD- DELTA-N Nitrogen X N Lost (NOx + (TKN + Day1-19 Day 2-20 SUMRT) RCTR#2 Lost (Day20-1)ColF-G ColH*100 NOx) NOx) N In N Out X 4.8 (mg/L) (mg/L) X 0.24 X 0.24 Co ID 1 652.90 527.01 20.59 2 735.48 473.19 Moving Average Mass Balance X Removed = 25.87 3 536.08 530.51 Overall Mass Balance X Removed = 4 437.18 498.19 5 401.10 472.91 Nitrogen 6 395.92 462.16 7 438.49 478.37 Day 1-57 Day 2-58 (FD-RT) Day 58-1 Removed -911 1730 8 294.20 456.44 6688 5869 819 9 647.48 455.19 10 713.72 472.05 11 464.09 480.04 12 563.69 461.61 13 688.07 470.44 14 397.14 475.96 15 475.21 463.56 16 355.23 470.6 17 616.35 432.37 18 552.07 442.06 19 408.69 435.47 -343 556 23.7 2346 213 2133 20 446.18 455.57 -167 339 14.8 2296 171 2124 21 511.16 438.32 -414 552 24.6 2242 138 2104 22 426.18 444.28 -249 373 16.8 2216 124 2091 23 554.24 446.37 -127 286 2244 159 12. 2085 24 508.10 446.47 -119 310 2269 190 13. 2079 25 453.41 437.35 -186 400 2283 214 17. 2070 26 414.25 439.57 -17 225 2277 209 9. 2069 27 559.24 452.94 -80 356 2341 276 15. 2065 28 520.34 438.59 -215 471 2311 256 20. 2054 29 423.16 427.3 -345 549 2241 204 24. 2037 30 631.57 408.08 -73 320 2281 248 14. 2033 31 533.57 446.5 -135 382 2274 247 16.8 2026 32 472.31 442.28 -222 428 2222 207 19.3 2015 33 423.23 429.75 -164 386 2228 221 17.3 2007 34 450.30 429.31 -216 442 2222 226 19.9 1996 35 556.24 425.66 -56 333 2271 277 14.7 1994 36 513.26 420.69 -12 265 2246 253 11.8 1993 37 510.30 439.47 -149 399 2236 250 17.9 1986 38 486.30 404.42 -122 397 2254 275 17.6 1979 39 400.74 430.14 -144 416 2243 271 18.5 1972 40 457.39 408.26 -142 408 2231 266 18.3 1965 41 0.00 414.67 -215 389 2128 174 18.3 1954 42 0.00 401.61 -242 295 1995 53 14.8 1942 43 517.22 395.99 -128 314 2122 186 14.8 1936 44 510.36 410.74 -179 510 2258 331 22.6 1927 45 453.57 402.25 -365 724 2267 359 31.9 1909 46 465.25 376.81 -131 473 2245 343 21.1 1902 47 470.04 411.34 -120 456 2233 336 20.4 1896 48 422.56 402.38 -57 396 2232 339 17.7 1893 49 456.62 396.27 -264 574 2190 310 26.2 1880 50 402.42 391.57 -274 567 2159 293 26.3 1866 51 436.65 385.15 -207 502 2150 294 23.3 1856 52 408.88 386.6 -358 667 2147 309 31.1 1838 53 509.15 354.68 -269 605 2161 336 28.0 1825 54 475.21 369.69 -295 626 2142 332 29.3 1810 55 436.35 359.28 -425 759 2123 335 35.8 1789 56 422.65 350.96 -192 515 2102 323 24.5 1779 57 429.37 364.49 -446 777 2088 332 37.2 1757 58 333.27 337.28 -303 634 2072 331 30.6 1742 59 316.31 345.15 -290 601 2038 311 29.5 1727 60 429.21 354.3  DAY  oo CN  n«0(Mo-<r-r-^in-(iO(M>0'<iOMNn'-'00inoNO(M(M>-in^MtoonMMinN»ro C04)NIMin''OI>N04l<l>00'0'OON'-IVIOOOO"«IMnaSMMN40»nNtOOinO ca 3 O * 00 -C > in a. o «-  u  <l  —» -M I (0 I A U . «J O —•  eg  f  O _l o *u a. t\i . • =8: i CO < a o •  I  i  a x a  U K  a  N-OOU1000N>-0^»OnffllMCMO'ON(OJ CM in i eo<jOincONS»->-Mcoeor-'0'OOMcS «- r• • »»-CMtM«-*-CM«-tM«-CMi  • * C M o o « - o o o c M ««-,-m t n- -**--** c M r o c i ~ » > o » » i n - * o > » o o p i « - - * - * ~ » « * « O O C M C M « - O O C O C M > O lneo»*»»o^^JCMCM^O'— •«» **— * CM *— «— «— «~ I I o<-mSi-o>coincvin>»SCMinK)r-S.r»iin>t«t ( M O ' - ' O ' O O n K M M S O «-«-CMCMt*lCMCMCMCMCMCMCM»-«-«-»-«-tMT-»-«i  I  I  I  I  I  I  I  I  I  I  I  I  I  I  I  I - 00  in h* CM in  >r  o o  1 >• 3 co a. x c <0  c/>  V)  to  o o -a UJ «- c CM • O  x >*a. u CO x co o CM  <*N  ocas ex  I  I  1  t  I  1  I  I  » - » - « - » - « - • - » - . - » - • -  « N O M O N ' 0 ^ i - ' O O N ' * 0 ' » C « S i n M O S ' - K l S ' - N ' - > t ' O C > O i n i - - * M M | < 1 0 r - i n O O O t > C O N N « ' 0 < l i n i c l M N O t > N ' O i n > » M ' - « - 0 0 > 0 ' C O N ' O i n > » l f \ l l l ' 0 ' 0 > O N r > . N C O C l ) 0 3 CIMCMCMCMCMCMCMCMCMCMCMCMCM" O O O O O O O O O O O O O O O O O O  i o » - CM  >  CO  X o  O  a  •*ini-i-Kl^-oN>OinT-^K)>-<0'OSNrMOOO'-inN>-Ck|<l>-wp>'OT-eooMOO>MM>0 «vt(\lt-NM>llO«^C>^r-c>C>(>«-OOOC>0>>»CO-JC>OC>COSinvfMIO>»^KlMrvlt-0 ooooooooooo>ooc>c>c>ooooo>c>o>eo<>c>oo>o<o>c>c>c>c>c>c>(>>(>o<c>c>  ^ ^ S > * I O N C O O M e O < - K l ^ N M U 1 r - m C O ^ t > S m C > I N p ^ O N S O C > N N ' O C O < ) i n K ) r j N < - i n « j N C O C O S N i n C > u 1 i n C > S N O ^ S W O C O ^ O I > C > ^ C O C O f l O ( > e O c 5 c O C O C O N N v c 5 S - 0 - O r ^ S < ) K S N O ^ M N W N N T - N ^ ( \ l » - » t > » s f > » M ( \ l n M M l^rOr^rOCMNNCMCMCMCMCMCMCMCMCMrvlrvlCMCMrvlCMrtlCMNCMCMCMNr^CMCMCMCMCMraCMCMrvlCMCMCMCMN  w  Stj o  (  10  o N o in o  a  iu i u. » -  •  . . .N. -o> ._ - O m. K-m _. o^r-NcojoO"-neooo]oono>N-»oifl fNinocO'*'0-j'Oo (M ^ i n ^ o ^ iCM-» n h o cCM C M C h « -' i n c M » - ^ c > c o i n ^ ^ c M ^ c M i n ^ i n e O ' > o S . t ~ - h - c > T - c< M c M C M C M r o ~ * i n > o c o CMCMCMC\ICMCMCMCM«-CMf\iCMCMCM«-«-»-»-T-«-T-T-«-CM«-  ce  I  CO  o  a </> o  >  o  CM CM -* K I PfM 0 CM 3 .  C/> 3  ,  OK  • o eo -o m ro  I - ( - CM ~ * _J O > .  n  S'r O^ cOMr c' iM- itnc«o-ionoct oo «r -M- 4O r- ot i>-oMoion>ionooc^ >N-i«' -l  ca e > o S  r>- CM N Nt^< w~ -Nino>^oini-int-inM»-stMN»<)inioc\iNC\iin«c\icoSr-o>Qrvieom»-oc>MOO<t(\iooo>»in>-oeos N M 1(1 >0 I f l - » O CM oo N M O i S S » M M N o ^ o f l o i n « ^ c o o N O > - » r \ i o c o i n - t c > c > ^ i - c o o r o c v i N < - 4 ( > C M c M o o o e o o e o o owoM C M O O o o r O T - m CM r O C M « - « - « - « - « - r ' » « * C M C M r O « - C M » - < M C M « - C M C M « - C M C M C M « - C M C M « - C M C M C M « - C M C M C M C M C M » - T C M C M C M C M C M « - C M « - * - w» - CM CM CM «- *— « - « - « -  »-Nio^inM)NeockO»-rMm^inMjNeoc»o^NM>»inMiNODC>o<-rMio-*in>oscoO'0'-CMM-»in>oscoc>o»-CMto>*in'OScoc>o '-'-'-'-•-'-•-'-•-•-rM(MfMrM(MCMrMfMCMCMMnMMK)nntorOM-»<»>l'*-i>*^>»-»-»inininininininininin'0  288  AAS0#2 ALKALINITY MASS BALANCE - REAL-TIME REACTOR Note: Mass Balance has used 58 days of data.  DAY  1 2 3 4 5 6 7 3 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60  FEED RCTR#2 SUMFEED SUMRCT2 (SUMFD- DELTA-A ALK RCTR#2 Lost ALK 0ay1-19 Day 2-20 SUHRT) ALK (Day20-1)ColF-G (mg/L) (mg/L) ALK In ALK Out X 4.8 X 0.24 X 0.24 204 194 188 150 180 178 165 136 172 164 180 190 208 220 178 162 220 190 166 152 152 128 160 154 150 138 168 164 148 182 186 192 152 170 256 204 248 220 176 200 0 0 180 190 196 208 188 192 184 196 186 190 232 218 220 220 238 166 160 218  X ALK Lost ColH*100  ColD 140 13.41 140 Moving Average Mass Balance X Removed = 174 Overall Mass Balance X Removed = 16.19 166 142 138 Alkalini ty 140 Day 1-57 Day 2-58 (FD-RT) Day 58-1 Removed 1998 124 2533 535 125 410 124 110 126 128 130 128 130 136 134 132 138 10 142 827 620 207 198 23.9 620 194 10 142 814 185 22.7 194 134 804 611 -192 386 48.0 134 -154 341 603 187 790 43.1 600 192 -58 130 792 250 31.5 -48 128 786 598 188 236 30.1 -58 128 779 595 185 242 31.1 19 128 596 177 773 158 20.4 597 184 19 128 780 165 21.1 602 177 106 132 779 71 9.1 605 169 67 140 775 102 13.2 609 167 67 142 775 99 12.8 176 774 620 155 221 -66 -8.6 156 626 144 134 770 10 1.2 148 754 631 123 86 37 4.9 641 180 111 752 211 -100 -13.3 645 67 148 775 130 63 8.1 148 771 648 122 46 77 5.9 150 785 651 58 133 76 9.7 160 798 656 86 142 56 7.0 660 158 804 144 67 77 8.4 150 815 663 152 77 75 9.2 168 784 672 163 113 -50 -6.4 144 746 675 71 67 4 0.5 150 680 106 795 115 10 1.2 156 851 687 164 134 29 3.4 164 864 696 169 173 -4 -0.4 156 874 702 134 37 172 4.3 160 709 880 171 134 36 4.1 152 890 712 179 58 121 13.6 160 716 891 175 86 88 9.9 154 711 893 182 -106 288 32.2 158 892 711 180 10 171 19.2 162 901 715 186 67 119 13.2 162 916 710 205 -86 292 31.9 158 907 713 194 48 146 16.1 162 716 911 194 67 127 14.0 170 904 721 183 96 87 9.6 166 908 722 186 29 157 17.3 218 906 737 169 288 -119 -13.1 222 896 754 346 142 -204 -22.7  289  APPENDIX 6 SOME BIO-P CALCULATIONS  Page A Inorganic P Additions to Bio-P*l  290  B Acetate Additions  290  290 APPENDIX 6 SOME BIO-P CALCULATIONS A Inorganic P Additions Adding Na 2 HP0 4  M.W. = 142 gms/mole contains 31 gms/mole of P.  Since target is around 7 mg/L P in the Feed Bucket... Thus, need  142 x 7 = 32 mg Na 2 HP0 4 /Litre of Influent. 31  Feed Bucket contains approximately 3 Carboys Add 32 mg x 48 L x L  1 cm 1000 mg  (approx. 48 L ) . . .  = 1 . 5 gms Na 2 HP0 4 /Feed Bucket Fill  B Sodium Acetate Additions Calculate oxidation)  COD  equivalent  NaCH 3 COO +  2 0 2 <=>  82 gms  64 gms  of  Acetate...  NaHC0 3 + 84 gms  C02  (Assume  +  complete  H20  44 gms  18 gms  If assumed to add 30 mg/L RBD COD (must be >= 25 mg/L) 82 x 30 = 64 Each min.  Influent  Feed  38 rag of NaAc" / L of influent must be added  is  Thus.. 3 8 m g x 2 . 4 L x  2.4  L; Acetate  1 x 30 mL  Pump  1000 mL x L  delivers  3 0 mL/6  1 am 1000 mg  = 3.04 gms/L Acetate Solution must be made up in volumetric flask  APPENDIX H CHEMICAL DATA - BIO-P Parameter  Page  Solids Concentrations Bio-P#l  292  Bio-P*2  293  Nitrogen and Phosphorus Feed (Bio-P*l and Bio-P*2) Fixed-Time Reactor (Bio-P*l and Bio-P#2)  294 295  Real-Time Reactor (Bio-P#l and Bio-P#2)  296  pH, Alkalinity and Carbon Feed (Bio-P#l) Fixed-Time Reactor (Bio-P*l) Real-Time Reactor (Bio-P*l) Feed (Bio-P*2) Fixed-Time Reactor (Bio-P*2) Real-Time Reactor (Bio-P#2) Carbon Decay Data  297 297 298 299 299 3 00 301  BIO-P #1  Feb/19/91-Har/30/91  Solids Concentrations Day of Run  Date  FEED FT RCTR SOLIDS FT EFFLUEMT SOLIDS TSS VSS Ratio TSS VSS Ratio TSS VSS Ratio mg/L mg/L mg/L mg/L mg/L mg/L mg/L mg/L mg/L  1 Feb/19/91 99 2 /20/ 3 /21/ 4 /22/ 5 /23/ 80 6 /24/ 7 /25/ 8 /26/ 9 /27/ 77 10 /28/ 11 Mar/01/91 12 /02/ 13 /03/ 116 14 /04/ 15 /05/ 16 /06/ 17 /07/ 97 18 /08/ 19 /09/ 20 /10/ 21 /11/ 105 22 /12/ 23 /13/ 24 /14/ 25 /15/ 113 26 /16/ 27 /17/ 28 /18/ 29 /19/ 107 30 /20/ 31 /21/ 32 /22/ 33 /23/ 121 34 /24/ 35 /25/ 36 /26/ 37 /27/ 85 38 /28/ 39 /29/ 40 /30/ Maximum Mean Minimum Std. Dev.  121 100 77 15  RT RCTR SOLIDS RT EFFLUENT SOLIDS TSS VSS Ratio TSS VSS Ratio mg/L mg/L mg/L mg/L mg/L mg/L  89 0.90 2212 1722 0.78  2  2 1.00  2366 1880 0.79  3  3 1.00  69 0.86 2352 1804 0.77  2  2 1.00  2612 2012 0.77  2  2 1.00  68 0.88 2128 1632 0.77  11  11 1.00  2384 1822 0.76  3  3 1.00  105 0.91 2376 1834 0.77  2  2 1.00  2466 1892 0.77  1  1 1 00  87 0.90 2342 1826 0.78  4  4 1.00  2404 1870 0.78  2  2 1.00  93 0.89 2014 1542 0.77  5  5 1.00  2156 1636 0.76  5  5 1.00  94 0.83  1620 1208 0.75  5  5 1.00  1890 1392 0.74  4  4 1 00  96 0.90 1860 1344 0.73  5  5 1.00  2012 1428 0.71  5  5 1 00  107 0.89 2170 1618 0.75  5  5 1.00  2252 1646 0.73  4  4  75 0.88 2166 1625 0.75  1  1 1.00  2272 1696 0.75  2  2 1.00  2612 2012 0.79 2281 1727 0.76 1890 1392 0.71 205 195 0.02  5 3 1 1  5 3 1 1  107 88 68 13  0.91 2376 1834 0.78 0.88 2124 1616 0.76 0.83 1620 1280 0.73 0.02 226 196 0.02  11 4 1 3  11 4 1 3  1.00 1.00 1.00 0.00  1.00  1.00 1.00 1.00 0.00  BI0-P #2 Apr/22/91-Hay/31/91 SoI ids Concentrations Day of Run  Date  1 Apr/22/91 2 /23/ 3 /24/ 4 /25/ 5 /26/ 6 /27/ 7 /28/ 8 /29/ 9 /30/ 10 May/01/91 11 /02/ 12 /03/ 13 /04/ 14 /05/ 15 /06/ 16 /07/ 17 /08/ 18 /09/ 19 /10/ 20 /11/ 21 /12/ 22 /13/ 23 /14/ 24 /15/ 25 /16/ 26 /17/ 27 /18/ 28 /19/ 29 /20/ 30 /21/ 31 /22/ 32 /23/ 33 /24/ 34 /25/ 35 /26/ 36 /27/ 37 /28/ 38 /29/ 39 /30/ 40 /31/ Maximum Mean Minimum Std. Dev.  FEED FT RCTR SOLIDS FT EFFLUENT SOLIDS RT RCTR SOLIDS RT EFFLUENT SOLIDS TSS VSS Ratio TSS VSS Ratio TSS VSS Ratio TSS VSS Ratio TSS VSS Ratio mg/L mg/L mg/L mg/L mg/L mg/L mg/L mg/L mg/L mg/L mg/L mg/L mg/L mg/L mg/L 174  158 0.91  3018  2648 0.88  10  10 1.00  3026 2650 0.88  10  10  1.00  181  162 0.90  2578 2222 0.86  2  2 1.00  2582 2216 0.86  2  2  1.00  146  129 0.88  2440 2082 0.85  4  4  1.00  2460 2106 0.86  4  4  1.00  2486 2074 0.83  10  10 1.00  2494 2066 0.83  8  8  1.00  6  6 1.00  2108  1732 0.82  6  6  1.00  79  71  0.90  86  79 0.92  2084  1722 0.83 -'  78  73  0.94  2128  1756  0.83  6  6  1.00  2010  1664  0.83  7  7  1.00  65  59 0.91  1998  1616 0.81  6  6 1.00  1824  1484 0.81  8  8  1.00  78  70 0.90  1986  1568 0.79  4  4 1.00  1806  1428 0.79  4  4  1.00  86  78 0.91  1598 1266 0.79  8  8  1.00  1630  1276 0.78  7  7  1.00  99  88 0.89  1628  1297 0.80  5  5 1.00  1656  1290 0.78  2  2  1.00  3018 2648 0.88 1825 1825 0.83 1266 1266 0.79 410 410 0.03  10 6 2 2  10 1.00 6 1.00 2 1.00 2 0.00  3026 2650 0.88 2159 1791 0.82 1630 1276 0.79 439 431 0.03  10 6 2 3  181 107 65 41  162 97 59 36  0.94 0.90 0.88 0.01  10 1.00 6 1.00 2 1.00 3 0.00  BIO-P #1  Feb/19/91-Mar/30/91  FEED  BIO-P #21 Apr/22/91-Hay/31/91  Nitrogen and Phosphorus Day of Run  Date  Ortho TP -P mg/L mg/L  1 Feb/19/91 7.42 2 /20/ 3 /21/ 4 /22/ 5 /23/ 7.64 6 /24/ 7 /25/ 8 /26/ 9 /27/ 4.91 10 /28/ 11 Mar/01/91 12 /02/ 13 /03/ 7.43 14 /04/ 15 /05/ 16 /06/ 17 /07/ 6.21 18 /08/ 19 /09/ 20 /10/ 21 /11/ 6.21 22 /12/ 23 /13/ 24 /14/ 25 /15/ 5.55 26 /16/ 27 /17/ 28 /18/ 29 /19/ 6.72 30 /20/ 31 /2V —32 /22/ 33 /23/ 6.80 34 /24/ 35 /25/ 36 /26/ 37 /27/ 5.53 38 /28/ 39 /29/ 40 /30/ Maximum Mean Minimum Std. Dev.  7.64 6.44 4.91 0.87  9.9  Nitrogen and Phosphorus  NOx  NH3  TKN  mg/L  mg/L  mg/L  0.09  17.0 28.2  0.14  17.0  0.18  9.1 0.00  12.5  0.11  11.3  0.06  0.35  9.7 0.06  9.7 9.5 9.1 0.4  13.8  9.8 30.3  10.7  0.17  12.0  0.35 0.14 0.00 0.09  26.8  13.0  0.21  FEED  17.0 30.3 13.0 28.4 9.8 26.8 2.4 1.4  Day of Run  Date  Ortho TP -P mg/L mg/L  1 Apr/22/91 2.41 6.3 2 /23/ 3 /24/ 2.61 4 /25/ 5 /26/ 2.45 6 /27/ 7 /28/ 2.53 8 /29/ 9 /30/ 2.56 10 May/01/91 11 /02/ 3.18 12 /03/ 13 /04/ 1.60 3.7 14 /05/ 15 /06/ 1.69 16 /07/ 17 /08/ 1.72 18 /09/ 19 /10/ 1.95 20 /11/ 21 /12/ 2.04 22 /13/ 23 /14/ 2.04 24 /15/ 25 /16/ 2.13 26 /17/ 27 /18/ 2.15 4.1 28 /19/ 29 /20/ 1.99 30 /21/ 31 /22/ 2.03 32 /23/ 33 /24/ 2.14 34 /25/ 35 /26/ 2.17 36 /27/ 37 /28/ 2.14 38 /29/ 39 /30/ 2.29 ---Maximum 6.3 40 /31/ 3.18 Mean 2.19 4.7 Minimum 1.60 3.7 Std. Dev. 0.36 1.1  NOx  NH3  TKN  mg/L  mg/L mg/L  0.16 11.95 41.2 0.30 0.04 12.59 0.08 0.17 11.97 0.10 0.14 11.64 24.0 0.09 0.20 12.04 0.22 0.10 12.54 0.22 0.19 13.78 0.14  27.7  0.19 12.00 0.11 0.19 12.33 0.19 0.27 12.98 0.18 0.30 0.16 0.04 0.06  13.78 41.2 12.38 31.0 11.64 24.0 0.60 7.4  BIO-P #2 Apr/22/91-May/31/91 FT RCTR  BIO-P #1 Feb/19/91-Mar/30/91 FT RCTR  Nitrogen and Phosphorus  Nitrogen and Phosphorus Day of Run  Date  Ortho Percent NOx -P P mg/L (X) mg/L  1 Feb/19/91 3.39 2.95 2 /20/ 3 /21/ 4 /22/ 5 /23/ 7.46 2.92 6 /24/ 7 /25/ 4.93 8 /26/ 9 /27/ 8.27 3.23 10 /28/ 11 Mar/01/91 12 /02/ /03/ 4.60 3.10 13 /04/ 14 /05/ 5.87 15 /06/ 16 /07/ 8.10 2.92 17 /08/ 18 /09/ 4.76 19 /10/ 20 9.30 3.35 21 /1V /12/ 22 /13/ 5.29 23 /14/ 24 /15/ 9.60 3.50 25 /16/ 26 /17/ 3.26 —27 /18/ 28 /19/ 10.70 3.56 29 /20/ 30 31 /21/ 5.88 32 /22/ /23/ 7.71 3.45 33 /24/ 34 /25/ 3.89 35 /26/ 36 /27/ 7.12 3.52 37 /28/ 38 /29/ 4.78 39 /30/ 40 Maximum Mean Minimum Std. Dev.  10.70 6.38 3.26 2.17  3.56 3.25 2.92 0.25  7.79  8.22  NH3 Percent N mg/L (X) 0.1  4.81  -- 5.04  8.21 5.32  9.22  Day of Run  M/D 5.31  7.61 8.05  N/D  5.42  8.44 9.26  N/D  5.50  8.09 8.24  N/D 5.35  8.35 8.97  N/D  5.16  6.44 6.64  N/D  5.53  6.31 6.68  N/D  5.72  9.43  9.43 7.97 6.31 0.94  0.1 5.72 N/D 5.32 N/D 4.81 M/D 0.25  Note: N/D - Not Detectable Less than lowest standard 0.05 mg/L  Ortho Percent NOx -P P mg/L (X) mg/L  1 Apr/22/91 0.03 2 /23/ 3 /24/ 0.02 4 /25/ 5 /26/ 0.02  6 7 8 9 10  7.48  Date  11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40  mi  m/ /29/ /30/ May/01/91 /02/ /03/ /04/ /05/ /06/ /07/ /08/ /09/ /10/  1.12  1.48  2.06  9.71  N/D 6.27  8.96  N/D 6.41  9.22 2.29  0.02 0.33  5.45  8.33  0.03 0.00  N/D  9.18  0.02 0.03  7.68  NH3 Percent N mg/L (X)  9.16  N/D 6.75  7.47 2.75  7.19  0.12  7.38  2.07 2.57  8.41  0.16  8.24  2.07 3.05  8.66  0.12  8.62  N/D 6.82  /1V /12/ /13/ /14/ /15/ /16/ /17/ /18/ /19/ /20/ /21/ /22/ /23/ /24/ /25/ /26/ /27/ /28/ /29/ /30/ /31/  Maximum Mean Minimum Std. Dev.  1.73  3.13  0.11 1.90  N/D 6.37  N/D 6.15  8.52 3.15  8.73  N/D 6.11  8.71  0.11 1.51  8.21  N/D 6.50  3.36  8.95  0.09  8.53  2.07 3.36 0.52 2.50 0.00 1.12 0.78 0.71  9.71 8.49 7.19 0.65  N/D 6.35  N/D N/D N/D N/D  6.82 6.32 5.45 0.36  Nitrogen and Phosphorus  Day of Run  Date  1 Feb/19/91 /20/ 2 3 /2V 4 mi /23/ 5 /24/ 6 /25/ 7 /26/ 8 9 mi 10 mi 11 Mar/01/91 1021 12 /03/ 13 /04/ 14 /05/ 15 1061 16 1071 17 1081 18 1091 19 20 mi 21 mi 22 mi 23 mi /14/ 24 1151 25 1161 26 27 mi 28 mi 29 mi 120/ 30 31 mi 1221 32 33 mi 34 mi 35 mi 126/ 36 37 mi 1281 38 1291 39 /30/ 40 Maximum Mean Minimum Std. Dev.  Ortho Percent NOx  -P  Nitrogen and Phosphorus  NH3 Percent N  mg/L  P (%)  mg/L  5.10  2.53  7.83  0.2 4.53  5.30  2.63  8.07  4.78  4.20  mg/L  m  8.08 3.06  8.75  4.93  4.37 3.27  5.91  N/D 5.19  5.21  6.57  6.90  7.00  2.73  3.28  4.05 8.49  3.36  4.07  3.69  0.1  4.94  12.89  N/D 5.07  9.19  N/D 5.00  2.69 3.68  3.01  8.80 5.60 2.51 1.70  12.39  8.65  5.72 5.51  N/D 5.02  7.61  4.49 7.32  8.30 5.51  2.51 8.80  N/D 4.87  3.89  5.13 8.01  7.13  8.85  2.5 5.18  6.69  4.07 3.20 2.53 0.40  12.89 7.70 2.69 2.40  2.5 0.4 N/D 0.8  5.19 4.90 4.53 0.10  Note: N/D - Not Detectable Less than lowest standard 0.05 mg/L  Day of Run  Date  Ortho Percent NOx NH3 Percent P N -p mg/L (X) mg/L (%) mg/L 1 Apr/22/91 0.03 N/D 5.53 1.22 7.46 2 /23/ 3 /24/ 0.03 9.14 4 /25/ 5 /26/ 0.03 N/D 6.02 1.55 8.99 6 /27/ 7 /28/ 0.02 ---- 10.58 8 /29/ 9 /30/ 0.02 N/D 5.81 2.09 8.96 10 May/01/91 11 /02/ 0.03 9.02 12 /03/ 13 /04/ 0.01 N/D 6.26 2.38 9.23 14 /05/ 15 /06/ 0.02 7.69 16 /07/ 17 /08/ 1.59 N/D 6.09 2.58 9.28 18 /09/ 19 /10/ 0.50 7.40 20 /11/ 21 /12/ 1.92 N/D 6.05 2.76 9.44 22 /13/ 23 /14/ 0.72 8.30 24 /15/ 25 /16/ 1.36 N/D 5.68 2.86 9.21 26 /17/ 27 /18/ 0.20 8.46 28 /19/ 29 /20/ 0.95 N/D 5.58 3.12 9.97 30 /21/ 31 /22/ 0.15 8.53 32 /23/ 33 /24/ 0.86 N/D 5.68 3.30 9.87 34 /25/ 35 /26/ 0.76 10.68 36 /27/ 37 /28/ 1.13 N/D 5.63 3.52 9.38 38 /29/ 39 /30/ 0.12 8.48 40 /31/ Maximum Mean Minimum Std. Dev.  1.92 3.52 0.52 2.54 0.01 1.22 0.59 0.71  10.68 9.00 7.40 0.88  N/D N/D N/D N/D  6.26 5.83 5.53 0.24  BIO-P #1  FEED Day of Run  Date  pH  1 Feb/19/91 7.49 /20/ 2 /21/ 3 4 mi 5 /23/ 7.34 6 /24/ 7 /25/ 8 /26/ 9 /27/ 7.37 10 /28/ 11 Mar/01/91 12 /02/ 13 /03/ 7.56 14 /04/ 15 /05/ 16 /06/ 17 /07/ 7.18 18 /08/ 19 /09/ 20 /10/ 21 /11/ 7.13 22 /12/ 23 /13/ 24 /14/ 25 /15/ 7.27 26 /16/ 27 /17/ 28 /18/ 29 /19/ 7.50 30 /20/ 31 /21/ 32 /22/ 33 /23/ 6.81 34 /24/ 35 /25/ 36 /26/ 37 /27/ 7.15 38 /28/ 39 /29/ 40 /30/ Maximum Mean Minimum Std. Dev.  7.56 7.28 6.81 0.21  Feb/19/91-Mar/30/91  pH/Atkatinity/Carbon  Alk. Diss. FEED mg/L Oxygen as mg/L TC CaCOj 33:30pm mg/L  FT RCTR  FEED  FEED  FEED  IC mg/L  TOC mg/L  COO mg/L  320  108  66  42  298  103  61  42  131  pH  pH/Alkalinity/Carbon  Alk. Diss. RCTR mg/L Oxygen EFFL as mg/L TC CaCO, 33:30pm mg/L  RCTR EFFL IC mg/L  RCTR EFFL TOC mg/L  RCTR EFFL COD mg/L  7.16  270  0.70 0.80  55  46  7.02  284  6.40  63  52  11  5.50 6.90 7.00  58  48  10  27  7.00 7.00 4.70 4.10 5.30 1.10  32  25  7  29  31  25  6  34  27  7  --  46  39  7  28  54  46  8  28  222  82  44  38  118  7.37  288  228  90  42  48  141  7.12  192  206  92  44  48  6.90  212  164  97  49  48  --  7.37  260  278  114  54  60  155  7.03  266  6.50 3.30 5.60 5.50 6.80  248  98  48  50  155  7.28  310  5.20 6.50  29  4.00  186  89  43  46  147  6.84  222  6.00  44  36  8  20  42  35  8  28  63 45 31 11  52 37 25 10  11 8 6 1  29 27 20 3  224  79  31  48  151  7.13  250  1.45 2.60 5.50 1.80 3.30  320 237 164 47  114 95 79 11  66 48 31 10  60 47 38 6  155 143 118 13  7.37 7.12 6.84 0.18  310 254 192 37  7.00 4.60 0.70 2.07  BIO-P #1  Day of Run  Fet /19/91 -Mar/30/91 RT RCTR pH/Alkalinity,'Carbon  Date  1 Feb/19/91 /20/ 2 3 mi 1221 4 1231 5 /24/ 6 /25/ 7 /26/ 8 /27/ 9 /28/ 10 11 Mar/01/91 /02/ 12 /03/ 13 /04/ 14 /05/ 15 /06/ 16 /07/ 17 /08/ 18 /09/ 19 /10/ 20 21 /11/ /12/ 22 /13/ 23 /14/ 24 /15/ 25 /16/ 26 /17/ 27 /18/ 28 /19/ 29 /20/ 30 /21/ 31 /22/ 32 /23/ 33 /24/ 34 /25/ 35 /26/ 36 37 mi 1281 38 1291 39 40 1301 Maximum Mean Minimum Std. Dev.  pH  Alk. Diss. RCTR mg/L Oxygen EFFL mg/L as TC CaCOj 33:30pm mg/L  IC  TOC  COD  mg/L  mg/L  mg/L  RCTR EFFL  RCTR EFFL  RCTR EFFL  7.10  252  0.70 0.80  53  44  9  27  7.08  282  5.40  63  53  10  --  7.32  290  0.70 1.00 6.50  56  47  9  15  7.05  178  34  28  6  27  6.97  220  6.40 6.00 0.80 4.70 2.70 1.00  31  25  6  --  7.38  258  36  30  6  --  7.06  268  6.90 0.70 0.80 4.20 6.90  47  39  8  28  7.34  312  0.80 5.10  52  45  7  28  0.90 7.02  232  5.80  44  38  6  28  7.21  242  1.00 1.10 1.50 1.50 1.60 ----  37  30  7  24  7.38 7.15 6.97 0.14  312 253 178 36  6.90 2.90 0.70 2.37  63 45 31 10  53 38 25 9  10 7 6 1  28 25 15 4  BIO-P #2 FEED  Day of Run  Date  1 Apr/22/91 122,1 2 3 nu /25/ 4 /26/ 5 6 mi 7 mi 3 /29/ /30/ 9 10 May/01/91 /02/ 11 12 /03/ /04/ 13 14 /05/ 15 1061 16 1071 17 1081 18 1091 19 noi 20 mi 21 Ml 22 IMI 23 /14/ 24 /15/ 25 1161 26 mi 27 1181 28 1191 1201 29 30 121/ 31 1221 /23/ 32 /24/ 33 34 1251 35 1261 36 1271 37 128/ 38 1291 39 1301 40 /31/ Maximum Mean Minimum Std. Dev.  pH  7.54  Alk. mg/L  1:T RCTR  pH/Alkalin ity/Carboil  Diss. Oxygen mg/L as CaCO, 33:30pm  360  Apr/22/91-May/31/91  FEED  FEED  FEED  FEED  TC mg/L  IC mg/L  TOC mg/L  COD mg/L  129  79  50  72  pH  7.80  pH/Alk alinity/Carbon  Atk. mg/L  Diss. Oxygen as mg/L CaCOj 33:30pm  392  6.90  RCTR EFFL  RCTR EFFL  RCTR EFFL  RCTR EFFL  TC  IC  TOC  COD  mg/L  mg/L  mg/L  mg/L  78  64  14  20  70  61  9  12  7.30 7.29  276  101  54  47  66  7.86  352  8.00 -  7.11  7.43  220  210  93  74  43  42  5C  32  71  44  7.58  7.56  310  5.90 6.30  49  40  9  14  196  1.20 6.00 7.30  41  33  8  10  38  31  7  12  40  31  9  14  7.20 7.39  212  75  43  32  47  7.49  220  7.80 6.80  7.59  268  92  59  33  42  7.51  172  7.10 6.70  7.43  264  82  54  28  44  7.51  296  7.10  59  53  6  12  7.47  292  97  63  34  50  7.11  240  7.40  53  47  6  11  59  52  7  11  63  55  8  12  78 55 38 13  64 47 31 12  14 8 6 2  20 13 10 3  7.00 7.43  312  102  68  34  46  7.48  290  6.60 7.20  7.09  232  85  51  34  49  7.46  306  6.30 6.80  7.59 7.38 7.09 0.16  360 265 210 46  129 93 74 15  79 56 42 11  50 37 28 8  72 53 42 11  7.86 7.54 7.11 0.19  392 277 172 66  8.00 6.65 1.20 1.36  BIO- P #2 Apr /22/91-May/31/91  Day of Run  Date  1 Apr/22/91 /23/ 2 /24/ 3 /25/ 4 /26/ 5 6 mi /28/ 7 /29/ 8 /30/ 9 10 May/01/91 /02/ 11 /03/ 12 /04/ 13 /05/ 14 /06/ 15 /07/ 16 /08/ 17 /09/ 18 /10/ 19 20 /1V /12/ 21 /13/ 22 /14/ 23 /15/ 24 /16/ 25 /17/ 26 /18/ 27 /19/ 28 /20/ 29 /21/ 30 /22/ 31 1231 32 /24/ 33 /25/ 34 /26/ 35 36 mi 1281 37 1291 38 /30/ 39 /31/ 40 Maximum Mean Minimum Std. Dev.  pH  7.86  RT RCTR  Alk. Diss. RCTR mg/L Oxygen EFFL mg/L as TC CaCOL 33:30pm mg/L  390  8.00  pH/Alkalinityj'Carbon RCTR EFFL  RCTR EFFL  RCTR EFFL  IC  TOC  COO  mg/L  mg/L  mg/L  78  65  13  18  7.80 7.97  343  8.00  75  66  9  4  7.69  330  7.60 7.90  56  45  11  14  200  4.20 7.60 7.90  41  33  8  10  35  28  7  10  40  32  8  12  7.92  7.50 7.61  218  7.80 6.60  7.57  170  7.20 6.80  7.61  290  7.30  60  53  7  14  7.34  230  7.60  51  45  6  9  58  51  7  11  61  53  8  11  78 56 35 14  66 47 28 13  13 8 6 2  18 11 4 3  7.20 7.50  306  7.00 6.30  7.49  340  7.30 7.50 ....  7.97 7.66 7.34 0.19  390 282 170 69  8.00 7.26 4.20 0.84  Carbon Decay in Cold Room Raw Influent Sewage Day  COD  TC  TIC  TOC  1 2 3 4 5 6 7 8 10 11 12 13 14 15 16  128 137 120 110 110 110 101 82 73 92 64 64 73 55 46  62.4 60.4 56.8 55.1 56.1 52.8 52.3 45.0 49.9 46.9 49.7 46.7 43.2 44.6 44.7  21.2 21.4 22.0 20.8 22.9 22.2 22.4 19.4 23.0 21.3 26.0 24.7 23.3 25.2 25.0  41.2 39.0 34.8 34.3 33.2 30.6 29.9 25.6 26.9 25.7 23.7 22.0 19.9 19.4 19.7  Carbon Decay in Feed Bucket Raw Influent Sewage Day  COD  TC  TIC  TOC  1 2 3 4  110 70 64 64  62.5 54.1 48.1 46.6  21.5 21.8 21.3 21.2  41.0 32.3 26.8 25.4  

Cite

Citation Scheme:

    

Usage Statistics

Country Views Downloads
China 155 5
United States 30 3
Canada 21 0
United Kingdom 16 1
Zimbabwe 4 0
Germany 3 6
France 3 0
India 3 0
Hungary 2 0
Russia 2 0
Poland 2 0
Mexico 2 0
Japan 2 0
City Views Downloads
Hangzhou 99 0
Unknown 35 7
London 13 0
Guangzhou 10 0
Ashburn 10 0
Beijing 6 0
Dongguan 5 0
Hefei 4 0
Hamilton 4 0
Ottawa 4 0
Kunming 4 0
Nanjing 3 0
Los Angeles 3 0

{[{ mDataHeader[type] }]} {[{ month[type] }]} {[{ tData[type] }]}
Download Stats

Share

Embed

Customize your widget with the following options, then copy and paste the code below into the HTML of your page to embed this item in your website.
                        
                            <div id="ubcOpenCollectionsWidgetDisplay">
                            <script id="ubcOpenCollectionsWidget"
                            src="{[{embed.src}]}"
                            data-item="{[{embed.item}]}"
                            data-collection="{[{embed.collection}]}"
                            data-metadata="{[{embed.showMetadata}]}"
                            data-width="{[{embed.width}]}"
                            async >
                            </script>
                            </div>
                        
                    
IIIF logo Our image viewer uses the IIIF 2.0 standard. To load this item in other compatible viewers, use this url:
http://iiif.library.ubc.ca/presentation/dsp.831.1-0050500/manifest

Comment

Related Items