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Comparison of RBC and SBR systems for ammonia removal from landfill leachate Besler, David A. 1996

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COMPARISON OF RBC AND SBR SYSTEMS FOR AMMONIA R E M O V A L F R O M LANDFILL L E A C H A T E By David A . Besler B. A . Sc. (Mechanical Engineering) University of British Columbia, 1991 A THESIS SUBMITTED IN PARTIAL FULFILLMENT OF THE REQUIREMENTS FOR THE DEGREE OF MASTER OF APPLIED SCIENCE IN THE FACULTY OF GRADUATE STUDIES CIVIL ENGINEERING W E ACCEPT THIS THESIS AS CONFORMING TO THE REQUIRED STANDARD THE UNIVERSITY OF BRITISH COLUMBIA DECEMBER, 1995 © DAVID A . BESLER, 1995 In presenting this thesis in partial fulfilment of the requirements for an advanced degree at the University of British Columbia, I agree 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 my department or by his or her representatives. It is understood that copying or publication of this thesis for financial gain shall not be allowed without my written permission. Civil Engineering The University of British Columbia 2075 Wesbrook Place Vancouver, Canada V6T 1Z1 Date: Abstract Pilot scale RBC and SBR systems were compared in order to find out which system would be more cost effective for full scale treatment of Vancouver Landfill leachate. The leachate is an older leachate with NH X -N concentrations between 83 and 336 mg/L, B O D 5 concentrations between 20 and 89 mg/L, and BODs:COD ratios between .06 and .19. Therefore, the primary objective of the study was to investigate NH X -N removal through nitrification. In general, the RBC recovered from nitrogen loading increases and process upsets more quickly and completely than the SBR did, and RBC process upsets were less frequent and less severe. This was attributed to the RBC's superior solids retention capabilities. The RBC was operated successfully at an average nitrogen loading of 4.15 g/m 2 /d at an HRT of 0.35 days. However, loadings of 2 g/m 2 /d or less were required in order for effluent NOJ-N levels to remain below 4 mg/L. The RBC was unable to acclimatize to several of the applied loadings due primarily to provision of insufficient HRT. HRTs greater than 0.3 days were required for NH X -N removals between 2 and 8 g/m 2 /d, and P limitation at the higher loadings inhibited complete nitrification. The SBR achieved complete nitrification at an average loading of 107 g/m 3 /d at an HRT of 1.93 days. Complete NH X -N removals were achieved at an average loading of 331 g/m 3 /d at an HRT 0.71 days, but complete nitrification was not. It appeared that the lack of complete nitrification in the SBR system was also caused by P limitation. Both systems were able to perform at low temperatures. The RBC achieved an NH X -N removal of 1.51 g/m 2 /d at 2.5°C, and the SBR was able to remove 23.3 g/m 3 /d at 3°C. Nitrogen balance calculations were performed for both systems, but neither system exhibited significant N disappearances. The two systems performed similarily with respect to BOD5 removal, but the RBC was superior in terms of COD and colour removal. While neither system produced large amounts of excess solids, the RBC solids had better settling characteristics. Evidence of precipitation of inorganic solids was found for both systems, but neither system had scale problems. No differences between the two systems were found in terms of Cd or Co removal, but the RBC tended to remove about 40% of Fe and Mn while the SBR removed 30%. Both systems tended to add rather than remove Zn, but the RBC was more likely to achieve positive removals. Overall, the performance of the RBC system was superior to the performance of the SBR ii system. Toxicity studies were carried out in order to determine whether a substitute could be found for the traditional 96 hour rainbow trout L C 5 0 tests. Rainbow trout L C 5 0 was found to vary with leachate NH X -N according to the relationship T = 2259/N, where T = 96 hour L C 5 0 (%) and N = NH X -N concentration (mg/L), R 2 = 0.90. Daphnia magna 48 hour L C 5 0 results correlated well with fish results based on the above relationship, but Microtox E C 5 0 results did not, due to the high tolerance of the Microtox test for NH X -N. The sucrose modified Microtox test is supposed to be more sensitive to NH X -N, but it did not produce meaningful results in this experiment, as sucrose solutions tended to be toxic. The 2259/N relationship was found to be the best way to predict fish toxicity. iii Table of Contents Abstract ii Table of Contents iv List of Tables viii List of Figures ix Acknowledgement xi 1 Introduction 1 2 Research Rationale and Objectives 3 2.1 City of Vancouver 3 2.1.1 Research Rationale 3 2.1.2 Research Objectives 4 2.2 Nitrification of Landfill Leachate Ammonia . . . ; 4 2.2.1 Landfill Biochemistry 4 2.2.2 Nitrification Biochemistry 5 2.2.3 Description of Fixed Film Processes 6 2.2.4 Review of Fixed Film Literature 7 2.2.5 Description of Suspended Growth Processes 10 2.2.6 Review of Suspended Growth Literature 10 2.2.7 Comparison Studies 12 2.2.8 Research Objectives 14 2.3 Nitrogen Disappearance from Nitrification Systems 14 2.3.1 Simultaneous Nitrification and Denitrification . . 15 2.3.2 Aerobic Denitrification 15 2.3.3 Research Objectives 16 iv 2.4 Toxicity of Landfill Leachate 16 2.4.1 Previous Research at U.B.C 16 2.4.2 Comparison Studies 16 2.4.3 Research Objectives . 18 2.5 Research Rationale and Objectives - Summary • • • 1$ 3 Study Design 1 9 3.1 Site Description . . 19 3.2 Treatment Systems 20 3.2.1 Leachate Supply • • • 20 3.2.2 Phosphorus Addition 21 3.2.3 RBC System 21 3.2.4 SBR System . 24 3.2.5 Effluent Discharge . 2 9 3.3 Sample Collection ; 29 3.4 Analytical Methods 30 3.4.1 Preparation of Glassware 30 3.4.2 Temperature, pH, Dissolved Oxygen, and Conductivity 32 3.4.3 Suspended Solids 32 3.4.4 Dissolved Ammonia Nitrogen 33 3.4.5 Volatilized Ammonia Nitrogen • 33 3.4.6 Nitrate and Nitrite Nitrogen 34 3.4.7 Total Kjeldahl Nitrogen 34 3.4.8 Orthophosphate 35 3.4.9 Alkalinity • • 35 3.4.10 Metals .35 3.4.11 FishLCso 3 6 3.4.12 Daphnia L C 5 0 • 3 6 3.4.13 Microtox E C 5 0 • . 38 4 Results and Discussion 41 4.1 Ammonia Nitrogen • 41 v 4.1.1 Responses to Increased Loading 41 4.1.2 Process Upsets 4 4 4.1.3 Loadings and Removals . • 48 4.1.4 Temperature Effects 52 4.1.5 HRT Effects 58 4.1.6 Alkalinity Consumption 63 4.1.7 Phosphate Addition and Consumption . . . 64 4.2 Other Nitrogen Forms . 68 4.2.1 TKN 68 4.2.2 Nitrogen Balances . ' 69 4.2.3 Nitrite . 71 4.3 Organics and Suspended Solids 75 4.3.1 BOD 5 • • 7 5 4.3.2 COD , 76 4.3.3 Comparison of BOD 5 and COD 78 4.3.4 Suspended Solids • 81 4.3.5 Colour 84 4.4 Metals : • 84 4.4.1 Cadmium 85 4.4.2 Chromium 85 4.4.3 Cobalt 85 4.4.4 Copper . 85 4.4.5 Iron -86 4.4.6 Lead 87 4.4.7 Manganese . . • • • 87 4.4.8 Nickel 87 . 4.4.9 Zinc . 88 4.4.10 Summary of Metal Removal Results 90 4.5 Toxicity : 90 4.5.1 Rainbow Trout L C 5 0 9 0 4.5.2 Daphnia L C 5 0 93 vi 4.5.3 Microtox E C 5 0 5 Summary and Recommendations 5.1 Summary . . . . 5.2 Recommendations Bibliography Appendices A Calculation Definitions B Raw and Calculated Data List of Tables 3.1 Analytical Parameters 31 3.2 Analytical Instruments 32 4.1 RBC Loading History 41 4.2 SBR Loading History 42 4.3 RBC Process Upsets 45 4.4 SBR Process Upsets 45 4.5 Low T/Low P SBR Data 48 4.6 Activated Sludge Loading Data 52 4.7 Comparison of RBC and SBR 0 Values 58 4.8 RBC Loading and HRT Data . 59 4.9 RBC N Loading and HRT Data from HRT Investigation 60 4.10 RBC 6 and R 2 Values with HRT Experiment Data 61 4.11 Alkalinity Consumption . 64 4.12 RBC Phosphate Addition and Consumption 65 4.13 SBR Phosphate Addition and Consumption 66 4.14 TKN Data 68 4.15 RBC Nitrogen Balance Data 70 4.16 SBR Nitrogen Balance Data 70 4.17 RBC NChJ-N and PO^-P Data from HRT Investigation 74 4.18 BOD5:COD Ratios 79 4.19 RBC Disk Scrapings 82 4.20 Fish L C 5 0 Correlation Calculations 91 viii List of Figures 3.1 Photograph showing RBC, SBR, and Trailer 20 3.2 RBC System Schematic 22 3.3 Photograph of RBC Unit . . . 23 3.4 Crane 25 3.5 SBR System Schematic 26 3.6 Photograph of SBR 27 4.1 Leachate and Effluent NHX-N versus Time 42 4.2 RBC NHX-N Removal versus NHX-N Loading 49 4.3 SBR NHX-N Removal versus NHX-N Loading (g/m3/d) 50 4.4 SBR NHX-N Removal versus NHX-N Loading (g/g MLVSS/d) 50 4.5 RBC NHX-N Loading and Removal versus Temperature 53 4.6 RBC Ln(NHx-N Loading and Removal) versus Temperature 53 4.7 SBR NHX-N Loading and Removal versus Temperature 56 4.8 SBR Ln(NHx-N Loading and Removal) versus Temperature 57 4.9 RBC NHX-N Loading and Removal versus 1/HRT 60 4.10 SBR NHX-N Loading and Removal (g/m3/d) versus 1/HRT 62 4.11 SBR NHX-N Loading and Removal (g/g MLVSS/d) versus 1/HRT 63 4.12 Leachate and Effluent NOJ-N versus Time 71 4.13 Leachate and Effluent B O D 5 versus Time . . . 76 4.14 RBC B O D 5 and COD versus TSS • 7 7 4.15 SBR B O D 5 and COD versus TSS 77 4.16 Leachate and Effluent COD versus Time . 78 4.17 Comparison of RBC COD and BOD 5 Removal . . . 80 4.18 Comparison of SBR COD and B O D 5 Removal 80 4.19 Leachate and Effluent Total Suspended Solids 81 4.20 SBR Mixed Liquor Suspended Solids 83 ix 4.21 Leachate and Effluent Total Iron 86 4.22 Leachate and Effluent Total Manganese ' . . 88 4.23 Leachate and Effluent Total Nickel 89 4.24 Leachate and Effluent Total Zinc 89 4.25 Fish L C 5 0 versus 1/NHX-N 94 4.26 Relationship of NHX-N and NH3-N to Fish LC5o 94 4.27 Relationship of Daphnia L C 5 0 to Fish L C 5 0 and NHX-N 95 4.28 Relationship of Microtox E C 5 0 to Fish L C 5 0 and NHX-N 95 x Acknowledgement Financial support for this research was provided by the Natural Sciences and Engineering Research Council of Canada (through a Postgraduate Scholarship and the Operating Grants of Dr. D. S. Mavinic and Prof. J . W. Atwater) and the City of Vancouver. I would like to thank J. Paul Henderson of the City of Vancouver for initiating the project and for all his help along the way. Many thanks are also extended to George Twarog for all his efforts in making the project run smoothly. I would also like to thank Susan Harper, Jufang Zhou, and Paula Parkinson at the Environmental Engineering Laboratory as well as my advisors Don Mavinic and.Jim Atwater for all their help and useful advice. Thanks are also extended to Dr. Sheldon Duff for allowing me to use his Microtox Toxicity analyser, and to Steve, Belinda, and Tanya at the Pulp and Paper Laboratory for showing me how to use it and fitting my time into their busy schedules. I would also like to thank Sandra Nelson at Paprican, EVS Consultants, and Environment Canada for supplying me with Daphnia. Finally, I would like to thank my wife Lori for putting up with me throughout my thesis writing and for giving me the incentive to get it done. xi Chapter 1 Introduction Like many North American municipalities, the City of Vancouver disposes of its solid waste in a landfill. Precipitation which falls on a landfill percolates through the emplaced waste, picks up contaminants, and exits as a wastewater known as leachate. Landfill leachate can cause a variety of environmental problems, including eutrophication and deoxygenation of nearby surface or ground water, and toxicity to organisms living in or drinking the contaminated water. These problems have been recognized for approximately thirty years, and regulations requiring collection and treatment of leachate have been developed and imposed over the last twenty years [52]. Landfill leachate strength and composition are influenced by many factors, including local precipita-tion, site geology, and waste composition, and therefore vary widely from site to site. The composition of leachate at a given site also varies with time, depending upon the degree of stabilization of the waste. While the stabilization process can be divided into five stages [11, 55], leachates are commonly characterized as young/acidic or old/methanogenic [16, 22]. Leachate from the Vancouver Landfill has a high NHx-N:BODs ratio and a low BOD5:COD ratio, and can therefore be considered an old/methanogenic leachate [4, 24]. In this study, NHX-N concentrations ranged from 83 to 336 mg/L and averaged 200 mg/L, while B O D 5 concentrations ranged from 20 to 89 mg/L and averaged 44 mg/L. COD concentrations ranged from 198 to 483 mg/L and averaged 353 mg/L. Leachate is collected and pumped from the Vancouver Landfill to the Annacis Island sewage treatment plant, which is currently being upgraded from primary to secondary treatment. The leachate makes up a significant portion of the inflow to the plant, and the high influx of leachate ammonia has the potential to upset the new process or to result in unacceptable effluent toxicity. As a result, the Greater Vancouver Sewerage and Drainage District required the City of Vancouver to investigate the removal of leachate ammonia as a condition of the City's 1993 permit for discharge to sewer. The City decided to investigate ammonia removal through a pilot scale study. The UBC Environ-mental Engineering Group has carried out an ongoing program of leachate treatment research for over 1 Chapter 1. Introduction 2 twenty years, and was therefore asked to participate in the study. The Environmental Engineering Group agreed to contribute their expertise and equipment to the study if the City allowed a graduate student to take part in the project. This thesis is the result of UBC's participation. Chapter 2 Research Rationale and Objectives This chapter is divided into five sections. In the first section, the City of Vancouver's research rationale and objectives are stated. Each of the next three sections consists of a literature review and a set of potential research objectives identified as a result of that review. The final section states which ofthese potential objectives came to be emphasized as the study progressed. 2.1 City of Vancouver 2.1.1 Research Rationale The City of Vancouver's 1993 permit for discharge of leachate to sewer required that removal of NHX-N to levels of 20, 60, and 120 mg/L be investigated. The City's initial literature review indicated that aerobic biological treatment would be the most effective method of accomplishing this task [27]. Previous research at UBC [26, 4, 24, 52] and elsewhere [22] has indicated that both fixed film and suspended growth biological nitrification systems are effective in removing ammonia from leachates similar to Vancouver's. However, few studies are available which directly compare the effectiveness of fixed film and suspended growth systems. Therefore, it was decided that the pilot scale study would focus on comparison of fixed film and suspended growth aerobic biological systems. Fixed film biological systems which have been used for nitrification of leachate ammonia include trickling filters and rotating biological contactors (RBCs) [22]. Previous experience with RBC treatment and the availability of a pilot scale RBC unit led to the selection of the RBC as the fixed film process to be studied [27]. Nitrification of ammonia in leachate has been achieved in suspended growth systems including con-ventional activated sludge, extended aeration, and aerated lagoons [22]. The sequencing batch reactor (SBR) is a simple activated sludge system in which aeration and settling are accomplished in the same basin. Because SBR systems are simpler to build, operate, and automatically control than continuous flow systems with recycle, and since parameters obtained for an SBR system would be valid in other 3 Chapter 2. Research Rationale and Objectives 4 types of activated sludge systems, an SBR was chosen to be the suspended growth process to be tested in the study [27]. 2.1.2 Research Objectives The City's research objectives were to determine operating parameters (eg. loading rates, nutrient additions, etc.) for each system, and to monitor leachate composition and flow. Loading rates resulting in effluents of < 1, 20, 60, and 120 mg/L of NHX-N were to be determined. These could be used to compare the costs of full scale systems which either treated the entire leachate stream to 20, 60 or 120 mg/L, or treated part of the stream more fully and mixed it with untreated leachate to achieve the effluent concentration desired. The results of the study will be used to design a full scale system which would give the best combination of performance and cost. 2.2 Nitrification of Landfill Leachate Ammonia This section reviews literature pertaining to nitrification of landfill leachate ammonia, and emphasizes treatment of older leachates with RBCs and activated sludge. The purpose of this section is to provide background information and to emphasize the importance of the study as a whole. 2.2.1 Landfill Biochemistry Waste placed in a landfill is initially degraded aerobically. Anaerobic conditions eventually predominate as waste is covered and compressed, precipitation percolates into the waste, and aerobes consume any remaining oxygen. The capacity of the waste to absorb water is eventually exceeded, leachate production begins, and anaerobic decomposition becomes fully established. At this point, the landfill is generally referred to as "young" or "acetogenic." Leachates of young landfills are characterized by low pH, high B O D 5 and COD, high BODs:COD ratio, and high ammonia. These leachate characteristics are caused by the predominance of acid forming anaerobic bacteria, which convert organic compounds in the solid waste to short chain fatty acids [11, 55]; Acidic conditions found in younger landfills also tend to mobilize metals. Within 2 to 10 years [22], a large population of methanogenic bacteria typically develops, and the landfill is referred to as "old" or "methanogenic." Anaerobic methanogenic bacteria convert fatty acids to methane and carbon dioxide. As a result, leachates of old landfills are characterized by low BODs, Chapter 2. Research Rationale and Objectives 5 COD, and BODsiCOD ratio, and by near neutral pH. Metal concentrations decrease, and recalcitrant humic and fulvic compounds are responsible for most COD. While anaerobic mineralization of organic compounds results in conversion of organic carbon to gaseous products, anaerobic mineralization of organic nitrogen (from proteins for example) stops at the production of ammonia. As a result, ammonia concentrations in older leachates remain high [11, 55]. Eventually, the landfill reaches a state of final stabilization. GELS production ceases as organic car-bon resources are exhausted. Degradation of recalcitrant compounds may increase release of humic substances, some of which can remobilize metals [11, 55]. 2.2.2 Nitrification Biochemistry Biological treatment of younger landfill leachates involves removal of B O D 5 and ammonia. B O D 5 can be removed aerobically or anaerobically in fixed film or suspended growth biological reactor [22]. Because this research deals with an older leachate, B O D 5 removal is of secondary importance, and ammonia removal will be emphasized in the remainder of the literature review. Ammonia can exist in water in two forms, ammonium ion ( N H 4 ), and free ammonia ( N H 3 ) . Ammonia dissociates according to Equation 2.1 [46]. NH+ *=- NH 3 +H+ K a = 5.848 x IO"10 (20°C) (2.1). N H 3 is more abundant at higher pH and temperature, while NHj is more abundant at lower pH and temperature. At near neutral pH and normal leachate temperatures, most ammonia is in the N H 4 form. In this thesis, the terms "ammonia" or "NHX" are used to refer to the sum of NH* and N H 3 , and N H 3 is referred to as "free N H 3 " to avoid confusion. While ammonia can be removed through incorporation into biomass when sufficient B O D 5 is present [61, 59], ammonia is more commonly removed from older landfill leachates through nitrification. Nitri-fication is a two stage process carried out by autotrophic bacteria which use ammonia or nitrite as an energy source and oxygen as the final electron acceptor. In the first stage (Equation 2.2), ammonia is oxidized to nitrite, typically by Nitrosomonas. In the second stage (Equation 2.3), nitrite is oxidized to nitrate, typically by Nitrobacter. 55NH+ +7602 +IO9HCO3 — C5H7NO2 +54NO-f + 5 7 H 2 0 + 104H2CO3 (2.2) Chapter 2. Research Rationale and Objectives 6 400NO-2 +NH+ +4H 2 C0 3 + HCOJ + 19502 — • C 5 H 7 N0 2 +3H 20 +400NOJ (2.3) Source: [19] Assuming that nitrifier biomass can be represented by the formula CsHVNO;?, theoretical cell yields of 0.15 mg cells/mg NH+-N and 0.02 mg cells/mg NOJ-N can be calculated for Nitrosomonas and Nitrobacter, respectively [19]. Omitting cell synthesis, 7.16 mg of alkalinity must be destroyed for every mg of NHX-N nitrified [19]. Factors influencing nitrification include temperature, dissolved oxygen (DO), pH, free N H 3 N0 2 and total B O D 5 concentration. The optimum pH range for Nitrosomonas is 7.9 to 8.2, while that for Nitrobacteria 7.2 to 7.6 [16]. It is generally recommended that DO concentration be kept above 2.0 mg/L if nitrification is to be achieved [43]. However, nitrification has been reported at DO levels as low as 0.3 mg/L, and values greater than 2.0 mg/L are sometimes reported to be necessary [63]. Nitrification can be accomplished at DO concentrations between 0.5 and 1.0 mg/L only if sufficient Mean Cell Residence Time (MCRT) is provided, and lower MCRTs will require higher DO concentrations [63]. Inhibition at low DO is often attributed to competition with faster growing heterotrophs, which can inhibit nitrifiers through competition if sufficient total B O D 5 (soluble or particulate) is available [20]. Nitrification is easily accomplished at ambient temperatures above 10 to lS'C, but may be difficult to maintain at lower temperatures [4, 24]. However, nitrification has been accomplished by acclimatized organisms at temperatures as low as 1 and 2°C in RBCs and SBRs, respectively [21, 47]. High concentrations of free N H 3 and NOJ can be inhibitory, particularly to Nitrobacter. Free N H 3 begins to inhibit Nitrosomonas at 10 to 150 mg/L, and 0.1 to 1.0 mg/L can inhibit Nitrobacter. Free nitric acid begins to inhibit nitrifiers at concentrations between 0.22 and 2.8 mg/L [1]. However, it is difficult to maintain N H 3 or NOJ inhibition, as the nitrifiers tend to become acclimatized to formerly inhibitory concentrations [65, 42]. 2.2.3 Description of Fixed Film Processes Fixed film processes which have been used for biological nitrification of wastewater ammonia include rotating biological contactors (RBCs) and trickling filters. In a typical RBC, several sets of plastic disks are mounted on a common shaft. The shaft is situated Chapter 2. Research Rationale and Objectives 7 on the axis of a semi-cylindrical tank which is divided into stages, one for each set of disks. For aerobic processes such as nitrification, the disks are usually 40% submerged. While the disks are commonly rotated directly by driving the shaft with a motor, air driven versions also exist. In an air drive RBC, compressed air is introduced into the tank and caught in cup like projections on the disks, causing the disks to rotate. In either type of RBC, biofilms grow on the disks, and wastewater is introduced into the tank. Rotation of the disks creates turbulence and provides mixing and aeration of the wastewater. Oxygen also reaches the biofilm through the thin film of liquid which covers the biofilm when disk rotation exposes it to the atmosphere. Supplemental aeration is sometimes provided to motor driven RBCs, and the drive air contributes to aeration and mixing in air driven RBCs. In a trickling filter, wastewater is sprayed over filter media which are usually arranged in a vertical cylindrical tank. The filter media are typically plastic or rock, and provide the surface on which the biofilm grows. The wastewater flow introduced is sufficient to keep the surface of the biofilm wet without filling the pore spaces in the media. Aeration is provided by oxygen diffusing into the thin film of wastewater trickling over the biofilm. 2.2.4 Review of Fixed Film Literature The following literature review will emphasize nitrification of landfill leachate ammonia using RBCs. 2.2.4.1 Leachate Nitrification Studies Henderson [26] used a lab scale RBC/anaerobic filter system to nitrify and denitrify an older leachate from a Taiwan landfill; The system was found to be effective in removing very high NHX-N concentrations. Large, unexplained N disappearances occurred in the nitrification reactor, possibly due to simultaneous nitrification and denitrification or aerobic denitrification. Knox [34] reported five years of full scale RBC leachate treatment at the Pitsea landfill, an older landfill in the U.K. The primary purpose of this plant was to nitrify leachate ammonia. The RBC process was chosen after pilot studies that also included trickling filter and suspended growth systems (see Section 2.2.7). While the system generally worked well, some problems with formation of calcium carbonate scale were encountered. The plant was designed to compensate for low temperature conditions by heating the leachate with landfill gas, supplemented by propane. Heating and pH adjustment were said to have contributed to the scale problem. Spengel and Dzombak [62] treated an older landfill leachate with bench scale RBCs. First stage DO Chapter 2. Research Rationale and Objectives 8 was correlated with loading; lighter loading produced higher first stage DO. In the three least heavily loaded RBCs, almost all influent ammonia was removed in the first stage, and first stage DOs were 3.5, 1.9, and 1.8 mg/L. In the more heavily loaded RBC, first stage DO was 1.4 mg/L, and significant nitrification occurred in the first and third stages. Besides nitrifying ammonia, the RBCs removed most BOD 5, 30 to 38% of the COD, and some of the Fe and Mn. Opatken and Bond [48] treated synthetic high ammonia leachate with a pilot scale RBC. Ammonia concentration was found to decrease at a constant rate with time at a given temperature (zero order reaction) at initial concentrations up to 700 mg NHX- N/L. This lead these authors to conclude that changing the reactor configuration to a plug flow, completely mixed, series of stirred reactors, or batch operation would not affect the reaction time. Reactor pH values below 7.2 were found to inhibit nitri-fication, and the maximum treatable influent NHX-N concentration was determined to be between 700 and 1000 mg/L for their system. Prediction of the effect of temperature on the reaction rate constant was judged to be possible using the Arrhenius equation, although temperatures investigated only ranged from 15.0 to 21.0°C. Peddie [52] treated a younger landfill leachate with the same RBC pilot plant used in this study. Nitrification was achieved in conjunction with B O D 5 removal in most cases. However, heterotrophs were found to consume all the available ammonia through assimilation when the BODs:NHx-N ratio exceeded 20:1. Low temperatures were found to be less inhibitory to nitrification than predicted by the Arrhenius equation with 0 — 1.09 (a value found by Peddie in his literature review). Extended HRTs used in cold temperature conditions were credited, with reducing temperature effects. Nitrification efficiency was found to be reduced sharply at HRTs less than about four hours. This relationship was relatively independent of temperature. Peddie's thesis also included a very extensive literature review dealing with landfill leachate treatment. 2.2.4.2 Other Related Studies Several studies in which high ammonia wastewaters, including landfill leachate, are treated by RBC systems focussed on simultaneous nitrification and denitrification [25, 66, 10, 41, 29, 67]. These studies are described further in Section 2.3.1. Klees and Silverstein [32] used a pilot scale RBC system to treat secondary effluent from a full scale trickling filter plant used to treat municipal sewage. Recirculation of RBC effluent such that 50 or 75% of the influent flow was recirculation was found to improve nitrification compared to no recirculation. The Chapter 2. Research Rationale and Objectives 9 postulated reason for this was that recirculation diluted B O D 5 in the RBC influent, although extremely low concentrations of influent B O D 5 did not improve nitrification to the extent expected. Boiler et al. [7] investigated tertiary treatment of secondary effluent using pilot and full scale RBCs. They found periodic flow reversal to enhance nitrification performance, particularly under a fluctuating ammonia load. Flow reversal was said to allow more slow growing nitrifying biofilm to build up on the final disks, and therefore allow more effective use of the available surface during high loading situations. Without flow reversal, biofilm would not be able to build up on the final disks fast enough to contribute to treatment during peak loads. Tertiary nitrification was enhanced if secondary effluent was filtered before entering the RBC system, preventing build up of non- nitrifying biological matter on the disks. Surampalli and Baumann [64] upgraded a full scale RBC plant treating municipal sewage. The plant had been designed for secondary treatment, but failed to meet secondary effluent criteria. Upgrading the plant by providing supplemental aeration not only allowed the plant to meet its secondary effluent standards, but also provided nitrification capabilities. Improved nitrification was reported to be the result of higher mixed liquor DO. Figueroa and Silversteen [20] used synthetic wastewater to simulate tertiary treatment of municipal sewage in a pilot scale RBC. Particulate B O D 5 was found to inhibit nitrification in the same manner as dissolved B O D 5 , i.e. through competitive exclusion of slow growing autotrophs by heterotrophs. Mixed liquor DO concentration was found to be independent of influent B O D 5 and ammonia removal, and mixed liquor suspended solids were extremely low in comparison to attached biomass. It was postulated that improved nitrification due to increased mixed liquor DO, such as that found by Surampalli and Baumann [64], is due to increased activity, of suspended organisms rather than biofilm organisms. This theory is supported by the findings of Paolini [50] who found that the dominant aeration mechanism in RBC systems is "oxygen diffusion through the liquid film during the air exposure cycle." Forgie [21] investigated low temperature effects on lab scale RBCs treating synthetic sewage intended to be "representative of individual households or workcamp installations" in northern Canada. Nitrifi-cation was achieved at temperatures as low as 1°C. Temperature effects at low temperatures were not found to follow the Arrhenius model traditionally used to model temperature effects. A replacement empirical approach which gave a better fit to the data was determined. Chapter 2. Research Rationale and Objectives 10 2.2.5 Description of Suspended Growth Processes Suspended growth processes which have been used for biological nitrification of landfill leachate ammonia include continuous flow activated sludge (AS) plants, sequencing batch reactors (SBRs), and extended aeration systems. In suspended growth systems, active organisms grow in small clumps or "floes" which are kept in suspension by mixing the contents of the reactor vessel, generally referred to as mixed liquor. Mixing is achieved through aeration or a combination of aeration and other forms of mechanical mixing. In continuous flow AS plants, influent and effluent enter and leave (respectively) the reactor vessel continuously. A clarifier vessel receives the effluent, and settled sludge is generally pumped back to the reactor vessel. SBRs combine mixing and settling in one vessel which operates on a timed cycle (eg. fill, aerate/react, settle, withdraw). Extended aeration systems can operate in a continuous or batch mode, and have lower F/M ratios and significantly longer HRTs than conventional activated sludge systems. 2.2.6 Review of Suspended Growth Literature The following literature review will emphasize nitrification of landfill leachate ammonia using activated sludge systems. 2.2.6.1 Older Leachate Nitrification Studies Azevedo [4] investigated nitrification and denitrification of high ammonia landfill leachate in a lab scale activated sludge system. The Vancouver (Burns Bog) Landfill leachate was used as the base wastewater, but ammonia was added to produce higher loadings. Influent ammonia concentrations as high as 1500 mg NHX- N/L were successfully nitrified and denitrified at temperatures between 12 and 20°C; nitrification failed when the temperature was decreased from 12 to 10°C. Nitrification resumed at 10°C when aerobic wasting and methanol addition ceased, indicating that short solids retention times inhibit nitrification at temperatures below 12°C. Nitrification also failed when the influent NHX-N concentration was raised from 1500 to 2000 mg/L, possibly due to insufficient DO, solids/scum/foaming problems, or inhibition by high N H 3 levels. Guo [24] investigated the effects of low temperatures on nitrification and denitrification using the same treatment system and Vancouver Landfill leachate without adding extra ammonia. Ammonia removal was accomplished at 20, 12 and 4°C with aerobic solids retention times of 20 and 60 days. The 60 day aerobic SRT system achieved better ammonia removal than the 20 day aerobic SRT system at Chapter 2. Research Rationale and Objectives 11 4°C, although the 20 day system was capable of reducing an influent NHX-N concentration averaging 210 mg/L to less than 14 mg/L. Nitrifiers were observed to require lengthy periods of acclimatization in order to recover from sudden drops in temperature. While membrane filtered PO^-P concentrations above 0.5 mg/L were adequate at 20°C, 0.8 mg/L were required at 12 and 4°C. Manoharan et al. [40] used the same system and leachate to investigate the effects of high metal concentrations on leachate treatment. Zinc, chromium, and nickel were added to the leachate in order to determine their effects on the process. Apparent inhibition by high zinc concentrations was actually caused by zinc induced precipitation of PO 3 - -? . P O 3 - - ? concentrations which appeared to be adequate when filtered through Whatman No. 4 filters were found to be inadequate when filtered through .45 pm membrane filters. It was recommended that membrane filtered P0 3~-P levels should be kept above 0.5 mg/L in order to avoid P limitation. Robinson et al. [60] and Last et al. [36] have been involved with the design and operation of full scale leachate treatment plants in the U.K. since the early 1980s. Many successful plants have been built using a combination extended aeration/SBR approach to treat leachate in automated aerated lagoons. Advantages of this approach over conventional activated sludge systems include robustness due to long HRTs (days instead of hours), complete and simple automation, and more allowable settlement time. Because of the "notoriously problematic" settling characteristics of slow growing nitrifiers, the provision of long HRTs and long settling times were said to be particularly important. Removal of ammonia in these systems has been accomplished by assimilation (when the BOD5:NH3-N ratio is 100:3.6 or greater), and by nitrification when less B O D 5 is available. Mena et al. [42] used a lab scale SBR reactor to treat leachate from an older landfill. DO was found to be a good indication of nitrification; during nitrification, DO remained between 1 and 2 mg/L, but when all NHX-N had been nitrified, DO increased to saturation values. Free ammonia (NH3) con-centrations in the range of 30 to 40 mg/L inhibited Nitrobacter, producing nitrite buildups. However, acclimatization occurred within four months. Nitrification was found to occur as a zero order reaction, and high nitrification rates were attributed to the low BODs:NHx-N in the leachate. Hosomi et al. [30] also used a lab scale SBR reactor to treat older landfill leachate. Nitrification was successful, but denitrification required addition of methanol as a carbon source. Attempts to initiate endogenous denitrification were unsuccessful. Pretreatment with ozone was found to enhance COD removal. Knox [33] used activated sludge and trickling filter pilot plants to treat an older landfill leachate. Chapter 2. Research Rationale and Objectives 12 Difficulty was encountered in using SRT as a process control parameter, as influent and effluent VSS were often high compared to expected solids production; also, it was impossible to determine what proportion of VSS was lost in the effluent. Settling problems were said to be common in nitrification systems with low B0D5:NHX-N ratios. Deliberate solids wasting was never found to be necessary. 2.2.6.2 Other Related Studies Azimi and Horan [5] found that plug flow activated sludge reactors were superior to completely mixed activated sludge reactors for nitrification. Improved performance in plug flow situations was attributed to reduced free ammonia ( N H 3 ) inhibition. Liu et al. [38] treated a younger landfill leachate with lab scale SBRs. SBR treatment was found to be effective in removing ammonia and metals with and without pretreatment by ammonia stripping and metal precipitation. Ying et al. [68] found that addition of powdered activated carbon to SBRs treating younger landfill leachate resulted in improved organic removal, better sludge settling and dewaterability, and improved nitrification. Oleszkiewicz and Berquist [47] used lab scale SBRs to treat a mixture of domestic sewage and high nitrogen effluent from an estrogen factory. Four reactors were operated, two on a 12 hour cycle and two on an 8 hour cycle. Each had 2 hour "fill and mix" and "settle and decant" periods, and an HRT of 24 hours. The nitrification performance of the reactors was similar at 15°C, but the 12 hour cycle reactors were superior at 7, 5, and 2°C. Hourly measurements were found to be superior to daily measurements for determining if reactors were underloaded or operating at full capacity. The variation of reaction rate with temperature was found to be discontinuous. 2.2.7 Comparison Studies Knox [34] described a decision to build a full scale RBC plant to treat leachate from an older landfill. Pilot studies were conducted with RBC, trickling filter, and activated sludge systems. Projected capital costs for a trickling filter system were much higher than for activated sludge and RBC systems, which were similar. Operating costs for an RBC system were expected to be much lower than those for an activated sludge system due to reduced power demands. Settling problems encountered in activated sludge pilot studies were another reason for the choice of an RBC system. While no problems with scale formation and metal precipitation were experienced at pilot scale, two serious incidents occurred at full Chapter 2. Research Rationale and Objectives 13 scale. A carbonate/bicarbonate equilibrium shift caused by leachate heating and pH adjustment was blamed for these incidents. The lack of scale problems at pilot scale was attributed to "pretreatment" in the open ditch leachate collection system at the landfill [33]. Lugowski et al. [39] compared pilot scale activated sludge and RBC plants for treatment of an older landfill leachate. No settling problems were found in either system, and both systems were severely inhibited by calcium and iron encrustation. After a pretreatment system for metal removal was installed, the systems were compared again, and both were found able to meet the required effluent criteria. Estimation of full scale costs indicated that the activated sludge system would have significantly lower capital and operating costs, and therefore a full scale activated sludge system was built. Pisano et al. [53] compared the performance of lab scale RBCs and SBRs when subjected to shock loads of toxic organics, including toluene, benzene, and 2,4,6-trichlorophenol. A synthetic wastewater containing 85 mg/L of TKN and no NHX or NOx w a s u s e ( L Shock loads resulted in inhibition of nitrification in the RBC, although recovery occurred within 24 hours. Nitrification was unaffected by shock loading in the SBR. Shock loadings were said to represent "equivalent mass loading of organic shock within a 24 hour period." The concentrations of toxic organics added to the RBC system were six times those added to the SBR system, and it is unclear how the equivalence of mass loading was determined. Galil and Rebhun [23] compared lab scale activated sludge and RBC systems treating oil refinery wastewater. The reactors studied had equivalent volumes, and therefore the RBC system developed about 10 to 50 times the mass of volatile solids as the activated sludge system. The RBC was also operated at one third of the HRT of the activated sludge system. Stressing the system by increasing phenol concentrations caused increased effluent solids levels in the activated sludge system, but not in the RBC system. As a result, the RBC system recovered more quickly from shocks. The RBC was found to produce less sludge with better settling and dewatering characteristics than the activated sludge system, even under normal operating conditions. Ehrig [16] used a variety of systems including aerated lagoons, activated sludge, and RBCs to treat both older and younger landfill leachates at a variety of scales. While both suspended growth and fixed growth systems were investigated, no side by side comparisons were reported, and only general observations of a comparative nature can be gleaned from the study. Activated sludge systems were difficult to start up when older leachate was being treated unless nitrifying sludge was available. Such startup problems were not reported for aerated lagoons or RBCs. Both aerated lagoon and activated Chapter 2. Research Rationale and Objectives 14 sludge systems experienced nitrification and BOD removal problems at temperatures below 5°C. Low temperatures were also reported to cause settling problems in activated sludge systems, particularly at higher loading rates. No low temperature data were reported for RBC systems. RBC units were found to be capable of removing up to 95% of the NHX-N at loadings of up to 10 g/m2/d, and continue removing a"high" proportion of NHX-N at loadings up to 17 g/m2/d. However, loadings above 2 g/m2/d resulted in inhibition of NOj oxidation, and therefore were not recommended. Paolini and Variali [51] treated solid waste processing effluent (similar to younger leachate) with lab scale activated sludge and RBC systems. RBC sludge had better settling characteristics than activated sludge, and sludge recycle was not required in the RBC. Clark et al. [12] treated domestic sewage with a pilot scale RBC. Full scale costs were estimated for an RBC system and several activated sludge configurations. Calculated capital costs were significantly higher for the RBC, while calculated operating costs were significantly lower. Labellaet al. [35] treated winery wastes (high B O D 5 , low N) with pilot scale aerated lagoon, activated sludge, and RBC systems. While solids for all systems settled satisfactorily, RBC solids settled more quickly. Estimated full scale capital and operating costs were both found to be lower for an RBC system. 2.2.8 Research Objectives Although both fixed growth and suspended growth systems have been studied extensively, very few side by side comparisons have been made. Even in a side by side study, it is difficult to compare the two types of systems, especially in terms of cost effectiveness. Only full scale costing based on pilot scale loading parameters could determine which system is more cost effective, and this is beyond the scope of this thesis. However, several useful comparisons can be made. Some of the topics which deserve coverage include comparisons of response to shocks (loading, temperature etc.), recovery from failures, waste solids production, incidental removal of metals, COD, B O D 5 , colour, alkalinity etc. during nitrification, and general ease of maintenance and operation. 2.3 Nitrogen Disappearance from Nitrification Systems Nitrification systems are designed to convert NHX-N to NOJ-N through the aerobic biological process of nitrification (see Section 2.2.2). Small amounts of dissolved N are expected to be lost due to NHX-N volatilization and assimilation by bacteria, but the majority of the N is expected to remain in solution. Chapter 2. Research Rationale and Objectives 15 In contrast, the conversion of NOJ-N to gaseous N compounds, or denitrification, is expected to result in the loss of dissolved N. However, biological denitrification is generally considered to be an anaerobic process, and is therefore not expected to occur in nitrification systems. In a recent UBC study, significant N disappearances were noticed in a nitrification reactor [26]. Two possible explanations for this N disappearance are simultaneous nitrification and denitrification (SND) and aerobic denitrification. 2.3.1 Simultaneous Nitrification and Denitrification Masuda, Watanabe, et al. [41, 66, 67] published a series of studies in which simultaneous nitrification and denitrification (SND) was found to occur in systems intended primarily for nitrification of landfill leachate NHX-N. Increased denitrification was found to occur with increased organic loading, increased temperature, and decreased atmospheric oxygen partial pressure. Acetate and methanol were found to be good carbon sources for SND. Biofilms were microscopically examined, and nitrifiers, denitrifiers, and other heterotrophs were found to coexist. The occurance of SND was attributed to the presence of micro-aerobic and micro-anaerobic environments, which temporarily exist within the biofilm due to the rotation of the disk. Chen et al. [10] proved that the products of endogenous decay could be used as a carbon source for denitrification in both fixed growth and suspended growth systems. Synthetic wastewaters and lab scale systems were used. Hosomi et al. [29] compared B O D 5 and ammonia removals from a high BOD, high ammonia landfill leachate in two lab scale systems. One system was a standard RBC, while the other was an RBC which had an anaerobic biofilter added to the tank beneath the disks. Addition of the biofilter was found to enhance COD and nitrogen removal (i.e. denitrification). SND occurred in both systems. 2.3.2 Aerobic Denitrification Researchers at Delft University of Technology in the Netherlands published a series of articles dealing with Thiosphaera pantotropha [28, 58, 57]. This organism, which was isolated from a domestic sewage treatment plant, was found to be capable of aerobic denitrification, and was found to grow well in fixed and suspended growth situations. Gupta et al. [25] evaluated the use of T. pantotropha in treating a high strength synthetic nitrogenous fertilizer wastewater. The organism was found to be capable of high N removals at loading rates up to 9.36 g/m2/d in an RBC system with an HRT of 2.0 days. HRT and loading rate were found to be Chapter 2. Research Rationale and Objectives 16 important process parameters. 2.3.3 Research Objectives Disappearance of nitrogen from nitrification systems has been reported in a variety of studies and attributed to either aerobic denitrifying organisms or SND. Therefore, it was decided that if NHX-N disappearance was noted, it should be investigated through rigorous N balances, including quantifying ammonia volatilization and possibly using 15-N tracer techniques. 2.4 Toxicity of Landfill Leachate 2.4.1 Previous Research at U.B.C. Most local regulations and permits measure toxicity in terms of rainbow trout L C 5 0 . Previous research at U.B.C. found that Daphnia L C 5 0 and rainbow trout L C 5 0 test results compared favourably for landfill leachate toxicity testing [3, 9]. Daphnia L C 5 0 tests require smaller sample volumes, less laboratory space, and less time (48 hours versus 96 hours) than fish L C 5 0 tests, and are therefore considerably less expensive. The Microtox(TM) E C 5 0 test requires even less time (< 1 hour), smaller sample volumes, and less laboratory space than the Daphnia L C 5 0 test. If results for Microtox E C 5 0 compared as favourably with rainbow trout as Daphnia L C 5 0 test do, considerable savings of time and money could be achieved. The following section reviews studies in which fish, Daphnia, and Microtox bioassays are compared. 2.4.2 Comparison Studies In the Microtox(TM) test, the decrease in light output of a marine luminescent bacteria (Photobacterium phosphoreum) upon exposure to toxicants is measured. This test was developed in the late 1970's by Microbics Corporation, and was first offered for sale in 1978 [18]. Bulich et al. [8] compared Microtox E C 5 0 tests to published fish data for 20 pure compounds. Results were generally found to be similar. Also published were side by side comparisons of Microtox E C 5 0 results to fish (mostly fathead minnow) and invertebrate (mostly Daphnia) L C 5 0 results for 56 complex effluents. Microtox results were found to correlate better with fish than invertebrates. Lebsack et al. [37] compared the Microtox assay to fish (rainbow trout and fathead minnow) L C 5 0 tests for fossil-fuel process waters and phenolic constituents. They found good correlations between Microtox and rainbow trout, and poorer correlations with fathead minnows. Results for the two fish Chapter 2. Research Rationale and Objectives 17 species were found to be as different from each other as from Microtox results. Fish were more sensitive than Microtox in about half the cases, and were more sensitive to phenolic compounds in particular. Curtis et al. [14] evaluated the potential of the Microtox test for predicting acute toxicity of organic chemicals to fathead minnows. Microtox E C 5 0 results were compared to published fathead minnow L C 5 0 results for 68 organic chemicals and pesticides. The reproducibility of the Microtox test was found to be similar to that expected of Daphnia and fish bioassays. Correlations were found to be better for organic chemicals (particularly alcohols) than for heavy metals. It was concluded that Microtox E C 5 0 could only give an order of magnitude prediction offish L C 5 0 , and that the Microtox test was therefore only suitable for toxicity screening. Qureshi et al. [56] compared the Microtox test to rainbow trout, Daphnia, and Spirillum bioassays. The Microtox test results compared favourably with the other bioassays in general. Better correlations were achieved with organic chemicals and complex effluents than with inorganic chemicals. The Microtox test was found to be a poor indicator of toxicity in wastewaters where the primary toxicants were ammonia or cyanide. As Microtox was not consistently the most sensitive test, it was advised that it could only be used in conjunction with other tests rather than as a replacement. It was mentioned that the addition of 2% NaCl to freshwater samples for osmotic protection of the marine bacterium could reduce sample integrity. The influence of using Microtox diluent, which may have a significantly different pH than the receiving water, was also questioned. Plotkin and Ram [54] compared the toxicity of a low NHX-N landfill leachate to fathead minnows, Daphnia magna, and P. phosphoreum. The leachate was highly toxic to P. phosphoreum, but not very toxic to fish or Daphnia. Toxicity to Daphnia and fish was attributed to NHX, Ag, Hg, Pb, Cd, and Mn, but no source of Microtox toxicity was reported. Kaiser and Esterby [31] used regression and cluster analysis to compare published acute toxicity results of 267 chemicals for several bioassays, including Microtox E C 5 0 , Daphnia L C 5 0 and fathead minnow LCso- The 267 chemicals included a wide variety of organic chemicals, and high colinearity was found between Microtox and fathead minnow results. Cronin et al. [13] compared published data for fathead minnows and Daphnia to their own Microtox data. Forty common organic pollutants were used. Correlations between fathead minnow results and Daphnia results were found to be better than correlations between fathead minnow results and Microtox results. Day et al. [15] evaluated the toxicity of leachates from automobile tires based on several bioassays, Chapter 2. Research Rationale and Objectives 18 including Microtox E C 5 0 and rainbow trout, fathead minnow, and Daphnia L C 5 0 . Leachates were produced by immersing whole new or used tires in water; samples were removed after 5, 10, 20, and 40 days. Tire leachates were found to be non-toxic to Daphnia and fathead minnows, but toxic to rainbow trout and P. phosphoreum. The Microtox test was more sensitive than the rainbow trout test to leachates from new tires, and the two bioassays had similar sensitivity to leachates from older tires. 2.4.3 Research Objectives The above comparison studies show that the Microtox test varies in its ability to predict toxicity to other organisms. Only one study was found which compared Microtox E C 5 0 data to rainbow trout or Daphnia L C 5 0 data for landfill leachate. Therefore, the initial toxicity research objective identified for this study was to determine how well Microtox E C 5 0 results correlate with rainbow trout L C 5 0 results for landfill leachate. As the study progressed, ammonia was identified as the primary toxicant affecting rainbow trout. Because of P. phosphorevm's high ammonia tolerance, correlations between standard Microtox tests and rainbow trout L C 5 0 were found to be poor. Substituting sucrose for NaCl for osmotic adjustment is said to increase the sensitivity of the Microtox test to ammonia [18], but little published information is available where this substitution has been used. Therefore, it was decided to investigate the use of sucrose as an osmotic adjustment, and to determine whether the modified Microtox test compares more favourably with the rainbow trout L C 5 0 test. 2.5 Research Rationale and Objectives - Summary The original plan for the study was that the City would keep both plants operating and contract a private laboratory (Cantest) to obtain the analytical data needed to achieve the City's objectives. The author would assist in monitoring and maintaining the plants while pursuing the objectives indicated in Sections 2.2.7, 2.3.3, and 2.4.3. By December 1993, it became apparent that keeping the pilot plants operating and collecting samples for analysis required more time than City personnel had allotted for the task. Also, significant nitrogen loss had not been detected up to this point. Therefore, it was decided that the author should spend more time operating and monitoring the pilot plants, share the objectives in section 2.1.2 (loading rates and leachate composition), and de-emphasize the objectives in Section 2.3.3 (nitrogen disappearance), while continuing with the objectives in Sections 2.2.7 (comparison of fixed and supended growth systems) and 2.4.3 (toxicity test comparisons). Chapter 3 Study Design 3.1 Site Description The Vancouver Landfill is located in the southwest corner of Burns Bog in the municipality of Delta. Burns Bog is a peat bog situated on the Fraser River delta. The soil layers beneath the landfill include a 2-5 m thick layer of peat overlying a 1-6 m layer of silt, overlying several hundred metres of silt and sand. The total area of the landfill is 635 ha, of which 172 ha have been filled since the landfill was opened in 1966. Refuse is accepted from Vancouver, Delta, Richmond, UBC, and Whiterock; the landfill currently serves approximately 700,000 people. Refuse received averaged about 200,000 tonnes per year between 1966 and 1981, increased linearly to nearly 800,000 tonnes per year in 1987, then decreased again, averaging almost 500,000 tonnes per year since 1989. Before refuse is emplaced in a given landfill cell, a 3 m thick demolition layer is deposited. The demo-lition layer consists of waste wood, concrete, asphalt, and soil, and has a higher hydraulic conductivity than the compressed peat and silt beneath it. The leachate is conveyed through the demolition layer to a ditch surrounding the site, and is pumped from a pump station at the south west corner of the site to the Annacis Island Sewage Treatment Plant. A drainage ditch surrounding the leachate ditch intercepts surface water approaching the landfill from off-site. Because leachate is pumped from the inner ditch, the water level in the inner ditch is approximately 30 cm below the water level in the outer ditch, and any flow between the ditches is from the outer ditch to the inner ditch. According to City of Vancouver data, 54% of the total precipitation that fell on the site during the study was collected as leachate. Previous hydrogeological studies estimated that approximately 50% of the total yearly precipitation which fell on the site evaporated. Source: [27] 19 Chapter 3. Study Design 20 Figure 3.1: Photograph showing RBC, SBR, and Trailer 3.2 Treatment Systems Two pilot plants, an RBC and an SBR, were operated in parallel during the study. The pilot plants were both placed at the south west corner of the landfill site, near the pump station. Both pilot plants were automatically controlled using a programmable logic controller (PLC) and a series of solenoid valves. These items, and other expensive or sensitive equipment such as the air compressor and the field instruments, were housed in a trailer which was kept locked. The City of Vancouver supplied the trailer and all other equipment with the exception of the SBR reactor vessel, the RBC unit, and a few minor items, which were supplied by UBC. A photograph showing the trailer, SBR, and RBC is provided in Figure 3.1. 3.2.1 Leachate Supply A common leachate supply was provided for both systems by running a 3/4" PVC line from the pressure side of the leachate pump to head tanks on the roof of the trailer. Leachate flow from the head tanks to each system was regulated by the PLC/solenoid valve control system. The original set up included a 50 Chapter 3. Study Design 21 L head tank supplied by the City. This was replaced by a set of two 70 L head tanks supplied by UBC on April 18, 1994, when problems with SBR filling indicated the need for greater storage capacity. 3.2.2 Phosphorus Addition The leachate was deficient in phosphorus (P), and therefore a nutrient solution of Na3PG"4. dissolved in tap water was fed to each system. Nutrient solution was mixed in 20 L plastic gasoline cans and poured into 20 L graduated plastic reservoirs from which it was pumped to the systems. The graduations on the reservoirs were used to determine the flow of nutrient solution to each system. At the beginning of the study, nutrient solution was pumped using two parallel Brooks Model EX225-419 bellows pumps supplied by UBC and 0.5" plastic tubing. Later, one bellows pump failed, and the other pump was used to operate two bellows at once. The bellows pumps were found to be somewhat unreliable, and therefore were replaced by the City with a double headed Masterflex pump on February 6, 1994. With the bellows pumps, P additions to the reactors could be varied by varying the flow rate of nutrient solution, but the Masterflex pump delivered at one flow only. Therefore, P additions from this point onward were achieved by varying the amount of NaaPO-j added when making nutrient solution. Nutrient solution reservoirs and pumps were housed in the trailer. 3.2.3 RBC System A schematic of the RBC system, including a flow chart detailing the process control, is given in Figure 3.2. The RBC unit was a Model S5 package plant manufactured by CMS Equipment Limited of Mississauga Ontario, and was the same unit used by Peddie in a previous UBC leachate treatment study [52]. Specifications of the unit are also given in Figure 3.2. The RBC unit includes a primary settling tank, a disk zone, and a secondary settling tank. However, only the disk zone was used for this study. Leachate was added directly to the first stage, and effluent samples were taken from the final stage. The disk zone was divided into four stages during Peddie's study [52], but the divider between the second and third stages had been removed prior to this study, so that the disk zone consisted of three stages. The first stage contained one set of fifteen disks, the second stage two sets of seven disks, and the third stage one set of seven disks. Each set of disks consisted of two solid fibreglass disks and thirteen or five plastic mesh disks (see Figure 3.3). The mesh disks were 4 mm thick and had 10 mm square openings. Chapter 3. Study Design 22 70 L H e a d T a n k 70 L H e a d T a n k I — O v e r f l o w L e a c h a t e S u p p l y f r o m L e a c h a t e Pump D i s c h a r g e V a l v e A 3 / 4 ' S o l e n o i d 2 L D o s i n g T a n k V a l v e B 3 / 4 ' S o l e n o i d 20 L N u t r i e n t T a n k P u n p 2 L / d a y RBC S P E C I F I C A T I O N S Disk D i a m e t e r : 0.9 m No. o f S t a g e s ^ 3 No. o f D i s k s : 36 A r e a : 4 7 V o l u m e : 2 4 5 L S p e e d : 6 RPM E l e c t r i c M o t o r : 0.5 HP E f f l u e n t P R L X E S S C O N T R O L F L O W C H A R T S T A R T F I L L C Y C L E Fil l D o s i n g T a n k - V a l v e A: O p e n - V a l v e B: C l o s e d Time: 2 t o 5 9 min. DOSE C Y C L E E m p t y D o s i n g T a n k - V a l v e A; C l o s e d - V a l v e B: O p e n Time: 1 min. Figure 3.2: RBC System Schematic Chapter 3. Study Design 23 Figure 3.3: Photograph of RBC Unit The disks were rotated by a 0.5 horsepower electric motor, and were 30% submerged. Aeration was accomplished by disk rotation alone. When setting up the system, it was discovered that cross leaks occurred between all three sections of the RBC unit. Several attempts were made to seal the leaks, but leakage continued. As a result, it was decided that all three sections would be filled to the same level, and that effluent would be withdrawn from the final clarifier at a level just high enough to allow disk zone effluent to exit the disk zone by the normal pathway. It was assumed that the lack of hydraulic gradients between sections would prevent any inappropriate mixing. 3.2.3.1 Gas Collection Modifications In order to allow collection of gases from the disk zone without mixing disk zone and primary or secondary clarification zone air space, the RBC unit was modified as follows. Plexiglass sheets were cut to size, placed over the clarification zones, and screwed down. Silicone sealant was used to seal the edges, screwholes, and any other cracks or holes. An inverted weir was constructed at the channel where disk zone effluent enters the secondary clarification zone, so that the effluent could flow from one zone to the Chapter 3. Study Design 24 other without contacting the atmosphere. The vents at the top of the RBC cover were sealed using the vent covers, plexiglass, and silicone sealant. Any other holes in the cover were also sealed with silicone sealant. The male end of a plastic coupling was then attached to the rear of the cover. The female end of this coupling was attached to the gas collection apparatus, which included an air pump. When the RBC cover was closed tightly, and the pump was turned on, it was assumed that air would exit only through the pump and enter everywhere else. 3.2.3.2 Crane A crane was constructed so that the RBC lid could be lifted easily by a single operator. The crane is shown in Figure 3.4. A T shaped beam made by nailing wooden two by sixes together was suspended between the top of the trailer and a post made of another two by six. Clothesline pulleys were attached to the beam directly above the ends of the disc/axle assembly, and cables were attached to the lid at corresponding points. Lifting cables were clipped to the lid, and strung through the pulleys to a boat winch fastened to the beam. The lifting cables could be removed from the lid in order that the crane could also be used to lift and weigh the disk/axle assembly. However, the crane was never used to weigh the disk/axle assembly. 3.2.4 SBR System A schematic of the SBR system, including a flow chart detailing the process control, is given in Figure 3.5 (from [27]). The reactor vessel used was a high density polyethylene container supplied by UBC. When filled to the overflow point, the total liquid depth was 100 cm, and the volume was 365 L. Ten ports at depths of 7,17,27,...,97 cm were used to vary the loading by moving the effluent discharge line and adjusting the fill time. A photo of the SBR vessel showing these ports and the perforated pipe used to distribute raw leachate during loading is provided in Figure 3.6. Originally, aeration began immediately after filling stopped, and solids were wasted by draining a small percentage of the mixed liquor at the end of each aeration cycle. 3.2.4.1 Process Control Modifications When the SBR was set up in early July 1993, a solids wasting cycle was inserted between the aerate and settle cycles in order to provide a theoretical SRT of approximately 20 days. However, problems retaining solids led to the discontinuation of intentional solids wasting on November 21, 1993. Solids wasting was never reinstated, so the SBR operated with an infinite theoretical SRT for the balance of the study. In order to get the SBR going (after all the solids washed out during the 1993/94 Christmas break), leachate loading and effluent withdrawal were discontinued for a short time. The reactor was reinoculated with sludge from the UBC Pilot Plant at B.C. Research, heated with two 300 W aquarium heaters, and fed ammonium sulfate and sodium bicarbonate beginning on January 17th. On January 26th, leachate loading and effluent withdrawal were reinstated. On January 28th, settling time was increased from 1 hour per cycle to two hours per cycle. In order to retain an 8 hour cycle, the aeration time was reduced by 1 hour. One heater was removed on February 16th, and the second was removed on February 18th. After intentional wasting was discontinued, it was noticed that unintentional wasting continued to occur due to mixed liquor overflow. Mixed liquor overflow occurred for two reasons, each requiring its own remedy. First, aeration began immediately after filling stopped, so that mixing occurred before extra leachate had finished overflowing; maximum level in the tank was regulated by an uncontrolled open overflow port. It was difficult to ensure that the reactor would fill exactly to the overflow point each time by regulating fill time alone. Therefore, an overflow cycle (in which no aeration or filling occurred) Chapter 3. Study Design 26 20 L N u t r i e n t Tank Pump 2 L / d a y V a l v e B 1/2' Solenoid - L X -Air C o m p r e s s o r Flow=0.5 SCFM 70 L Head Tank 70 L Head Tank V a l v e A 3 / 4 ' Solenoid r \ ^ 1 1— Over f low L e a c h a t e Supply f r o m L e a c h a t e Pump D ischarge V a l v e C 3 / 4 ' Solenoid - £ X ] — Over f low 365 L T r e a t m e n t V e s s e l V a l v e D 3 /4 * Solenoid • E f f l u e n t V A L V E DESCRIPTIONS A* Fill V a l v e B: Air Supply V a l v e O Over f low V a l v e (was Solids Wast ing V a l v e ) D; E f f l u e n t D ischarge V a l v e PROCESS CONTROL FLOW CHART START FILL OVERFLOW AERATE S E T T L E DISCHARGE A: 0 A: C A: C A: C A: C B> C B* C B« 0 B< C B* C o c O 0 O C . D C Ci C D= C D: C D= C D: C D: a 5-30 min. 10 min. 5.5-6.5 h. 1-2 h. 15 min. T o t a l Cyc le Time = 8 h o u r s Figure 3.5: SBR System Schematic Figure 3.6: Photograph of SBR Chapter 3. Study Design 28 was inserted between the fill and aerate cycles on March 30th. Extra leachate could then freely overflow before significant mixing occurred. The second source of unintentional mixed liquor loss was noticed at this time. When aeration began, the free surface of the mixed liquor raised slightly, presumably due to the volume displaced by the air bubbles. This extra volume flowed out the uncontrolled overflow port. In order to stop this, the unused solids wasting valve was placed on the overflow port and the PLC was programmed to open it only during the overflow cycle, leaving it closed at all other times. From this point on the only solids lost were unsettlable solids in the effluent. The process control flow chart in Figure 3.5 shows the process control scheme as of April 11th, when this final modification was implemented. 3.2.4.2 Gas Collection Modifications The SBR vessel was supplied as shown in Figure 3.6, and therefore a cover was required if gas collection was to be accomplished. While a simple cover could have been fashioned by sealing a flat plate over the lip of the reactor, this would have allowed a headspace of only a few centimetres above the surface of the mixed liquor. Such a headspace would not have been comparable to the RBC headspace. This could have been remedied by lowering the fill point and changing the reactor volume, but the experiment was already underway before the cover was added, and therefore changing the volume was considered undesirable. A cover for the SBR vessel was fashioned from an inverted plastic container (a child's sandbox) which allowed a headspace of 23 cm. To facilitate access to the inside of the SBR during normal operation, a portal was fashioned into the top of the cover. A rectangular hole was cut into the sandbox, and a plexiglass sheet with a 30 cm diameter hole in the center was fastened to the sandbox with screws. A piece of aluminum extrusion was fastened to the sandbox along each edge of the plexiglass sheet to provide rigidity. All edges and screw holes were sealed with silicone, and a silicone bead was placed around the circular hole to act as a gasket. A 35 cm diameter plexiglass disk was used to cover the hole during gas collection, when it was fastened down with six screws. The threads of the screws were sealed with teflon tape. The cover was attached to the top of the SBR vessel with screws, and the seam and screw holes were sealed with silicone sealant. The male end of a plastic coupling was attached to the wall of the cover, and the matching female end of this coupling was attached to the gas collection apparatus, as for the RBC. While it is somewhat difficult to make out, the SBR can be seen with the gas collection apparatus Chapter 3. Study Design 29 installed in Figure 3.4. Originally, it was intended that the entire gas stream produced by aeration would pass through the gas collection apparatus without operating the air pump. However, the gas collection apparatus created too much back pressure, causing some silicone seals on the cover to burst. If the pump was turned on during gas collection, most seam bursting was prevented, but air still escaped between the plexiglass disk and the silicone gasket. As a result, it was assumed that the air in the headspace was completely mixed, and the airflows from the compressor to the SBR, and through the gas collection apparatus, were both measured. 3.2.5 Effluent Discharge Effluents from both plants and overflows from the head tanks, RBC dosing tank, and the SBR were allowed to flow back to the leachate ditch. Since the combined daily flow through the pilot plants was less than 0.2% of the total leachate flow, it was assumed that concentrations of leachate constituents and leachate flow measurements would not be significantly affected. 3.3 Sample Collection Both City personnel and the author collected samples for laboratory analyses. Unless otherwise noted, information in this section refers to equipment and techniques used by the author. Samples were collected once weekly by City personnel and one to three times weekly by the author. City personnel placed samples in plastic bottles supplied by Cantest, and transported them to Cantest in coolers with ice packs. The author's samples were not placed in coolers, as they were delivered to the UBC laboratory within two hours of collection. Once at the laboratory, samples were either prepared for analysis immediately or refrigerated at 1°C. Refrigerated samples were usually prepared for analysis the following morning, although samples were sometimes refrigerated for two days, particularly when sampling was done on two consecutive days. Leachate samples were generally taken from the head tank overflow line, although City personnel used a Watera pump to take samples from the leachate well for the first few months of the study. Leachate samples on which Daphnia and Fish LC50 were to be done were taken from the leachate well in a 15 litre galvanized steel bucket. RBC effluent samples were taken from the final stage of the RBC with a Watera pump. SBR effluent and mixed liquor samples were either dipped out of the top of the reactor or poured Chapter 3. Study Design 30 from a valve on the side. Samples were usually placed in 500 mL to 1 L bottles. When analyses required greater volumes per sample, several 500 mL or 1 L containers were filled. In order to ensure uniformity among different bottles of the same sample, a 15 litre galvanized steel bucket was rinsed several times with the sample in question, filled, and stirred, and bottles were filled from the bucket. 3.4 Analytical Methods Laboratory analyses of samples collected by City personnel were carried out by Cantest. Analyses of samples collected by the author were carried out at the UBC Environmental Engineering Laboratory by the author or with the assistance of laboratory staff. Table 3.1 lists the parameters determined during the experiment, detection limits, and the frequency with which they were determined by Cantest and UBC. When detection limits differed between Cantest and the UBC laboratory, two numbers are given. The number in brackets is the UBC detection limit. Cantest's analyses were conducted according to procedures found in Laboratory Manual for the Che-mical Analysis of Water, Wastewater, Sediments and Biological Materials, 2nd Edition, published by the Government of B.C. , Ministry of the Environment, Water Resource Services, 1976, and Standard Methods for the Examination of Water and Wastewater, 17th Edition, 1989, and 16th Edition, 1985, published by the American Public Health Association. According to City instructions, Cantest analyzed samples of leachate and SBR effluent directly for all listed parameters. SBR mixed liquor samples were analyzed for TSS only, and RBC samples were analyzed directly for TSS, then settled for 30 minutes and analyzed for all listed parameters (including TSS). Unless otherwise noted, information in the remainder of this section refers to equipment and proce-dures used by the author. 3.4.1 Preparation of Glassware Glassware for most occasions was prepared by rinsing once with hot tap water and twice with distilled water. Visible stains, if present, were scrubbed off with detergent and a brush before rinsing. When analyses were to include metals or when diluent solutions and reference toxicant solutions were made for Microtox testing, all glassware and other apparatus (eg. filtering apparatus, sample containers, measuring apparatus) were acid washed with 10 or 20% nitric acid before thoroughly rinsing with Chapter 3. Study Design Table 3.1: Analytical Parameters Parameter Detection Limit Cantest Frequency UBC Frequency pH weekly 1 to 3 times per week True Colour 5 units weekly never TSS 1 mg/L weekly 1 to 3 times per week VSS 1 mg/L rarely 1 to 3 times per week Total Alkalinity 0.5 mg/L as CaC0 3 weekly during SBR recovery N O 3 - N 0.02 mg/L weekly never NOJ-N 0.002 mg/L weekly never NO--N 0.02 mg/L weekly 1 to 3 times per week COD 25 mg/L weekly never NHX-N 0.02 mg/L weekly 1 to 3 times per week p o r - p 0.02 mg/L weekly 1 to 3 times per week TKN 0.5 mg/L monthly 1 to 2 times per month B O D 5 10 mg/L monthly never Total Cd 0.004 mg/L never 4 times total Total Cr 0.03 mg/L (.01 mg/L) monthly 4 times total Total Co 0.02 mg/L never 4 times total Total Cu 0.01 mg/L never 4 times total Total Fe 0.03 mg/L (1.0 mg/L) monthly 4 times total Total Pb 0.08 mg/L monthly never Total Mn 0.003 mg/L monthly never Total Ni 0.025 mg/L (0.02 mg/L) monthly 4 times total Total Zn 0.015 mg/L (0.02 mg/L) monthly 4 times total Dissolved Cd 0.004 mg/L never 4 times total Dissolved Cr 0.01 mg/L never 4 times total Dissolved Co 0.02 mg/L never 4 times total Dissolved Cu 0.01 mg/L never 4 times total Dissolved Fe 1.0 mg/L never 4 times total Dissolved Ni 0.02 mg/L never 4 times total Dissolved Zn 0.02 mg/L never 4 times total Chapter 3. Study Design 32 distilled water. 3.4.2 Temperature, pH, Dissolved Oxygen, and Conductivity Instruments used to determine temperature, pH, dissolved oxygen, and conductivity in the field and in the laboratory are listed in Table 3.2. Towards the end of the study, the field DO meter could no longer be used, and therefore the laboratory DO meter was brought to the site occasionally . Table 3.2: Analytical Instruments Parameter Field Laboratory pH Hanna HI 8314 Beckman Dissolved Oxygen Hanna HI 8543 YSI 54ARC Temperature Glass bulb mercury thermometer same Conductivity Hanna HI 8033 same The DO meter was calibrated using Hanna zero dissolved oxygen solution to set the zero and the air calibration method to set the slope. Membranes were changed as problems were noticed. The field pH probe was calibrated using pH 7.01 buffer solution in the field, and pH 4.00, 7.01, and 10.0 solution in the lab. The conductivity meter was calibrated using Hanna 12880 microsiemen solution. 3.4.3 Suspended Solids Whatman 934AH glass fibre filters were placed in aluminum foil dishes and dried at 104°C for 30 to 60 minutes before cooling in a dessicator and using an electronic balance to record their tare weight. Samples were shaken and small amounts were poured into a graduated cylinder, then into a filter apparatus containing one of the tared filters. The graduated cylinder was rinsed once with approximately 10 mL of distilled water, which was also poured over the filter. The filter was then replaced in its aluminum dish and dried at 104°C for at least one hour, cooled in a dessicator, and weighed. If volatile suspended solids (VSS) were to be determined, the filter and dish were then fired at 550°C for at least 15 minutes, cooled in a dessicator, and weighed. Samples were dried and weighed once, then fired and weighed once. Calculations of total suspended solids (TSS) and VSS were performed as indicated in Standard Methods [2]-Samples on which Daphnia L C 5 0 was to be done were also tested for settleable suspended solids. Samples were allowed to stand in their bottles for one hour after shaking. A small volume of sample was then removed from near the middle of the container with a 25 mL wide mouthed graduated pipette Chapter 3. Study Design 33 and poured through a filter apparatus fitted with a filter paper as described above. The remainder of the procedure was identical to that indicated above, and calculations were again performed according to Standard Methods [2]. 3.4.4 Dissolved Ammonia Nitrogen Samples were prepared for dissolved NHX-N analysis by filtering through a Whatman 934AH filter and adjusting to pH 3 with 10% sulphuric acid. If the sample was expected to be above the highest standard, it was diluted accordingly before pH adjustment. pH adjusted samples were poured into plastic test tubes, capped, and refrigerated at 4°C until analysis. Prepared NHX-N samples were generally analyzed within a few hours to a day, but were occasionally refrigerated for up to a week before analysis. Adjustment to pH 3 served the dual purpose of preserving the sample and bringing it to the same pH used in making standards, as the analysis method used is sensitive to pH. For the major part of the research, verification of pH adjustment was accomplished using pH paper to achieve a reading between 2.5 and 3. During the final weeks of the research, a pH probe was used to measure the pH more accurately. Samples were adjusted to various pH values between 2 and 3 in order to quantify the error which may have been caused by relying on pH paper. Analysis of NHX-N was carried out with a Lachat Quickchem Automated Ion Analyzer according to Methods Manual for the QuikChem Automated Ion Analyzer (1987). 3.4.5 Volatilized Ammonia Nitrogen The procedure and apparatus used to collect and measure volatilized NHX-N was essentially the same as that used by Miller in a previous UBC study [45]. While it is somewhat difficult to make out, the gas collection apparatus can be seen in Figure 3.4. The female end of a plastic coupling was connected to the inlet of a residential gas flow meter with 3/4" PVC tubing. A right angled bend was placed in the tubing with a copper elbow in order that the coupling could be horizontal while the flow meter could stand upright on the ground. A 1/2" plastic barbed fitting was placed on the outlet of the meter, and 1/2" tygon tubing was used to connect this barb to the inlet of the air pump. 1/2" tubing connected the outlet of the air pump to the inlet of the first gas bubbler. The other two bubblers were connected to the first in series, also with 1/2" tygon tubing. The 12 V DC air pump was powered by an automotive battery charger. Chapter 3. Study Design 34 Seventy mL of 20,000 mg/L boric acid was placed in each bubbler with a 100 mL graduated cylinder. The cylinder and the bubblers were rinsed with distilled water between runs, and samples were stored in plastic bottles filled to exclude air space. The samples were stored in a refrigerator at 4°C for several months before analyzing them for NHX-N. Miller [45] stated that standards were found to be stable for well over a month, and it was therefore assumed that this storage period was acceptable. NHX-N analysis was carried out exactly as in Section 3.4.4 above, except that boric acid standards were made and a special run was done. The term NHX has been used for "volatilized" ammonia, as the method of collection and analysis can not separate NH3 gas from NH4 aerosols. A more detailed explanation for this phenomenon is given by Miller [45]. Both can be considered lost N, and therefore measuring them together serves this author's objective of obtaining an N balance. 3.4.6 Nitrate and Nitrite Nitrogen Samples were prepared for Nitrate + Nitrite (NOx) analysis by filtering through a Whatman 934AH filter, diluting with distilled water if necessary, pouring into plastic test tubes, then, preserving with one drop of phenyl mercuric acetate solution. Samples were capped and refrigerated at 4°C before analysis. While samples were occasionally prepared immediately before analysis, they were usually refrigerated for up to a week after preparation. Analysis of NO~-N was carried out with a Lachat Quickchem Automated Ion Analyzer according to Methods Manual for the QuikChem Automated Ion Analyzer (1987). 3.4.7 Total Kjeldahl Nitrogen Samples were preserved for TKN analysis by freezing. Dissolved TKN samples were filtered through a Whatman 934AH filter before freezing in all cases except for the November 1993 samples, which were filtered after thawing. Total TKN samples were not filtered, and were shaken before pipetting into a TKN tube with a wide mouthed pipette. TKN samples were frozen for up to two months before analysis. After thawing, samples were pipetted into TKN tubes in appropriate volumes according to TKN estimates based on NHX measurements. They were then digested in a Technicon Block Digester BD40 according to the Technicon Block Industrial Method No. 376-75W (1975), and analyzed according to the Technicon Methodology No. 329-74W (1975). Chapter 3. Study Design 35 3.4.8 Orthophosphate Routine PO^-P measurements were done simultaneously with NOj-N measurements, using the same samples. More accurate measurements were made using membrane filtered, undiluted samples when metal samples were being prepared. These samples were always analyzed on the same day, while routine samples were usually refrigerated for up to a week. Undiluted samples filtered with Whatman 934AH filters were also done near the end of the research, typically on the same day as preparation and sampling. Analysis of PO^-P was carried out with a Lachat Quickchem Automated Ion Analyzer according to Methods' Manual for the QuikChem Automated Ion Analyzer (1987). 3.4.9 Alkalinity Alkalinity measurements were done during January and February when the SBR was being heated and fed ammonium sulfate, in order to determine the amount of sodium bicarbonate to add to stabilize the pH. Alkalinity measurements were carried out according to Standard Methods [2]. Unfiltered samples were used. 3.4.10 Metals Metal samples were prepared for analysis as follows: 1 L samples of leachate or effluent were shaken, then poured through a clean filter apparatus equipped with a Whatman 934AH filter until the sample container was roughly half empty. The filtrate was collected in a flask, then poured back through the filtering apparatus, now fitted with a .45 /un cellulose acetate membrane filter and a clean flask. This filtrate was measured in a clean graduated cylinder, then poured into a clean plastic bottle for storage. The remainder of the original sample was shaken, poured into the above graduated cylinder, measured, and poured back into the original sample container. Any sample beyond 500 mL was discarded. Subsequently, both filtered and unfiltered samples were preserved with 5 mL of concentrated nitric acid. Samples were stored in the cold room at 1°C until analysis. All glassware and other apparatus allowed to touch samples during preparation for metal analysis were previously acid washed with 10 or 20% nitric acid, except for Whatman 934AH and membrane filters. To correct for metals which may have been added by filtration or other error sources, controls for both total and filtered metals were prepared by conducting the above procedure with distilled water Chapter 3. Study Design 36 before allowing samples to touch the apparatus. Three sets of apparatus were prepared (leachate, RBC, and SBR), and the control was prepared using the leachate apparatus, as it would likely have the most metals and therefore be least affected by metals which could have been washed away or added by the distilled water. Metal samples were filtered and/or preserved within 5 hours of sample collection. 3.4.11 Fish L C 5 0 Rainbow trout 96 hour L C 5 0 tests were carried out for the City by Beak Consultants on a monthly basis until April 1994. Tests were done according to Biological Test Method: Reference Method for Determining Acute Lethality of Effluents to Rainbow Trout EPS l/RM/13 (July 1990), and the B.C. Ministry of Environment, 1982. L C 5 0 was calculated according to the method found in Aquatic Toxicology and Hazard Evaluation, American Society for Testing and Materials, 1977. Fish L C 5 0 was determined on raw leachate only. 3.4.12 Daphnia L C 5 0 A starter culture of Daphnia magna was obtained from EVS consultants in early September, 1993. Although Environment Canada culturing instructions (found in [17]) were followed as closely as possible, difficulty was encountered in meeting the health criteria required for accurate testing. Specifically, the fecundity requirement of 15 offspring per female per brood was never reached. This culture died out due to inattention over the Christmas 1993/1994 break. Subsequently, an alternate source for neonates (i.e. Daphnia less than 24 hours old, as required for testing) was found. A researcher at Paprican agreed to supply neonates and dilution water, and did so for the February and March tests, after which sufficient surplus neonates were no longer available. Another starter culture was obtained, this time from the Environment Canada Aquatic Toxicity Laboratory in North Vancouver. This culture was used to produce neonates for the April tests. As the organisms were in the process of being acclimatized to their new environment when neonates were removed for testing, fecundity was approximately 10 offspring per female per brood. Since fish testing frequency was reduced after the April test, Daphnia testing was discontinued. Daphnia 48 hour L C 5 0 tests were conducted according to procedures recommended by Environment Canada [17]. Raw leachate, RBC effluent, and SBR effluent were tested. Unused culture water was used for diluent (i.e. clean culture water with no food). Samples to be tested were stored in clean 1 L containers and refrigerated at 1°C for 24 to 48 hours before use. 200 mL volumes of sample or diluted Chapter 3. Study Design 37 sample were placed in identical, clean (acid washed), 500 mL plastic beakers, and allowed to reach room temperature. Temperature, pH, and DO were measured in selected beakers before adding Daphnia. Ten neonates were added to each beaker, with the exception of nine control beakers, each of which contained 200 mL of undiluted sample (three each for raw, RBC, and SBR) to be used for subsequent chemical analysis. All beakers were then randomly placed on a shelf in a temperature controlled room (February) or incubator (March and April) set at 20°C. Paper covers were placed over the beakers, and the photoperiod was maintained at 16 hours light/8 hours darkness using a fluorescent light and a timer. Since the turbidity and colour of the leachate and effluents made it impossible to count the neonates by sight, counting was only done at the end of the test (i.e. after 48 hours). All samples were counted by pouring the contents of the beaker into a fine net, then resuspending the contents of the net in clean culture water. Neonates were considered dead if gentle prodding with a probe produced no movement. L C 5 0 was calculated according to the method found in Aquatic Toxicology and Hazard Evaluation, American Society for Testing and Materials, 1977. When pouring out the beakers, the net was placed over another beaker (either a clean one or an empty beaker formerly containing more dilute sample), and the pH, and sometimes temperature were measured after the organisms had been removed. DO measurements obtained after pouring out the beakers would not be accurate due to agitation of the sample. Putting the DO probe in the beaker with the Daphnia could cause counting errors, as organisms could adhere to the probe. As a result, end-of-experiment DO measurements were only made on the controls containing no Daphnia. The controls always had sufficient DO to support Daphnia, and it was therefore assumed that the less concentrated samples would also have sufficient DO. After Daphnia were counted and end-of-experiment measurements were finished, the control samples were combined by pouring them into a clean 1000 mL plastic beaker. Care was taken to avoid resuspen-ding particulate matter which had settled to the bottom or adhered to the sides of the beaker. To avoid including this material in the combined sample, a small amount of liquid was left in the bottom of each 500 mL beaker. The combined sample was then mixed, and prepared and analyzed for NHX-N, NOj-N, PO^-P, total metals, and dissolved metals as described above in Sections 3.4.4, 3.4.6, 3.4.8 and 3.4.10. These measurements were done in order to indicate an "after" number to correspond to the "before" number produced by analysis of samples which had not been left in a plastic beaker for two days at 20°C. Total and settleable suspended solids (see Section 3.4.3) were only determined as "before" quantities. Chapter 3. Study Design 38 3.4.13 Microtox E C 5 0 Microtox E C 5 0 testing was done on a Microbics Toxicity Analyzer Model 500 belonging to the UBC COFI Chair and set up in the laboratory of the Pulp and Paper Centre. Procedures recommended by Environment Canada [18] were followed. Microtox E C 5 0 values were determined at 5 and 15 minute exposure times. Both Basic and 100% test protocols were followed, and Microtox Osmotic Adjustment Solution (MOAS), solid NaCl, and solid sucrose were used for osmotic adjustment at various times. Three samples were usually tested at once when performing the Basic test, and four to six samples were tested at once when performing the 100% test. Samples were collected on Wednesday and/or Thursday mornings, and refrigerated at 1°C until Thursday afternoon. On Thursday afternoon, 10 mL aliquots of sample were placed in clean vials with teflon lined caps (COD vials) using a wide mouthed graduated pipette. If solid NaCl or solid sucrose were to be used for osmotic adjustment, 0.2 +0.025 -0.000 g of NaCl or 2.0 0.025 - 0.000 g of sucrose were added to the vial before the sample was added. Sucrose and NaCl were weighed in clean disposable plastic dishes, one for each chemical. A clean, dry funnel was used to add the chemical to the vial. The vials were then capped and shaken until all NaCl or sucrose had dissolved. As a final preparatory step , the vials were centrifuged to remove interference which may have been caused by turbidity. Although the centrifuged samples of leachate and effluent were still quite coloured, the Colour Correction Protocol was not used. Since colour correction is intended to account for light absorption due to sample colour [18], neglecting colour correction should give an EC50 value which is lower than or equal to the value achieved using colour correction. It is therefore conservative to neglect colour correction, because a lower EC50 value indicates a more toxic solution. Although Microtox cuvettes are intended to be disposable, they are very expensive. Testing indica-ted no significant decrease in light emission between diluent held in new cuvettes and diluent held in previously used cuvettes that had been thoroughly rinsed with distilled water. As a result, disposal of used cuvettes was stopped, and cuvettes were rinsed with distilled water between uses. COD vials used to contain samples during centrifugation were also washed by rinsing with distilled water, except when metals were being determined or when high purity reference toxicants were being prepared, in which case the vials were also acid washed and rinsed with deionized distilled water. Preliminary results indicated that the Microtox test was not very sensitive to leachate ammonia concentration. Microbics [44] indicates that using 20% sucrose instead of 2% NaCl for osmotic adjustment Chapter 3. Study Design 39 can increase the sensitivity of the test to ammonia and certain metals. Environment Canada [18] recommends that sucrose tests be done in addition to NaCl tests if ammonia is suspected to be a significant source of toxicity in a sample. Therefore, sucrose tests were also done. In order to test a sample which has been osmotically adjusted with sucrose, sucrose diluent must be prepared. Sucrose diluent was prepared using distilled water, deionized distilled water, pH adjusted (with sodium bicarbonate and sulphuric acid) deionized distilled water, and Microtox Reconstitution Solution (recon) with 20% solid reagent grade sucrose added. 2% NaCl diluent was also prepared in exactly the same manner using solid reagent grade NaCl and MOAS. The procedure followed in preparation of diluent using deionized distilled water is described below. When distilled water was used, it was used for rinsing and filling volumetric flasks. When pH adjusted deionized distilled water and recon were used, deionized distilled water was used for rinsing. First, glassware and utensils which would contact the solutions or dry chemicals were acid washed with 20% nitric acid and rinsed thoroughly with deionized distilled water. Scoops and funnels, which would be used with dry chemicals, were dried by placing them on a clean paper towel in the 104°C oven. A separate funnel was used for each solution prepared, and separate scoops were used for NaCl and sucrose. Dry chemicals were weighed out into new disposable plastic dishes, poured into funnels, and washed into volumetric flasks with deionized distilled water. After shaking to dissolve solids, finished solutions were poured into clean Microtox Diluent vials and taken directly to the Pulp and Paper laboratory for analysis. Environment Canada [18] recommends monthly testing of reference toxicants to ensure precision and reliability of results. Reference toxicants should also be tested if the reconstituted reagent is used for more than two hours. Although Microtox testing was done over a period of six months, the same batch of reagent was used for all but the first three tests, and a given vial of reagent was rarely used for longer than two hours after reconstitution. As a result, testing of reference toxicants was left to the end of the experimental program. Because both zinc and ammonia were expected to be present in the leachate, and since Microtox is reportedly more sensitive to both when sucrose is used for osmotic adjustment, zinc and ammonia were chosen as reference toxicants. Reference toxicant solutions were prepared as described for diluent above, with a few exceptions. Zinc sulphate (ZnSGvTR^O) and ammonium sulphate ((NH^SO-j) were used as sources of zinc and ammonia. The same scoop was used to measure out NaCl, ZnS04-7H20, and (NH^SGv Diluents were prepared before reference toxicants, and the scoop was wiped between uses with a clean Kimwipe. Chapter 3. Study Design 40 A separate scoop was used for sucrose. After all solutions were prepared, samples to be tested with sucrose had dry sucrose added as described above for leachate and effluent samples. As no turbidity was present, reference toxicant solutions were not centrifuged before use. However, all solutions were placed in capped vials and shaken (i.e. whether they had solid sucrose added or not). Solutions tested included 14 mg/L and 1.4 mg/L ZnS04-7H20 (i.e. 3.18 and .318 mg Z n + + / L ) , and 25000 and 1000 mg/L (NH 4) 2S0 4 (i.e. 5301 and 212 mg N/L). Chapter 4 Results and Discussion 4.1 Ammonia Nitrogen 4.1.1 Responses to Increased Loading Figure 4.1 summarizes the operational history of the systems with respect to the most important pa-rameter in this study, NHX-N. Both systems were set up and innoculated with nitrifying sludge from the UBC pilot plant in early July 1993. The first effluent samples were taken on August 12th, which corresponds to day 0 on Figure 4.1. The last date recorded on the graph, day 391, corresponds to September 7, 1994. In Tables 4.1 and 4.2, "Acclimatization Time" is the time taken to reach greater than 90% NHX-N removal consistently, i.e. for more than one week. "N/A" is entered in this column when this criterion was never achieved, and "< x" is entered when the criterion has been reached by the next measurement, taken x days after the loading increase. Where less than 90% removals were measured, but a measurement Was not taken the day before the recovery date, an envelope is given. "Operating Time" is the time between acclimatization (if reached) or loading increase (if not reached) until the next loading increase or the next prolonged degradation in performance. Table 4.1: RBC Loading History Start Start Average Average Acclimatization Operating Average Day Date HRT Loading Time Time Temperature (days) (g/m2/d) (days) (days) CC) 0 Aug 12 5.24 0.29 ? 55 17.0 55 Oct 6 2.25 0.38 < 6 95 8.4 150 Jan 9 0.80 0.83 < 2 21 8.2 171 Jan 30 0.65 1.29 12<t<14 21 5.8 206 Mar 6 0.41 2.18 < 1 35 9.9 241 Apr 10 0.27 4.88 N/A 68 15.9 309 Jun 17 0.17 6.02 N/A 44 19.9 353 Jul 31 0.35 4.15 < 5 38 20.5 41 Chapter 4. Results and Discussion 42 Figure 4.1: Leachate and Effluent NHX-N versus Time 4 0 0 | 3 5 0 -400 Table 4.2: SBR Loading History Start Start HRT NHX-N Acclimatization Operating Average Day Date Loading Time Time Temperature (days) (g/m3/d) (days) (days) C C ) 0 Aug 12 4.64 63.5 9 34 17.1 55 Oct 06 2.15 87.8 6<t<13 17 8.2 131 Dec 21 4.66 23.3 N/A . 27 6.6 - 158 Jan 17 4.63 33.0 9 23 12.5 190 Feb 18 4.59 30.2 < 3 24 5.8 214 Mar 14 1.93 107 52 36 13.4 302 Jun 10 0.71 331 14<t<18 31 19.6 351 Jul 29 0.43 580 N/A 25 22.2 Chapter 4. Results and Discussion 43 Tables 4.1 and 4.2 show that when it did recover from loading increases, the RBC generally recovered more quickly than the SBR. The only case in which the RBC had not recovered from a loading increase by the next effluent measurement was during the loading increase starting on January 30th. In this case, the RBC was also struggling aginast temperature shock (for example, ice formed on the disks on February 8th) and occasional phosphate deprivation (see section 4.3). It should perhaps be noted that, while removals of greater than 90% were consistently reached after the March 6th loading increase, it was 3 days before removal returned to 99%. Also, unexplained process upsets occurred on March 15th and 17th during which less than 90% removals were achieved (see Table 4.3). While it never reached the defined acclimatization condition at the high NHX-N loadings applied during the periods starting on April 10th and June 17th, the RBC did consistently remove 3 to 5 g/m2/d during these periods. Paolini [50] indicated that oxygen transfer through the liquid film on the exposed disks is more important in RBC systems than oxygen transfer through the mixed liquor, so mixed liquor dissolved oxygen concentration in not necessarily indicative of oxygen limitation. However, RBC mixed liquor DO measurements were always greater than 2 mg/L during these loading periods, so it is unlikely that DO limitation was responsible for the lack of acclimatization. The SBR never recovered from an increase in loading by the next effluent measurement (there was no loading increase on February 18th). The minimum SBR recovery times were in the range of the maximum RBC recovery times. One could conclude from this that the RBC recovers more quickly from increased loading. However, it could be argued that the SBR increases were somewhat more severe than the RBC increases, as the HRT was generally halved when the RBC loading was increased and the HRT was generally decreased by more than half for an SBR loading increase. It should be noted that the 9 day recovery time listed for the loading applied starting January 17 was the amount of time the SBR was heated and fed dry ammonium sulfate before leachate feed was renewed on January 26th. No adjustment period was required when the leachate feed began, but feeding leachate rather than dry ammonium sulfate resulted in a decrease in loading. While Table 4.2 shows that the SBR recovered from the June 10th loading increase, this is not strictly true. NHX-N removals of greater than 90% were obtained consistently from June 28th to July 19th, but only 3 to 13% of the influent NHX-N was being fully nitrified; the rest remained in the form of NO J-N. The author was making weekly visits to the site at this time, but was no longer taking measurements. The nitrite buildup was not noticed until sometime in September, by which time the SBR loading had been increased once more and the process had failed. Chapter 4. Results and Discussion 44 A possible cause for the lack of full nitrification was low dissolved oxygen. Regular measurement of DO had been suspended earlier in the study when the site's DO meter had failed. DO was measured in the SBR twice during July, on the 8th and the 15th. On the 8th, the DO was greater than 2 mg/L for the greater part of the reactor a few minutes after aeration began. However, the DO was lower at the reactor bottom, and DO continued to drop as aeration continued. The DO ranged from 1 to 1.8 mg/L in the reactor after about one hour of aeration, and the air was turned up from 0.5 cfm to 0.55 cfm. After 20 more minutes of aeration, the DO had not changed much, but the airflow was not increased further, for fear the compressor would fail. (The dual compressor had been operating on one side only for several weeks already, and had previously failed when operating on only one side. The single sided operation was caused by failure of the other motor, and since it was near the end of the study, the City did not plan to repair the compressor again if another failure occurred). On the 15th, measurement ceased after 20 minutes of aeration, when the DO was 2.5-3 mg/L throughout the reactor, but the DO could have continued to drop as it did on the 8th. Because nitrification is possible at DO less than 2.0 mg/L if MCRT is long enough [63], and because there was very little BOD 5 in the leachate (and therefore little concern about competition with heterotrophs), the slightly low DO levels did not seem important at the time. However, they could have been a factor in the final failure of the process. Another possible cause for the occurrence of incomplete nitrification at this time could have been inhibition of Nitrobacter by high free NH3 levels. The reactor was heavily loaded, and therefore there was less treated effluent in the reactor to dilute influent raw leachate in the initial stages of the aeration cycle. Nitrobacter is known to be more sensitive to high free NH3 levels than Nitrosomonas [16, 1]. Nitrobacter is also sensitive to NOJ, so as NH 3 was converted to NOJ, the NH 3 inhibition could be replaced by NOJ inhibition. More discussion of this possibility is found in Section 4.2.3. Phosphate deprivation may also have been a factor (see Section 4.1.7). 4.1.2 Process Upsets Examination of Figure 4.1 reveals several process upsets which were caused by factors other than in-creased loading.' Tables 4.3 and 4.4 describe these upsets. Events were entered in the process upset table when unusual (generally low) NHX-N removals were achieved. In the Table 4.3, two instances of no flow were entered to explain the unusually low effluent NHX-N seen on days 271 and 309 in Figure 4.1. Otherwise, upsets were generally defined as events in which less than 90% NHX-N removal was achieved. "Recovery Time" was entered as N/A when recovery had not occurred by the time of the next upsetting Chapter 4. Results and Discussion 45 Table 4.3: RBC Process Upsets Start Start Duration Recovery Day Date (days) Time (days) Cause 98 Nov 18 2 N/A cold? 101 Nov 21 < 3 N/A power failure, cold 103 Nov 23 7 N/A system frozen 113 Dec 3 7 < 6 disk no. 1 failed, cold 215 Mar 15 1 < 1 unknown 217 Mar 17 1 < 4 unknown 271 May 10 < 5 < 2 wet well pump failed, no flow 309 Jun 17 1 < 1 clogged valve, no flow Table 4.4: SBR Process Upsets Start Start Duration Recovery Day Date (days) Time .(days) Cause 12 Aug 24 < 12 < 7 unknown 61 Oct 12 N/A N/A improper sample collection 89 Nov 9 N/A N/A improper samplecollection 89 Nov 9 > 3 N/A no nutrient flow, cold 101 Nov 21 < 3 N/A power failure, cold 104 Nov 23 7 . N/A system frozen 111 Dec 1 22 N/A nutrient pump failure 135 Dec 25 1 N/A compressor failure 139 Dec 29 1 N/A influent valve leak 198 Feb 26 2 2<t<5 no nutrient flow, cold 271 May 18 < 1 < 1 unknown event, or when the system never recovered on its own. In Table 4.4, "improper sample collection" entries refer to cases where it is known that a mixed liquor sample was collected instead of an effluent sample. During the time period from about day 89 (November 9th) to day 158 (January 17th) the SBR completely failed. While the high NHX-N value reported on November 9th was clearly caused by collecting a mixed liquor sample instead of an effluent sample, no phosphate was reaching the SBR on the 9th or the 12th. Lack of phosphate combined with cold temperatures could have caused the low NHX-N removal observed on the 12th. It is interesting to note that a similar phosphate pump failure on October 19th, when it was warmer, had no effect on effluent NHX-N levels. The low NHX-N removals on November 16th and 18th, when phosphate was apparently reaching the reactor, could have been the result of a failure to recover from the cold aggravated phosphate deficiency. Low solids levels may also have been a factor. While the mixed liquor TSS remained at about 200 mg/L Chapter 4. Results and Discussion 46 from October 12th (when the SBR was apparently still working) to November 16th, it was felt that 200 mg/L was rather low, and solids wasting was discontinued on November 21st in an attempt to build up solids levels. Unfortunately, after the system froze on the 23rd, the SBR was never able to fully recover. Poor solids settleability continued throughout the failure period, probably due to low temperatures and phosphate deprivation. Phosphate deprivation occurred almost continuously until December 23rd, and was caused first by freezing, then by running out of phosphate solution, and finally by the failure of the bellows pump. Mixed liquor and effluent suspended solids remained almost equal, and the solids were gradually washed out. The first mixed liquor TSS measurement after the freeze up (December 8th) was only 93 mg/L, and subsequent measurements on the 14th and 21st were only 49 and 52 mg/L. The SBR HRT was increased to 4.66 days on December 21st in order to give the reactor a chance to recover. On December 29th, an influent valve leak was discovered, which probably caused any remaining solids to be lost. The system was reinoculated with UBC pilot plant sludge on January 7th. After about 10 days, it became obvious that mere innoculation would have little effect at low January temperatures. On January 17th, the SBR was reinoculated, fed dry ammonium sulfate and heated. After 9 days, the system seemed to be doing well, so leachate feeding and effluent withdrawal were resumed. The heaters were removed by February 18th, and the system's performance remained satisfactory. No phosphate was delivered by the nutrient pump between February 26th and 28th, causing a noti-ceable decrease in performance. 2 L of phosphate solution were added manually on the 25th, but this addition occurred only during the first cycle on the 25th, and wouldn't necessarily produce the same effect as continuous addition throughout 3 cycles. It is interesting to note that a phosphate failure on February 13th, when the reactor temperature was 12°C, had a less significant effect. The data in Table 4.5 illustrate more fully the combined effect of phosphate deprivation and low temperature. Both low temperature and phosphate deprivation appeared to cause minor upsets when acting alone, but seemed to cause more significant process upsets when acting together. A similar relationship between phosphate addition and temperature was reported by Guo [24], who found that higher effluent PO^-P concentrations were required at low temperatures in order to maintain nitrification. This phenomenon did not appear to occur in the RBC system. While no phosphate was delivered to the RBC on several occasions, these occasions never appeared to correspond to process upsets. When the RBC was attempting to recover from a loading increase in early February, there were two occasions when low temperatures (5.5 and 2.5°C) were accompanied by lack of phosphate delivery. This may have been part of the reason that the RBC took an uncharacteristic 12 to 14 days to recover from the loading Chapter 4. Results and Discussion 47 increase. However, there were two occasions when RBC reactor temperatures were low (Dec. 21 and 29, T = 4 and 4.5°C), no phosphate was delivered, and performance remained satisfactory. On both of these occasions, the RBC was receiving leachate in significant quantities (134 and 110 L/day, respectively). For the SBR system, every time phosphate deprivation occurred in conjunction with low temperatures, a process upset occurred. It should perhaps be noted here that there were 13 instances between the end of May and the beginning of the experiment when no nutrient flow reached the RBC and an effluent P O 4 - measurement was taken. While these PO4 - measurements were often lower than neighbouring measurements taken during normal nutrient pump operation, they were frequently similar or even greater. For the SBR, there were only four occasions on which nutrient flow was zero and an effluent P O 4 -measurement was taken. Again, there was no clear trend relating the effluent P O 4 - concentration to the lack of nutrient flow. A possible explanation for this is that if excess P O 4 - was not typically supplied, then the organisms would use up the available phosphate to a limiting concentration, regardless of whether or not the nutrient pump was operating properly. This limiting concentration would be between 0.1 and 1.0 mg/L PO^-P. Interestingly, this range of P0 4 - -P concentrations is roughly similar to the level of PO^-P supplied in the leachate. Another possible explanation could be that P04~-P samples were not always membrane filtered, and therefore PO^-P apparently left in the effluent was not necessarily available to the nitrifying organisms. Lack of nutrient flow was used as the criterion defining nutrient deprivation rather than effluent PO^'-P concentration because of the lack of correlation between the two, and because nutrient pump failure and process upset appeared to be linked, at least for the SBR. Throughout this study, the SBR experienced process upsets more frequently, more severely, and for longer time periods than the RBC. Process upsetting events such as power outages, cold temperature episodes, nutrient pump failures, and valve leaks tended to either directly (through hydraulic washout) or indirectly (through reducing solids settleablility) result in solids loss from the SBR. Similar events did not cause solids sloughing in the RBC, and this could have been why the RBC was able to recover more quickly, as recovery did not require replacing lost solids. When the influent RBC valve was stuck open resulting in continuous flow, the flow rate seen was not typically that much higher than the normal flow rate. Other investigators have also noticed solids settling and washout problems in response to shocks in suspended growth nitrification systems [16, 34, 60]. While low temperature episodes, nutrient pump failures, and valve leaks could cause solids washout in any activated sludge system, losses due to power Chapter 4. Results and Discussion 48 Table 4.5: Low T/Low P SBR Data Date Reactor Effluent NHX-N Phosphate Temperature NHX-N Removal Flow CC) (mg/L) (%) (L/day) Feb 8 11.0 0.13 99.9 1.6 Feb 9 11.5 0.21 99.9 0.0 Feb 11 13.5 2.5 Feb 13 12.0 4.3 96.9 0.0 Feb 14 13.0 0.05 100 2.5 Feb 15 11.5 0.17 99.9 2.4 Feb 18 12.5 0.03 100 1.0 Feb 21 5.5 0.82 99.4 1.3 Feb 22 3.5 3.5 97.3 2.3 Feb 23 4.0 5.8 95.6 1.0 Feb 25 0.5 11.0 91.7 2.3 Feb 26 3.0 30.5 78.2 0.0 Feb 28 8.5 18.3 81.4 0.0 Mar 3 9.5 1.1 99.5 2.3 outages may have been a problem specific to this experimental set up. When the power came back on after an outage, the system would be aerated continuously until it was reset. When reset, the fill cycle would begin immediately, which would result in mixed liquor overflow unless appropriate precautions were taken. This could be particularly severe in cases where the SBR was heavily loaded, and may have been a major factor in the failure of the SBR from July 29th to the end of the study. (A power failure and restart was reported on August 4th, but solids levels were still high on August 5th. Major solids losses occurred later, but no other power failures were reported). 4.1.3 Loadings and Removals 4.1.3.1 RBC Figure 4.2 includes all the results prior to the HRT experiment (see Section 4.1.5.1), and shows that while much higher loadings were applied, the maximum RBC NHX-N removal was 5.38 g/m2/d at a loading -of 6.22 g/m2/d. The NOJ-N concentration was not measured that day, but surrounding measurements on which the loading was equal or higher and the removal was lower had NOJ-N concentrations of 4.8 and 10.2 mg/L. The maximum loading at which the RBC was able to achieve 99% NHX-N removal was ' 3.75 g/m2/d (September 7, 1994), but full removals occurred much more commonly at loadings below 2.5 g/m2/d, and always occurred at loadings below 1 g/m2/d. The NOJ-N concentration on Sept. 7th Chapter 4. Results and Discussion 49 Figure 4.2: RBC NHX-N Removal versus NHX-N Loading 0 2 4 6 8 10 NHx-N Loading (g/mVday) was 34.8 mg/L, which was 16% of NO~-N. Effluent NOJ-N concentrations were 2 mg/L or less (with one exception of 3.2 mg/L) at loadings below 2 g/m2/d, but at loadings above 2 g/m2/d the NOJ-N level always exceeded 4 mg/L. These results agree with the findings of Ehrig [16], who concluded that NHX-N loadings should be kept below 2 g/m2/d in order to avoid NOJ buildups. Ehrig also found that NHX-N removals of greater than 95% were possible at a loading of 10 g/m2/d. The RBC system used in our study did not seem to be capable of such high removals. Further discussion of factors limiting the RBC system are found in Sections 4.5 and 4.1.5.L 4.1.3.2 SBR Figures 4.3 and 4.4 show that most of the data for the SBR system were gathered under rather lightly loaded conditions. Activated sludge loadings are generally expressed in terms of g NHx-N/g MLVSS/d. However, the City did not monitor MLVSS, and solids levels in the SBR were extremely variable. Therefore, results are expressed the conventional way as well as in g/m3/d (where m 3 refers to reactor volume). MLVSS was calculated in cases where no measurement was taken by multiplying MLSS by the average MLVSS:MLSS ratio, which was found to be 0.62. Chapter 4. Results and Discussion 50 Chapter 4. Results and Discussion 51 In terms of MLVSS, the maximum SBR NHX-N loading at which >90% removal was achieved was 1.01 g/g MLVSS/d (99.9%). This removal occurred on May 17th, 1994, during the time the SBR was operating successfully at a 1.9 day HRT. Most of the higher loadings occurred shortly before May 17th, during the period of acclimation to the 1.9 day HRT. It should be noted that the effluent NOJ-N was rather high (15 mg/L or 7 % of NO"-N) at that time. The next highest loading at which full nitrification (99.5%) was achieved was 0.87 g/g MLVSS/d and occurred a week later. There were a few other times during the study when the loading was between .87 and 1.01 g/g MLVSS/d and full NHX-N removal was achieved, but these occasions also corresponded to NOJ buildups. The maximum volumetric SBR NHX-N loading at which full removal was achieved was 371 g/m3/d, but the effluent NO x was 18% NOJ at that time. This removal occurred on June 21, 1994, shortly after the SBR's HRT had been lowered from 1.9 days to 0.7 days. Full nitrification was never achieved during this loading phase. The next highest loading at which full nitrification (99.9%) was achieved was 143.7 g/m3/d on May 10, 1994, when the HRT was 1.9 days. Table 4.6 compares data from this study to data from three other studies in which activated sludge systems were used to nitrify NHX-N in older landfill leachates. The loading values reported represent the range of values for which full NHX-N removal was achieved. The parameter which most distinguishes this study from the others is MLVSS, which is significantly lower for this study. The fact that the g/g MLVSS/d loadings are lower is probably a direct result of the low MLVSS concentration, given the fact that the g/m3/d loadings are similar in the other study reported. While the g/m3/d loadings are not directly comparable due to the fact that Knox's system was continuously aerated, adjusting the data to account for aeration period would not cause the loadings observed in our study differ significantly from those tested by Knox [33]. While low influent BOD5 and NHX-N concentrations would result in lower MLVSS concentrations in the short term, over the long term solids should build up. A possible reason for the lack of solids buildup in this study was the rather poor settling characteristics of the effluent (see Section 4.3.4). However, settling problems were also observed in two of the other studies [33, 16], and solids concentrations reached quite high levels. While similar effluent solids concentrations would have a greater impact on a system with lower influent BOD5 and NHX-N concentrations, this factor alone may not be sufficient to explain the lack of solids build up observed. Another factor which differentiates the studies is period of continuous aeration. Knox [33] and presumably Ehrig [16] used conventional activated sludge systems, which are continuously aerated. Mena Chapter 4. Results and Discussion 52 Table 4.6: Activated Sludge Loading Data Parameter This Study Knox [33] Ehrig. [16] Mena et al [42] NHX-N loading (g/g MLVSS/d) 0.09- 1.01 0.008- 0.131 0.02 - 0.3 0.23 - 0.44 NHX-N loading (g/m3/d) 18 - 371 17 - 508 not given not given HRT (days) 0.4 - 4.7 0.5-8 6 1.16- 2 Temperature (°C) 0.5 - 23 0-23.7 not given 25 - 30 MLVSS (mg/L) 45 - 1290 1000 - 4000 2000 (MLSS) not given Leachate NHX-N (mg/L) 83 - 336 241 - 487 1200 300 - 750 Leachate BODs(mg/L) 27 - 89 56 - 290 <300 100 (ave) System Type SBR CMAS CMAS? SBR et al [42] used an SBR system for which the aeration time ranged from 14 to 23 hours per 18.5 to 24 hour cycle. This SBR was operated on an 8 hour cycle with an aeration time of 5.5 to 6.5 hours. Mena et al [42] noted that an increase in leachate feed concentration caused a greater upset when the aeration period was shorter, and suggested that systems with longer aeration periods are more stable. Oleskiewicz and Berquist [47] found that SBRs with a 4 hour aeration period were less tolerant of temperature decreases and loading changes than SBRs with an 8 hour aeration period. They also found that more efficient nitrification could be achieved at lower temperatures with the longer aeration period. The short aeration period herein may have contributed to the rather poor performance of the SBR. Other investigators at UBC, who also used Vancouver Landfill leachate, were able to build up and maintain high solids concentrations in their laboratory scale conventional activated sludge systems [4, 24]. However, both of these systems were single sludge nitrification-denitrification systems. Therefore, an external carbon source was added, and a heterotrophic population made up a significant portion of the biomass. However, the fact that the nitrification reactor was continuously aerated may also have been a factor. 4.1.4 Temperature Effects 4.1.4.1 RBC Figure 4.5 shows that the RBC system was found to be capable of nitrification at temperatures below 5°C. However, few data were available in this temperature range. One point appears to show quite good NHX-N removal at a mixed liquor temperature of only 0°C. It should be noted that at this time the RBC effluent port was frozen, causing the RBC to fill to about twice its normal volume. In addition, the sample on which measurements were taken was collected from Chapter 4. Results and Discussion 53 « 0 a <i K S5 1 M Figure 4.5: RBC NHX-N Loading and Removal versus Temperature 10 9 8 7 6 5 4 3 2 1 J i u ® • • o + • S 9 + • i i_ 10 12 —'—i — i — i m i m m — L _ 14 16 18 20 Temperature ("C) • Loading + Removal Loading' (A) Removal' Figure 4.6: RBC Ln(NHx-N Loading and Removal) versus Temperature Chapter 4. Results and Discussion 54 the effluent port (after it was freed) instead of from the last stage mixed liquor. As a result, significant dilution could have taken place, and the results can not be considered accurate. It is .impossible to determine whether the observed NHX-N removal included any removal which took place at 0°C or if it was only the result of dilution by effluent which had been treated before the temperature dropped to 0°C. The next day (February 9th), the effluent sample was collected normally, overfilling was no longer occurring, and the HRT was 0.34 days, so the diluted mixed liquor of the previous day had been replaced several times. Although the effluent NHX-N concentration was 72 mg/L, a removal of 1.51 g/m2/d was achieved at a temperature of only 2.5°C. While NOJ-N was not measured on February 9th, the fact that NOJ-N concentrations on February 8th and 11th were 14.6 and 19.0 mg/L indicates that there was probably a NOJ-N concentration greater than 10 mg/L on the 9th as well. The removal reported at 2°C, which occurred on February 25th, also requires some explanation. While the effluent port also froze on this occasion, resulting in overfilling, the sample was collected normally. Therefore, less dilution uncertainty is present than on February 8th, especially since the effluent NHX-N concentration was only 1 mg/L. The NHX-N removal was 0.9 g/m2/d. The NOJ-N concentration was not measured on the 25th, but on the 26th it was 1.72 mg/L. The effect of temperature on biological processes is often modelled with the Arrhenius equation (Equation 4.4). Manipulation of this equation yields Equation 4.5. According to Equation 4.5, a plot of ln(NHx-N removal) versus temperature should yield a straight provided that loadings greater than or equal to the maximum for a given temperature are provided. kT = k2O0T-™ (4.4) Where: T = Temperature (°C) kT = NHX-N removal rate at T°C (g/m2/d) k20 = NHX-N removal rate at 20°C (g/m2/d) 9 = 1.10 Source: [49] lnKT = mT + b (4.5) Chapter 4. Results and Discussion 55 Where: m = ln0 = slope b = lni^o - 201n# = y-intercept Figure 4.6 includes all RBC data for which less than 95% NHX-N removal was achieved. (Data with greater than 95% removal were excluded in order to avoid skewing 0 calculations with removals for which the applied loading was much less than the theoretical maximum). A linear regression on these data yields a 0 value of 1.07 (R2 = 0.62). If only the the data for temperatures less than or equal to 20 and 15°C are included in the regression, the 0 values calculated are 1.09 and 1.11, respectively. The R 2 value in both cases is 0.80, indicating a significantly better line fit than if the entire temperature range is included. If only the data for temperatures greater than or equal to 15°C are included, the 0 value is 0.99. While the correlation is poor (R2 = 0.02), the 0 value is less than one, and therefore the reaction rate no longer appears to increase with increasing temperature after a point somewhere between 15 and 20°C. It is important to note that the maximum removal achieved prior to the HRT experiment (defined below) was 5.38 g/m2/d on day 258 (April 27, 1994) when the temperature was only 15°C. Values of 0 for RBC nitrification found in the literature include 1.09 and 1.10 [49, 52]. These values agree well with the 0 values calculated at temperatures below 20°C. It is unclear why the rate of nitrification did not appear to continue to increase with temperature after a point somewhere between 15 and 20°C, but several possibilities exist. Forgie [21] suggests that the use of the Arrhenius equation with constant 0 values may only be valid for small temperature ranges, as 0 is a function of temperature. Knox [34] did not report 0 values, but did report similar overall removals at 15 and 20°C. It is possible that the relationship in Equaton 4.5 is no longer valid after a certain maximum point, which in this case was somewhere between 15 and 20°C. The rate of oxygen transfer from air into wastewater is generally considered to be proportional to the difference between the existing and equilibrium concentrations of dissolved oxygen [43]. As temperature increases, the equilibrium concentration decreases, and therefore the rate of oxygen transfer decreases. It is possible that the rate of oxygen transfer could slow down enough to limit the nitrification rate at high temperatures. Other investigators have suggested this possibility [34]. It is also possible that some other factor unrelated to temperature was limiting the RBC at higher temperatures. One limiting factor investigated was HRT. The points labelled Loading' and Removal' on Chapter 4. Results and Discussion 56 St •d N ro < a z I M in z 1 7 0 1 6 0 1 5 0 1 4 0 1 3 0 1 2 0 1 1 0 1 0 0 9 0 8 0 7 0 6 0 5 0 4 0 3 0 2 0 1 0 6 - 1 0 Figure 4.7: SBR NHX-N Loading and Removal versus Temperature • JEBL? m a • • d • + • • • s D D B t + D + + i + + + 9? • 4 + „ V " S% 1 B £ ffi ffl ffl B Q o + + i • + 8 1 2 1 6 2 0 Figures 4 discussed Temperature ('C) • Loading + Removal .5 and 4.6 are the results of this investigation. These points and the HRT investigation are further in Section 4.1.5.1. 4.1.4.2 SBR Figure 4.7 shows that several good NHX-N removals were achieved at temperatures below 6°C. Fewer low temperature data are available for the SBR than are available for the RBC, since the SBR failed during the winter and had to be heated in order to restart the process. The point at 0;5*C occurred on February 25th, and was included because some questionable points were included for the RBC during this time period. However, the actual loading which was applied at this time is uncertain because the influent and effluent lines to the SBR were frozen solid when the temperature measurement was taken, and ifwould therefore be wise to ignore this point. There were no problems with any of the other measurements which occurred at temperatures below 4°C; the experiment log shows that the system was operating normally at those times. Although the SBR effluent NOJ-N was not measured for every low temperature event, NOJ-N measurements at temperatures below 6°C were always 1 mg/L or less. Chapter 4. Results and Discussion 57 Figure 4.8: SBR Ln(NHx-N Loading and Removal) versus Temperature 7 > 0 S 0 K Z 1 0 4 8 12 16 20 Temperature ("C) • Loading + Removal 0=1.11 Equations 4.4 and 4.5 can be used to describe the relationship of nitrification rate to temperature in both suspended growth and fixed growth systems. The nitrification rate for activated sludge systems is typically expressed in terms of g NHx-N/g MLVSS/d. However, unreliable solids measurements (see Section 4.3.4) caused high variability in reaction rates in terms of g/g MLVSS/d compared to variability in reaction rates in terms of g/m3/d. For example, over the period from April 5th to 7th, 1994, nitrification rate varied from 0.48 to 1.32 g/g MLVSS/d, but only ranged from 43.7 to 59.7 g/m3/d, while NHX-N removal ranged from 86 to 116 mg/L. Therefore, it was decided to express nitrication rate in terms of g/m3/d in this case. In Figure 4.8, all data for which less than 95% NHX-N removal was achieved are plotted. A linear regression on these data yields a 6 value of 1.11 (R2 = 0.35). A textbook value for suspended growth nitrification processes is 6 = e0 0 9 8 = 1.10 [43]. While there is considerable data"scatter and the correla-tion is poor, these data exhibit the general relationship expected. However, it should be mentioned that not all researchers agree with the textbook model. For example, Oleskiewicz and Berquist [47] found that the response of SBR nitrification to temperature was discontinuous, with data below 7'C having a steeper slope on the ln(K) versus T graph (0 = 1.40) than data above 7°C (8 = 1.02). Chapter 4. Results and Discussion 58 Table 4.7: Comparison of RBC and SBR 9 Values Temperature Range RBC SBR °C 9 R 2 9 R* 0 to 25 1.07 0.62 1.11 0.35 0 to 20 1.09 0.80 1.07 0.14 0 to 15 1.11 0.80 1.06 0.09 15 to 25 0.99 0.02 1.29 0.67 Unlike the RBC, the SBR temperature data show no evidence of leveling off as temperature continues to increase. Table 4.7 shows that the opposite tendency is exhibited; 9 values increase as higher tempe-ratures are used in the regression calculation. The 9 values determined for the SBR are very similar to the values determined for the RBC, except in the temperature interval from 15 to 25°C, where the SBR shows its highest 9 value, and the RBC its lowest. Two of the possible reasons that RBC removals leveled off while temperature continued to increase were: a) the nitrification rate may not continue to increase with temperature beyond a certain point; and b) oxygen transfer rate may have become the rate limiting factor as temperature increased. If reason a) were true, one would reasonably expect to observe the same phenomenon in the SBR, since the same microorganisms are probably involved in the nitrification reaction. If reason b) were true, the argument that the same phenomenon should be observed in the SBR is weaker, since aeration mechanisms are so different. However, it still seems reasonable to expect that oxygen transfer rate would limit both systems in a similar fashion; the limitation expected is based on the temperature dependent solubility of oxygen, and the RBC and SBR systems tended to have similar temperatures. The SBR results therefore seem to add force to the argument that something other than temperature was limiting the RBC above temperatures between 15 and 20°C. 4.1.5 HRT Effects 4.1.5.1 R B C During the late spring/early summer months of 1994, it was noticed that while loading continued to be increased, removals leveled off. This trend is clearly visible in Figure 4.9. The first three lines of Table 4.8 illustrate that while N loading was increased, removal decreased as HRT decreased. The cause of the decrease in removal may have been HRT limitation. The fourth line of the table, and the points labelled Loading' and Removal' in Figures 4.9, 4.6, and 4.5 are the results of an investigation conducted Chapter 4. Results and Discussion 59 Table 4.8: RBC Loading and HRT Data Average HRT (days) Average Loading (g/m2/d) Average Removal (g/m2/d) Maximum Removal (g/mVd) Average Temperature CC) 0.17 6.02 2.72 4.54 19.9 0.27 4.88 3.60 5.38 15.9 0.35 4.15 3.93 4.63 20.5 0.29 8.68 6.20 8.21 14.8 by the City after the author discontinued laboratory work to begin writing this thesis. In order to determine whether or not the RBC system was unable to achieve higher removals due to HRT limitation, the HRT was increased and the RBC was fed a nutrient mixture containing NHX-N, Na3PG*4, and NaHC03 in addition to leachate. However, the City only collected four data points during this portion of the investigation. Comparing lines 2 and 4 of Table 4.8, one sees that with similar HRTs, increased average loading results in increased average removal, but percent removals remain similar. Increasing and decreasing the average HRT appeared to have caused percent removals to increase and decrease, respectively. However, Figure 4.9 illustrates that the four data points obtained are considerably scattered. The effect of HRT appears to be quite different when the individual data obtained in the City's HRT investigation are examined (see Table 4.9). If the data are sorted in order of HRT, one can easily observe that the highest removal occurred at the highest HRT, while the lowest removal occurred at the lowest HRT. The highest removal did not occur at the highest loading, nor at the highest temperature. While the highest removal occurred at the lowest NH3-N loading, the lowest removal occurred at the second lowest NH3-N loading, indicating that the limiting factor was probably not free NH3 inhibition. Since removal increased with HRT, and no other factor appears to have been the cause of inhibition, it seems probable that HRT was the limiting factor at higher loadings. (Note: free NH3-N loading was calculated as a function of temperature and pH using an empirical formal for Ka found in reference [46]). Peddie [52], using the same RBC plant, stated that nitrification was limited at HRTs below 4 hours (0.17 days), while these data seem to indicate that an HRT of at least 0.30 days is required for full NHX-N removal. Peddie used a younger landfill leachate, with lower NHX-N concentrations and higher BOD5 concentrations, and his NHX-N removal rates ranged up to about 1.2 g/m2/d with loadings of up to 4 g/m2/d. The differences in loading may account in part for the difference in required HRT. Examination of his data also reveals that, while nitrification efficiency is very poor at HRTs below 0.17 Chapter 4. Results and Discussion 60 Figure 4.9: RBC NHX-N Loading and Removal versus 1/HRT 1/HRT (1/dayg) • Loading + Removal X Loading' (2) Removal' Table 4.9: RBC N Loading and HRT Data from HRT Investigation Date HRT NHX-N NHX-N Temperature pH NH3-N Loading Removal Loading (days) (g/m2/d) (g/m2/d) (°C) g/m2/d 10/20/94 0.27 9.43 4.65 14 7.92 0.194 10/26/94 0.28 8.75 5.76 13 8.78 1.082 09/29/94 0.30 8.03 6.18 17 8.22 0.402 10/05/94 0.31 8.49 8.19 15 7.5 0.073 Chapter 4. Results and Discussion 61 Table 4.10: RBC 0 and R 2 Values with HRT Experiment Data Temperature Range °C No HRT Expt. Data All Data 0 R 2 0 R 2 0 to 25 1.069 0.62 1.068 0.50 0 to 20 1.093 0.80 1.096 0.69 0 to 15 1.109 0.80 1.129 0.75 15 to 25 0.989 0.02 0.972 0.08 days, nitrification performance is more clearly independent of HRT at HRTs above 0.3 days. In between 0.17 days and 0.3 days, performance increases with increasing HRT, ranging from about 70 to 100%. These data likewise include many points at which greater than 70% NHX-N removal is achieved at HRTs between 0.17 and 0.30 days. Therefore, the two data sets agree reasonably well; while an HRT of 0.17 days is sufficient for full NHX-N removal if the NHX-N loading is below about 1.2 g/m2/d, an HRT greater than 0.30 days is required for full removal of NHX-N loadings between 2 and 8 g/m2/d. It is important to note that while full NHX-N removal was achieved at the highest HRT, full nitri-fication was not, and large NOJ buildups occurred. Further discussion of this phenomenon is found in Section 4.2.3. Referring to Figure 4.6, the four points from the HRT experiment appear to fit reasonably well with the rest of the data, although they tend to be higher than corresponding points at a given temperature. If they are included in the linear regression calculations, as shown in Table 4.10, they do not typically change the 0 values significantly, although they tend to decrease the R 2 value. Unfortunately, the HRT experiment data were collected at temperatures of 13, 14, 15, and 17*C; they lie in the range of temperatures where removals begin to level off as temperature continues to increase. A much stronger argument for or against HRT limitation could have been made had there been HRT experiment data at temperatures between 17 and 25°C. Peddie [52] indicated that the HRT limitation he found was independent of temperature. This HRT investigation did not take place over a wide enough range of temperatures to verify or deny this result. 4.1.5.2 SBR Figures 4.10 and 4.11 show the relationship of SBR loading and removal to HRT in terms of g/g MLVSS/d and g/m3/d. Figure 4.10 shows a clear linear relationship between increasing 1/HRT and increasing volumetric loading, which is to be expected given that the leachate concentration was fairly constant over the period of decreasing HRT. It also shows that removals follow loading up to the lowest HRT. Chapter 4. Results and Discussion 62 Figure 4.10: SBR NHX-N Loading and Removal (g/m3/d) versus 1/HRT N n Z I z 700 600 500 400 300 200 100 -100 9 S + + 0.2 I L 0.4 i I I I I L ' i l l I L 0.6 1.4 1.6 1.8 2.2 2.4 0.8 1 1.2 1/HRT (1/days) • Loading + Removal The SBR never achieved full nitrification at the two lowest HRTs (0.43 and 0.71 days), and at some point nitrification would probably have been limited by HRT. Knox [33] achieved nitrification in a similar leachate with an HRT of 0.5 days in continously aerated activate sludge system. Oleskiewicz and Berquist [47] achieved nitrification of a high N wastewater with an HRT of 1 day in an SBR, but since aeration occurred for only 4 hours out of an 8 hour cycle, the "aerated ERT" would have been only 0.5 days. Since this SBR was aerated for 5.5 out of 8 hours, the equivalent aerated HRTs at the lowest HRTs were about 0.3 and 0.5 days. The low "aerated HRT'" value may have contributed to the difficulty encountered in achieving full nitrification at the 0.71/0.5 day HRT, but it is probable that full nitrification would have been achieved had the system been given longer to acclimatize. Since the 0.43/0.3 day HRT is lower than any found in the literature, it is more likely that the SBR was limited by HRT in that case, and that full nitrification may never have been achieved. Figure 4.11 shows that removals in terms of g/g MLVSS/d show no apparent relationship to 1/HRT. While removals between 0.3 and 0.6 g/g MLVSS/d are possible at all HRTs investigated, higher removals were achieved at the longer HRTs. If full nitrification had been achieved at the two lowest HRTs, the solids concentration probably would have been higher (due to a higher population of Nitrobacter), and Chapter 4. Results and Discussion 63 •d Si a > 0 a « Z 1 w Figure 4.11: SBR NHX-N Loading and Removal (g/g MLVSS/d) versus 1/HRT 2.1 2 1.9 1.8 1.7 1.6 1.5 1.4 1.3 (-1.2 1.1 1 0.9 0.8 0.7 0.6 0.5 h 0.4 \ -0.3 0.2 0.1 0 -0.1 • + + • J I 1 I 1 L J !_ J I I L 0.2 0.4 0.6 0.8 1 1.2 1.4 1.6 1.8 2 2.2 2.4 1/HRT (1/days) • Loading + Removal therefore removals in terms of g/g MLVSS/d would have been lower. It therefore seems probable that the highest nitrification rates in terms of g N/g MLVSS/d would still have occurred at the 1.9 day HRT. Intentional solids wasting was not performed for the greater part of the experiment; the theoretical SRT was infinite except during the first few months (when it was approximately 17 days). However, considerable amounts of solids were lost in the effluent throughout the experiment. Therefore, actual SRTs were longer when HRTs were longer. The longer SRTs, which resulted from the longer HRTs, could have been responsible for the higher g/g MLVSS/d removals seen during the longer HRTs. 4.1.6 Alkalinity Consumption Theoretically, 7.16 mg of alkalinity (as CaCOs) should be consumed for every mg of NHX-N nitrified [19]. Table 4.11 gives the results for this study. While values far above and far below 7.16 were found, the values were generally above 7.16, as shown by the averages given. (Note: for the SBR, the values obtained during the winter failure period from December 14th to January 16th were not included in the results given in Table 4.11, as no real nitrification was taking place and therefore results appeared questionable). The ratio was not calculated during periods of dry ammonium sulfate feeding. All other Chapter 4. Results and Discussion 64 Table 4.11: Alkalinity Consumption RBC SBR AVERAGE 9.24 8.99 MAXIMUM 19.06 19.73 MINIMUM 4.92 4.21 values were used, since the wide scatter of the data made it difficult to identify outliers. Many values of the ratio, such as the minimum and maximum values given in the table, are very different from theoretical values. Alkalinity consumption in excess of the theoretical requirement for nitrification could be caused by CaC03 precipitation, and consumption ratios lower than the theoretical value could be caused by dissolution of previously precipitated CaC03. It is not known if this mechanism would be sufficient to account for the observed variation. There was always sufficient natural alkalinity in the leachate for nitrification; no alkalinity additions were necessary when the systems were operating normally. Alkalinity addition to the SBR was required in late January when it was being heated and fed dry ammonium sulfate in order to build up solids. Alkalinity addition was required for the RBC during the HRT experiment, when NHX-N was added to the RBC to test higher loadings at a longer HRT. The alkalinity consumption ratio was not calculated during either of these periods. 4.1.7 Phosphate Addition and Consumption Tables 4.12 and 4.13 show PO 3 , --? addition and consumption data for the loading periods given in Tables 4.1 and 4.2. "Average Influent P0 3 - -P" includes P0 3 - -P pumped into the reactor by the nutrient pump as well as the background PO^-P concentration in the leachate. "Average N:P Ratio" refers to the average of individually calculated NHX-N removed to P0 3 - -P consumed ratios. Referring to Tables 4.12 and 4.1, the loading period at which the longest RBC acclimatization period was required began on day 171. During this period, the RBC suffered several severe temperature shocks and experienced its lowest average temperature. It was previously stated that low temperatures and temperature shocks during acclimatization were responsible for the long acclimatization time. Table 4.12 shows that the RBC also experienced its lowest average influent and effluent P0 3 - -P levels during this time; a low P supply may have contributed to the lengthy acclimatization period. However, the system was able to acclimatize eventually, and the N:P ratio was similar to those of surrounding loading periods. The RBC was never able to acclimatize during the loading periods beginning on days 241 and 309. J Chapter 4. Results and Discussion 65 Table 4.12: RBC Phosphate Addition and Consumption Start Average Average Acclimatization Average Average Average Average Day Loading HRT Time Influent Effluent Leachate N:P PO^--P PO*--P NHX-N Ratio (g/m2/d) (days) (days) (mg/L) (mg/L) (mg/L) 0 0.29 5.24 ? 8.91 1.29 298 41 55 0.38 2.25 < 6 1.77 0.89 168 62 150 0.83 0.80 < 2 1.92 0.31 129 121 171 1.29 0.65 12<t<14 1.08 0.14 146 130 206 2.18 0.41 < 1 1.45 0.22 169 138 241 4.88 ' 0.27 N/A 1.56 0.20 224 171 309 6.02 0.17 N/A 4.98 0.65 238 50 353 4.15 0.35 < 5 3.32 2.85 275 67 The average HRTs during these periods were 0.27 and 0.17 days, respectively. In Section 4.1.5.1, fairly conclusive evidence indicates that the RBC requires an HRT greater than 0.3 days in order to achieve full NHX-N removal at loadings above 2 g/m2/d. Since sufficient P appears to have been provided during the day 309 period, and since the 0.17 day HRT is clearly less than 0.3 days, the failure of the RBC to acclimatize was probably solely due to insufficient HRT. The day 241 period's HRT is much closer to 0.30 days, and the effluent PO^-P concentration was not significantly lower than the effluent PO^-P maintained during the previous successful loading periods (P addition was determined based on the effluent P concentration achieved during the previous successful loading periods). However, the N:P ratio for the day 241 period is much higher than it was for any other loading period. While the RBC was probably unable to acclimatize to the loading applied during the day 241 period due to insufficient HRT, P limitation could have been a contributing limiting factor. Referring to Tables 4.13 and 4.2, the SBR appears to have had a sufficient PO^-P supply during the second loading period, and therefore chronic P limitation was probably not a factor in the failure which occurred during this time. A low P supply may have contributed to the failure of the SBR to recover when the loading was decreased on day 131, but low temperatures and solids loss were more likely the cause. The effluent PO^-P level during the day 158 period refers to measurements taken after the dry ammonium sulfate feeding period, i.e. during the period when the SBR was fed leachate but heated. This effluent P level can therefore be considered a healthy effluent P level. Given that 0.92 mg/L is an acceptable POJ^-P level, the SBR should not have been P limited during the day 190 and day 214 periods. The ratio of average leachate NHX-N to influent PO^-P was lower during the day 214 period than during the day zero period, which would also seem to indicate that PO^-P was Chapter 4. Results and Discussion 66 Table 4.13: SBR Phosphate Addition and Consumption Start Day Average Loading (g/m3/d) Average HRT (days) Acclimatization Time (days) Average Influent PO^-P (mg/L) Average Effluent PO^-P (mg/L) Average Leachate NHX-N (mg/L) Average N:P Ratio 0 63.5 4.64 9 2.85 2.78 298 128 55 87.8 2.15 6<t<13 2.00 1.82 178 81 131 23.3 4.66 N/A 2.61 0.28 110 6.4 158 33.0 4.63 9 2.97 0.92 150 61 190 30.2 4.59 < 3 3.99 2.49 142 55 214 107 1.93 52 2.56 1.02 208 165 302 331 0.71 14<t<18 3.44 0.42 234 71 351 580 0.43 N/A 5.09 0.07 275 37 not limiting. However, the N:P ratio is much higher for the day 214 period than for any other loading period, so P limitation could have contributed to the long acclimatization time after day 214. The SBR loading period beginning on day 302 had the lowest average effluent P 0 3 - - P concentration, but had a mid range N:P ratio and had a high influent P concentration in relation to the leachate N concentration. While the effluent P concentration was higher than was typically required for proper RBC operation, the two processes may not be comparable in that respect. The SBR achieved complete NHX-N removal but did not achieve complete nitrification during this period. Effluent NOJ-N concentrations below 50 mg/L corresponded to effluent P0 3 - -P concentrations above 0.68 mg/L, and effluent P O 3 - -P concentrations below 0.142 mg/L corresponded to effluent NOJ-N concentrations above 186 mg/L. While additions of P0 3 - -P were generally intended to correspond to loading increases, examination of the experiment log indicates that the PO|~-P addition was only doubled after the loading was tripled on day 302. It is very likely that P0 3 - -P limitation was a major factor in the failure of the SBR to achieve full nitrification during this time. While the loading and P0 3 - -P addition were both doubled on day 351, the P0 3 - -P addition was insufficient on day 302, and was therefore still insufficient. It is unclear why the SBR experienced total solids washout between days 369 and 376, rather than achieving incomplete nitrification as it had after day 302. It would have been interesting to see if the incomplete nitrification with full NHX-N removal experienced between days 302 and 351 could have been maintained indefinitely, had the loading not been increased, or if the failure was inevitable. Chapter 4. Results and Discussion 67 4.1.7.1 Membrane Filtered PO^'-P Results Manoharan [40] recommended that soluble PO^-P concentrations greater than 0.5 mg/L be maintained in order to avoid P limitation, where "soluble" indicates that the sample has been filtered through a 0.45 /im membrane filter. Membrane filtered P samples were collected by the author when membrane filtration was being performed for metals samples on March 9th, April 13th, and May 18th, 1994 (days 209, 244, and 279). Membrane filtration was not done more regularly as it was very tedious. Effluent PO^-P measurements on the majority of effluent samples were performed in combination with NO~-N analyses on samples which had been diluted 1:10 or 1:20, preserved with phenyl mercuric acetate, and refrigerated for up to a week. Measurements of undiluted samples for PO^-P only on April 4th and May 18th indicated that preserved/diluted sample measurements tended to be significantly lower than direct sample measurements. However, the author's measurements were not typically lower or higher than the City's measurements. PO^-P measurements on membrane filtered SBR effluent samples were all above 0.50 mg/L on the days tested, but the day 244 and 279 samples were lower than the day 209 sample. Membrane filtered measurements were 52 to 80% of unpreserved sample measurements, and 56 to 450% of preserved/diluted sample measurements. Overall, these observations support the previously made arguments that the SBR was not P limited between days 190 and 214, and may have been P limited between days 214 and 302. The RBC is a different system, and the 0.50 mg/L criterion may not be valid for it (as evidenced by the fact that effluent PO^'-P measurements without membrane filtration were frequently below 0.5 mg/L during successful operation). However, the RBC measurements on days 209, 244, and 279 were 1.2, 0.12, and 0.05 mg/L, respectively. These measurements add force to the argument that the RBC may have been PO^-P limited between days 241 and 309; they also support the argument that the RBC was not PO^-P limited between days 206 and 241. The City's laboratory (Cantest) did not begin reporting membrane filtered P measurements until August 5th (day 358), when the City began requesting membrane filtration. Cantest had not been required to membrane filter P samples prior to this date. While the City received a letter in August indicating that PO^-P samples prior to August 5th were membrane filtered, they had never been reported as such, and they were not found to be significantly different from the author's Whatman 934 AH filtered samples. Because of this confusion, City measurements prior to August 5th were not considered to be membrane filtered. The following paragraph refers to results reported by the City after Chapter 4. Results and Discussion 68 Table 4.14: TKN Data Leachate Organic N Removed TKN Removed: TKN:NHX-N (mg/L) NHX-N Removed RBC SBR RBC SBR AVERAGE 1.069 4.33 5.14 1.00 0.98 MAXIMUM 1.184 47.9 40.1 1.37 1.24 MINIMUM 0.929 -33.0 -25.5 0.84 0.87 August 5th. The ratio of membrane filtered to normal samples ranged from 0 to 0.6 and averaged 0.4 for the RBC, and ranged from 0 to 0.5 with an average of 0.23 for the SBR. The RBC was not P limited in the loading period which began on day 353, judging by its performance, and effluent membrane filtered P only dipped below 0.5 mg/L twice during this time. The SBR's effluent membrane filtered P measurements were 0.02, 0, and 0 on days 358, 362, and 369, respectively, which reinforces the assertion that the SBR was P limited after day 351. Because the ratio of P supplied to loading was the same after day 302 and after day 351, these measurements are also evidence that the SBR was P limited after day 302. Membrane filtered P analysis was also performed by the City during the HRT experiment. Ratios ranged from 0.19 to 0.62 and again averaged 0.4. While the RBC achieved full ammonia removal at the highest HRT during the HRT experiment, it did not achieve full nitrification. More discussion of this phenomenon is found in Section 4.2.3. 4.2 Other Nitrogen Forms 4.2.1 T K N During the course of the research, the ratio of leachate TKN to NHX-N was determined 20 times. There were two clear outliers, one at 0.792, and another at 1.401. The remainder of the data are summarized in Table 4.14. TKN values below the NHX-N values were found a total of 3 times, (0.792, 0.929, 0.985). Each of these results was produced by the author at the U.B.C. laboratory rather than by Cantest. Two of these results were obtained from samples collected on the same day (0.792 and 0.985), and the lower of the two was probably caused by a low NHX-N measurement, as the TKN measurements and NO" measurements were similar. Another U.B.C. graduate student who used the same leachate also had trouble with TKN results being below NHX-N results and found NHX-N measurements to be more reproducible [4]. Chapter 4. Results and Discussion 69 Table 4.14 also gives the organic N (i.e. TKN - NHX-N) removed and the ratio of TKN removed to NHX-N removed in each system. For both systems, the average value of the ratio was very nearly 1, and little organic N was generally removed. Both systems also occasionally appeared to create organic N. This could be due to cell lysis, but could be exaggerated by experimental errors and lack of correlation between NHX-N and TKN measurements. In general, the results indicate that NHX-N removal accounted for most TKN removal, and there were no significant differences in TKN removal between the two systems. (Note: the only outlier removed in calculating the TKN data for the SBR and RBC was the point mentioned above when the TKN:NHX-N ratio was 0.792. There were no RBC or SBR TKN measurements on the day when the ratio was 1.401 for the leachate). 4.2.2 Nitrogen Balances Leachate nitrogen was primarily in the form of NHX-N, but included small amounts of organic N (see Section 4.2.1) and NO~-N. The average NOj-N concentration in the leachate was 0.76 mg/L, and the average NOJ-N concentration was 0.03 mg/L; influent NOj-N was primarily NOJ-N. Effluent NOj-N from both systems was also primarily NOJ-N, except under stressed conditions when NOJ-N buildups occurred in both systems (see Section 4.2.3). Tables 4.15 and 4.16 give nitrogen balance data for the RBC and SBR respectively. "Lost N" is the difference between total influent and effluent N, where total N = TKN + NO"-N. "Lost NH x+NO xN" is the same figure calculated with NHX-N in place of TKN on occasions when TKN was measured. The only value excluded from the calculations for these first two columns was the point for which theTKN:NHx-N ratio of the leachate was found to be 0.792 (see Section 4.2.1). "Overall Lost NH x+NO xN" includes data from the entire experiment (i.e. data is included whether or not TKN was measured). SBR data obtained during the period of dry (NH4)2S04 feeding and for 5 days (1 HRT) afterward were excluded, as were RBC data obtained during the HRT experiment (when the leachate feed was augmented with dry (NH4)2S04). Extreme minimum values (-106% for the RBC and -163% for the SBR) were excluded from the table in order to avoid skewing the average value. If these extreme values are included, the average is -3.6% for the RBC and 1.8% for the SBR. On average, neither system was observed to lose much nitrogen, and the percentage differences between influent and effluent nitrogen were usually small enough to be attributed to sums of acceptable measurement error limits. For example, repeated NHX-N analyses of the same sample were found to vary by up to 10%. If Chapter 4. Results and Discussion 70 Table 4.15: RBC Nitrogen Balance Data Overall Lost Lost Lost NHx+NO- NH x+NO x N N 1 N (%) (%) (%) AVERAGE 1.5 -0.7 -1.9 MAXIMUM 26.0 16.3 64.3 MINIMUM -18.6 -18.6 -37.5 Table 4.16: SBR Nitrogen Balance Data Overall Lost Lost Lost NHx+NO- NH x+NO x N N N (%) (%) (%) AVERAGE 7.7 8.1 4.7 MAXIMUM 20.9 24.9 78.0 MINIMUM -21 -6.2 -48.9 the pH difference between the two samples was adjusted to approximately 0.5 units, the possible total variation was found to be just over 20%. However, the variation between repeated measurements was usually under 5% both with and without small pH differences. Lost TKN values are very close to lost NHX-N values obtained at the same time, but overall lost NHX-N values are somewhat different. However, the differences are probably not large enough to be significant. Ammonia volatilization was measured twice for each system during November 1993. The RBC he-adspace was found to contain approximately 0.2 to 0.4 mg of NHX-N during each trial, and approximately 400 mg of NHX-N were added to the reactor every 30 minutes. During these measurements, the air pump was removing about 28 % of the RBC headspace volume every 30 minutes. Assuming that neglible he-adspace air left the RBC from points other than the air pump inlet, 0.01 to 0.03 % of the NHX-N added was lost to volatilization. For the SBR, approximately 1 to 5 mg of NHX-N volatilized during the 5.5 hour aeration cycle, while 10 to 10.8 g of NHX-N were added in the leachate; 0.01 to 0.05 % of the NHX-N added was lost through volatilization. While some volatilized NHX-N was detected for each system, the amount of N lost to volatilization was neglible. This result was expected due to the mixed liquor temperatures and pH values observed at Chapter 4. Results and Discussion 71 Figure 4.12: Leachate and Effluent NOJ-N versus Time z I (VI O z 2 1 0 2 0 0 1 9 0 -1 8 0 -1 7 0 1 6 0 1 5 0 1 4 0 1 3 0 1 2 0 1 1 0 1 0 0 9 0 8 0 7 0 6 0 5 0 4 0 3 0 2 0 1 0 0 o o o o o + o+ © ° o + + + * ° + ° + + 2 0 0 3 0 0 4 0 0 0 1 0 0 ' Time (days) , • Leachate + RBC O SBR that time (Temperature 4 to 10°C, pH 7.8 to 8.4). No subsequent ammonia volatilization measurements were undertaken in the warmer months due to time constraints and the lack of N loss observed as the study progressed. 4.2.3 Nitrite Figure 4.12 shows that N0J-N buildups were fairly common in both systems. Dates of loading increases and process upsets are given in Tables'4.1, 4.2, 4.3, and 4.4. 4.2.3.1 R B C For the RBC, the first significant NOJ-N buildups occurred between days 171 and 185, and were probably caused by the loading increase on day 171. Effluent P O 3 - - ? concentrations taken when the NOjT-N buildups occurred were somewhat lower than average measurements before day 171. P O 3 - - ? addition was not increased in conjunction with the loading increase, so PO^-P limitation resulting from the loading increase may have been a factor. (It should be noted that these were not membrane filtered samples, but that any P0 3 - -P measurement taken at the same time as an NOJ-N measurement was Chapter 4. Results and Discussion 72 performed by the City laboratory > and was therefore less prone to preservation/dilution error than the author's PO^-P measurements). The next NOJ-N spike occurred on day 208, and followed the loading increase on day 206. PO^-P was not detected in the effluent on day 208, but PO^-P addition had been doubled on day 206. NOJ-N concentrations generally remained above 4 mg/L until day 309, and the loading increase on day 241 did not have a significant effect, even though PO^-P addition was not increased until day 287. On day 271, the wet well pump failed, which resulted in lack of leachate feed to both systems for several days. The shock of resumed leachate feed could be partly responsible for the NOJ-N spike on day 278. However, effluent PO^-P was not detected, and PO4--P levels continued to be low while the NOJ-N buildups worsened from day 278 to day 299. The experiment logbook shows that POf'-P addition was tripled on day 287 due to suspected P limitation, but effluent P remained below 0.03 mg/L until day 306 when it was 1.0 mg/L. The NOJ-N level on day 306 was only 5 mg/L, while it had been 94 mg/L on day 299. Existing P O 4 - solution may have been used up rather than making up a new batch immediately. The HRT averaged 0.27 days from day 241 to day 308. The loading increase on day 309 did not occur in conjunction with a PO^'-P addition increase, and was not followed by an immediate NOJ-N buildup. A spike occurred on day 320 when the NHX-N loading abruptly more than doubled due to influent valve malfunctions. The increased loading also resulted in a very low effluent PO^'-P concentration. PO^-P addition was doubled again on day 334, and effluent NOJ-N was 4 mg/L on day 334 and day 341 while effluent NHX-N increased from 61 to 121 mg/L even though loading decreased from 6.2 to 4.3 g/m2/d. The HRT averaged 0.17 days from day 309 to day 352, The loading decrease on day 353 was followed by NOJ-N levels at 2 to 7.6% of NO~-N from day 358 to day 369 when membrane filtered PO^'-P levels were 1 to 2.9 mg/L. The NOJ-N levels from day 376 to 391 were 15.6 to 19.8% of NO~-N while membrane filtered PO^-P levels were 0 to 0.8 mg/L. The lack of complete nitrification from day 358 to day 369 may have been due to free NH3-N inhibition, since effluent PO^-P levels were satisfactory. However, P limitation may have occurred between days 376 and 391. Free NH3-N inhibition of Nitrosomonas begins at 10 to 150 mg/L NHX-N, while inhibition of Nitro-bacter begins at 0.1 to 1.0 mg/L [1]. Nitrobacter is more sensitive to free NH3 than Nitrosomonas, and almost every NOJ-N buildup in the RBC system occurred in conjunction with an increase in NHX-N loading. It is therefore possible that NOJ-N buildups were caused by free NH 3 inhibition. Chapter 4. Results and Discussion 73 However, NOJ-N buildups also tended to occur in conjunction with low effluent PO^-P concen-trations. Because low effluent PO^-P concentrations could be caused by increasing loading without increasing P addition, it is difficult to determine whether the increased loading itself, or the P limitation caused by the increased loading resulted in NOJ-N buildups. The situation is further complicated by the fact that the RBC was likely HRT limited at higher loading rates. No evidence linking P limitation and incomplete nitrification was' found in the literature. The last few points on Figure 4.12 were collected during the HRT experiment conducted by the City. Huge NOJ-N buildups occurred at first, but the system gradually returned to a more normal (but still high) NOJ-N level. Table 4.17 includes data from the HRT experiment, and shows that effluent NOJ-N levels of 23, 72, 224, and 245 mg/L corresponded to free NH3-N loadings of 0.073, 0.402, 0.194, and 1.082 g/m2/d, respectively. The two highest NOJ-N loadings were the first two measurements, and therefore the fact that 0.194 g/m2/d was associated with a higher NOJ-N concentration than 0.402 g/m2/d could be explained by acclimatization. It could also be explained by the fact that these numbers are loadings rather than concentrations. (Meaningful concentration values are difficult to calculate for the RBC system since it is not completely mixed). In any case, the highest and lowest NH3-N loadings correspond to the highest and lowest effluent NOJ-N levels. While it appears that the NOJ-N levels decreased with time, Table 4.17 shows that arranging the results with respect to time also arranges the results with respect to increasing effluent membrane fil-tered PO 3 , --? concentration and decreasing NOJ-N fraction. While NH3-N loading shows an apparent relationship to effluent NOJ-N concentration, the relationship between NH3-N loading (or NH3-N lo-ading fraction) and NOJ-N fraction is less clear. NOJ-N fraction is a better indication of differential Nitrobacter inhibition than NOJ-N concentration because NO~-N levels were variable. Examination of the NOJ-N and P O 3 - - ? results does not change the fact that NHX-N removal increased with increasing HRT, but it does indicate that complete nitrification may have been prevented in the HRT experiment through PO^-P limitation, rather than through NH 3 inhibition. If NOJ-N buildups during the HRT experiment were caused by P limitation, it is likely that P limitation was also primarily responsible for NOJ-N buildups observed in the RBC system during the rest of the study. Chapter 4. Results and Discussion 74 Table 4.17: RBC NOJ-N and PO^~-P Data from HRT Investigation Date HRT NHX-N Effluent NOJ-N/NOJ-N Effluent NH3-N Removal NOJ-N Fraction Soluble PO^-P Loading (days) (%) (mg/L) (%) (mg/L) (g/m2/d) 09/29/94 0.30 76.9 224 65.7 0.08 0.402 10/05/94 0.31 96.5 245 50.0 0.17 0.073 10/20/94 0.27 49.3 72 41.5 0.27 0.194 10/26/94 0.28 65.8 23 11.2 1.20 1.082 4.2.3.2 SBR Referring to Figure 4.12, the SBR experienced three small NOJ-N buildups prior to its first loading increase on day 55. One of these corresponded with an unexplained process upset which occurred on day 12, and effluent quality was somewhat poor on the other two occasions, but neither higher than normal NHX-N loading nor lower than normal effluent P0 3 - -P occurred on any of these occasions. The NOJ-N spike on day 68 (55 mg/L) came almost two weeks after the loading increase on day 55. The effluent PO|~-P level on day 68 was 0.93 mg/L, but on day 82, when the effluent P03""-P level was 0.29 the NOJ-N level was only 0.62. However, both of these P levels were significantly lower than surrounding values, and the NHX-N loading on day 82 was only 70% of day 68's. After this, NOJ-N levels stayed near zero until day 215 when the NOJ-N concentration was 4.7 mg/L. The loading had been increased on day 214, but the effluent P O 3 - - ? (0.88 mg/L) was similar to P levels observed during acceptable operation in the previous loading period. Three high NOJ-N concentrations occurred on days 257, 261, and 278 when the NHX-N loading exceeded 120 g/m3/d and effluent P levels were 0.43 to 0.6. On days 271 and 299, similar loadings did not produce NOJ-N buildups when effluent P0 3 - -P concentrations were higher (1.3 and 0.69), but similar loadings on days 285 and 292 did not produce NOJ-N buildups even though effluent P0 3 - -P concentrations were low (0.43 to 0.62). Initial free NH3-N levels in the reactor were calculated using site pH and temperature measurements and an empirical formula from reference [46]. The first three high NOJ-N events corresponded to higher than average initial NH3-N levels for that time period. However, not all high initial NH3-N events produced a high NOJ-N event. Between day 167 when leachate feed was resumed and the next loading increase on day 214, calculated initial free NH3-N levels exceeded 1 mg/L only once. After day 214 initial free NH3-N levels almost always exceeded 1 mg/L. However, initial free NH3-N levels on days when NOJ-N buidups occurred after day 214 (i.e. days 257, 261, and 278) were not significantly different from levels Chapter 4. Results and Discussion 75 on surrounding days without NOJ-N buildups. Neither free NH3 inhibition nor P limitation appears to be an adequate explanation for NOJ-N buildups observed prior to day 302. Effluent NOJ-N levels following the loading increase on day 302 increased dramatically, and complete nitrification was never achieved in this loading period or in the following period which began on day 351. Initial free N H 3 - N levels between days 302 and 351 were similar to those in the previous loading range when full nitrification was achieved. In contrast, effluent NOJ-N concentrations below 50 mg/L corresponded to effluent PO^-P concentrations above 0.68 mg/L, and effluent PO^-P concentrations below 0.142 mg/L corresponded to effluent NOJ-N concentrations above 186 mg/L. These results seem to indicate that the nitrite buildups after day 302 were caused by P limitation, rather than by free NH3 inhibition. The low NOJ-N levels shown after day 375 are the result of the SBR system's failure. In an SBR system, the free NH3-N concentration would be relatively high during the "fill" stage, and would taper off as NHX-N was nitrified during the "react" stage Therefore, nitrifiers would be exposed to a much more variable NH3-N concentration than they would be in a continuous flow activated sludge system. The high variability might make acclimatization more difficult in an SBR system than in a completely mixed system. While free NH3 inhibition was not shown to be the prime cause of NOJ-N buildups during this experiment, it could be partly responsible for the overall poor performance of the SBR. 4.3 Organics and Suspended Solids 4.3.1 B O D 5 Figure 4.13 shows that while leachate BOD5 concentration varied from 20 to 89 mg/L, it was generally nearer the average value of 45.5 mg/L. While both systems were capable of removing BOD5 during periods of relatively light NHX-N loading, each tended to be more likely to add BOD5 under heavier NHX-N loading conditions. RBC BOD5 was measured on samples which had been settled in the laboratory for 30 minutes, while SBR BOD5 was measured directly on effluent samples which had been settled in the reactor for 1 to 2 hours. However, total (i.e. unfiltered) BOD5 was measured for both systems. Therefore, it is possible that more BOD5 was added under heavier loading conditions because effluent solids exhibited poorer settlability. Figures 4.14 and 4.15 show BOD5 and COD plotted against total suspended solids for the RBC and Chapter 4. Results and Discussion 76 Figure 4.13: Leachate and Effluent BOD5 versus Time in o m Time (days) • Leachate + RBC O SBR SBR, respectively. Both BOD5 and COD seem to increase with TSS for the RBC, but the relationship is not definite. The relationship between BOD5 COD, and TSS is even less clear for the SBR. Since the City did not measure VSS regularly, and since the author did not measure oxygen demand, a plot of BOD5 or COD versus VSS, which may have provided more insight, could not be produced. While it is possible that increased BOD5 measurements at higher loadings were caused by poor solids settlability, the data do not prove this assertion conclusively, particularly for the SBR. While there is very little BOD5 data on which to base a comparison, it appears that the two systems performed similarly with respect to BOD5 removal. 4.3.2 COD Figure 4.16 shows the performance" of each system with respect to COD removal. The RBC system generally performed better than, or similar to, the SBR system. The SBR performed better for a short period from about day 250 to day 300 (mid April to mid June), but this was a period during which the RBC received its second highest loading while the SBR received its third highest loading. During the SBR's two most heavily loaded phases, beginning on days 306 and 358, SBR effluent COD was typically Chapter 4. Results and Discussion 77 Figure 4.14: RBC BOD 5 and COD versus TSS o o u •d a d P. O ffl Q O o •d d d P O m fl 7 0 0 6 0 0 h 5 0 0 4 0 0 3 0 0 2 0 0 1 0 0 h 7 0 0 6 0 0 5 0 0 4 0 0 3 0 0 2 0 0 1 0 0 TSS (mg/L) • BOD + COD Figure 4.15: SBR BOD 5 and COD versus TSS + + + + + + + + J 4nJ 1 1 [h • J L J I I I I L 1 0 3 0 5 0 7 0 9 0 1 1 0 TSS (mg/L) • BOD + COD 1 3 0 1 5 0 Chapter 4. Results and Discussion 78 Figure 4.16: Leachate and Effluent COD versus Time ft o u 7 0 0 6 0 0 h 5 0 0 h 4 0 0 3 0 0 2 0 0 1 0 0 1 0 0 2 0 0 3 0 0 4 0 0 Time (days) Leachate + EBC SBR greater than or equal to influent COD. Most of the points which lie on the influent COD line fall after day 376, when the SBR solids were almost completely washed out. In contrast, while the RBCs performance suffered during its most heavily loaded phase, it usually still achieved some COD removal. The overall average COD removal for the RBC was 21.2%, while that for the SBR was 11.0%. If the average is taken over the period from August 24/93 to June 7/94 (day 12 to 299), in order to exclude most negative removals by the SBR, then the numbers are closer (24.0 and 19.2 for the RBC and SBR, respectively). If the average removal for the RBC is calculated with points during the period of heaviest loading removed, the result is 26.6%. In summary, the RBC system performed better than the SBR system with respect to COD removal, particularly under heavily loaded conditions. 4.3.3 Comparison of BOD 5 and COD Influent and effluent BOD5:COD ratios are given in Table 4.18, and Figures 4.17 and 4.18 show the relationship of COD removal to BOD5 removal for the RBC and SBR, respectively. Figures 4.17 and 4.18 clearly show that both systems generally removed more COD than BOD5 when there was a net removal of BOD5, indicating that some recalcitrant compounds (i.e. COD) were Chapter 4. Results and Discussion 79 Table 4.18: BOD5:COD Ratios Leachate RBC SBR AVERAGE 0.124 0.320 0.175 MAXIMUM 0.188 0.689 0.376 MINIMUM 0.063 0.036 0.000 converted to more readily biologically oxidizable compounds (BOD5) and removed. When there was a net addition of BOD5 and a net removal of COD, the addition of BOD5 was usually smaller than the removal of COD for the SBR, and much larger than the removal of COD for the RBC; however, it is difficult to make a meaningful conclusion based on this observation. Since COD includes BOD5, a zero or net positive removal of COD in combination with a net increase in BOD5 could mean that some recalcitrant compounds were converted to more readily oxidizable compounds and/or biomass, but only part of the BOD5 created was removed. > BOD5 addition tended to occur under more heavily loaded conditions. It is possible that this was because the systems were unable to finish the process of oxidizing recalcitrant compounds when the systems were heavily loaded. ' An addition of both COD and BOD5 to the effluent could also indicate addition of effluent BOD5 due to losses of unsettlable biological solids. On days 313 and 341 (see Figure 4.18), when the SBR was heavily loaded and experiencing nitrite buildups, the BOD5 measurements were 94 and 246 mg/L, while the TSS measurements were 103 and 86 mg/L, respectively. Unfortunately, no VSS measurements are available for days 313 or 341. These data do not prove that the increases in BOD5 were related to unsettlable solids in the effluent. The fact that TSS and BOD5 are not clearly related could indicate that another factor, such as cell lysis, contributed to the increase in BOD5. Addition of BOD5 due to cell lysis is difficult to identify if a net removal of COD has occurred, because the addition of BOD5 due to cell lysis would be masked by the addition of BOD5 due to COD conversion. It is therefore difficult to know if any addition of BOD5 by the RBC was due to cell lysis. In any case, Figure 4.16 indicates that the effluent COD concentration was greater than the influent COD concentration more often for the SBR than the RBC, so it appears that the SBR was more likely to add BOD 5 due to cell lysis than the RBC. Chapter 4. Results and Discussion 80 Figure 4.17: Comparison of RBC COD and BOD 5 Removal •d x > 0 s OS 3 4 6 8 9 6 1 1 0 1 3 1 1 6 6 1 9 4 2 1 5 2 5 0 2 7 8 3 1 3 3 4 1 Time (days) COD BOD Figure 4.18: Comparison of SBR COD and BOD 5 Removal 100 5 0 •d N n - 5 0 - 1 0 0 - 1 5 0 - 2 0 0 - 2 5 0 - 3 0 0 3 4 6 8 9 6 1 1 0 1 3 1 1 6 6 1 9 4 2 1 5 2 5 0 2 7 8 3 1 3 3 4 1 Time (days) COD BOD Chapter 4. Results and Discussion 81 Figure 4.19: Leachate and Effluent Total Suspended Solids C O C O 4 0 0 3 5 0 3 0 0 2 5 0 2 0 0 h 1 5 0 1 0 0 h Time (days) Leachate + RBC O RBC Settled SBR 4.3.4 Suspended Solids Figure 4.19 shows the leachate and effluent total suspended solids data obtained during the study. "RBC" refers to RBC mixed liquor removed from the final stage, while "RBC Settled" refers to this sample after half an hour of quiescent settling in the lab. "SBR" refers to SBR effluent, which was settled in the reactor for 1 hour prior to January 28th (Day 169), and 2 hours subsequently. The SBR removed solids reasonably well until approximately day 90 (Nov. 10/93), after which SBR effluent solids were typically similar to leachate solids. The RBC effluent solids began to climb after about day 200 (Feb. 28/94), possibly due accumulated solids on the reactor bottom (there was no provision for solids wasting). However, laboratory settling continued to remove solids to low levels, ranging from 1 to 44 mg/L and averaging 15 mg/L. In contrast, SBR effluent TSS (reactor settled) ranged from 13 to 156 mg/L and averaged 64 mg/L. Leachate TSS ranged from 10 to 308 mg/L and averaged 67 mg/L. While the average TSS levels were similar, the average VSS:TSS ratio was 0.60 for the SBR effluent and 0.50 for the leachate. There was not much overlap between the leachate and SBR effluent VSS:TSS data; the maximum recorded for Chapter 4. Results and Discussion 82 Table 4.19: RBC Disk Scrapings Date VSS TSS VSS:TSS (%) (%) April 20 3.6 8.1 0.45 May 17 4.36 10.5 0.415 June 21 0.57 10.1 0.056 July 19 4.00 16.8 0.238 August 5 3.50 13.4 0.261 September 7 4.45 11.1 0.401 the leachate was 0.63 (similar to the average for the SBR), while the minimum for the SBR was 0.51 (greater than the average for the leachate). These data indicate that the solids leaving the SBR were not typically the same ELS the ones that entered in the leachate; some removal of fixed solids appears to have occurred within the SBR. One possible mechanism for fixed solids removal is accumulation of fixed solids, or "scale" on the walls of the supply tank, the plumbing, and the reactor itself. The fixed solids, which can make up scale, include calcium and iron compounds such as CaC03 and Fe(OH)3 [33, 39]. While supply and effluent lines for both reactors were periodically changed when scale built up, no major problems with scale occurred, and neither reactor was observed to have a large scale buildup on its walls. Consequently, there was no proof that fixed solids removal in the SBR was caused by accumulation within the reactor. Precipitation of inorganic compounds can cause trouble in activated sludge systems by encrusting the biological floes [39], but no evidence of this was seen. The RBC VSS:TSS ratio averaged 0.58 and ranged from 0.48 to 0.68, but since the effluent solids levels were not similar to leachate levels, this fact can not be used to indicate whether or not inorganic solids were building up. However, no tendency for the effluent VSS:TSS ratio to increase or decrease was observed over the course of the experiment. In order to determine whether inorganics were building up on the discs, several samples of disc scrapings were .analyzed for VSS and TSS over the last few months of the experiment. The results are given in Table 4.19. The net amount of VSS in a given sample does not change significantly (with the exception of the June 21 result, which may have been a poor sample). While the VSS:TSS ratio varies quite significantly, there does not appear to be a trend for it to decrease with time; it reached low levels but was able to recover. Other investigators have had severe scale problems with RBC systems [39, 34]. However, open ditch leachate collection systems, such as the system at the Vancouver Landfill, can prevent scale formation in the reactor by acting as a "pretreatment stage" [33]. No problems due to scale were observed during Chapter 4. Results and Discussion 83 Figure 4.20: SBR Mixed Liquor Suspended Solids i s 0 CO co C Time (days) • MLSS + MLVSS this study, and it is unlikely that encrustation would become a problem in the long term. Figure 4.20 shows the variation in mixed liquor total and volatile solids for the SBR with time. MLVSS data shown are direct measurements. The average VSS.TSS ratio was 0.62, and this value was used to calculate MLVSS from MLSS for loading calculations when necessary. Tables 4.2 and 4.4 give the times at which loading increases and process upsets occurred. Loading increases occurred on days 55, 167, 214, 302, and 351. The SBR was reinoculated with bio-P sludge and fed dry (NH^SO^ from day 158 to 167. Following a loading increase, the SBR suspended solids concentration typically increased significantly, then fell off until the next loading increase occurred. In one case (day 214 to day 302), solids concentrations began to increase before the next loading increase was applied. The decreases in MLSS between days 100 and 158 were associated with process upsets caused by cold and/or various equipment failures (power, compressor, nutrient pump, leaking influent valve). The heaters were removed from the reactor on day 190, which corresponds to the beginning of a solids loss trend that lasted until the loading was increased again on day 214. The large solids losses which occurred shortly after day 167 were probably caused by a decrease in N loading due to the transition from dry Chapter 4. Results and Discussion 84 (NH4)2S04 feeding to leachate feeding. The cold/no nutrient flow event on day 198 took place during a period of decreasing solids concentration, but may have contributed to the overall solids loss. Significant day to day variations in both MLSS and MLVSS occurred between day 200 and day 300. Solids balances performed to check these variations indicate that more variation is sometimes seen than one would expect, given the influent and effluent solids concentrations and the growth rates of nitrifying organisms. Solids measurements were based on the average of duplicate samples, and all calculations were checked carefully. Solids samples were usually taken 5 minutes after the start of aeration, which may not have been long enough for complete mixing to have occurred. However, City solids measurements were generally taken an hour or more into the aeration cycle, and they show the same type of variability as the author's. There is no tendency for City measurements (MLSS) to be higher or lower than the author's. One possible cause for the unexpected variations in suspended solids measuements is poor reactor mixing. 4.3.5 Colour , The colour of the leachate ranged from 150 to 1000 units, and averaged 615 units. RBC colour removals ranged from -100 to 62.5% and averaged 20.1%. SBR colour removal ranged from -60 to 50% and averaged 12.8%. The leachate was typically brown or red-brown in colour, and these colours are typically associated with humic materials. Humic materials are typically biologically recalcitrant, and are therefore repre-sented by COD rather than BOD5. Another possible source of red-brown colour is iron oxides. Since the RBC removed more COD and more iron than the SBR, it is not surprising that the RBC also removed more colour. 4.4 Metals The City measured total chromium, iron, lead, manganese, nickel and zinc once per month. The author selected total and dissolved cadmium, chromium, cobalt, copper, iron, nickel, and zinc as metals to monitor in conjunction with toxicity studies. These metals were selected because historical data indicated that their concentrations i n the leachate occasionally reached or exceeded toxicity thresholds for Daphnia. Metals were measured i n samples which had been preserved shortly after collection and in samples which had been kept at 20°C i n control beakers during Daphnia LC50 tests prior to preservation. Chapter 4. Results and Discussion 85 4.4.1 Cadmium Cadmium measurements ranged from 0.004 mg/L to 0.010 mg/L, and averaged .007 mg/L. The detection limit was 0.004 mg/L. There were no significant differences between leachate and effluent concentrations, or between dissolved and total values. Samples left standing in control beakers showed no significant differences from samples preserved immediately. 4.4.2 Chromium The City's laboratory never detected chromium in the leachate or the effluents. Their detection limit was 0.03 mg/L. Total chromium measurements from the UBC lab, using a graphite furnace indicated that all leachate samples were between 0.005 and 0.010 mg/L. Measurements were complicated by double peak responses and a low signahnoise ratio, and thus it was recommended that the chromium concentrations be listed as "<0.01 mg/L" for all samples. As a result, no other samples were analyzed for chromium by the author. 4.4.3 Cobalt The detection limit for cobalt was 0.02 mg/L. Measurements ranged from 0.02 to 0.05 mg/L and avera-ged 0.034 mg/L. No significant differences were observed between leachate, effluent, dissolved, or total samples. Samples left in beakers were not significantly different than those preserved immediately. 4.4.4 Copper The detection limit for copper was 0.01 mg/L. Measurements ranged from 0.01 mg/L to over 1 mg/L. Effluent results were always higher than leachate results, and dissolved results were always higher than total results. The nutrient solution added to the reactors was made using tap water and low grade (i.e. not reagent grade) Na3P04. It is possible that the effluent results were higher than the total results due to contamination by the nutrient solution. While the chemical composition of the nutrient solution was not analyzed, it is not uncommon for water supplies in the area to have high copper concentrations. Deionized distilled water with pure nitric acid added had a copper concentration of 0.02 mg/L, and distilled water plus acid measured 0.04 mg/L. The sample concentrations measured were typically between .02 and .04 mg/L for total samples. Dissolved samples were sometimes within this range, but 1 Chapter 4. Results and Discussion 86 Figure 4.21: Leachate and Effluent Total Iron j 0 9 / 1 5 I 1 1 / 3 0 | 0 1 / 2 5 | 0 3 / 0 9 | 0 4 / 1 3 | 0 5 / 1 7 | 0 6 / 2 1 | 0 8 / 0 3 | 1 0 / 1 9 1 2 / 2 1 0 2 / 2 2 0 3 / 1 5 0 4 / 1 9 0 5 / 1 8 0 7 / 1 9 0 8 / 2 3 Date Leachate l ^ ^ l RBC [% |^ SBR were often much higher. Both total and dissolved samples were probably contaminated by the dilution water supply during the digestion process. Additional contamination in the dissolved samples may have occurred during filtration. 4.4.5 Iron Figure 4.21 summarizes the total iron concentration data obtained in the study. Out of twelve occasions on which iron was measured in both systems, 7 showed superior RBC performance, 4 showed superior SBR performance, and 1 showed similar performance. RBC removal ranged from -76.0 to 88.0% and averaged 37.4%. If the minimum removal (-76%; a fairly clear outlier) is not included in the calculation, the average is 46.9%. SBR removal ranged from -6.9 to 84.8%, and averaged 32.3%. Excluding the highest and/or lowest removals from the calculations makes very little difference to the average SBR' removal value. In general, the RBC was somewhat more successful in removing total iron than the SBR. Measurement of leachate and effluent dissolved iron was only undertaken on three occasions. Effluent dissolved iron measurements for both systems exceeded leachate dissolved iron twice. On one occasion, the SBR dissolved iron level was far above the total leachate level, indicating possible contamination. Chapter 4. Results and Discussion 87 On the other two occasions, the SBR had lower dissolved iron than did the RBC, but the measurements were fairly close together. It is probable that the RBC removed more total iron than the SBR due to better effluent settling characteristics. In general, the dissolved iron concentration was a small fraction of the total, particularly for the leachate. Samples left in beakers during Daphnia LC50 tests generally showed significant removals of both total and dissolved iron. This was probably due to precipitation of Fe(0H)3. 4.4.6 Lead Lead was only measured by the City's laboratory (Cantest). No lead was detected in any leachate or effluent samples. The detection limit was 0.08 mg/L. 4.4.7 Manganese ; Figure 4.22 summarizes total manganese measurements taken during the study. Out of 9 occasions on which total manganese measurements were obtained, the RBC effluent concentration was lower 4 times, and the SBR concentration was lower 5 times. RBC removals ranged from -9.0 to 95.2% and averaged 42.4%. SBR removals ranged from -47.0 to 93.8% and averaged 22.3%. The average works out to 30.5% if the -47.0 point is removed from the calculation, but no significant changes to either system's average are obtained if the top and bottom points are removed from the calculations. While the SBR's effluent total manganese concentration was often lower than the RBCs, the SBR's two best manganese removals occurred on Dec. 21/93 and on Aug. 23/94. The SBR was not removing significant NHX-N on either of these occasions due to near total losses of MLSS, so these removals can not be attributed to uptake by nitrifying organisms. 4.4.8 Nickel Figure 4.23 summarizes total nickel data obtained during the study. While the SBR tended to have a lower total nickel concentration than the RBC, both effluents tended to have higher concentrations than the leachate. RBC removals ranged from -42.9 to 16% and averaged -7.2%. Positive nickel removals were only measured 3 times. SBR removals ranged from -21.4 to 14.3% and averaged -3.3%, also with three positive removals. There could have been a source of nickel in each system, such as the stainless steel Chapter 4. Results and Discussion 88 Figure 4.22: Leachate and Effluent Total Manganese 1.7 r— — : 1.6 -Date Leachate RBC SBR bar used as a weight on the SBR aeration tube, and perhaps some fasteners in the RBC. The nutrient solution may also have been a source of nickel contamination. While three sets of dissolved nickel measurements were attempted, the dissolved nickel concentration was typically higher than the total nickel concentration. Stainless steel filter apparatus used in filtration was probably the source of sample contamination. Since all metal analysis was performed on preserved samples at the conclusion of the study, there was no opportunity to correct this error. There was no significant change in total nickel concentration when samples were left standing in beakers during Daphnia LC50 tests. 4.4.9 Zinc Figure 4.24 summarizes total zinc measurements obtained during the study. The RBC achieved a positive total zinc removal on 6 out of 13 occasions on which leachate and RBC effluent zinc were determined. Removals ranged from -122.9 to 47.8% and averaged -4.8%. Average removals of 5.0 and 15.4% are obtained by excluding the lowest one and two removals from the calculations, respectively. The SBR achieved positive removals on only 3 out of 12 occasions on which SBR effluent total zinc Chapter 4. Results and Discussion 89 Figure 4.23: Leachate and Effluent Total Nickel 0 . 0 6 0 . 0 5 0 . 0 4 h 0 . 0 3 0 . 0 2 h 0 . 0 1 h 0 9 / 1 5 | 1 1 / 3 0 | 0 1 / 2 5 | 0 3 / 0 9 | 0 4 / 1 3 | 0 5 / 1 7 | 0 6 / 2 1 | 0 8 / 0 3 | 1 0 / 1 9 1 2 / 2 1 0 2 / 2 2 0 3 / 1 5 0 4 / 1 9 0 5 / 1 8 0 7 / 1 9 0 8 / 2 3 Date Leachate SBR ^ RBC [ Figure 4.24: Leachate and Effluent Total Zinc 0 . 7 0 . 6 0 . 5 0 . 4 0 . 3 0 . 2 0 . 1 0 9 / 1 5 | 1 1 / 3 0 | 0 1 / 2 5 | 0 3 / 0 9 | 0 4 / 1 3 | 0 5 / 1 7 | 0 6 / 2 1 | 0 8 / 0 3 | 1 0 / 1 9 1 2 / 2 1 0 2 / 2 2 0 3 / 1 5 0 4 / 1 9 0 5 / 1 8 0 7 / 1 9 0 8 / 2 3 Date . Leachate RBC VZ&X SBR Chapter 4. Results and Discussion 90 was determined. While removals ranged from -780.6 to 44.4% and averaged -127.5, the three lowest removals were significantly different from all the other data. However, exclusion of these points from the calculation still yields an average removal of-12.1%. The frequent occurrence of negative removals in both systems indicates that there may have been an intermittent source of zinc contamination in both reactors. The author's samples were mixed on site in a galvanized bucket in order to achieve combined samples for toxicity, metals, and other analyses. However, leachate and effluent samples were treated equally, zinc concentrations were high relative to the detection limit, and City results were similar to the author's, so it is doubtful that the bucket caused a problem. The nutrient solution is another possible source of zinc contamination. The dissolved zinc concentration was typically a small fraction of the total for effluent and leachate samples. The RBC and SBR effluents had similar dissolved zinc concentrations. Samples left standing during Daphnia LC50 tests typically had significantly lower total zinc concentrations and similar dissolved zinc concentrations, compared to samples preserved immediately after collection. 4.4.10 Summary of Metal Removal Results No indication of performance based on chromium, copper, lead or nickel could be obtained due either to poor results or to extremely low concentrations. No significant removals of cadmium or cobalt were achieved by either system. The RBC performed better in terms of iron and manganese removal, with removals averaging ap-proximately 40% compared to the SBR's 30%. While frequent negative total zinc removals were obtained by both systems, the RBC system achieved more positive removals. However, the zinc results are suspect due to the high number of negative removals. 4.5 Toxicity 4.5.1 Rainbow Trout L C 5 0 One of the initial aims of the experiment was to directly compare the city's monthly rainbow trout LC50 data to Microtox EC50 and Daphnia LC50 tests based on a shared sample. A relationship between leachate ammonia concentration and fish LC50 was discovered by the City in February 1994, and as a result the conditions of the discharge permit changed so that after April 1994 the City was required to perform fish L C 5 0 tests quarterly, rather than monthly. As a result, toxicity tests were only performed Chapter 4. Results and Discussion 91 Table 4.20: Fish LC50 Correlation Calculations Leachate Constituent ln(LC50) vs. ln(X) L C 5 0 vs. 1/X R/ X-Coefficient R 2 X-Coefficient NHX-N 0.64 -0.95 0.78 2092 Cu 0.03 -0.89 0.01 0.55 Zn 0.26 0.41 0.24 -0.83 Ni 0.10 0.58 0.13 -0.24 Mn 0.52 2.32 0.51 -35.7 Fe 0.05 0.33 0.06 -107 on three shared leachate samples. The three shared samples each had a 96 hour rainbow trout L C 5 0 value of 13%. Fish toxicity values reported by the City during 1993 and 1994 ranged from 7 to 24%. Since a reliable comparison between fish, Daphnia and Microtox can not be made with only three points, toxicity comparisons will be primarily based on correlations between toxicity measurements and chemical analyses of leachate. The first step in this process is determining the leachate constituents associated with fish toxicity. Table 4.20 gives the results of calculations based on City data obtained in the first 9 months of 1993 (prior to the study). Chemical analyses were performed on 24 hour composite samples, and L C 5 0 tests were performed on a grab sample taken at the end of the 24 hour period. All metals are totals. While measurements of chromium, lead, cadmium, molybdenum, and cobalt were also taken during this time, these metals were seldom detected, and therefore there was insufficient data to show correlations with toxicity. Calculated R 2 values are based on linear regressions. Regressions were done on a ln-ln basis first, but when the x-coefficient of NHX-N was found to be near -1, the L C 5 0 versus 1/X relationship was evaluated. Table 4.20 clearly shows that fish LC50 is correlated with NHX-N concentration to a much greater degree than the metals, and that the LC50 versus 1/NHX-N relationship is better than the ln-ln relati-onship. The positive x-coefficient of the L C 5 0 vs. 1/NHX-N relationship indicates that L C 5 0 decreases with increasing NHX-N concentration. Since a low LC50 indicates a high toxicity, this means that toxi-city increases with increasing NHX-N concentration. The negative x-coefficient of the ln-ln relationship indicates the same general trend. Out of the five metals shown, only copper has x-coefficients with the same sign as NHX-N, and its R 2 values are very low. All of the other metals have higher R 2 values than Chapter 4. Results and Discussion 92 copper. However, their x-coefficients have the opposite sign to NHX-N's x-coefficient, indicating decre-asing toxicity with increasing concentration. Since toxicity of a solution does not typically decrease as the concentration of a toxic substance increases, it is clear that the other metals have even less influence on toxicity than copper. Therefore, it seems obvious that NH X -N has the greatest influence on leachate toxicity. The City calculated the relationship in Equation 4.6 using the 1993 data and 3 points from a 1977 investigation [6]. While the 1977 data may not seem relevant due to its age, it is the only other rainbow trout L C 5 0 data available based on Vancouver Landfill leachate. The 1994 data fit into the relationship in Equation 4.6 well; adding them into the calculations does not significantly change the constants or the R 2 value. However, a better correlation (R 2 = 0.906) is achieved by the relationship given in Equation 4.7. If the 1977 points are not used in the calculations, the R 2 value is 0.78 and the x-coefficient is 2098; these values are very similar to values obtained using data from the first 9 months of 1993 (see Table 4.20). The constant in Equation 4.8 is calculated by using the same data (all data) as Equation 4.7 and setting the y-intercept to zero. Equation 4.8 fits the data similarly (R 2 = 0.902) to Equation 4.7, and is simpler; therefore, it will be used when comparing fish LC50 data to Daphnia and Microtox data in the following sections. While the constants change depending on which data is included in the regression, the lines drawn using the constants are fairly close together (see Figure 4.25). Figure 4.25 also illustrates the importance of the 1977 data; the two right most points belong to the 1977 data set, and no other fish data in the high L C 5 0 (i.e. low toxicity) range is available for this leachate. T = 40.3e -0.00606AT (4.6) Where: T = Rainbow trout L C 5 0 (%) N = NH X -N concentration (mg/L) R 2 = 0.67 T - 2407/N-1.28 (4.7) T = 2259/N (4.8) Chapter 4. Results and Discussion 93 While fairly good correlations are achieved by comparing NHX-N concentration to fish LC50 the toxic component of NHX-N is usually considered to be free N H 3 - N . N H 3 - N concentrations were calculated using NHX-N and pH data with K a = 6.053 x 1 0 - 1 0 . The K a value was taken from reference [46] assuming a temperature of15?C, since LC50 tests were done with temperature kept between 14 and 16°C. However, the best R 2 value which could be calculated from these data was only 0.50. Figure 4.26 illustrates the relative lack of correlation between N H 3 - N and fish LC50 in comparison to NHX-N. 4.5.2 Daphnia L C 5 0 Previous work at UBC has indicated that Daphnia L C 5 0 correlates well with rainbow trout LC50 for landfill leachate [9]. In this study, Daphnia testing was performed in conjunction with fish testing 3 times, and 9 data points were obtained (3 leachate and 3 of each effluent). Figure 4.27 shows the Daphnia data together with fish data taken simultaneously and the fish LCso/NHx-N relationship given in Section 4.5.1. The Daphnia data correlate well with the L C 5 0 / N H X - N relationship. Four of the effluents tested showed no Daphnia toxicity (i.e. LC50 > 100%). On each occasion, the NHX-N concentration was 2 mg/L or less; i.e. removal of NHX-N corresponds to removal of toxicity. Unlike the fish data, the Daphnia correlates well with the free NH3-N data. The R 2 value for L C 5 0 versus I/NH3-N is 0.83, provided that N H X - N and pH data from the end of the Daphnia experiment are used to calculate free NH 3. If the data from the beginning of the Daphnia experiment are used, R 2 is only 0.02. The R 2 values for NH X -N are 0.88 and 0.90 for before and after data, respectively. Perhaps the fish data would also correlate better with free N H 3 data if end-of-experirnent pH and NHX-N data were available. If free NH3 were the toxic component of NHX, one would expect NH3 to correlate better with the toxicity data. One possible reason for the slightly poorer correlation (0.83 vs. 0.90) is that different dilutions of sample used in the L C 5 0 tests would have somewhat different pH values, so that the NH3-N fraction would not be constant from one dilution to the next. No differences in toxicity removal which could not be accounted for by differences in NHX-N concen-tration were observed between the RBC and SBR effluents. 4.5.3 Microtox EC50 Figure 4.28 shows that Microtox EC50 does not correlate well with either fish L C 5 0 or NHX-N. This is not surprising, since EC50 values for N H X - N reported in the literature range from 3600 to 4500 mg/L as NH 3 [44, 56]. Chapter 4. Results and Discussion 94 Figure 4.25: Fish L C 5 0 versus 1/NHX-N 45 40 H 35 30 H o 25 O 20 H 5 IT 15 10 • in a 15 n 0.002 0.006 0.01 1/NHx-N (IVmg) o LC50 — A l l Data (Eqn 4.7) - - No 1977 Data 0.014 A l l Data (Eqn 4.8) Figure 4.26: Relationship of NHX-N and NH3-N to Fish L C 5 0 0.018 + + + + + • • • • J 1 i i i i i J I u 1.9 2.1 2.3 2.5 2.7 2.9 3.1 3.3 3.5 3.7 ln(LC50 (%)) Q ln(NH3-N) + ln(NHx-N) Chapter 4. Results and Discussion 95 Figure 4.27: Relationship of Daphnia LC50 to Fish L C 5 0 and NHX-N o in o •J o in o w 100 0 0.002 0.004 0.006 0.008 0.01 0.012 0.014 0.016 0.018 0.02 1/NHx-N (L/mg) 2259/N X daphnia lc50 V fish lc50 Figure 4.28: Relationship of Microtox E C 5 0 to Fish L C 5 0 and NHX-N 100 0.005 0.007 0.009 0.011 0.013 0.015 0.017 0.019 1/NHx-N (L/mg) • 5 m i n + 15 min O 25 min A 35 min - 2259/N V Fish LC50 Chapter 4. Results and Discussion 96 One suggested cause of the decreased sensitivity of Microtox to NHX is that the toxic component of NHX is free N H 3 , and Microtox diluent solutions tend to have low pH (eg between 6.0 and 6.5 compared to 7.3 to 7.8 for rainbow trout) [56]. Microbics indicates that pH between 6.3 and 7.8 causes no problems with light production, and Environment Canada widens this range to 6.0 to 8.5, based on an allowable pH range of 5.5 to 9.0 found in another study [18]. The pH values measured by the author in reference toxicants prepared with Microtox diluent or reconstitution solution ranged from 5.5 to 5.9, which seemed low at the time, but are fairly close to the values given by Qureshi et al [56]. However, even when these pH values are used to calculate free NH3, the graph of E C 5 0 versus I/NH3 -N looks very similar to Figure 4.28; the correlation between E C 5 0 and I/NH3 -N is still very poor. Microbics suggests that the sensitivity of the Microtox E C 5 0 test to ammonia can be improved by using sucrose as the osmotic adjusting agent rather than NaCl [44]. Sucrose based Microtox ECso tests were attempted several times in order to determine if the modified test would improve the correlation of the E C 5 0 test to Rainbow trout L C 5 0 . Sucrose diluent was made with reagent grade sucrose and progressively purer sources of dilution water, including distilled water, deionized distilled water, and finally Microtox reconstitution solution. As a control, normal diluent was made at the same time using reagent grade NaCl. While the home made NaCl diluent tended to be slightly toxic compared to the Microtox diluent (light losses from 0 to 33% after 5 minutes), home made sucrose diluent never came close to being non- toxic (light losses ranged from 50 to 68% after 5 minutes). When samples were tested with sucrose diluent (100% test, dry sucrose added to 100% sample), the control typically had lower light readings than leachate or effluent samples (dilutions no. 2, 3, and 4). Although the control readings were higher than the 100% dilution's (no. 1), no result could be calculated. When samples were tested with reference toxicant solutions prepared in sucrose diluent, the responses had normal ratios (i.e. control > no. 4 > no. 3, etc.), but light levels in sucrose solutions were still approximately 50% lower than light levels in corresponding NaCl solutions. While it is possible that light was absorbed by sucrose in the sucrose diluent, this seems unlikely since equal amounts of sucrose were added to all four' dilutions of leachate and effluent, and all but the no. 1 dilution gave off more light than controls. Therefore, it appears that sucrose is toxic to P. phosphoreum. In the Daphnia L C 5 0 test, one has to be very careful to provide healthy controls or the test is considered invalid (i.e. greater than 10% dead in control invalidates the test) [17]. Therefore, it seems rather strange to place a marine bacterium in a 20% sucrose solution rather than a 2% NaCl solution and to expect valid toxicity results. Because sucrose results were so poor, and because sucrose Chapter 4. Results and Discussion 97 appeared to be toxic to P. phosphoreum, the sucrose modification of the Microtox EC50 does not appear to be a valid test. The E C 5 0 value for ammonia determined in the sucrose test by Microbics is 124 mg/L as N H 3 . This value is considerably higher than reported values for rainbow trout (62 mg/L of NHX as N H 3 , or 1.4 mg/L free ammonia) [56]. Therefore, whether or not the sucrose test is valid, it is clear that the Microtox E C 5 0 test is not as sensitive to ammonia as the rainbow trout LC50 test. A substitute bioassay should either correlate well with the substituted bioassay, or be more sensitive. Therefore, Microtox E C 5 0 is not a good substitute for rainbow trout LC50 for Vancouver Landfill leachate, and probably would not be a good substitute for any other waste water-in which ammonia was the main toxic component. On three of the occasions when Microtox-EC50 tests were performed, metal analyses (total and dissolved Cd, Co, Cr, Cu, Fe, Ni, and Zn) were also performed. This would have given a total of 9 data points for each metal, but in two cases the effluent EC50 values were both > 100%, so there were only 5 useful points for each metal. No correlations or trends worth mentioning were found. The source of Microtox EC50 toxicity in the leachate is therefore unknown. Both RBC and SBR effluents were almost always non-toxic, and no differences in toxicity removal between the two systems were observed. Chapter 5 Summary and Recommendations 5.1 Summary Pilot scale RBC and SBR systems were compared inorder to determine which system would be more cost effective for full scale treatment of Vancouver Landfill leachate. The leachate is an older leachate with NHX-N concentrations between 83 and 336 mg/L, BOD5 concentrations between 27 and 89 mg/L, and BODs:COD ratios between 0.06 and 0.19. The systems were primarily compared based on nitrification performance. Other topics compared included nitrogen balances, removal of BODsand COD, solids settlability, and metal removal. The possibility of using Microtox bioassays to predict the traditional fish toxicity determination for this leachate was also investigated. The main part of the study lasted from August 12, 1993 to September 7, 1994, for a total of 391 days. In general, the RBC recovered from NHX-N loading increases more quickly than the SBR did. Ho-wever, loading increases to the SBR tended to be more severe. The RBC unit used in this investigation was also used by Peddie [52]. Combined results indicated that this unit was capable of complete nitrification of NHX-N loadings less than 1.2 g/m2/d at HRTs greater than 0.17 days; however, an HRT greater than 0.3 days was required for full NHX-N removal at loadings between 2 and 8 g/m2/d. The RBC was operated successfully at an average loading/HRT of 4.15 g/m2/d/0.35 days. However, loadings of 2 g/m2/d or less were required in order for effluent NOJ-N levels to remain below 4 mg/L. The RBC was unable to acclimatize to average loadings of 4.88 and 6.02 g/m2/d at HRTs of 0.27 and 0.17 days, respectively. In the latter case, insufficient HRT was likely responsible for the lack of acclimatization. In the former case, insufficient HRT was probably responsible, but phosphate limitation may also have played a role. While the RBC was able to provide high NHX-N removals at high NHX-N loadings if the HRT was sufficient, incomplete nitrification was frequently observed, particularly during the HRT experiment. Free N H 3 inhibition and P limitation were investigated as possible causes of incomplete nitrification 98 Chapter 5. Summary and Recommendations 99 during the HRT experiment; P limitation appeared to be the most likely explanation. While it was difficult to tell if NOJ-N buildups observed during the rest of the experiment were caused by NH3-N inhibition or P limitation, the results of the HRT experiment indicate that P limitation was most likely responsible. The SBR achieved complete nitrification at an average loading of 107 g/m3/d when the HRT averaged 1.93 days. Complete NHX-N removals were achieved at an average loading of 331 g/m3/d when the HRT averaged 0.71 days, but complete nitrification was not. Free N H 3 inhibition, HRT limitation, low dissolved oxygen concentration, and P O 3 - - ? limitation were investigated as possible causes of incomplete nitrification; again P limitation appeared to be the most likely explanation. During the final loading phase (580 g/m3/d, 0.43 days), the SBR experienced total solids washout. The reason for this is unclear, but the SBR may have been HRT limited in addition to being P limited. NOJ-N buildups experienced during the rest of the experiment were unexplained. Process upsets occurred less frequently in the RBC than in the SBR, and the RBC was more likely to recover from upsets than the S B R . The SBR completely failed twice during the experiment, and it was unable to recover without heating and reinoculation in the first instance. Causes of process upsets in both systems included cold temperatures, mechanical failures, and power failures. The SBR was probably more susceptible to process upsets than the RBC because these events tended to cause solids washout in the SBR. While both nutrient pump failure and cold temperatures are capable of causing process upsets on their own, the SBR was particularly affected when these two events coincided. This phenomenon was not apparent for the RBC system. Both systems were able to perform at low .temperatures. The RBC achieved a NHX-N removal of 1.51 g/m2/d at only 2.5°C, and the SBR was able to remove 23.3 g/m3/d at only 3°C. Average alkalinity consumption ratios for each system were higher than theoretically required for nitrification. This was probably due to precipitation of CaC03. Nitrogen balance calculations were performed for both systems including and excluding organic nitro-gen. In both cases, N losses in the SBR were greater than N losses in the RBC, but the differences were not significant. Lost N results determined in nitrogen balance calculations could easily be accounted for by sums of acceptable measurement errors. The two systems performed similarily with respect to BOD5 removal, but the RBC was superior in terms of COD and colour removal. While, neither system produced large amounts of excess solids, the Chapter 5. Summary and Recommendations 100 RBC solids had better settling characteristics. Evidence of precipitation of inorganic solids was found for both systems, but neither system had scale problems. No differences between the two systems were found in terms of cadmium or cobalt removal, and results based on chromium, copper, lead, and nickel were inconclusive. However, the RBC tended to remove about 40% of iron and manganese while the SBR removed 30%. Both systems tended to add rather than remove zinc, but the RBC was more likely to achieve positive removals. Rainbow trout LCsowas found to vary with leachate NHX-N according to the relationship T = 2259/N, where T = 96 hour LC5o(%) and N = NHX-N concentration (mg/L), R 2 = 0-90. Daphnia L C 5 0 results correlated well with fish results based on the above relationship, but Microtox EC50 results did not. Both Daphnia and rainbow trout results correlated better with NHX-N than with free NH3-N. Free NH3-N correlations could probably be improved if pH variations between sample dilutions could be accounted for or eliminated. Microtox EC50 results did not correlate well with fish LCsoresults because of the insensitivity of the Microtox test to ammonia. Using sucrose rather than NaCl as the osmotic adjustment agent is purported to increase the sensitivity of the Microtox test to ammonia. However, sucrose dilution water tended to be more toxic than all but the 100% leachate dilution. The usefulness of the sucrose modified Microtox test is therefore questionable. Even if the sucrose test is valid, published results indicate that the modified Microtox test is still much less sensitive to ammonia than the rainbow trout or Daphnia bioassays.. No differences in toxicity removal were observed between the RBC and SBR, other than differences in Daphnia toxicity which could be completely accounted for by NHX-N concentration. The RBC used in this experiment was a very simple system, and only loading could be varied. Other parameters such as rotational speed and % submergence of the disks were basically set by the manufacturer and were therefore probably near optimum values. Many more parameters could have been varied in the SBR system. Besides increasing the settling time in the reactor, no attempt was made to optimize the SBR cycle times. It therefore may not have been performing to its full potential. For example, information found in the literature indicates that the aeration cycle may have been too short. As such, this experiment may not have been a fair comparison of the two systems. It is also possible that a completely mixed or plug flow continous flow system would have performed better than even a fully optimized SBR system, indicating that this experiment may not have been a fair comparison of suspended growth to fixed growth systems in general. Chapter 5. Summary and Recommendations 101 5.2 Recommendations While this experiment may not have been a completely fair comparison of fixed and suspended growth systems, the RBC outperformed the SBR in every respect in which a difference was observed between the two systems. The major deficiency of the SBR was its inability to recover quickly from process upsets and loading increases, and the reasons for this are documented in other studies: the slow growth rate of nitrifying organisms, poor solids settlability in general, and even poorer solids settlability when stressed. Therefore, it is recommended that an RBC system should be used to treat the Vancouver landfill leachate at full scale. Few studies have been done which directly compare the effectiveness of fixed and suspended growth systems. The original intent of this study was that a comparison based on cost effectiveness be made between two systems, both of which had been shown to be successful in treating the leachate in question. Unfortunately, the SBR seldom performed adequately, so a comparison based on cost effectiveness derived solely from this study would undoubtedly favour the RBC. If another study such as this is undertaken, each system should be optimized before attempting to make a comparison based on cost effectiveness. Phosphate limitation was suggested as a possible cause for incomplete nitrification or slow acclima-tization to a given VNH X-N loading several times for each system. It is obvious that more care should have been taken to prevent P limitation. Higher effluent P O ^ - P values should have been maintained and more membrane filtered P O 3 - - ? measurements should have been done. In future studies, it is recommended that more attention be paid to P O ^ - P . Additions of leachate to the SBR were conducted by using a timed fill cycle and allowing excess leachate to overflow from the reactor. Any overflow has the potential to result in solids loss if mixing has occurred during filling. It is recommended that a level switch be used to determine when filling should stop in future SBRs in order to! prevent overflow and solids loss. Phosphate limitation may have been responsible for prolonged nitrite buildups in both systems. It is unclear whether these nitrite buildups could have been maintained for any length of time. More study is needed to determine if P limitation could be used to produce extended NOJ-N buildups, particularly for the RBC, for which less data were available from this study. The ability to maintain a nitrite buildup could be useful in shortening the nitrification-denitrification pathway (as proposed by Turk and Mavinic [65)). Bibliography Anthonisen, A. C , R. C. Loehr, T. B. S. Prakasam, and E. G. Srinath. Inhibition of nitrification by ammonia and nitrous acid. Journal WPCF, 48:835-852, 1976. APHA. Standard Methods for the Examination of Water and Wastewater. American Public Health Association, Washington, D.C, 17th edition, 1989." Atwater, J. W., S. Jasper, D. S. Mavinic, and F. A. Koch.. Experiments using Daphnia to measure landfill leachate toxicity. 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Cameron, R. D., E. C. McDonald, M. G. Mager, S. C. Liptak, and P. D. Parkinson. Toxicity of landfill leachates. Technical Report EPS 4-EC-82-7, Waste Management Branch, Environmental Protection Service, Environment Canada, 1982. Chen, G. H., H. Ozaki, and Y. Terashima.. Endogenous denitrification in biofilm. Water Science and Technology, 26(3-4):523-534, 1992. Chian, E. S. K., F. G. Pohland, K. C. Chang, and.S. R. Harper. Leachate generation and control at landfill disposal sites. In Proceedings of the International Conference on New Directions and Rese-arch in Waste Treatment and Residuals Management, pages 14-30. University of British Columbia, 1985. Clark, J. H., E. M. Moseng, and T. Asano. Performance of a rotating biological conatactor under varying wastewater flow. Journal WPCF, 50(5):896-911, 1978. Cronin, M. T. D., J. C. Dearden, and A. J. Dobbs. QSAR studies of comparative toxicity in aquatic organisms. The Science of the Total Environment, 109/110:431-439, 1991. 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Appendix A Calculation Definitions Note: Quantities denned for a previous section are not redefined. Leachate N Data NO--N = NOJ-N + NOJ-N NHX-N = N H 3 - N + NH+-N Alk. = Alkalinity in mg/L as CaC0 3 AVERAGE = overall average of all data MAXIMUM = maximum value recorded MINIMUM = minimum value recorded Quantities following Loading Periods are averages calculated for that loading period. R B C Nitrogen Data Flow (L/d) = (Flow L/cyc)x(24 hr/d)x(60 min/hr)/(Fill Time min + 1 min) HRT = (245 L)/(Flow L/d + Nut. Flow L/d) NHX-N Ldg. (g/m2/d) = (Flow L/d) x(Leachate NHX-N mg/L)x(lg/1000 mg)/(47 m2) NHX-N Removal (g/m2/d) = NHX-N Ldg. - (Flow L/d) x (RBC NHX-N mg/L)x(lg/1000 mg)/(47 m2) NHX-N Rem. (%) = NHX-N Removal/NHx-N Ldg. x 100% NHx-N+NO--N Removal (%) = ((Leachate NHx-N+NOx-N)-(RBC NHX- N+NOx-N))/(Leachate NHx-N)xl00% Alk:NHx-N Removal = (Leachate Alk. - RBC Alk.)/(Leachate NHX-N - RBC NHX-N) SBR Nitrogen Data HRT = (365 L)/(Flow L/d + Nut. Flow L/d) 107 Appendix A. Calculation Definitions 108 NHX-N Loading (g/m3/d) = (Leachate NHX-N mg/L) x (Flow L/d)x(lg/1000 mg)x(1000 L/m 3)/ (365 L) NHX-N Removal (g/m3/d) = NHX-N Loading - (SBR NHX-N mg/L)x(Flow L/d)x(lg/1000 mg) x(1000 L/m3)/(365 L) NHX-N Removal (%) = NHX-N Loading/NHx-N Removalx 100 NHX-N Loading (g/g/d) = (Leachate NHX-N mg/L) x (Flow L/d)/(MLVSS mg/L)/(365 L) NHX-N Removal (g/g/d) = NHX-N Loading (g/g/d) - (SBR NHX-N mg/L) x (Flow L/d)/(MLVSS mg/L)/ (365 L) MLVSS = 0.62xMLSS if MLVSS not measured R B C P and Misc. Data Nutrient Addition (g/20 L) = g Na 3P0 412H 20 added to 20 L of Nutrient Solution Nutrient Addition (mg/L) = ((Nutrient Addition g/20 L)x(1000 mg/g)/(20 L)) x((mw P)/ (mw Na3P04-12H20))x ((Nutrient Flow L/day)/(Flow L/day + Nutrient Flow L/day)) mw P •= 30.9738 g mw Na 3P0 412H 20= .30.9738+3x22.9898+16x15.9994+24x1.0079 Influent P0 3~-P (mg/L) = (Leachate P03~-P mg/L) + (Nutrient Addition mg/L) Cond. mS = Conductivity /^ Siemens Leachate T K N TKN = Total TKN TKN Diss. = Dissolved TKN ' TKN:NHX= TKN/NHX-N R B C T K N Organic N Removed (mg/L) = (Leachate TKN - NHX-N) - (RBC TKN - NHX-N) TKN Rem (g/m2/d) = ((Leachate TKN mg/L) - (RBC TKN mg/L))x(Flow L/d)x(lg/1000 mg)/ (47 m2) j NHX-N Rem:TKN Rem = (NHX-N Rem g/m2/d)/(TKN Rem g/m2/d) Lost N (%) = ((Leachate TKN + NOj-N) - (RBC TKN + NOj- N))/(Leachate TKN + NO"-N)xl00% Appendix A. Calculation Definitions 109 Total N Rem (%) = ((Leachate NHX-N + NO"-N) - (RBC NHX-N + NOx-N))/(Leachate NHX-N + NOx-N)xl00% (misnomer, should be NHx-N+NO~-N removal) SBR TKN TKN Rem (g/m3/d) = (Leachate TKN - SBR TKN mg/L) x (Flow L/d)x(lg/1000 mg)(1000 L/m 3)/ (365 L) NHX-N RemrTKN Rem = (NHX-N Rem g/m3/d)/(TKN Rem g/m3/d) Miscellaneous Leachate Data BOD:COD = BOD 5/COD RBC Organics < COD Loading (g/m2/d) = (Flow L/d)x(Leachate COD mg/L)x(lg/1000 mg)/(47 m2) COD Removal (g/m2/d) = COD Loading (g/m2/d) - (Flow L/d) x (RBC COD mg/L)x(lg/1000 mg)/ (47 m2) BOD Loading (g/m2/d) = (Flow L/d) x (Leachate BOD5 mg/L)x lg/1000 mg)/(47 m2) BOD Removal (g/m2/d) = BOD Loading (g/m2/d) - (Flow L/d) x (RBC BOD 5 mg/L)x(lg/ 1000 mg)/(47 m2) COD Removal (%)•= (COD Removal)/(COD Loading)x 100% BOD Removal (%) = (BOD Removal)/(BOD Loading) x 100% COD:BOD Removal = (COD Removal g/m2/d)/(BOD Removal g/m2/d) Colour Removal = (Leachate Colour - RBC Colour) x 100% TSS = RBC last stage MLSS TSS Stld. = RBC last stage MLSS settled, for 30 minutes SBR Organics COD Loading (g/m3/d) = (Leachate COD mg/L)x(Flow L/d)x(lg/1000 mg)x(1000 L/m3)/(365 L) COD Removal = COD Loading (g/m3/d) - (SBR COD mg/L)x(Flow L/d)x(lg/1000 mg) x(1000 L/m3)/(365 L) Appendix A. Calculation Definitions 110 C O D Removal (%)•= (COD Removal g/m3/d)/(COD Loading g/m3/d)xl00% B O D Loading (g/m3/d) = (Leachate BOD 5 mg/L) x (Flow L/d)x(lg/1000 mg)x(1000 L/m 3)/(365 L) B O D Removal = BOD Loading (g/m3/d) - (SBR BOD 5 mg/L)x(Flow L/d)x(lg/1000 mg) x(1000 L/m3)/(365 L) BOD Removal (%) = (BOD Removal g/m3/d)/(BOD Loading g/m3/d)xl00% C O D T B O D Removal = (COD Removal g/m3/d)/(BOD Removal g/m3/d) Metals Metal Removal (%) = (Leachate Metal - Effluent Metal)/(Leachate Metal)xl00% Toxicity Data Quantities are defined on data sheets Appendix B Raw and Calculated Data Leachate N Data 112 Date Day Flow Airpt. Airpt. Precip. leap • 3 /day •i *C 08/12/93 0 0 0 17.6 08/24/93 12 0 0 15.7 08/31/93 19 946 0 15.4 09/02/93 21 893 0 18.3 09/08/93 27 893 0 16.6 09/09/93 28 899 0 19.2 09/10/93 29 858 0 18.9 09/15/93 34 854 0 13.9 09/16/93 35 800 0 14.3 09/21/93 40 962 0 10.9 09/29/93 48 978 0 14.3 10/01/93 50 873 0 13.6 10/05/93 54 938 1.4 11.4 10/12/93 61 956 1.5 14.6 10/19/93 68 957 0 11 10/27/93 76 14/0 0 7.5 11/02/93 82 2095 11.5 9.9 11/05/93 85 2025 0 7.3 11/09/93 89 1724 0 3.6 11/12/93 92 1580 0 4.5 11/16/93 96 1997 0 4.3 11/18/93 98 1704 0 3.4 11/30/93 110 2655 6.8 4.5 12/08/93 118 5192 14.7 6.4 12/14/93 124 6343 4.4 7.3 12/21/93 131 3486 0 1.6 12/29/93 139 3316 4.6 4.3 01/04/94 145 8353 13.4 8.5 01/05/94 146 6128 0.4 5.8 01/11/94 152 5772 3 7.4 01/13/94 154 7045 6.8 3.6 01/17/94 158 4160 0 6.5 01/13/94 159 4003 0.8 5.1 01/20/94 161 3733 0 4.6 01/24/94 165 4297 0.2 6.5 01/25/94 166 3724 0 7 01/27/94 168 3304 0 6.2 01/28/94 169 3216 0 3.8 02/01/94 173 2377 0 -0.7 02/03/94 175 2665 0 1.3 02/08/94 180 2600 1.2 -2.5 02/09/94 181 2381 7.2 2.3 02/11/94 183 2603 3.8 3 02/13/94 185 3243 9.6 4.7 02/14/94 186 3604 4.8 5.5 02/15/94 187 4382 5.2 8.2 02/18/94 190 5581 0.2 5.4 02/21/94 193 4222 4.3 4 02/22/94 194 4353 3.2 3.3 02/23/94 195 3328 0 3.5 02/25/94 197 4053 .6.2 -0.7 02/26/94 198 4811 8 4.9 02/28/94 200 8445 12.2 9.7 03/03/94 203 10278 6.2 7.6 03/04/94 204 7632 5.2 6.8 03/07/94 207' 5073 0 4.6 03/08/94 208 4773 0 5.2 Air Te»p Cond. Site pH TSS Teep pH •c •c «S •g/L 7.4 70 20 7.8 50 20 7.2 60 20 7.2 125 22 21 6.74 7.4 17.25 7.4 43 16.5 16.5 6.3 7.6 14.5 16 5.3 7.6 7.43 62 16.5 7-4 50 18.4 14.75 6.1 7.5 7.3 109 17.5 17.5 6.34 7.6 7.9 58 16 17.5 6.04 7.5 7.5 56 14 7.7 103 11 12 4.6 7.5 7.2 74 8 9.5 4.75 7.4 7.1 73 6 8.5 4.18 7.3 12 11 4.72 7.3 7.2 82 3 7 4.34 7.5 6 8.5 3.69 7.3 7.3 46 7.5 10 3.73 7.4 7.2 173 9 11 7.1 37 0.5 7 4.11 7.23 7.5 54 3 9 4.98 7.3 79 8.75 9.5 2.41 7.3 106 7 6.5 3.21 8 10 3.27 7.1 7.1 31 10 11 3.05 6 10 4.18 7.3 7.1 174 1.5 8 4.75 7.3 8 12 7.1 7.5 10.5 4.11 7.2 8.0 99 7 11 3.9 3 9 4.5 7.0 5 8.5 5.1 7.0 8.0 64 -1 5.5 5.51 7.4 7.8 56 1 4.73 7.6 5.5 9 7 3 3.8 7.4 6 7.5 8 3 3.7 7.6 ' 67 6 8.5 3.1 6 3.5 3.8 4.5 7.5 4.4 7.4 50 2.5 6 0.5 6 4.53 5 5 3.03 7.3 9.5 10.5 9.5 12 3.64 7.2 8.0 53 9.5 11 3 7.4 3.5 8.5 9.5 13 7.2 7.2 49 Alk. N03-N N02-N NOx-N NHx-N P04-P •g/L •g /L •g /L •g /L •g/L cg/L 2870 0.32 0.00 0.32 305 0.31 2720 0.00 0.02 0.02 336 0.33 3140 0.20 0.06 0.26 293 0.52 14.30 315 0.86 3210 0.04 0.00 0.04 290 0.68 7.76 276 0.38 0.87 280 0.32 2950 0.33 0.00 0.33 331 0.66 300 3650 0.64 0 0.64 304 0.84 2910 0.08 0.00 0.08 289 16.03 250 0.18 3420 0.04 0.00 0.04 307 0.88 2590 0.83 0.00 0.83 299 0.73 2470 0.36 0.00 0.36 273 0.58 3360 1.10 0.23 1.33 204 0.65 3810 0.68 0.00 0.68 191 0.39 1.00 173 0.36 1850 0.03 0.00 0.03 192 0.31 1.43 153 0.36 1760 0.60 0.03 0.63 190 0.80 2.535 155.2 0.221 1650 0.02 0.01 0.03 144 0.99 1700 0.02 0.01 0.03 100 0.69 1250 0.68 0.00 0.68 85.5 0.10 1700 0.03 0.00 0.03 147 0.13 0.03 0.00 0.03 183 0.00 3.40 0.01 3.41 101 0.00 85 1005 0.57 1.10 1.67 96 0.05 0.78 83 0.12 0.78 141 0.28 1940 0.03 0.00 0.03 148 0.04 1576 1.06 153 0.32 1185 2.65 126 0.28 1950 0.05 0.05 121 0.21 0.72 148 0.28 0.80 145 0.34 2220 0.66 0.00 0.66 153 0.06 1.16 177 0.31 2310 0.03 0.00 0.03 179 0.12 1.07 172 0.30 0.42 158 0.32 1.30 0.00 138 3.33 153 0.35 1480. 1.40 0.01 1.41 128 0.03 0.96 92 0.25 0.65 140 0.32 1720 0.15 0.15 0.30 132 0.05 1.20 132 0.26 2.06 133 0.27 0.72 0.00 0.72 140 1.07 98 0.26 1540 0.04 0.00 0.04 241 0.07 0.63 114 0.21 0.42 130 0.29 1830 0.33 0.00 0.33 168 0.05 Leacnate N Data Date Day Flow Airpt . Airpt . Precip. Teap n 3/day 1A • c 03/10/94 210 4157 3.2 7.5 03/14/94 214 3666 0 8.7 03/15/94 215 3568 0.6 8.7 03/16/94 216 3535 3.6 6.5 03/17/94 217 3328 3.8 5.7 03/21/94 221 2946 6.2 4.1 03/22/94 222 3011 10.6 3.8 03/23/94 223 2684 0.8 4.6 03/24/94 224 2821 0 4.4 03/30/34 230 2301 0 10.5 03/31/94 231 2411 0 9.8 04/05/34 236 2932 1.2 8.9 04/06/94 237 2905 19.2 7.5 04/07/34 238 3153 3.2 9.1 04/12/94 243 2415 9.4 9.6 04/13/94 244 2491 0.8 9.2 04/14/94 245 2436 0.4 7.9 04/19/94 250 2000 1.8 14.4 04/20/94 '251 2134 0 11.1 04/21/94 252 2087 6.8 13.3 04/26/34 257 1755 1.2 12.7 04/27/94 258 1741 0 12.9 04/28/94 259 1763 0 13.1 05/03/94 264 1710 0 9.8 05/04/94 265 1756 3.4 13.2 05/05/94 266 1595 0 12 05/10/94 271 5391 0.2 16.5 05/17/94 278 .1432 0 14.2 05/18/94 279 2355 0 14.8 05/19/94 280 1335 0 16 05/24/34 285 1133 0 17.4 05/26/94 287 1246 0 13.4 05/30/94 291 1456 0 12.9 05/31/94 292 1179 4.6 14.2 06/06/94 298 1390 5.3 13.5 06/07/94 299 1136 0 12.6 06/08/94 300 773 0 15 06/14/94 306 1388 5.4 13.1 06/17/34 309 1837 0 14.4 06/21/94 313 1394 0 16.9 06/24/34 316 1502 0 15.1 06/28/94 320 1204 0 18.9 07/05/34 327 1496 07/12/94 334 1132 07/13/34 341 0 08/05/94 358 03/03/34 362 08/16/94 369 08/23/34 376 03/01/94 385 03/07/94 331 09/23/34 10/05/94 10/20/34 10/26/94 Air Te«p Cond. Site pH TSS Teap pH •C *C iS •g/L 8 12 12.5 14 7.5 7.6 64 13 9 7.7 9 7.3 16 7.3 7.5 55 10 11 7.4 13 19.5 7.5 7.8 71 14 7.5 7.6 53 10.5 11 7.5 17 7.5 7.8 53 13.5 21 53 18.5 14.5 17 7.9 30 17 18.5 16.5 7.7 40 15 16.5 22 7.6 18 22 7.9 107 18 21 25.5 8.0 75 21 16.5 19 7.8 57 17.5 17.52 7.8 308 18.5 17 7.5 61 21 24.5 7.5 10 17.5 19.5 7.7 74 18 7.7 48 20 7.7 106 21 7.6 70 21 7.43 62 21 7.15 32 19.5 7.79 42 23 7.64 26 21 7.54 56 20 6.77 46 17 7.84 51 17 7.8 18 13 7.36 18 13.5 8.54 57 Alk. N03-N N02-N NOx-N NHx-N P04-P •g/L •g/L •g/L •g/L •g/L •g/L 1.05 133 0.09 0.45 160 0.29 2200 0.03 0.00 0.03 176 0.04 1.38 181 0.15 0.13 166 0.12 0.03 173 0.17 1930 0.54 0.00 0.54 196 162 0.28 169 0.26 0.16 182 0.24 2330 0.04 0.00 0.04 206 0.07 2510 0.05 0.00 0.05 200 0.04 1.72 150 0.16 1.09 175 0.28 2060 0.05 0 0.05 175 0.05 1.07 172 0.33 1.61 175 0.28 2400 0.06 0 0.06 196 0.06 0.57 175 0.20 0.77 168 0.21 2440 0.02 0 0.02 243 0.07 0.57 231 0.19 0.55 177 0.21 2500 2.70 0 2.70 243 0.06 0.42 234 0.58 0.41 194 0.33 2610 0.95 0 0.95 281 0.08 2130 0.27 0 0.27 282 0.04 1.54 264 0.18 1.12 244 0.05 2750 0.02 0 0.02 266 0.11 3.27 220 0.00 1.04 215 0.38 2770 0.79 0 0.73 262 0.12 0.96 238 0.15 2590 0.00 0 0.00 257 0.14 1.58 234 0.10 1880 0.04 0 0.04 243 0.04 0.32 206 0.30 2580 0.03 0 0.03 263 0.19 0.70 213 0.34 2590 0.00 0 0.00 244 0.23 2510 0.00 0.00 0.00 241 0.47 . 2550 0.00 0.00 0.00 220 0.05 2800 0.02 0.00 0.02 246 0.15 2810 0.12 0 0.12 274 1.1 2730 0.04 0 0.04 242 1.6 2890 0 0 0 238 0.9 2490 0.02 0 0.02 273 0.8 2900 0.05 0 0.05 301 1.2 2770 0.02 0 0.02 322 1.5 2850 0.15 . 0 0.15 213 1.4 2470 0 0 0 258 1.5 2380 0 0 0 233 0.83 1670 0.03 0 0.03 183 0.78 Leachate N Data Day Flow Airpt. Airpt. Air Teap j'ond. Site PH TSS Alk. N03-N N02-N NOx-N NHx-N P04-P Precip. leap leap PH • 3 /day in •c ' C •c aS ag/L ag/L ag/L ag/L ag/L ag/L ag/L AVERAGE 2798 2.52 9.3 7.62 14.17 4.36 7.37 7.51 70 2380 0.38 0.03 1.11 199.5 0.32 HAXIHUH 10278 19.20 19.2 22.00 25.50 6.74 7.67 8.02 308 3810 3.40 1.10 16.03 336.0 1.60 MINIMUM 0 0.00 -2.5 -1.00 5.00 2.41 7.00 6.77 10 1005 0.00 0.00 0.00 83.3 0.00 0-54 • 762 0.09 12.63 10.20 14.73 4.17 5.02 6.57 57 2487 0.16 0.01 2.95 258.5 0.46 55-149 3124 3.61 6.57 6.23 10.70 4.39 7.40 7.34 78 2214 0.65 0.02 0.B7 167.6 0.42 150-170 4362 1.20 6.34 6.38 10.19 3.97 7.17 7.39 101 1531 0.22 0.55 0.95 128.9 0.21 171-205 4579 4.58 4.09 5.28 8.34 4.03 7.33 7.76 58 1854 0.70 0.02 0.98 145.9 0.21 206-240 3442 3.80 6.85 7.13 12.12 3.13 7.42 7.55 58 2172 0.20 0.00 1.01 169.1 0.16 241-308 1837 1.64 13.03 18.28 7.50 7.74 80 2413 0.49 0.00 0.85 224.5 0.17 309-352 1223 16.33 20.21 7.63 62 2606 0.01 0.00 0.15 233.3 0.25 352-391 20.92 7.39 44 2765 0.04 0.00 0.04 275.0 1.18 HRT Ex. 15.12 7.885 36 2342. 0.045 0 0.045 221.7 1.127 Loading Period AVERAGE 2798 2.5 9.3 7.6 14.2 4.4 7.4 7.5 70 2380 0.4 0.0 1.1 199.5 0.3 MAXIMUM 10278 15.2 19.2 22.0 25.5 6.7 7.7 8.0 308 3810 3.4 1.1 16.0 336.0 1.6 HIHI«UH 0 0.0 -2.5 -1.0 5 2 7 7 10 1005 0 0 0 83 0 0-54 762 63.5 15.5 17.9 18.0 6.26 7.5 7.4 71 3109 0.2 0.0 3.4 298.2 0.5 55-130 2476 87.8 6.6 8.6 11.1 4.65 7.4 7.4 76 2214 0.4 0.0 0.7 177.9 0.5 131-157 6124 23.3 7.2 7.4 9.6 3.38 7.1 7.2 72 1005 1.3 0.4 1.5 109.6 0.0 158-189 3339 33.0 4.0 5.0 8.8 4.43 7.3 7.7 92 1809 0.7 0.0 1.0 149.8 0.2 190-213 5537 30.2 5.5 6.3 9.6 '3.65 7.3 7.5 , 51 1697 0.3 0.0 1.4 142.0 0.2 214-301 2254 107 11.0 16.3 7.5 7.7 76 2406 0.4 0.0 0.8 208.2 0.2 302-350 1244 331 15.7 19.8 7.6 62 2485 0.0 0.0 0.1 234.5 0.2 351-376 580 20.5 7.5 45 2810 0.1 0.0 0.1 251.3 1.2 RBC Nitrogen Data NHx-N Alk: Date Day F i l l flow Flow Nut. HRT Alk P04-P NHx-N N02-N NOx-N NHx-N NHx-N NHx-N NHx-N tNOx-N NHx-N Tiae Flow +NOx-N Ldg. Removal Ren. Removal Removal • in L/Cyc L/d L/d days • g/L ag/L •g/L cg/L ag/L •g/L g / «J / d g/«*/d X X 08/12/93 0 59 2.0 48 0 5.10 214 0.2 2.9 0.30 335.3 338.2 0.31 0.31 99.0 -11 8.8 08/24/93 12 59 2.0 48 • 0 5.10 179 0.1 0.3 0.02 318.02 318.3 0.34 0.34 99.9 5 7.6 08/31/93 19 59 1.5 36 0 6.81 160 3.6 . 0.2 0.06 352.05 352.2 0.22 0.22 99.9 -20 10.2 09/02/93 21 59 1.5 36 6.61 0.0 18.4 294.00 312.4 0.24 0.23 94.2 5 09/08/93 27 59 1.3 44 4 5.06 190 1.4 0.5 0.00 351 351.5 0.27 0.27 99.8 -21 10.4 09/09/93 28 59 1.9 44 3.3 5.14 1.4 5.2 323 328.5 0.26 0.26 98.1 -16 09/10/93 25 53 1.9 44 3.3 5.14 1.4 0.2 275 275.6 0.26 0.26 99.9 2 09/15/93 34 59 2.0 48 4.2 4.63 183 2.8 0.3 0.00 277.00 277.3 0.34 0.34 99.9 16 8.4 09/16/93 35 53 2.0 43 2.25 4.88 0.8 0.31 0.31 99.7 ' 09/21/93 40 59 2.8 bb 1.59 3.59 185 1.4 16.7 0.023 290.02 306.7 0.43 0.40 94.5 -1 12.1 09/29/93 48 59 1.8 43 1.2 5.52 165 1.0 0.3 0.02 350.02 350.3 0.27 0.27 99.9 -21 9.5 10/01/93 50 59 1.9 46 .305 5.22 1.3 0.4 322 322.3 0.24 0.24 99.8 -21 10/05/93 54 59 2.0 48 0 5.10 151 1.0 0.2 0.03 384.03 384.2 0.31 0.31 99.9' -25 10.7 10/12/93 61 25 2.0 36 4.5 2.43 188 1.4 0.2 0.00 333.00 333.2 0.61 0.61 99.9 -11 6.0 10/19/93 68 29 1.7 82 0 3.00 129 0.9- 0.01 317.01 317.0 0.47 0.47 100.0 -16 8.6 10/27/93 76 25 2.2 106 0.031 2.32 137 0.8 0.3 0.01 246.01 246.3 0.46 0.46 95.5 -20 15.8 11/02/93 82 29 2.3 108 1.2 2.24 176 0.3 0.4 0.00 198.00 138.4 0.44 0.44 33.8 -3 19.1 11/05/93 85 29 2.3 110 2.22 0.957 180.4 181.4 0.41 0.40 55.4 -4 11/09/93 83 29 2.5 118 0.125 2.08 135 2.9 0.4 0.01 192.01 192.4 0.48 0.48 35.8 -0 9.0 11/12/93 32 29 2.5 118 0 2.08 11/16/93 96 29 1.9 51 0 2.69 168 1.5 0.4 0.08 176.08 176.5 0.37 0.37 39.8 7 8.3 11/18/93 98 29 1.9 31 2 2.63 17.729 153.9 171.6 0.30 0.27 88.6 -9 ,11/30/93 110 14 12/08/93 118 29 2.70 130 1.89 598 0.4 14.2 2.00 102.00 116.2 0.28 0.24 85.8 -16 12.9 12/14/93 124 29 2.70 130 1.48 1.87 475 0.4 0.2 0.14 96.94 97.1 0.24 0.24 99.8 -13 9.1 12/21/93 131 29 2.80 134 1.82 581 0.1 2.7 0.38 137.38 140.1 0.42 0.41 98.2 5 7.8 12/29/93 139 29 2.30 110 0 2.22 532 0.5 0.2 0.01 164.01 164.2 0.43 0.43 99.9 10 01/04/94 145 29 2.40 115 0 2.13 400 0.1 1.9 0.13 110.13 112.0 0.25 0.24 98.1 -7 01/05/94 146 29 2.45 116 2.08 0.4 0.21 0.21 99.5 01/11/94 152 14 3.80 365 2.77 0.67 483 0.2 1.0 0.59 101.59 102.6 0.75 0.74 99.0 -5 5.5 01/13/94 154 14 2.85 274 3.65 0.88 2.2 97.319 99.5 0.48 0.47 97.4 -18 01/17/94 156 14 3.00 288 4.24 0.84 0.4 2.6 116.50 119.3 0.86 0.85 98.0 16 01/18/94 159 14 3.10 233 1.5 0.82 583 0.1 7.2 3.20 128.20 135.4 0.94 ' 0.85 55.1 9 9.6 01/20/94 161 14 3.10 296- 1.04 0.82 476 0.3 2.8 136.17 139.0 0.97 0.55 98.2 10 7.3 01/24/94 165 14 3.10 233 1.55 0.82 357 0.4 0.1 128.13 128.3 0.80 0.80 55.9 0 6.6 01/25/34 166 14 3.10 258 0.58 0.62 466 0.1 0.4 0.50 139.50 139.9 0.77 0.76 99.7 -16 12.3 01/27/94 168 14 3.20 307 0.30 2.2 134.0 136.2 0.96 0.35 98.5 8 01/28/94 169 14 3.30 317 11 0.75 8.5 . 130.2 138.7 0.98 0.32 94.1 5 12.4 02/01/94 173 8 3.60 576 0 0.43 1060 0.1 59.7 13.00 257.00 316.7 1.88 1.14 61.0 02/03/94 175 8 2.11 338 1.04 0.72 14.7 164.84 179.5 1.27 1.17 91.7 -1 02/08/94 180 8 4.30 688 2.06 0.36 947 0.1 48.6 14.60 139.60 188.2 2.62 1.31 72.8' -5 10.5 02/09/94 181 8 4.45 712 0 0.34 71.8 131.00 202.8 2.60 1.51 58.2 -17 02/11/34 183 8 3.30 528 2.75 0.46 55.4 159.76 215.2 1.77 1.15 64.9 -36 02/13/94 165 8 1.93 303 2.75 0.79 1.6 19.00 160.00 161.6 0.91 0.50 98.8 -17 02/14/34 186 8 2.00 320 3 0.76 0.4 163.67 164.0 1.04 1.04 99.8 -5 02/15/94 187 8 2.20 352 3 0.69 412 0.2 1.6 1.20 164.20 165.8 0.96 0.55 98.8 -28 8.4 02/18/94 190 8 2.30 464 2.83 0.52 0.1 100.35 100.4 0.91 0.51 95.5 -8 02/21/94 193 8 1.83 233 2.83 0.83 0.3 137.73 138.1 0.87 0.87 99.8 2 02/22/94 194 8 1.30 304 2.75 0.80 473 0.1 17.0 0.95 139.35 157.0 0.85 0.74 87.1 -19 10.8 02/23/94 135 8 1.78 285 2.75 0.85 0.3 143.77 144.0 0.80 0.80 99.8 , -8 02/25/54 197 8 2.00 320 1.5 0.76 1.0 153.25 160.3 0.90 0.30 99.2 -19 02/26/94 138 8 2.00 320 2.5 0.76 0.8 1.72 145.72 150.5 0.95 0.95 99.5 -7 02/28/94 200 8 2.00 320 1.88 0.76 0.1 136.44 136.5 0.67 0.67 99.9 -38 03/03/94 203 8 2.40 384 0.9 0.64 355 0.2 0.1 1.00 85.50 86.0 1.97 1.37 100.0 64 4.9 03/04/94 204 8 2.60 416 1.8 0.59 0.2 107.46 107.7 1.01 1.01 99.8 6 03/07/94 207 4 2.35 677 2.4 0.36 10.7 130.73 141.5 1.67 1.71 91.7 -9 03/08/34 208 4 2.40 63! 2 0.35 67b 0.0 17.1 15.00 113.00 136.1 2.47 2.22 89.8 19 7.6 03/09/34 203 4 2.50 720 2.29 0.34 1.5 153.15 154.7 2.19 2.17 99.0 -3 fcbC Nitrogen Data NHx-N AU: Date Day F i l l Flow Flow Nut. HRT All; P04-F NHx-N N02-N NGx-N NHx-N NHx-N NHx-N NHx-N tNOx-N NHx-N Tiae Flow +N0x-N Ldg. Reaoval Rea. Reaoval Reaoval ain L/Cyc L/d L/d days ag/L ag/L ag/L ag/L ag/L ag/L g /a J /d g/a 2 /d X Z 03/10/94 210 4 2.40 691 2.5 0.35 6.8 164.22 171.1 1.95 1.85 94.8 -28 03/14/94 214 4 2.25 648 2.75 0.38 0.7 175.68 176.3 2.20 2.19 99.6 -10 03/15/94 215 4 2.70 778 2.4 0.31 798 0.2 33.5 6.60 139.60 173.1 2.91 2.36 81.0 2 9.8 03/16/94 216 4 2.28 657 2.5 0.37 2.3 165.30 167.6 2.53 2.50 98.7 8 03/17/94 217 4 2.20 634 2.29 0.39 21.613 133.93 155.5 2.24 1.95 87.0 6 03/21/94 221 4 1.85 533 2.25 0.46 4.3 163.76 168.0 2.03 1.98 97.6 6 03/22/94 222 4 1.70 490 0 0.50 509 0.1 1.4 1.20 177.20 178.6 2.04 2.03 99.3 9 7.6 03/23/94 223 4 1.83 527 2.12 0.46 0.2 1.82 1.82 99.9 03/24/94 224 4 1.83 527 2.32 0.46 1.3 1.89 1.88 99.2 03/30/94 230 4 1.55 446 2.38 0.55 0.942 208.94 209.3 1.73 1.72 99.5 -15 03/31/94 231 4 2.50 720 2.5 0.34 654 0.2 9.3 6.37 190.37 139.7 3.16 3.01 95.5 3 8.5 04/05/94 236 4 1.80 518 2.3 0.47 603 0.1 3.7 4.08 194.08 137.8 2.21 2.17 98.2 1 9.7 04/06/94 237 4 1.35 562 2.7 0.43 0.12 131.51 191.6 1.75 1.79 99.9 -27 04/07/94 238 4 1.91 551 0.44 0.439 163.01 163.4 2.05 2.05 99.7 7 04/12/94 243 2 1.66 797 2.6 0.31 618 0.1 6.4 7.30 154.30 160.7 2.97 2.86 96.3 8 8.6 04/13/94 244 2 1.10 528 2.86 0.46 0.072 176.84 176.9 1.93 1.93 100.0 -2 04/14/94 245 2 2.06 983 2 0.25 47.269 112.49 155.8 3.68 2.68 73.0 9 04/19/94 250 2 2.20 1056 0.23 1060 0.2 64.3 4.60 141.80 206.1 4.40 2.96 67.2 -5 10.2 04/20/94 251 2 2.20 1056 2.86 0.23 32.184 123.32 161.5 3.94 3.22 81.7 8 04/21/94 252 2 1.05 504 2.5 0.48 0.04 198.81 198.9 1.80 1.80 100.0 -18 04/26/94 257 2 3.50 1680 2.6 0.15 1300 0.2 115.0 4.80 106.80 221.8 8.69 4.58 52.7 9 8.9 04/27/94 258 2 2.64 1267 2.5 0.19 31.25 169.69 200.9 6.22 5.38 86.5 13 04/28/94 259 2 2.43 1166 0.21 59.063 120.06 173.1 4.33 2.92 66.6 -1 05/03/94 264 2 2.50 1200 2.5 0.20 1330 0.2 109.0 10.20 135.20 244.2 6.20 3.42 55.1 1 8.7 05/04/94 265 2 2.41 1157 2.5 0.21 38.145 224.69 262.8 5.75 4.82 83.7 -12 05/05/94 266 2 0.60 266 2.5 0.84 2.686 214.93 217.6 1.13 1.17 98.6 -12 05/10/94 271 2 0.00 0 2.5 371 0.5 0.9 0.13 233.13 234.0 0.00 0.00 17 8.0 05/17/94 278 2 2.40 1152 2.6 0.21 956 0.0 65.0 58.10 183.10 248.1 6.31 5.32 77.0 12 5.4 05/18/94 279 2 2.50 1200 2.4 0.20 62.45 181.3 243.8 6.75 5.15 76.4 8 05/19/94 280 2 2.35 1128 2.5 0.22 54.787 186.99 241.8 5.86 4.54 77.5 1 05/24/94 285 2 2.60 1248 2.5 0.20 1580 0.2 128.0 19.10 111.00 239.0 7.06 3.66 51.9 10 8.5 05/26/94 287 2 2.52 1210 2.25 0.20 28.342 184.22 212.6 5.67 4.94 87.1 5 05/30/94 291 2 2.31 1109 2.4 0.22 38.905 159.83 198.7 5.06 4.15 81.9 8 05/31/94 292 2 2.18 1046 2.7 0.23 1200 0.0 73.8 48.00 160.00 233.8 5.83 4.19 71.8 11 8.3 06/06/94 238 2 2.27 1088 0.23 33.56 203.55 237.1 5.51 4.73 85.9 1 06/07/94 239 2 2.22 1066 0.23 1100 0.0 66.8 94.30 183.00 249.8 5.83 4.31 74.0 3 7.8 06/08/94 300 2 2.21 1061 0.23 37.736 199.63 237.4 5.23 4.44 83.9 -1 06/14/54 306 2 2.53 1212 0.20 12 1.0 120.0 5.23 114.23 234.2 6.27 3.17 50.6 4 15.2 06/17/94 309 1 0.00 0 0.115 241.3 242.0 0.00 0.00 -17 06/21/34 313 1 2.45 1764 0.14 1600 0.7 142.0 13.50 110.00 252.0 5.87 4.54 46.0 4 8.1 06/24/94 316 1 2.20 1584 0.15 113.32 123.19 236.5 7.17 3.35 46.7 -11 06/28/34 320 1 3.50 2808 0.05 1730 0.1 170.0 50.30 73.70 243.7 14.58 4.42 30.3 0 11.6 07/05/94 327 1 0.00 0 546 0.8 1.8 0.40 216.40 218.2 0.00 0.00 9 8.2 07/12/34 334 1 1.84 1327 0.18 953 1.0 60.7 4.20 169.20 229.9 6.21 4.50 72.4 -5 10.0 07/19/94 341 1 1.15 82b 0.30 1410 1.3 121.0 4.43 116.43 237.4 4.33 2.20 50.8 3 11.1 08/05/34 358 3 2.00 720 0.34 818 4.7 7.2 11 220 227.2 4.20 4.09 97.4 17 7.5 08/09/94 362 3 1.78 642 0.33 733 5.7 1.9 4.5 219.5 221.4 3.30 3.28 99.2 9 8.3 08/16/34 365 3 2.10 756 0.32 1000 1.9 25.4 13.8 161.8 207.2 3.83 3.42 89.3 13 8.9 08/23/94 376 3 2.30 823 0,30 867 1.5 19.7 28.4 182.4 202.1 4.81 4.46 92.8 26 6.4 09/01/94 385 3 2.18 783 0.31 783 1.7 22.9 40.1 202.1 225 5.01 4.63 92.4 25 7.6 09/07/94 391 3 1.52 547 0.45 580 1.6 1.9 34.8 220.8 222.7 3.75 3.73 99.4 31 6.3 09/29/94 3 2.15 774 33.6 0.30 1750 0.42 108 224 341 449 8.03 6.18 76.9 10/05/94 3 2.10 756 38.4 0.31 946 0.55 17.4 245 490 507.4 8.43 8.19 96.5 10/20/94 3 2.40 864 38.4 0.27 2080 0.6 249 71.7 172.7 421.7 9.43 4.65 49.3 10/26/94 3 2.35 846 37.2 0.28 1100 1.9 159 23 205 364 8.75 5.76 65.8 RBC Nitrogen Data 1 1 7 NHx-N Alk: Date Day F i l l flow Flow Nut. HKF filk P04-P NHx-N N02-N NOx-N NHx-N NHx-N NHx-N NHx-N +N0x-N NHx-N Tme Flow +N0x-N Ldg. Reaoval Rei. Reaoval Reaoval am L/Cyc L/d L/d days aq/ l aq/L aq/L ag/L ag/L ag/L g/a 2/'d g /a 2 /d I I AVERAGE 1.18,694.0.92 27.93 22.3 181.83 209.71 2.76 2.04 87.1 -1.23 9.25 MAXIMUM 6.81 1750 5.70 170.00 224.0 384.03 449.00 14.58 6.18 100.0 64.33 19.06 MINIMUM 0.03 12 0.00 0.04 0.00 73.70 85.99 0.00 0.00 30.3 -37.52 4.92 0-54 1.92 46 1.80 5.24 178 1.29 3.6 0.06 322.7 326.5 0.29 0.29 98.8 -8.917 9.695 55-149 2.30 110 0.89 2.25 322 0.34 3.1 0.25 185.1 188.2 0.38 0.38 97.7 -5.957 10.938 150-170 3.17 305 3.29 0.80 473 0.26 3.0 1.43 123.5 126.5 0.83 0.81 97.8 0.907 8.274 171-.?0S 2.55 408 2.02 0.65 649 0.12 16.1 7.35 147.1 163.2 1.29 1.09 90.1 -8.457 9.419 206-240 2.12 610 2.26 0.41 648 0.11 6.8 7.45 164.7 172.3 2.18 2.08 95.9 -1.971 8.666 241-308 2.10 1009 2.52 0.27 953 0.24 50.7 25.20 166.0 216.7 4.88 3.60 77.4 3.217 8.961 309-352 1.65 1187 0.17 1248 0.78 87.0 14.57 150.1 237.1 6.02' 2.72 49.3 -2.176 9.815 352-331 1.98 713 0.35 793 2.85 13.2 22.10 204.4 217.6 4.15 3.93 95.1 20.111 7.585 HRT Ex. 2.25 810 36.90 0.29 1469 0.87 133.4 140.9 302.2 435.5 8.67 6.20 72.1 Loading Period SBR Nitrogen Data NHx-N' •Date Day Flow Nut. ML HRT Alk P04-P NHx-N N02-N NOx-N NHx-N NHx-N NHx-N NHx-N NHx-N NHx-N tNOx-N Alk:NHx-Flow Hasting +N0x-N Loading Loading Reaoval Reioval Reaoval Reaoval Reaoval L/d L/d L/day days ag/L ag/L aq/L ag/L ag/L ag/L g/a 3 /d g/g/d g/a 3 /d g/g/d Z X AVERAGE 2.85 616 1.64 44.1 30.24 155.0 195.9 126.1 0.68 86.9 0.54 77.0 4.6 7.5 MAXIMUM 4.63 2400 11.7 325.0 193.0 318.3 328.3 743.7 1.99 482.2 1.32 100.0 100.0 . 99.1 MINIMUM 0.43 144 0.00 0.0 0.00 0.9 35.7 17.8 0.09 -6.9 -0.00 -10.9 -162.7 -96.0 0-54 4.64 382 3.44 13.84 5.18 276.9 290.8 63.52 0.77 60.80 0.72 95.99 3.05 9.42 55-130 1.94 612 1.69 59.93 7.70 119.3 173.7 92.46 0.91 66.88 0.69 64.70 8.95 -1.31 131-157 4.66 1030 0.15 106.18 0.97 35.0 145.2 24.68 0.13 2.05 0.01 7.30 -4.43 16.23 158-189 4.63 610 0.76 1.00 0.88 186.6 187.5 32.98 0.21 32.82 . 0.21 99.47 12.56 5.33 130-213 4.60 495 5.50 5.78 0.21 113.5 119.3 29.42 0.28 28.19 0.27 95.42 4.87 7.23 214-301 2.00 538 u.83 43.70 6.13 153.0 188.2 104.65 0.91 82.27 0.69 . 76.75 5.34 8.37 302-350 0.71 797 0.30 21.35 143.2 210.8 232.1 330.86 0.55 300.73 0.49 90.73 0.40 7.32 351-376 0.43 1202 0.05 67.23 175.7 185.0 252.2 • 580.46 ' 0.63 425.20 0.44 73.06 -0.44 8.75 Loading Period SBR Nitroqen Data 11 8 NHx-N Date Day Flow Nut. ML HRT fllk P04-P NHx-N N02-N NOx-N NHx-N NHx-N NHx-N NHx-N NHx-N NHx-N +N0x-N Alk:NHx-Flow Hasting +N0x-N Loading Loading Reaoval Reioval Reioval Reioval Reaoval L/d L/d L/day days ig /L aq/L •g/L •g/L ig/L •g/L g / i 3 / d g/g/d g / i 3 / d g/g/d Z Z 08/12/93 0 78 0.0 21.9 4.69 584 0.00 22.9 0.00 197.0 220 65.0 1.05 60.1 0.97 92.5 28.0 8.10 08/24/93 12 78 21.9 4.69 816 3.10 75.2 11.00 205.0 280 71.6 0.81 55.6 0.63 77.6 16.6 7.30 08/31/93 19 78 21.9 4.69 281 0.23 9.8 1.70 303.7 314 62.4 60.3 96.7 -6.9 10.10 09/02/93 21 78 21.9 4.69 22.9 245.4 268 67.0 62.2 92.7 18.6 09/08/93 27 78 0.0 21.9 4.69 233 4.70 0.3 0.31 318.3 319 61.6 0.70 61.7 0.70 99.9 -9.8 . 10.27 09/09/93 28 78 0.8 21.9 4.65 0.2 271.3 272 58.8 58.8 99.9 4.1 09/10/93 29 78 21.9 4.69 0.1 263.2 263 59.7 59.7 100.0 6.3 09/15/93 34 78 4.1 21.9 4.46 233 5.20 1.8 1.60 309.6 311 70.5 0.78 70.1 0.77 99.5 6.0 8.25 09/16793 35 78 2.0 21.9 4.58 64.0 64.0 100.0 09/21/93 40 78 2.2 21.9 4.56 377 2.70 17.0 8.90 298.9 316 64.8 0.60 61.1 0.57 94.4 -3.7 11.40 09/29/93 48 78 2.0 21.9 4.58 215 8.40 1.1 0.54 307.5 309 61.6 0.70 61.3 0.70 99.6 -6.8 9.36 10/01/93 50 78 21.9 4.69 0.6 298.1 299 53.3 53.2 99.8 -12.1 10/05/93 54 78 1.9 21.9 4.58 317 3.20 14.2 17.40 304.4 319 65.4 62.4 95.4 -3.8 10.60 10/12/93 61 187 2.6 21.9 1.93 991 2.40 103.0 0.10 193.1 296 153.2 1.36 100.4 0.89 65.6 1.2 8.16 10/19/93 68 187 0.0 21.9 1.95 226 0.93 55.30 310.3 310 , 139.9 0.91 139.9 0.91 100.0 -13.5 8.22 10/27/93 76 187 0.9 21.9 1.94 330 5.90 16.4 3.75 206.8 223 104.5 0.78 96.1 0.72 92.0 -8.7 16.15 11/02/53 82 187 4.6 21.9 1.91 256 0.29 10.9 0.62 152.6 164 97.9 0.87 92.3 0.82 94.3 14.7 19.73 11/05/93 85 187 5.0 21.9 1.90 6.5 156.7 163 88.8 85.4 96.2 6.4 11/05/93 65 187 0.0 21.9 1.95 571 2.10 42.1 1.01 123.0 165 98.4 0.76 76.8 0.59 78.1 14.0 8.53 11/12/93 92 187 0.0 21.9 1.95 76.6 60.3 139 81.4 41.1 50.5 13.3 11/16/93 96 187 2.8 21.9 1.92 678 1.70 120.0 0.07 50.5 170 97.3 0.80 35.9 0.29 36.8 10.6 15.46 11/18/33 96 187 21.9 1.95 99.5 52.4 152 79.5 28.5 35.9 3.7 11/30/93 110 167 0 1.95 73.6 73.8 12/08/93 116 187 ii 1.95 1070 0.11 31.7 0.25 4.0 36 51.2 0.89 34.9 0.61 68.3 64.3 9.24 12/14/33 124 187 0.3 0 1.55 770 0.06 50.5 0.54 2.2 93 43.8 -2.6 -5.8 -7.6 -96.00 12/21/53 131 78 0 4.69 1070 0.15 125.0 0.42 1.9 127 31.3 4.7 15.0 13.7 28.64 12/29/93 139 78 1.5 0 4.61 1100 0.12 160.0 0.05 0.9 161 39.0 4.9 12.6 12.1 -47.83 01/04/94 145 78 0 4.69 1090 0.00 112.0 0.39 1.3 113 21.5 -2.3 -10.9 -8.5 99.09 01/05/94 146 78 0 4.69 86.4 18.0 0.12 -0.4 -0.00 -2.2 100.0 0.00 01/11/94 152 78 1.0 0 4.63 858 0.48 87.6 3.00 169.0 257 20.4 1.8 8.8 -162.7 17.50 01/13/94 154 78 0 66.1 2.1 68 17.8 0.14 3.7 0.03 20.6 18.9 0.00 01/17/94 158 0 59.4 53.5 113 01/18/94 159 0 01/20/94 161 0 144 01/24/94 165 0 152 01/25/94 166 0 01/27/94 168 76 0.5 0 4.65 31.5 31.5 100.0 100.0 0.00 01/28/94 169 78 0 4.68 31.0 0.09 31.0 0.09 100.0 100.0 0.00 02/01/94 173 76 1.2 0 4.62 713 0.85 1.0 0.31 32.6 0.10 32.4 0.10 99.4 9.91 02/03/94 175 78 0 4.69 1.2 37.7 37.5 99.3 02/08/94 160 78 1.6 > 0 4.60 588 0.92 0.1 0.08 216.1 216 38.1 0.43 38.1 0.43 99.9 -20.8 . 9.63 02/09/34 ldl 78 O.U 0 4.S3 0.2 174.8 175 , 36.5 0.16 36.5 0.16 99.9 -1.4 02/11/94 183 78 2.5 0 4.55 02/13/94 185 78 0.0 0 4.69 4.3 2.30 182.3 187 29.4 28.5 96.9 -35.2 02/14/94 lbb 78 2.5 0 4.55 0.0 173.8 174 32.7 0.30 32.7 0.30 100.0 -10.9 7.43 02/15/94 187 78 2.4 0 4.55 530 0.51 0.2 0.84 185.8 186 27.3 0.20 27.2 0.20 99.9 -43.7 02/18/94 190 78 1.0 0 4.63 0.0 131.0 131 19.6 0.14 19.5 0.14 100.0 -41.3 02/21/94 193 78 1.3 0 4.62 0.8 123.7 125 29.9 0.20 29.7 0.20 99.4 11.6 9.18 02/22/94 194 78 2.3 0 4.56 540 11.7 3.5 0.51 133.5 137 28.1 0.23 27.4 0.22 97.3 -3.6 02/23/94 195 78 1.0 0 4.63 5.8 122.1 128 28.1 0.23 26.9 0.22 95.6 4.0 02/25/94 197 78 2.3 0 4.56 11.0 120.5 132 28.3 0.25 25.9 0.23 91.7 2.4 02/26/94 198 78 0.0 0 4.69 30.5 0.27 109.3 140 29.8 23.3 78.2 0.7 02/28/94 200 78 0.0 0 4.69 18.3 109.1 127 20.9 0.21 17.0 0.17 81.4 -28.3 03/03/94 203 78 2.3 0 4.56 431 0.59 1.1 0.01 94.7 96 51.3 0.73 51.1 0.72 99.5 4.62 03/04/94 204 78 1.8 0 4.59 0.1 91.3 92 24.3 0.34 24.2 0.34 99.9 19.7 03/07/94 207 78 2.4 0 4.55 0.3 96.9 97 27.6 0.16 27.6 0.15 99.8 25.3 03/08/94 208 73 2.5 0 4.55 515 3.80 1.3 0.05 109.1 110 35.8 0.37 35.5 0.36 99.2 34.4 7.89 03/09/94 209 78 2.2 0 4.56 2.2 116.6 119 30.5 30.0 98.5 21.2 SBR Nitrogen Data iiq NHx-N Date ' Day Flow Nut. ML HRT Alk P04-P NHx-N N02-N NOx-N NHx-N NHx-N NHx-N NHx-N NHx-N NHx-N *N0x-N Alk:NHx-Flow Hasting +N0x-N Loading Loading Reioval Reaoval Reaoval Reaoval Reaoval aq/L g/e^/d g/g/d g/a=»/d g/g/d I X 117 28.2 0.22 28.2 0.22 39.9 12.3 138 34.1 0.29 34.1 0.29 100.0 13.7 147 90.2 81.0 89.8 16.7 9.40 165 92.7 0.77 84.9 0.71 91.6 9.6 160 85.1 0.78 67.4 0.62 79.3 3.5 134 91.6 1.02 66.6 0.74 72.7 24.9 211 100.4 33.3 33.2 -7.2 11.08 39 83.2 1.00 63.3 0.76 76.1 37 86.4 1.05 67.4 0.82 78.0 178 93.1 1.51 69.9 1.13 75.1 2.1 173 105.5 1.04 81.9 0.81 77.6 16.2 6.82 186 102.5 0.92 53.8 0.48 52.5 7.2 10.00 145 76.6 1.22 43.7 0.70 57.1 4.3 139 89.8 1.99 59.7 1.32 66.5 21.3 261 89.7 0.72 2.6 0.02 2.9 -48.9 150 88.2 1.31 61.3 0.91 69.5 13.3 154 89.6 0.82 53.5 0.49 59.7 12.5 200 100.4 48.2 48.0 -2.1 9.26 175 89.9 0.71 36.2 0.23 40.3 0.5 186 85.9 0.81 43.0 .0.41 50.0 -10.7 217 124.5 1.30 85.0 0.89 68.3 10.7 7.95 211 118.2 1.11 84.5 0.80 71.5 8.7 223 90.6 0.83 64.4 0.59 71.1 -25.7 233 124.5 1.47 103.7 1.22 83.3' 5.3 7.95 226 119.6 1.02 101.1 0.86 84.4 3.6 219 99.4 0.74 91.9 0.69 92.5 -12.5 205 144.0 0.59 143.7 0.59 99.8 26.0 7.42 228 144.5 1.01 144.4 1.01 99.9 19.1 5.91 227 135.4 109.0 80.5 14.8 227 125.0 0.93 115.8 0.86 92.7 7.3 222 136.3 0.88 136.0 0.87 99.8 16.6 8.20 224 112.9 0.55 112.8 0.55 100.0 -0.3 211 110.0 0.65 109.9 0.65 93.9 2.1 206 134.2 0.69 134.0 0.68 99.9 21.6 8.47 232 121.9 0.38 121.9 0.38 100.0 3.0 253 131.7 0.38 131.4 0.38 99.8 1.5 7.97 229 120.1 0.48 120.0 0.48 99.9 2.8 222 342.9 0.53 228.2 0.35 66.5 8.6 4.21 201 291.1 0.44 290.6 0.44 99.8 2.8 279 371.1 0.55 365.3 0.55 98.4 -6.2 7.55 312 300.0 0.76 204.5 .0.52 68.2 -46.3 210 344.3 0.59 321.8 0.55 93.5 14.0 7.47 206 340.0 0.51 339.6 0.51 99.9 14.4 7.89 224 310.4 0.48 309.5 0.48 99.7 -1.7 8.92 202 347.1 0.51 346.5 0.51 99.8 17.7 7.87 267 632.B 0.53 482.2 0.41 76.2 2.5 8.73 253 558.9 0.43 446.5 0.35 80.0 -6.8 8.53 231 549.7 0.92 346.4 0.58 63.0 2.9 9.00 • 277 630.5 -6.9 -1.1 -1.6 280 695.2 53.1 7.6 7.1 328 743.7 -6.9 -0.9 -2.0 L/d L/d L/day days aq/L aq/L ag/L aq/L ag/L 03/10/94 210 78 2.5 0 4.55 0.1 117.1 03/14/94 214 78 3.0 0 4.51 0.1 138.1 03/15/94 215 187 2.6 0 1.93 714 0.83 17.9 4.70 128.7 03/16/94 216 187 3.1 0 1.92 15.2 149.7 03/17/94 217 187 2.3 0 1.93 34.4 . 126.0 03/21/94 221 187 2.3 0 1.93 48.7 85.6 03/22/94 222 187 2.8 0 .1.92 1270 0.60 131.0 2.10 79.7 03/23/94 223 187 2.8 0 1.92 38.8 03/24/94 224 187 2.8 0 1.92 37.1 03/30/94 230 187- 2.6 0 1.92 45.2 132.8 03/31/94 231 187 2.0 0 1.93 1240 1.00 46.2 126.6 04/05/94 236 187 2.6 0 1.92 1460 2.30 95.0 3.55 .90.6 04/06/94 237 187 2.5 0 1.93 64.2 80.6 04/07/94 236 187 2.5 0 1.93 58.7 80.2 04/12/94 243 187 2.4 0 1.93 1300 0.67 170.0 5.10 90.7 04/13/94 244 187 2.9 0 1.92 52.6 97.7 04/14/94 245 187 2.5 0 1.93 70.4 84.0 04/19/94 250 187 0 1.95 1530 0.98 102.0 0.39 98.1 04/20/94 251 187 2.9 0 1.92 104.8 70.5 04/21/94 252 187 2.5 0 1.93 83.8 102.7 04/26/94 257 187 2.6 0 1.93 1120 0.62 77.0 14.00 140.0 04/27/94 258 187 2.8 0 1.92 65.6 145.4 04/28/94 253 187 2.5 0 1.93 51.1 171.8 05/03/94 264 187 2.5 0 1.93 890 0.43 40.5 25.20 192.2 05/04/94 265 187 2.3 0 1.93 36.4 189.4 05/05/94 266 187 2.5 0 1.93 14.6 204.2 05/10/94 271 187 2.5 0 1.33 529 1.30 0.4 0.17 208.2 05/17/94 278 187 2.6 0 1.93 463 0.44 0.2 15.10 228.1 05/18/94 279 187 2.4 0 1.93 51.6 175.0 05/19/94 280 187 2.5 0 1.93 17.9 209.3 05/24/94 285 187 2.6 0 1.93 574 0.60 0.5 1.20 221.2 05/26/94 287 187 2.5 0 1.93 0.0 224.2 05/30/94 291 187 2.5 0 1.93 0.2 211.0 05/31/94 292 187 2.3 0 1.93 554 0.23 0.4 0.58 205.6 06/06/94 298 167 0 1.95 0.1 231.6 06/07/94 299 187 0 1.95 546 0.63 0.5 1.50 252.5 06/08/94 300 187 0 1.95 0.2 229.2 06/14/94 306 515 0 0.71 1200 0.68 81.3 43.80 140.8 06/17/94 309 515 0 0.71 0.3 200.6 06/21/94 313 515 0 0.71 625 0.96 4.1 49.30 275.3 06/24/94 316 515 0 0.71 67.7 244.5 06/28/94 320 515 0 0.71 886 0.14 15.9 187.0 194.0 07/05/94 327 515 0 0.71 610 0.00 0.3 199.0 206.0 07/12/94 334 515 0 0.71 593 0.00 0.7 194.0 223.0 07/19/94 341 515 0 0.71 867 0.00 0.4 186.0 202.0 08/05/94 358 843 0 0.43 987 0.10 65.2 189.0 202.0 08/03/34 362 843 0 0.43 1080 0.00 48.5 196.0 210,0 08/16/94 369 843 0 0.43 1540 0.05 68.0 142.0 143.0 08/23/34 376 843 0 0.43 2250 2.10 276.0 1.30 1.3 09/01/94 385 843 0 0.43 2360 4.80 278.0 0.00 1.8 09/07/94 391 843 0 0.43 2400 3.50 325.0 0.01 3.3 RBC P and Hisc. Data no Date Day Nutrient Nutrient Nutrient Influent NHx-N HRT DO Tecp Cond. Site pH P04-P NHx-N N02-N NOx-N Flow Addition Addition P04-P :P04-P PH L/day (g/20 L) (•g/L) (ig/L) •g/L days ig/L •c •S •g/L •g/L •g/L •g/L 08/12/33 0 40 5.10 6.8 0.2 2.3 0.30 335.3 08/24/93 12 40 5.10 7.6 0.1 0.3 0.02 318.0 08/31/93 19 40 6.81 7.3 3.6 0.2 0.06 352.1 09/02/93 21 40 6.61 0.0 18.4 294.0 09/08/93 2/ 4 40 13.47 14.15 22.71 5.06 8.5 20 5.1 8 7.3 1.4 0.5 0.00 351.0 09/09/93 28 3.3 40 11.27 11.66 26.30 5.14 8.8 22 5.12 8 1.4 5.2 323.3 09/10/93 25 3.3 40 11.27 11.60 27.51 5.14 20 1.4 0.2 275.4 09/15/93 34 4.2 40. 13.11 13.77 30.14 4.69 8.1 16 5.04 8 7.9 2.8 0.3 0.00 277.0 09/16/93 35 2.25 40 7.30 4.83 8.9 15.5 4.67 7.8 0.8 09/21/93 40 1.99 40 4.75 5.59 68.52 3.59 10.4 13.5 4.09 8 7.35 1.4 16.7 0.023 290.0 09/29/33 48 1.2 40 4.40 5.52 8.6 19 4.45 7.9 7.6 1.0 0.3 0.02 350.0 10/01/93 50 1.305 40 4.53 4.72 72.73 5.22 15 1.3 0.4 321.9 10/05/33 54 0 40 0.00 0.88 5.10 11.6 11.6 4.18 8 7.2 1.0 0.2 0.03 384.0 10/12/33 61 4.9 40 7.91 . 8.64 41.24 2.43 9.6 17 4.72 7.9 7.2 1.4 0.2 0.00 333.0 10/19/93 68 0 40 0.00 0.58 3.00 10.2 14 4.82 7.9 7.3 0.3 0.01 317.0 10/27/33 76 0.091 40 0.14 0.79 2.32 11.4 12.5 3.82 8 7.3 0.9 0.3 0.01 246.0 11/02/93 82 1.2 40 1.79 2.18 100.28 2.24 11 3.56 7.9 7.5 0.3 0.4 0.00 198.0 11/05/93 85 40 0.00 2.22 1.134 0.357 180.4 11/09/33 89 0.125 40 0.17 0.48 2.08 6.75 3.42 7.9 7.1 2.3 0.4 0.01 192.0 11/12/93 92 0 40 0.00 0.36 2.08 5.5 3.12 7.7 11/16/53 96 0 40 0.00 0.80 2.69 8.5 3.21 7.9 7.5 . 1.5 0.4 0.08 176.1 11/18/93 98 2 40 3.50 3.72 52.63 2.63 5 3.42 7.8 1.106 17.72 153.9 11/30/93 110 40 6.75 3.31 8.1 12/08/93 118 40 0.00 1.89 6 2.76 8.6 8.0 0.4 14.2 2.00 102.0 12/14/93 124 1.48 40 1.84 1.94 54.73 1.87 8.5 7.3 0.4 0.2 0.14 96.9 12/21/33 131 40 0.00 1.82 4 3.31 8.3 7.8 0.1 2.7 0.38 137.4 12/29/93 133 0 40 0.00 0.00 2.22 4.5 3.47 8.0 0.5 0.2 0.01 164.0 01/04/94 145 0 40 0.00 0.00 2.13 8.75 2.42 8.2 0.1 1.3 0.13 110.1 01/05/94 146 40 0.00 2.08 6.5 2.57 0.4 01/11/94 152 2.77 40 1.23 1.28 50.29 0.67 8.5 2.7 8.3 7.3 0.2 1.0 0.53 101.6 01/13/94 154 . 3.65' 40 2.15 2.27 46.47 0.88 10.5 2.57 0.524 2.2 97.3 01/17/94 158 4.24 40 2.36 2.65 60.95 0.84 9 3.06 0.4 2.8 116.5 01/18/94 159 1.5 40 0.82 0.85 189.43 0.82 7 3.16 8.4 7.7 0.1 7.2 3.20 128.2 01/20/94 161 1.04 40 0.57 0.89 251.69 0.82 5 3.56 8.3 0.3 2.8 136.2 01/24/94 165 1.55 40 0.84 1.12 183.49 0.82 10.5 7.9 0.4 0.1 128.1 01/25/94 166 0.58 40 0.32 0.53 0.82 8.5 2.95 8.3 8.2 0.1 0.4 0.50 139.5 01/27/94 168 40 0.00 0.80 9 3.17 0.311 2.2 134.0 01/28/94 169 11 40 5.47 5.81 25.21 0.75 6 3.75 8.1 0.331 8.5 130.2 02/01/94 173 0 40 0.00 0.06 0.43 5.5 4.04 8.1 8.2 0.1 53.7 13.00 257.0 02/03/94 175 1.04 40 0.50 0.81 271.42 0.72 5 0.213 14.7 164.8 02/08/94 180 2.06 40 0.49 0.61 238.61 0.36 0 3.92 8.5 8.1 0.1 48.6 14.60 139.6 02/09/94 181 0 40 0.00 0.30 0.34 2.5 3.84 8.7 0.061 71.8 131.0 02/11/94 183 2.75 40 0.84 1.16 105.95 0.46 5.5 0.135 55.4 159.8 02/13/34 165 2.75 40 1.44 0.79 6.5 3.25 8.3 1.6 19.00 160.0 02/14/94 186 3 40 1.51 1.86 96.45 0.76 5.5 0.278 0.4 163.7 02/15/94 187 3 40 1.38 1.41 104.71 0.69 7.5 3.17 8.18 0.2 1.6 1.20 164.2 02/18/94 190 2.89 40 1.01 1.26 99.39 0.52 7.5 2.45 0.334 0.1 100.4 02/21/94 193 2.83 40 1.56 1.88 76.19 0.83 5.5 3.13 0.033 0.3 137.7 02/22/94 194 2./5 40 1.46 1.51 83.27 0.80 4.75 3.55 7.53 0.1 17.0 0.95 140.0 02/23/94 195 2.75 40 1.56 1.82 73.18 0.85 c J 0.02 0.3 143.8 02/25/94 137 1.5 40 0.76 1.03 133.49 0.76 2 3.35 0.04 1.0 159.3 02/26/54 198 2.5 40 1.26 0.76 5 2.41 0.8 1.72 149.7 02/28/94 200 1.88 40 0.95 1.21 84.89 0.76 9.5 0.051 0.1 136.4 03/03/94 203 0.9 40 0.38 0.45 0.64 11.5 2.03 8.13 8.22 0.2 0.1 1.00 85.9 03/04/94 204 1.8 40 0.70 0.91 187.88 0.59 10 2.42 8.4 0.306 0.2 107.5 03/07/94 207 '2.4 80 1.15 1.44 65.72 0.36 7 0.051 10.7 130.7 03/08/94 208 2 80 0.94 0.93 152.37 0.35 11 8.2 7.68 0.0 17.1 19.00 119.0 '/no 1 'lO pn i m 1 11 l C 7 f>7 n it 0 p ^ f\ 'SGI RBC P and Disc. Data Date Day Nutrient flow L/day 03/10/34 210 2.5 03/14/94 214 2.75 03/15/94 215 2.4 03/16/94 216 2.5 03/17/94 217 2.29 03/21/94 221 2.25 03/22/94 222 0 03/23/94 223 , 2.12 03/24/94 224 2.82 03/30/94 230 2.38 03/31/94 231 2.5 04/05/94 236 2.3 04/06/94 237 2 . 1 04/07/94 236 04/12/94 243 2.6 04/13/94 244 2.86 04/14/34 245 2 04/19/94 250 04/20/94 251 2.86 04/21/34 252 2.5 04/26/94 257 2.6 04/27/94 256 2.5 04/28/94 259 05/03/94 264 2.5 05/04/94 265 2.5 05/05/94 266 2.5 05/10/94 271 2.5 05/17/94 278 2.6 05/18/94 279 2.4 05/19/34 280 2.5 05/24/94 285 2.5 05/26/94 287 2.25 05/30/94 291 2.4 05/31/94 292 2.7 06/06/94 298 2.3a 06/07/94 299 2.5 06/08/34 300 2.5 06/14/94 306 2.5 06/17/34 309 1.87 06/21/94 313 2.5 06/24/34 316 2 06/28/94 320 2.75. 07/05/94 327 2.4 07/12/34 334 2.5 07/13/94 341 2.3 08/05/54 358 2.6 08/09/94 362 2.35 08/16/94 369 2.61 08/23/34 376 2.65 09/01/94 385 2.6 09/07/94 391 2.08 Nutrient Nutrient Influent Addition Addition P04-P lg/20 L) (ig/L) <«g/L) 80 1.17 1.26 80 1.38 1.66 80 1.00 1.04 80 1.24 1.39 80 1.17 1.29 80 1.37 1.54 80 0.00 80 1.31 1.59 80 1.73 2.00 80 1.73 1.97 80 1.13 1.20 80 1.44 1.48 80 1.56 1.72 80 0.00 30 1.06 1.11 80 1.76 2.09 80 0.66 0.94 80 0.00 80 0.88 1.08 80 1.61 1.82 80 0.50 0.5? 80 0.64 0.84 80 0.00 80 0.68 0.74 80 0.70 1.29 80 2.80 3.13 80 80 0.73 0.77 80 0.65 0.83 80 0.72 0.77 80 0.65 0.76 240 1.82 1.82 240 2.11 2.50 240 2.52 2.64 240 2.13 2.29 240 2.29 2.43 240 2.30 2.40 240 2.01 2.05 240 240 1.38 1.57 480 2.47 2.80 480 1.91 2.14 480 960 7.35 7.40 960 10.83 10.98 150 2.20 3.30 150 2.23 3.63 150 2.10 3.00 150 1.95 2.75 150 2.02 3.22 150 2.31 3.81 NHx-N HRT DO Teip :P04-P •g/L days ig/L •c 111.00 0.35 10.5 118.11 0.38 11 161.40 0.31 12 161.52 0.37 11 148.48 0.39 7 151.92 0.46 6 0.50 10.5 116.76 0.46 7.5 86.78 0.46 10 117.92 0.55 14 185.54 0.34 12 146.53 0.47 11.5 123.25 0.43 10 0.44 9 173.80 0.31 13 176.22 0.46 9.5 192.74 0.25 10 0.23 18.S 163.53 0.23 16.5 103.61 0.48 13 302.14 0.15 16 253.62 0.19 15 0.21 15 236.07 0.20 15 152.03 0.21 14.5 66.03 0.84 15.7 19 280.36 0.21 19.5 343.38 0.20 16.5 259.58 0.22 18.7 264.57 0.20 22.5 105.72 0.20 15.5 71.29 0.22 14.5 71.38 0.23 17.5 89.36 0.22 17.5 76.32 0.23 16 81.96 0.23 16.7 116.83 0.20 14.5 18.5 138.47 0.14 22 35.41 0.15 17 36.94 0.09 19 17.5 24.84 0.18 22.5 12.91 0.30 22.5 -190.4 0.34 19.5 -128.4 0.38 21 192.82 0.32 2! 202.69 0.29 22 182.65 0.31 20 144.57 0.45 19.5 Site pH P04-P NHx-N N02-N NOx-N pH •g/L •g/L •g/L ig/L 0.13 6.8 164.2 0.318 0.7 175.7 8.3 7.93 0.2 33.5 6.60 139.6 0.28 2.3 165.3 8.38 0.32 21.61 133.9 8 0.39 4.3 163.8 8.28 7.66 0.1 1.4 1.20 177.2 0.201 0.2 8.24 0.071 1.3 0.434 0.942 208.9 8.2 7.95 0.2 9.3 6.37 190.4 8.11 7.8 0.1 3.7 4.08 194.1 0.503 0.12 191.5 8.46 0.145 0.439 163.0 8.2 7.91 0.1 6.4 7.30 154.3 1.111 0.072 176.8 0.277 47.26 112.5 7.96 0.2 64.3 4.80 141.8 0.2 32.18 129.3 8.4 0.205 0.04 198.6 8.28 7.88 0.2 115.0 4.80 106.8 0.05 31.25 169.7 0.26 59.06 120.1 8.31 7.7 0.2 109.0 10.20 135.2 0 38.14 224.7 7.8 0.233 2.686 214.9 8.6 7.77 0.5 0.9 0.13 233.1 8.16 7.93 0.0 65.0 58.10 183.1 0.239 62.45 181.3 8.13 0.04 54.78 187.0 8.17 7.86 0.2 128.0 19.10 111.0 0 28.34 184.2 8.22 0.03 38.90 159.8 8.23 8.05 0.0 73.8 48.00 160.0 0 33.56 203.6 7.97 0.0 66.8 94.30 183.0 0 37.73 199.7 7.91 1.0 120.0 5.23 114.2 0.102 0.115 241.9 8.19 0.7 142.0 13.50 110.0 0 113.3 123.2 7.9 0.1 170.0 50.30 73.7 7.9 0.8 1.8 0.40 216.4 7.87 1.0 60.7 4.20 169.2 8.1 1.3 121.0 4.43 116.4 7.85 4.7 7.2 11 220.0 7.8 5.7 1.9 4.5 219.5 8.02 1.9 25.4 13.9 181.8 7.94 1.5 19.7 28.4 182.4 7.86 1.7 22.9 40.1 202.1 7.72 1.6 1.9 34.8 220.8 IZ2 RBC P and disc. Data Day Nutrient Nutrient Nutrient Influent NHx-N flow Addition Addition P04-P :P04-P L/day lg/20 L) (gg/L) (•g/L) •g/L AVERAGE 1.98 2.42 121.1 HAXIHUH 13.47 14.15 343.4 KINIHUH 0.00 0.00 -190.4 0-54 298.22 0.29 7.79 6.24 41.32 55-149 167.58 0.38 1.02 1.77 62.24 150-170 128.92 0.83 1.53 1.92 121.08 171-205 145.86 1.29 o;93 1.08 129.62 206-240 169.07 2.18 1.14 1.45 137.89 241-308 223.81 4.88 1.27 1.56 170.62 309-352 237.77 6.02 4.79 4.98 49.71 352-331 275.00 4.15 2.14 3.32 67.32 Loading Leachate NHx-N Period NHx-N Loading HRT DO Tenp Cond. Site pH P04-P NHx-N N02-N NOx-N pH days •g /L •c •S •g /L •g /L •g /L •g /L 9.6 12.2 3.48 8.16 7.78 0.60 22.70 10.07 180.8 11.6 22.5 5.12 8.70 8.22 5.70 170.0 94.30 384.0 8.1 0.0 2.03 7.70 7.06 0.00 0.04 0.00 73.7 5.24 9.3 17.0 4.66 7.96 7.37 1.29 3.56 0.06 322.7 2.25 10.4 8.4 3.42 8.00 7.66 0.89 3.07 0.25 185.1 0.80 8.2 3.12 8.22 7.92 0.31 3.02 1.43 123.5 0.65 5.8 3.13 8.36 8.05 •0.14 16.09 7.35 147.1 0.41 9.9 2.74 8.25 7.80 0.22 6.82 7.45 164.7 0.27 15.9 3.79 8.23 7.89 0.21 50.65 25.20 166.0 0.17 19.9 7.99 0.57 86.99 14.57 150.1 0.35 20.5 7.87 2.85 13.17 22.10 204.4 SbR P and Hisc. Data Day Nut. Nut. Nut. Inf. NHx-N HRT DO Teip Cond. Site pH P04-P NHx-N N02-N NOx-N MLSS HLVSS Eff flow Add. Add. P04-P :P04-P PH TSS L/day g/20 L •g/L •g/L days •g/L •C iS •g/L ig/L •g/L cg/L •g/L •g/L •g/L AVERA6E 2.8 3.0 108.5 1.45 44.1 30.2 155.0 343 181 84 HAXIHUN 8.2 8.8 847.9 11.70 325.0 199.0 318.3 2080 674 605 NINIHUH 0.0 0.3 -114 0.00 0.0 0.0 0.9 7 27 13 0-54 298 63.5 3.8 2.8 127.9 4.64 17.1 2.78 13.8 5.2 276.9 129 100 150 55-130 178 87.8 1.5 2.0 81.3 2.15 8.2 1.82 65.8 6.9 109.5 159 27 78 131-157 110 23.3 2.6 2.6 6.4 4.66 6.6 0.28 102.4 1.1 43.3 227 22 156-189 150 33.0 2.7 3.0 61.0 4.63 12.5 0.92 1.0 0.9 186.6 425 216 124 190-213 142 30.2 3.5 4.0 55.4 4.59 5.8 2.49 6.3 0.2 112.0 172 123 64 214-301 208 107 2.4 2.6 165.3 1.93 13.4 • 1.02 44.9 6.1 153.4 214 125 72 302-350 234 331 3.2 3.4 70.3 0.71 19.6 0.42 21.3 143.2 210.8 1023 600 85 351-376 251 560 3.9 5.1 36.5 0.43 22.2 1.76 180.1 88.1 93.6 855 ERR 66 Ldg. Leachate NHx-N Period NHx-N Ldg. SBR P and Misc. Data Date Day Nut. Nut. Nut. Inf. NHx-N HRT DO leap Cond. Site pH P04-P NHx-N N02-N NOx-N HLSS MLVSS Eff Eff How Add. Add. P04-P :P04-P pH TSS VSS L/day g/20 L •g/L •g/L days •g/L •c •S •g/L ig /L •g/L •g/L •g/L •g/L ag/L ig/L 08/12/93 0 40 0.3 4.7 7.25 0 22.9 0.002 197.0 100 144 08/24/93 12 40 0.3 4.7 7.78 3.1 75.2 11 205.0 142 112 08/31/93 19 40 0.5 4.7 7.03 0.23 9.8 1.7 303.7 09/02/93 21 40 4.7 0.064 22.9 245.4 09/08/93 27 0.0 40 0.0 0.7 4.7 5.8 19 4.75 7.5 7.37 4.7 0.26 0.31 318.3 142 13 09/09/93 26 0.8 40 1.6 1.3 4.6 4.4 22 5 7.4 1.708 0.196 271.9 09/10/93 29 40 4.7 2.41 0.128 263.2 09/15/93 34 4.1 40 8.2 8.8 30.3 4.5 6 16.5 4.76 7.4 7.5 5.2 1.8 1.6 309.6 146 100 17. 09/16/93 35 2.0 40 4.1 4.6 6.3 15 4.37 7.4 03/21/93 40 2.2 40 4.6 5.4 106.2 4.6 7 13 3.92 7.6 7.34 2.7 17 8.9 298.9 174 130 09/29/93 48 2.0 40 4.1 4.6 6.2 21.5 4.34 8 7.48 6.4 1.1 0.54 307.5 141 27 10/01/93.. 50 40 4.7 1.608 0.564 298.1 10/05/93 54 1.9 40 3.9 4.8 186.8 4.6 8.3 12.5 3.78 7.6 6.91. 3.2 14.2 17.4 304.4 58 605 10/12/93 61 2.6 40 2.2 3.0 347.0 1.9 4.4 16.5 5.1 7.8 7.55 2.4 103 0.1 193.1 182 46 10/19/93 68 0.0 40- 0.0 0.6 2.0 .4 14. 4.66 .7.5 7.18 0.93 55.3 310.3 248 42. 10/27/93 . 76 0.9 40 0.8 1.4 1.9 9.3 10.5 3.47 7.6 7.68 . 5.9 16.4 3.75 206.8 215 54 11/02/93 82 4.6 4u 3.3 4.3 44.9 1.3 9.7 3.25 7.7 7.13 0.29 10.9 0.62 152.6 182 29 11/05/93 65 5.0 40 4.2 4.6 -114 ^.9 6.059 6.526 156.7 11/09/33 89 0.0 40 0.0 0.3 2.0 '5.25 3.29 8.1 7.47 2.1 42.1 1.01 123.0 210 205 11/12/93 92 0.0 40 0.0 0.4 2.0 4.5 3.34 8.1 0.285 78.61 60.3 11/16/93 96 2.8 40 2.4 3.2 47.9 1.9 5.5 3.6 8.2 8.09 1.7 120 0.065 50.5 197 88 11/18/93 98 40 2.0 8 3.5 8.4 99.54 52.4 11/30/93 110 40 2.0 6 3.5 8.5 12/08/93 118 40 2.0 8 3.2 8.2 7.93 0.11 31.7 0.25 4.0 93 138 12/14/93 124 0.3 40 0.2 0.3 1.9 7.75 7.74 0.064 90.5 0.54 2.2 49 50 12/21/93 131 40 4.7 ' 3 3.76 8.5 7.98 0.15 125 0.42 1.9 52 27 52 12/23/93 133 1.5 40 3.1 3.1 7.8 4.6 3 3.85 7.75 0.12 160 0.05 0.9 01/04/94 145 40 4.7 8.5 2.72 7.91 0 112 0.39 1.3 01/05/94 146 40 4.7 6.5 2.95 86.4 251 22 01/11/94 152 1.0 40 2.1 2.1 5.0 4.6 6.5 2.66 8.8 8.19 0.48 87.6 3 169.0 01/13/94 154 40 8.5 2.71 0.515 66.1 2.1 203 01/17/94 158 40 8 2.B7 1.061 59.4 53.5 01/18/94 159 40 13 4.68 8.6 01/20/94 161 40 14.5 3.83 7.0B 828 01/24/94 165 40 16.5 5.8 699 01/25/94 166 40 15.5 7.23 8.3 01/27/94 168 0.5 40 1.0 1.3 4.6 17 6.75 0 551 284 01/28/94 169 40 4.7 15 6.02 7.7 0 545 352 02/01/94 173 1.2 40 2.5 2.5 30.1 4.6 11 5.8 7.7 8.24 0.85 0.96 0.31 513 156 02/03/94 175 40 4.7 1.431 1.209 273 172 115 71 02/08/94 180 1.6 40 3.2 3.3 75.0 4.6 11 4.67 8.78 6.32 0.92 0.13 0.079 216.1 144 50 02/09/94 181 0.0 40 0.0 0.3 4.7 11.5 3.97 8.6 1.275 0.206 174.8 315 233 02/11/94 183 2.5 40 5.1 4.5 13.5 02/13/94 185 0.0 40 0.0 4.7 12 3.3 8.1 4.3 2.3 182.3 02/14/94 186 2.5 40 5.1 5.4 49.7 4.5 13 2.345 0.048 173.8 165 108 74 55 02/15/94 187 2.4 40 4.3 4.3 29.1 4.6 11.5 3.36 8.35 0.51 0.17 0.84 185.8 219 62 02/18/94 190 1.0 40 2.1 2.3 66.6 4.6 12.5 2.75 0;94 0.029 131.0 233 139 66 36 02/21/94 193 1.3 40 2.7 3.1 66.4 4.6 5.5 3.01 1.443 0.82 123.7 224 146 62 38 02/22/94 194 2.3 40 4.6 4.6 -18.2 4.6 3.5 3.38 8.07 11.7 3.5 0.51 133.5 200 78 02/23/94 195 1.0 40 2.1 2.3 59.1 4.6 4 0.196 5.825 122.1 198 123 64 40 02/25/94 197 2.3 40 4.6 4.8 26.5 4.6 0.5 3.06 0.256 11.04 120.5 167 115 67 45 02/26/94 198 0.0 40 0.0 4.7 3 2.41 8.9 30.5 0.27 109.3 02/28/54 200 0.0 40 0.0 0.3 4.7 8.5 0.211 18.30 109.1 155 99 63 43 03/03/94 203 2.3 40 4.7 4.8 63.8 4.6 9.5 2.23 8.37 8.26 0.99 1.10.007 94.7 114 49 03/04/94 . 204 1.8 ' 40 3.7 3.3 53.6 4.6 9.5 2.32 8.4 1.773 0.102 91.9 111 72 56 35 03/07/94 207 2.4 40 4.3 5.2 43.9 4.6 3.5 2.217 0.298 96.9 178 03/08/34 208 2.5 40 5.1 5.1 125.6 4.5 8.5 7.8 7.77 3.8 1.3 0.053 109.1 158 70 SBR P and disc. Data Date Day Nut. Nut. Nut. Inf. NHx-N HRT DQ Teep Flow Add. Add. P04-P :P04-P L/day g/20 L ig/L ug/L days •g/L •c 03/10/34 210 2.5 40 5.1 5.2 44.5 4.5 8 03/14/94 214 3.0 40 6.0 6.3 36.3 4.5 9.5 03/15/94 215 2.6 40 2.2 2.3 113.4 1.9 10 03/16/94 216 3.1 40 2.6 2.8 104.1 1.9 10 03/17/94 217 2.3 40 2.0 2.1 125.3 1.9 6 03/21/94 221 2.3 40 1.9 2.1 179.2 1.9 6 03/22/94 222 2.8 40 2.4 1.9 9.5 03/23/54 223 2.8 40 2.4 2.7 123.5 1.9 6 03/24/34 224 2.8 40 2.4 2.7 847.9 1.9 8.5 03/30/94 230 2.6 40 2.3 2.5 82.8 1-9 12 03/31/94 231 2.0 40 1.7 1.8 201.2 1.9 12 04/05/94 236 2.8 40 2.4 2.4 728.4 1.9 12 04/06/94 237 2.5 40 2.1 2.3 193.2 1.9 9 04/07/94 238 2.5 40 2.1 2.4 375.7 1.9 7 04/12/94 243 2.4 40 2.0 2.1 3.6 1.9 13 04/13/94 244 2.9 40 2.5 2.8 84.6 1.9 9.5 04/14/94 245 2.5 40 2.1 2.4 85.7 1.9 9.5 04/19/34 250 40 2.0 04/20/94 251 2.5 40 2.5 2.7 83.1 1.9 17 04/21/94 252 2.5 40 2.1 2.4 68.7 1.9 13 04/26/94 257 2.6 40 2.2 2.3 98.5 1.9 14.5 04/27/94 258 2.8 40 2.4 2.6 82.2 1.9 15 04/28/94 259 2.5 40 2.1 2.4 64.1 1.9 16 05/03/94 264 2.5 40 2.1 2.2 113.8 1.9 14.5 05/04/94 265 2.3 40 1.9 2.5 98.2 1-9 14 05/05/94 266 2.5 40 2.1 2.5 108.9 1.9 14 05/10/94 271 2.5 40 2.1 2.2 301.7 1.9 16.5 05/17/94 278 2.6 40 2.2 2.3 153.6 1.9 18.5 05/18/94 273 2.4 40 2.1 2.2 147.8 1.9 16 05/19/94 280 2.5 40 2.1 2.2 124.0 1.9 20.5 05/24/94 285 2.6 40 2.2 2.3 152.1 1.9 22 05/26/94 287 2.5 40 2.1 2.1 149.4 1.9 17.5 05/30/94 291 2.5 40 2.1 2.5 108.3 1.9 15.25 05/31/94 292 2.3 40 2.0 2.1 144.5 1.9 17 06/06/94 298 2.63 80 4.5 4.7 64.3 '•3 16 06/07/94 293 2.5 80 4.3 4.4 68.4 1.9 17 06/08/94 300 2.5 80 4.3 4.4 67.3 1.9 17 06/14/94 306 2.5 160 3.1 3.2 64.4 0.7 14.5 06/17/94 309 2.4 160 3.0 3.3 70.0 0.7 20 06/21/94 313 2.7 160 3.4 3.6 56.5 0.7 22 06/24/94 316 2.33 160 .2.9 3.3 65.1 0.7 17.5 06/28/94 320 2.75 160 3.5 3.7 64.2 0.7 07/05/94 327 2.4 160 3.0 3.5 71.7 0.7 18 07/12/94 334 2.5 160 3.1 3.2 68.6 0.7 22 07/19/94 341 2.3 160 3.7 3.8 64.6 0.7 23 08/05/94 358 2.6 320 4.0 5.1 41.7 0.4 22 08/09/94 362 2.35 320 3.6 5.2 37.0 0.4 22 08/16/94 369 2.61 320 4.0 4.9 30.8 0.4 22.5 08/23/94 376 2.65 320 4.1 4.9 -1.1 0.4 21 09/01/94 385 2.6 320 4.0 5.2 56.3 0.4 20 09/07/94 391 2.6 320 4.0 5.5 -1.5 0.4 20 12-f Site pH P04-P NHx-N N02-N NOx-N HLSS HLVSS Eff Eff pH TSS VSS •g/L •g/L •g/L •g/L ag/L •g/L •g/L ag/L 2.183 0.121 117.1 220 126 54 35 1.922 0.068 136.1 164. 118.1 65. 36.1 8.2 7.84 0.88 17.3 4.7 128.7 1.19 15.22 149.7 177. 120.3 8.47 1.04 34.4 126.0 170. 108.4 57. 35.1 8.49 1.39 48.72 85.6 148. 89.5 64. 35.4 8.54 7.87 0.6 131 2.1 79.7 1.705 38.82 131. 83.4 8.7 2.53 37.13 136. 82.2 59 32.7 0.849 45.15 132.8 112. 61.7 8.09 1 46.17 126.6 163 76 7.84 2.3 95 3.55 90.6 180 55 1.869 64.16 80.6 121. 62.9 9.14 2.118 58.66 80.2 82.5 45.1 76. 39.3 8.5 8.07 0.67 170 5.1 90.7 201 61 1.372 52.6 97.7 124. 67.2 74. 42.1 1.266 70.33 84.0 209. 108.8 7.51 0.98 102 0.39 98.1 71 84 7.8 1.8 104.7 70.5 205 8.74 1.140 63.83 102.7 170. 60. 7.9 0.62 77 • ! 4 140.0 154 264 0.55 65.76 145.4 166. 106.2 8.09 0.4 51.09 171.8 169. 109.2 46. 28.1 7.94 7.73 0.43 40.5 25.2 192.2 137 56 0.511 36.41 189.4 183. 117.9 8.3 0.827 14.57 204.2 210. 133.7 58. 34.8 8.97 8.31 1.3 0.43 0.17 208.2 392 38 8.97 7.98 0.44 0.15 15.1 228.1 230 46 0.802 51.55 175.0 7.7 0.374 17.85 209.3 221. 135.1 49. 28.3 7.6 7.81 0.6 0.54 1.2 221.2 251 44 0.676 0.027 224.2 322. 203.6 64. 38.1 8.15 0.553 0.185 211.0 244 169 8.42 7.85 0.23 0.37 0.58 205.6 316 70 0.373 0.076 231.6 507. 322.2 .8.12 0.63 0.53 .1.5 252.5 565 102 0.32! 0.161 229.2 385. 247.7 77. 44.6 7.55 0.68 81.3 43.8 140.8 1050 81 0.377 0:344 200.6 1168 658.1 7.42 0.56 4.1 49.3 275.3 1080 103 1.047 67.70 244.5 702. 395.5 7.65 0.14 15.9 187 194.0 946 73 7.4 0.142 0.33 199 206.0 1064 671.6 85 7.76 0 0.68 194 223.0 1040 62 7.74 '0 0.44 186 202.0 1130 674 7.44 0.1 65.2 169 202.0 1920 63 7.56 0 48.5 19b 210.0 2080 67 7.94 0.05 88 142 143.0 965 116 8.26 2.1 276 1.3 1.3 116 8.42 4.8 27B 0 1.8 ' 7 32 8.3 3.5 325 0.007 3.3 40 51 Comparison of Different Phosphate Heasureaents Ratio Date RAU RBC SBR RAH RBC SBR Preserved Noraal Neabrane Pres/Dil Noraal Neabrane Pres/Dil Noraal Neabrane 03/09 0.076 1.007 0.391 1.637 2.592 11.606 04/13 0.332 0.208 0 0.293 1.111 0.121 1.263 1.372 0.712 0 0.108910 0.518950 05/18 0.068 0.176 0.011 6 0.239 0.048 0.37 0.802 0.644 0.0625 0.200836 0.802992 08/05 1.1 0.17 4.7 2.9 0.1 0.02 0. 154545 0.617021 0.2 08/03 1.6 0.16 5.7 2.9 0.05 0 0.1 0.508771 0 08/16 • 0.9 .0.14 1.9 1 0.05 0 0.155555 0.526315 0 08/23 0.8 0 1.5 0.8 2.1 1 0 0.533333 0.476190 09/01 1.2 0.04 1.7 0 4.8 1.6 0.033333 0 0.333333 09/07 1.5 0.1 • 1.6 0.31 3.5 1.3 0.066666 0.19375 0i371428 AVERAGE 0.085 0.397 0.230 rSAXIHUrl 0.156 0.617 0.476 N1NIHUN 0.000 0.000 0.000 OVERALL EFFLUENT AVERAGE AVERAGE 0.243 0.337 Preserved = preserved with phenyl aercuric acetate and stored for a week. Pres/Dil = diluted 1:10 or 1:20 then preserved Noraal = unpreserved, undiluted, filtered through Uhataan 334AH, aeasured iaaediately (Preserved and Pres/Dil were Hhataan 934AK filtered f irst . Neabrane = filtered through 0.45 aicro-s aeabrane f i l ter , undiluted, aeasured iaaediately Leachate TKN Date Day Alk N03-N N02-N NOx-N NHx-N TKN TKN Diss. TKN:NHx ig/L •g/L •g/L ag/L ag/L •g/L •g/L 09/15 34 2950 0.33 0.00 0.33 331 392 1.184 10/19 68 2470 0.36 0.00 0.36 273 273 1.000 11/04 84 0.66 188.68 149.51 160.26 0.792 11/04 84 0.863 171.48 168.94 167.4 0.995 11/05 85 1.276 159.76 163.44 146.38 1.023 11/12 92 1.488 158.79 183.6 157.05 1.156 11/30 110 1650 0.02 0.01 0.03 144 156 1.083 12/21 131 1700 0.03 0.00 0.03 147 151 1.027 01/25 166 1950 0.05 0.05 121 136 1.124 02/22 194 1720 0.15 0.15 0.30 132 185 1.402 03/14 214 0.448 159.68 188.66 177 1.181 03/15 215 2200 0.03 0.00 0.03 176 196 1.114 03/21 221 0.033 178.75 166.01 153.26 0.929 04/19 250 2400 0.06 0 0.06 196 218 1.112 05/1/ 278 2130 0.27 0 0.27 282 285 1.011 05/19 280 1.12 243.96 269.18 209.25 1.103 05/26 287 3.272 220.28 231.6 232.28 1.051 06/08 300 1.579 234.45 268.24 228.45 1.144 06/21 313 2580 0.03 0 0.03 263 264 1.004 07/19 241 2800 0.02 0 0.02 246 250 1.016 AVERAGE 201.3 '214.B 181.3 1.072 MAX IHUH 331.0 392.0 232.3 1.402 HIN1NUN 121.0 136.0 146.4 0.792 RBC TKN Date Day F i l l NHx TKN TKN Organic TKN: N03 N02 Time N Diss. N NHx N N Reaoved N (•in) ag/L ag/L ag/L ag/L ag/L ag/L 09/15 34 59 0.3 13.4 47.85 53.60 277 0.00 10/19 6B 29 7.2 317 0.01 11/04 84 29 0.4 10.88 8.38 28.94 11/04 84 29 15.4 11.63 9.27 1.21 0.76 11/05 85 29 11/12 92 29 76.6 96.17 84.7 7.252 1.22 11/30 110 14 12/21 131 29 2.7 9.3 -2.6 3.44 137 0.38 01/25 166 14 0.4 6.5 8.92 15.48 135 0.50 02/22 194 8 17.0 139 0.95 03/14 214 4 0.7 12.99 9.58 16.646 19.80 03/15 215 4 33.5 46.7 6.8 1.39 133 6.60 03/21 221 4 4.3 14.1 23.4 -22.58 3.32 04/19 250 2 64.3 74.5 11.8 1.16 137 4.80 05/17 278 2 65.0 68.4 -0.4 1.05 125 58.10 05/19 280 2 54.6 44.37 57.6 35.637 0.81 05/26 287 2 28.3 68.21 63.0 -28.54 2.41 06/08 300 2 37.7 51.53 56.3 19.936 1.37 06/21 313 1 142.0 176 -33 1.24 97 13.50 07/19 341 1, 121.0 129 -4 1.07 112 4.43 AVERAGE 39.2 49.5 39.1 4.3 8.6 NAxinun 142.0 176.0 84.7 47.9 53.6 HlNINUN 0.3 6.5 8.4 -33.0 0.8 SBR IKN Date Day HRT NKx TKN TKN Organic TKN: N03 N02 N Diss. N NHx N N Reaoved N days ag/L ag/L ag/L ag/L ag/L ag/L 09/15 34 4.5 1.8 22.7 40.1 12.61 308 1.6 10/19 68 4.7 20.4 255 55.3 11/04 84 1.9 11/04 84 1.9 11/05 85 1.9 6.526 13.7 14.1 -3.557 2.108 11/12 92 2.0 78.61 96.1 84.7 7.252 1.223 11/30 110 2.0 12/21 131 4.6 125 143 -14 1.144 1.5 0.42 01/25 166 02/22 194 4.6 3.5 133 0.51 03/14 214 4.5 0.068 11.5 8.46 17.538 169.2 03/15 215 1.9 17.9 31.4 6.5 1.754 124 4.7 03/21 221 1.9 48.12 61.5 79.6 -25.51 1.262 04/19 250 1.9 .102 110 14 1.078 97.7 0.39 05/17 278 1.9 0.15 6.6 -3.65 45.33 213 15.1 05/19 280 1.9 17.85 31.1 29.1 11.948 1.743 05/26287 1.9 0.02? 8.76 11.1 2.587 324.4 06/08 300 2.0 0.161 8.13 15.4 25.821 50.49 06/21 313 0.7 4.1 4.2 0.9 1.024 226 49.3 07/19 341 0.7 0.44 12.4 -7.96 26.18 16 186 AVERA6E 27.1 38.8 34.7 5.1 45.8 MAX 1 HUH 125.0 143 84.7 40.1 324.4 illNIMUrl 0.0 4.2 8.5 -25.5 1.0 NHx-N NOx Total NHx NHx NHx TKN Ret Lost Total N N. N N N :TKN N N Ldg Rea Rea Rea Rei Z Rea ag/L ag/L g/a 2 /d g/a 2 /d X g/a 2 /d Z 277 277.3 0.34 0.34 100 0.33 0.87 26.0 16 317 317.0 0.47 0.47 100 0.46 1.03 -18.6 -16 180 180.8 0.44 0.44 100 0.33 180 195.9 0.40 0.37 91 0.37 0.99 -13.1 -14 0.33 60 138.9 0.40 0.20 50 0.22 0.92 15.4 13 137 140.1 0.42 0.41 98 0.41 1.02 2.9 5 140 139.9 0.77 0.76 100 0.82 0.93 -7.3 -16 140 157.0 0.85 0.74 87 -19 176 176.3 2.25 2.24 100 2.48 0.91 0.2 -10 140 173.1 2.91 2.36 81 2.47 0.95 5.0 2 164 168.0 2.08 2.03 98 1.77 1.15 -7.1 6 142 206.1 4.40 2.96 67 3.22 0.92 0.8 -5 183 248.1 7.20 5.54 77 5.53 1.00 11.8 12 187 241.8 6.48 5.02 78 5.97 0.84 14.4 1 184 212.6 5.62 4.90 87 4.17 1.17 -7.5 5 200 237.4 5.27 4.42 84 4.87 0.91 6.9 -1 110 252.0 9.87 4.54 46 3.30 1.37 -8.3 4 116 237.4 4.33 2.20 51 2.13 1.03 1.8 3 205.5 ' 2.9 2.2 83.0 2.3 1.0 1 .5 -0.7 317.0 9.9 5.5 100 6.0 1.4 26.0 16.3 138.9 0.3 0.2 46.0 0.2 0.8 -18.6 -19 NHx-N NOx Total NHx NHx NHx TKN Rea Lost Total N N N N N :TKN N N Ldg Rea Rea Rea Rea Z Rea ag/L ag/L g/aA3/d g/aA3/d •'Z g/aA3/d Z 310 311.4 71 70 99 79 0.89 15.3 6.0 310 58 54 -21.0 97 Qfl 157 163.2 DO 82 79 96 77 1.02 -3.5 -1.4 60 138.9 81 41 50 45 0.92 15.4 13.3 74 2 126.9 31 5 15 2 4.0 13.7 134 137.0 28 27 97 -3.6 138 138.1 34 34 100 38 0.90 20.9 13.7 129 146.6 90 81 90 84 0.96 18.3 16.7 86 134.3 •92 67 73 54 1.24 11.4 24.9 98 200.0 100 48 48 55 0.87 4.6 -2.1 228 228.2 144 144 100 143 1.01" 17.7 19.1 209 227.1 125 116 83 122 0.55 11.1 7.3 224 224.2 113 113 100 114 0.99 0.8 -0.3 229 229.3 120 120 100 133 0.90 12.0 2.8 275 279.4 371 365 98 367 1.00 -5.9 -6.2 202 202.4 347 346 100 335 1.03 14.2 17.7 192.5 113.0 110.4 84.0 113.4 1.0 7.7 8.1 311.4 371.1 365.3 100 366.6 1.2 20.9 24.9 126.9 28.1 4.7 15.0 1.7 0.9 -21.0 -6 Miscellaneous Leachate Data Date Day Flow Precip. flirprt Air Te«p Te«p Conduct. Site pH pH Colour TSS NOx-N COD NHx-N P04-P B0D5 B0D:C0D Teap • 3 /day IS •c *c •c •S Units Units Units •g/L •g/L •g/L •g/L •g/L •g/L 08/12/93 0 0 0 17.6 7.4 500 70 0.32 438 305 0.31 08/24/93 12 0 0 15.7 20 7.8 700 50 0.02 413 336 0.33 08/31/93 19 346 0 15.4 20 7.2 600 60 0.26 336 293 0.52 09/08/93 27 833 0 16.6 20 7.2 800 125 0.04 407 230 0.68 09/15/93 34 854 0 13.3 17.25 7.4 850 43 0.33 392 331 0.66 37 0.09 09/21/93 40 362 0 10.5 14.5 16 5.3 7.6 7.43 1000 62 0.64 413 304 0.84 09/29/93 48 578 0 14.3 16.5 7.4 1000 50 0.08 400 289 10/05/93 54 336 1.4 11.4 16.4 14.75 6.1 7.5 7.3 600 109 0.04 385 307 0.88 10/12/93 61 956 1.5 14.6 17.5 17.5 6.34 7.6 7.9 800 58 0.63 324 299 0.73 10/15/93 68 357 0 11 16 17.5 6.04 7.5 7.5 800 56 0.36 341 273 0.58 38 0.11 10/27/93 76 1470 0 7.5 14 7.7 500 103 1.33 268 204 0.65 11/02/93 82 2095 11.5 5.3 11 12 4.6 7.5 7.2 600 74 0.68 344 191 0.39 11/09/93 89 1724 0 3.6 8 9.5 4.75 7.4 7.1 500 73 0.03 370 192 0.31 11/16/93 96 1997 0 4.3 12 11 4.72 7.3 7.2 500 82 0.63 410 190 0.80 70 0.17 11/30/93 110 2655 6.6 4.5 6 8.5 3.63 7.3 7.3 500 46 0.03 473 144 0.99 63 0.19 12/08/93 118 5192 14.7 6.4 7.5 10 3.73 7.4 7.2 400 173 0.03 299 100 0.69 12/14/93 124 6343 4.4 7.3 9 11 7.1 700 37 0.68 320 85.5 0.10 12/21/93 131 3486 0 1.6 0.5 7 4.11 7.23 7.5 500 54 0.03 295 147 0.13 37 0.13 12/29/93 133 3316 4.6 4.3 3 9 4.38 7.3 500 79 0.03 412 183 0.00 01/04/94 145 8359 13.4 8.5 8.75 9.5 2.41 7.3 200 106 3.41 289 101 0.00 01/11/94 152 5772 3 7.4 8 10 3.27 7.1 7.1 200 31 1.67 236 96 0.05 01/18/94 153 4009 0.8 5.1 6 10 4.18 7.3 7.1 150 174 0.03 280 148 0.04 01/25/94 166 3724 0 7 7.5 10.5 4.11 7.2 8.0 400 99 0.05 250 121 0.21 45 0.18 02/01/94 173 2977 0 -0.7 5 8.5 5.1 7.0 8.0 800 64 0.66 330 153 0.06 02/08/94 180 2600 1.2 -2.5 -1 5.5 5.51 7.4 7.8 800 56 0.03 330 179 0.12 02/15/94 187 4382 5.2 8.2 8 9 3.7 7.6 500 67 1.41 193 128 0.03 02/22/94 194 4353 3.2 3.3 4.5 7.5 4.4 7.4 300 50 0.30 300 132 0.05 46 0.15 03/03/94 203 10278 6.2 7.6 9.5 12 3.64 7.2 8.0 800 53 0.04 223 241 0.07 03/08/94 208 4773 0 5.2 9.5 13 7.2 7.2 600 49 0.33 300 168 0.05 03/15/94 215 3568 0.6 8.7 14 7.5 7.6 500 64 0.03 324 176 0.04 27 0.08 03/22/94 222 3011 10.6 3.8 16 7.3 7.5 550 55 0.54 257 196 0.06 03/31/94 231 2411 0 5.8 19.5 7.5 7.8 575 71 0.04 311 206 0.07 04/05/94 236 2532 1.2 8.9 14 7.5 7.6 600 53 0.05 357 200 0.04 04/12/94 243 .2415 5.4 5.6 17 7.5 7.8 600 53 0.05 308 175 0.05 04/19/94 250 2000 1.8 14.4 7.4 600 53 0.06 320 196 0.06 20 0.06 04/26/94 257 1755 1.2 12.7 7.9 550 30 0.02 361 243 0.07 05/03/94 264 1710 0 9.8 7.7 550 40 2.70 .360 243 0.06 05/10/94 271 5391 0.2 16.5 7.6 700 18 0.95 408 281 0.08 05/17/94 278 1432 0 14.2 7.9 450 107 0.27 385 282 0.04 36 0.09 05/24/94 285 1133 0 17.4 8.0 750 75 0.02 418 266 0.11 05/31/94 292 1179 4.6 •14.2 7.8 600 57 0.79 384 262 0.12 06/07/94 299 1136 0 12.6 7.8 700 308 0.00 333 257 0.14 06/14/94 306 1388 5.4 13.1 7.5 400 61 0.04 383 243 0.04 06/21/94 313 1394 0 16.9 7.5 800 10 0.03 437 263 0.19 49 0.11 06/28/94 320 1204 0 18.9 7.7 800 74 0.00 411 . 244 0.23 07/05/94 327 1496 7.7 600 48 0.00 424 241 0.00 07/12/94 334 1132 7.7 600 106 0.00 411 220 0.05 07/19/94 341 0 7.6 700 70 0.02 483 246 0.15 52 0.11 08/05/94 358 7.43 800 62 0.12 443 274 1.1 08/09/94 362 7.15 800 32 0.04 480 242 1.6 08/16/94 365 7.79 800 42 ND 448 238 0.9 08/23/94 376 7.64 800 26 0.02 465 273 0.8 09/01/94 385 7.54 800 56 0.05 532 301 1.2 09/07/94 331 6.77 800 46 0.02 146 322 1.5 MINIHUM 7 150 10 138 0.00 20 0.06 MAXIMUM 8 1000 308 483 1.10 89 0.19 AVERAGE 6 617 69 353 0.35 44 0.12 Rotating B i o l o g i c a l Contactor Organics Date Day F i l l Flow HRT COD BOD Col our COD BOD COD BOD COD BOD COD:BOD Colour TSS TSS Tiie Loading Loading Reaoval Reioval Reioval Reioval Reioval Reioval Stld (•in) L/day days iq/L •g/L •g/L g / i 2 / d g / i 2 / d g / i 2 / d g / i 2 / d Z Z Z •g/L •g/L 08/12/93 0 59 48 5.10 327 400 0.447 0.113 25.3 20.0 26 08/24/93 12 59 48 5.10 239 500 0.422 0.178 42.1 28.6 29.6 6.8 08/31/93 19 59 36 6.81 251 500 0.257 0.065 25.3 37.5 26.5 19 09/08/93 27 59 44 5.52 271 600 0.384 0.128 33.4 25.0 41 6 03/15/33 34 53 43 5.10 277 10 500 0.400 0.038 0.117 0.028 23.3 73.0 4.259 41.2 14.5 2 09/21/93 40 59 66 3.70 271 550 0.582 0.200 34.4 45.0 21.5 12.5 03/23/93 48 53 43 5.6/ 24b 500 0.368 0.140 38.0 50.0 16.5 13.5 10/05/93 54 59 48 5.10 23C 400 0.333 0.158 40.3 33.3 21.5 10.5 10/12/93 61 23 96 2.55 235 500 0.662 0.182 27.5 37.5 54 44 10/19/93 66 29 82 3.00 226 12 450 0.532 0.066 0.200 0.045 33.7 68.4 4.423 43.8 30 12 10/27/33 76 23 106 2.32 630 300 0.602 -0.813 40.0 30.5 15 11/02/93 82 29 108 2.27 199 500 0.790 0.333 42.2 16.7 19 1.5 11/09/93 89 23 118 2.08 380 1000 0.926 -0.025 -2.7 -100.0 43 7 11/16/93 96 29 91 2.69 250 19 500 0.796 0.136 0.310 0.099 39.0 72.9 3.137 0.0 33 9 11/30/93 110 14 12/08/93 118 29 130 1.83 223 400 0.824 0.210 25.4 0.0 86 43 12/14/93 124 29 130 1.89 146 300 0.882 0.480 54.4 57.1 19 7 12/21/93 131 29 134 1.82 191 43 300 0.844 0.106 0.297 -0.017 35.3 -16.2 40.0 31 16 12/29/93 133 23 110 2.22 237 350 0.968 0.411 42.5 30.0 8 8 01/04/94 145 29 115 2.13 267 150 0.708 0.054 7.6 25.0 18 01/11/94 152 14 365 0.67 162 200 1.832 0.574 31.4 0.0 22 20 01/18/94 153 14 298 0.62 143 300 1.773 0.867 48.9 -100.0 18 11 01/25/94 166 14 298 0.82 130 34 300 1.583 0.285 0.760 0.070 48.0 24.4 10.909 25.0 10 6 02/01/94 173 8 576 0.43 230 500 4.044 1.226 30.3 37.5 .28 1 02/08/94 180 8 688 0.36 240 500 4.831 1.317 27.3 37.5 15 2 02/15/34 187 8 352 0.70 198 400 1.483 -0.000 -0.0 20.0 15 3 02/22/94 194 8 304 0.81 200 33 200 1.940 0.298 0.647 0.084 33.3 28.3 7.692 33.3 65 9 03/03/34 203 8 384 0.64 121 300 1.822 0.633 45.7 62.5 32 8 03/08/94 208 4 691 0.35 244 400 4.412 0.824 18.7 33.3 29 9 03/15/94 215 4 778 0.32 255 153 320 5.360 0.447 1.142 -2.085 21.3 -466.7 36.0 46 9 03/22/94 222 4 450 0.50 236 350 '2.677 0.219 8.2 ' 36.4 45 15 03/31/94 231 4 720 0.34 288 350 4.764 0.352 7.4 39.1 113 21 04/05/94 236 4 518 0.47 249 400 3.938 1.191 30.3 33.3 38 36 04/12/94 243 2 797 0.31 242 350 5.222 1.119 21.4 41.7 40 14 04/19/94 250 2 1056 0.23 303 111 550 7.190 0.449 0.382 -2.045 5.3 -455.0 8.3 93 23 04/26/94 257 2 1680 0.15 322 500 12.904 1.394 10.8 3.1 64 22 05/03/94 264 2 1200 0.20 356 550 9.191 0.102 1.1 0.0 74 18 05/10/94 271 2 0 302 450 35.7 336 9 05/17/94 278 2 1200 0.20 370 255 500 9.830 0.919 0.383 -5.591 3.9 -608.3 -11.1 67 24 05/24/94 285 2 1248 0.20 379 400 11.099 1.036 9.3 46.7 69 16 05/31/94 232 2 1046 0.23 369 550 8.549 0.334 3.9 8.3 28 12 06/07/94 299 2 1066 0.23 410 550 7.550 -1.746 -23.1 21.4 123 29 06/14/94 306 2 1214 0.20 296 400 9.896 2.248 22.7 0.0 35 23 06/21/94 313 1 1764 0.14 398 169 650 16.401 1.839 1.464 -5.254 8.9 -285.7 16.8 49 18 06/28/94 320 1 2806 0.09 396 600 24.555 0.896 3.6 25.0 117 27 07/05/94 327 1 0 311 400 0.000 0.000 26.7 33.3 73 3 07/12/94 334 1 1325 0.18 316 500 11.585 2.678 23.1 16.7 35 6 07/19/94 341 1 828 0.30 347 198 400 8.509 0.916 2.396 -2.572 28.2 -280.8 42.3 18 9 06/05/94 353 3 720 0.34 41/ 600 6.796 0.398 5.9 25.0 183 08/09/94 362 3 641 0.38 361 550 6.544 1.622 24.6 31.3 147 08/16/94 369 3 756 0.32 371 600 7.206 1.239 17.2 25.0 118 14 08/23/94 376 3 828 0.30 448 600 6.192 0.299 3.7 25.0 221 48 09/01/94 385 3 785 0.31 489 700 8.883 0.718 3.1 12.5 192 34 09/07/94 391 3 547 0.45 466 700 1.700 -3.749 12.5 170 21 HIMHUM 121 10 150 0.00 0.04 -1.75 -5.59 -23.1 -608.3 3.1 -100.0 8.0 1.0 HAX1 HUM 630 255 1000 24.56 1.64 2.68 0.10 54.4 73.0 10.9 62.5 tt<ii44.0 AVERAGE 285 89 453 4.57 0.46 0.47 -1.90 21.2 -204.5 5.6 20.1 62.7 15.2 Activated Sludge Organics Date Day Flow HRT COD BOD Colour COD BOD' COD BOD COD BOD COD:BOD Colour Loading Loading Reioval Reioval Reioval Reioval Reioval Reioval L/day days ig/L ig/L ag/L g/i 3 /day g/t 3/day g/i 3 /day g/ i 3 /day X Z z 08/12/93 0 78 4.7 518 800 93.3 -17.0 -18.3 -60.0 08/24/93 12 78 4.7 341 600 88.0 15.3 17.4 14.3 08/31/93 19 78 4.7 326 71.6 09/08/33 27 76 4.7 284 500 66.7 26.2 30.2 37.5 09/15/93 34 78 4.5 299 0 600 83.5 7.3 15.8 7.9 23.7 100.0 2.514 29.4 03/21/93 40 78 4.6 359 600 68.0 11.5 13.1 40.0 09/29/93 4a 78 4.6 310 800 85.2 13.2 22.5 20.0 10/05/93 54 78 4.6 279 800 82.0 22.6 27.5 -33.3 10/12/93 61 187 1.9 331 600 166.0 -3.6 -2.2 25.0 10/10/33 68 187 2.0 289 70 750 174.7 13.5 26.6 -16.4 15.2 -84.2 -1.625 6.3 10/27/93 76 187 1.9 224 400 137.3 22.5 16.4 20.0 11/02/93 82 187 1.9 253 400 176.2 46.6 26.5 33.3 11/09/93 89 187 2.0 330 800 189.6 20.5 10.8 -60.0 11/16/93 96 187 1.9 300 67 800 210.1 35.3 56.4 1.5 26.8 4.3 36.667 -60.0 11/30/93 UO 187 2.0 12/08/93 118 187 2.0 266 500 153.2 5.6 3.7 -25.0 12/14/93 124 187 1.9 267 600 163.9 27.2 16.6 14.3 12/21/93 131 78 4.7 263 13 250 62.8 7.9 6.8 5.1 10.8 64.9 1.333 50.0 12/29/93 139 78 4.6 332 87.8 01/04/94 145 76 4.7 279 61.6 01/11/94 152 78 4.6 242 50.3 01/18/94 159 143 0.0 01/25/94 166 0.0 02/01/94 173 78 4.6 260 600 70.3 14.3 21.2 25.0 02/08/94 180 /8 4.6 250 400 70.3 17.0 24.2 50.0 02/15/94 187 78 4.6 235 500 42.2 -7.9 -18.7 0.0 02/22/94 194 78 4.6 260 31 150 63.9 3.8 8.5 3.2 13.3 32.6 2.667 50.0 03/03/94 203 78 4.6 179 400 47.5 9.4 19.7 50.0 03/08/94 208 78 4.5 231 500 63.9 14.7 23.0 16.7 03/15/94 215 187 1.9 253 71 166.0 13.8 36.4 -22.5 21.9 -163.0 -1.614 03/22/94 222 187 1.9 198 131.7. 30.2 23.0 03/31/94 231 187 1.9 226 450 159.3 42.5 26.7 21.7 04/05/94 236 187 1.9 257 400 182.9 51.2 28.0 33.3 04/12/94 243 187 1.9 258 350 157.8 25.6 16.2 41.7 04/19/94 250 187 2.0 303 40 550 163.9 10.2 8.7 -10.2 5.3 -100.0 -0.850 8.3 04/26/94 257 187 1.9 152 450 185.0 107.1 57.9 18.2 05/03/94 264 187 1.9 300 400 184.4 30.7 16.7 27.3 05/10/94 271 187 1.9 310 450 209.0 50.2 24.0 35.7 05/17/94 278 187 1.9 233 36 400 197.2 18.4 47.1 0.0 23.9 0.0 11.1 05/24/94 285 18/ 1.9 317 400 214.2 51.7 24.2 46.7 05/31/94 292 187 ' 1.9 263 400 196.7 62.0 31.5 33.3 06/07/94 299 187 2.0 236 550 170.6 19.0 11.1 21.4 06/14/94 306 515 0.7 335 600 540.4 -16.9 -3.1 -50.0 06/21/94 313 515 0.7 455 .94 650 616.6 63.1 -25.4 -63.5 -4.1 -91.8 0.400 18.8 06/28/94 320 515 0.7 512 600 579.9 -142.5 -24.6 25.0 07/05/94 327 515 0.7 505 600 598.2 -114.3 -19.1 0.0 07/12/94 334 515 0.7 485 700 573.3 -104.4 -18.0 -16.7 07/19/94 341 515 0.7 654 246 650 681.5 73.4 -241.3 -273.7 -35.4 -373.1 0.881 7.1 08/05/94 358 843 0.4 435 800 1023.1 -120.1 -11.7 0.0 08/09/94 362 843 0.4 453 700 1108.6 46.5 4.4 12.5 08/16/94 369 843 0.4 452 700 1034.7 -9.2 -0.9 12.5 08/23/94 376 843 0.4 461 700 1074.0 9.2 0.9 12.5 09/01/94 385 843 0.4 486 700 1228.7 106.2 8.6 12.5 09/07/94 391 843 0.4 468 800 337.2 0.0 MINIMUM 43.0 0.0 150.0 0.0 7.9 -241.3 -273.7 -35.4 -373.1 -1.625 -60.0 MAXIMUM 654.0 246.0 800.0 1023.1 73.4 107.1 7.9 57.9 100.0 36.667 50.0 AVERAGE 317.9 Mi. 7 S47.7 ?73.3 1 . 7 -SP i 11 n -BP « 9 07^  1 0 0 Leachate Total fletals - Both Data Sets Date Cr fe f'b Nn Ni Zn •g/L •g/L •g/L •g/L •g/L •g/L 09/15 ND 16.8 ND 1.07 0.041 0.1 10/19 ND 19.2 ND 1.11 0.023 0.067 11/30 ND 14.9 ND 1.03 ND 0.31 12/21 ND 17.3 ND 1.31 ND ' 0.23 01/25 ND 20.2 ND 1.54 0.023 0.2 02/22 0 14.2 0 1.48 0 0.27 03/09 0.01 19.1 0.028 0.417 03/15 0 13.8 0 1.36 0 0.07 04/13 0.U05 13 0.042 ' 0.18 04/15 0 13.4 0 1.38 0 0.062 05/17 0 14.4 0 1 0.028 0.032 05/10 0.005 18.2 0.042 0.186 Ob/21 ; 0 12.4 0 1.25 0.025 0.06 07/19 0 13.2 0.82 0.033 0.073 08/03 0.003 10.9 0.051 0.111 08/23 0 14.6 0 1.03 0.037 0.035 city di 0.03 0.03 0.06 0.003 0.025 0.015 iy dl 0.01 1 0.02 0.02 AVtKAGE 0.002 15.350 0.000 1.202 0.024 0.154 MAXIMUM 0.01 20.2 0 1.54 0.051 0.417 Hlnifiun 0 10.5 0 0.82 0 0.035 RBC Total Hetais - Botn Data bets Bate tr Fe Pb Mn Ni Zn Cr Fe Pb Hn Ni Zn Reioval Reaoval Reaoval Reaoval Reaoval Reaoval •g /L •g/L cg/L •g/L •g /L •g/L I Z Z Z Z Z 09/15 ND 3.02 ND 0.21 0.043 0.053 - 82.0 - 80.4 -4.9 47.0 10/19 ND 2.31 ND' 0.053 0.031 0.039 - 88.0 - 95.2 -6.9 41.8 11/30 12/21 ND 5.77 ND 0.36 ND 0.12 - 66.6 - 72.5 - 47.8 01/25 ND 4.44 ND 0.34 ND 0.13 - 78.0 - 77.9 >16 35.0 02/22 03/09 7 0.04 0.493 - 63.4 -42.9 -18.2 03/15 0 7.27 0 1.28 0 0.075 - 47.3 5.9 - -7.1 04/13 9.1 0.04 0.376 - 30.0 4.8 -108.9 04/19 0 11.7 0 1.46 0 0.084 - 12.7 - -5.8 - -35.5 05/17 0 11 0 1.09 0.026 0.057 - 23.6 - -9.0 7.1 38.0 05/18 19 0.05 0.199 - -4.4 -19.0 -6.5 06/21 0 9.96 0 0.65 0.031 0.072 - 19.7 - 49.6 -24.0 -20.0 07/19 0 5.85 0 0.31 0.041 0.042 - 55.7 - 62.2 -24.2 46.8 08/03 08/23 0 25.7 0 1.08 0.037 0.078 - -76.0 - -4.9 0.0 -122.9 city 0.03 0.03 O.Ob* O.003 0.025 0.015 •y di AVE u.000 3.394 U.000 0.663 0.02b 0.140 0.0 37.4 0.0 42.4 -8.5 -4.8 HAI 0 25.7 0 1.46 0.05 0.493 0.0 88.0 0.0 95.2 7.1 47.8 niN 0 2.31 0 0.053 0 0.039 0.0 -76.0 0.0 -9.0 -42.9 -122.9 SBR Total hetais - Both Data Sets Date Cr Fe Pb Nn Ni Zn Cr Fe Pb Hn Ni Zn Reaoval Reaoval Reaoval Reaoval Reaoval Reaoval ag/L ag/L ag/L •g/L ag/L •g/L Z Z X Z Z Z 09/15 ND 6.67 ND 0.96 0.043 0.11 - 60.3 - 10.3 -4.9 -10.0 10/19 NO 13.5 ND 1.03 0.032 0.59 - 29.7 - 7.2 -10.3 -780.6 11/30 12/21 ND 10.2 ND 0.22 ND 0.25 - 41.0 - 83.2 - -8.7 01/25 02/22 03/09 2.9 0.034 0.27 - 84.8 -21.4 35.3 03/15 0 10.8 0 1.23 0 0.36 - 21.7 - 9.6 - -414.3 04/13 13.9 0.036 0.1 - . -6.9 14.3 44.4 04/13 0 11.6 0 1.15 0 0.082 - 13.4 - 16.7 - -32.3 05/17 0 5.76 0 1.01 0 0.3 - 60.0 - -1.0 >12 -226.1 05/18 6.5 0.04 0.198 - 53.3 4.8 -6.5 06/21 0 11.9 0 0.98 0.029 o.n - 4.0 - 24.0 -16.0 -83.3 07/19 0 13.6 0 1.17 0.033 0.074 - -3.0 - -42.7 -18.2 6.3 08/03 08/23 0 10.3 0 0.064 0.037 0.054 - 29.5 - 93.8 0.0 -54.3 city 0.03 0.03 0.08 0.003 0.025 0.015 ay dl AVE 0.000 9.969 0.000 0.868 0.024 0.208 0.0 32.3 0.0 22.3 -4.3 -127.5 HAX 0 13.9 0 1.23 0.043 0.59 0.0 84.8 0.0 93.8 14.3 44.4 MIN 0 2.9 0 0.064 0 0.054 0.0 -6.9 0.0 -42.7 -21.4 -780.6 IttTAL AND TOXICITY DATA Note: "2" under date indicates aeasureaents on saaples left in control beakers during Daphnia LC50 tests. ' Cr Daph Totals Dissolved EC50-5 EC50-15 LC50 Date Raw Raw Raw RBC AS Raw RBC AS Rau RBC AS 03/09 0.010 12.0 80.15 88.2 13.38 45 31 18.1 100 100 2 0.010 04/13 0.005 45.4 100 100 46.6 100 100 11 100 28.5 2 (.001 05/11 0.005 50.0 100 100 50 100 100 08/03 0.009 0.012 Susan says best to say all less than 0.01. due to strange double peak response on rav saaples. Fe Daph Totals Dissolved EC50-5 EC50-15 LC50 Date Rav RBC AS Rau RBC AS Rau RBC AS Rav RBC AS Rav RBC AS 03/09 19.1 7.0 2.9 1.2 .2.0 24.8 12.0 80.15 86.2 13.38 45 31 18.1 100 100 2 10.7 4.0 4.4 ND 1.5 1.7 04/13 13.0 9.1 13.9 0.2 1.5 1.2 45.4 100 100 46.6 100 100 11 100 28.5 2 9.6 6.8 8.7 1.2 1.3 <1.0 05/11 18.2 19.0 8.5 2.8 1.8 1.1 50.0 100 100 50 100 100 08/03 10.9 0.5 Due to dilution/noise, detection l i c i t is about 1.0 igsoae saaples lover due to subtraction of non zero blank sotetiaes good reaovals no clear trend Diss less than total usually get pption no clear trend 2n Daph Totals Dissolved EC50-5 EC50-15 LC50 Date Rav RBC AS Rav RBC AS Raw RBC AS Rav RBC AS Rav RBC AS 03/09 0.417 0.493 0.270 0.018 0.232 0.728 12.0 80.15 88.2 13.38 45 31 18.1 100 100 2 0.183 0.112 0.100 0.032 0.071 0.063 04/13 0.180 0.376 0.100 0.061 0.077 0.030 45.4 100 100 46.6 100 100 11 100 28.5 2 0.033 0.251 0.033 0.054 0.100 0.020 05/11 0.186 0.138 0.198 0.028 0.038 0.033 50.0 100 100 50 100 100 06/03 0.111 0.033 Detection l ia i t = .02 (SD = 0.1) soae sig reaovals by alvays less than tot (except P) usually sig ppt'e no sig reaoval sonetiaes pptes, soaetiaes dissolves Cu Daph Totals Dissolved EC50-5 EC50-15 LC50 Date Rau RBC AS Rav RBC AS Rav RBC AS Rav RBC AS Rav RBC AS 03/03 0.010 0.013 0.048 0.117 0.501 1.013 12.0 80.15 88.2 13.38 45 31 18.1 100 100 2 0.025 0.020 0.039 0.022 0.225 0.214 04/13 (.01 0.017 0.031 0.021 0.166 0.041 45.4 100 100 46.6 100 100 II 100 28.5 2 0.013 U.013 0.012 0.020 0.035 0.034 05/11 0.017 0.022 0.032 0.029 0.332 0.036 50.0 100 100 50 100 100 08/03 0.036 0.046 13V Detection l i c i t is .01 ag/L (SD = .01 to .05) Diss saaples contaainated no s i ; reioval results probably unreliable Co Daph Totals Dissolved EC50-5 EC50-15 LC50 Date Rav RBC A5 Rav RBC AS Rav RBC AS Rau RBC AS Rav RBC AS 03/03 0.03 0.04 0.03 0.03 0.04 0.05 12.0 80.15 88.2 13.38 45 31 18.1 100 100 2 0.02 0.04 0.03 (.02 0.03 0.03 04/13 0.03 0.04 0.05 0.04 0.03 0.03 45.4 100 100 46.6 100 100 11 100 28.5 2 0.03 0.04 0.04 0.00 0.04 O.03 05/11 0.04 0.05 0.04 0.04 0.04 0.04 50.0 100 100 50 100 100 08/03 0.03 0.04 soae saaples lover due to subtraction of non zero blank Detection l ia i t is about 0.02 ag/L (SD = 0.1) diss about saae as total no sig reaovals no sig reaovals no sig precip no sig precip Cd Daph Totals Dissolved EC50-5 EC50-15 LC50 Date Rau RBC AS Rau RBC AS Rav RBC AS Rav RBC AS Rav RBC AS 03/03 0.006 0.008 0.007 0.007 0.007 0.010 12.0 80.15 88.2 13.38 45 31 18.1 100 100 2 0.004 0.008 0.007 <-004 0.006 0.008 04/13 0.006 0.008 0.007 0.006 0.003 0.006 45.4 100 100 46.6 100 100 11 100 28.5 2 0.006 0.007 0.007 0.004 0.008 0.008 05/11 0.008 0.008 0.008 0.010 0.006 0.007 50.0 100 100 50 100 100 08/03 0.006 0.008 Detection l ia i t is about 0.004 (SD of aeasureaents = 0.01 to 0.02) no sig reaoval or pptdiss saae as total no sig reioval or option \3S Ni Daph Totals Dissolved EC50-5 EC50-15 LC50 Date Rav RBC AS Rav RBC AS Rav RBC AS Raw RBC AS Rav RBC AS 03/03 0.028 0.040 0.034 0.480 0.745 1.039 12.0 80.15 88.2 13.38 45 31 18.1 100 100 2 0.022 0.038 0.028 0.079 0.330 0.900 04/13 0.042 0.040 0.036 0.044 0.130 0.063 45.4 100 100 46.6 100 100 11 100 28.5 2 0.038 0.033 0.037 0.041 0.144 0.065 05/11 0.042 0.050 0.040 0.041 0.184 0.074 50.0 100 100 50 100 100 08/03 0.051. 0.076 Detection l i c i t = .02 eg/L (SD = 0.1) no sig reaoval Diss > 1 etal probably contaainated no sig pption AHH0NIA TOXICITY DATA Total Total before after Daph Fish Total O i l / Extr. NHx NH3 NHx . NH3 Date Sample EC50-5 EC50-15 LC50 LC50 Phenol. Grease HC pH N N pH N N (X) (X) (X) (Xi (ag/L) (ag/t) (ag/L) (ag/L) 02/09 rav 20 18 12 13 ND 13 3 7.5 171.5 3.33 8.3 218.2 21.42 rbc 52 27 20 8.2 71.8 5.83 8.3 75.8 8.08 ase 100 100 100 8.4 0.2 0.03 8.6 1.5 0.30 03/09 raw 12 13 18 13 0.02 2 0.5 7.3 143.0 1.61 8.2 122.4 10.17 rbc 80 45 100 8.0 1.5 0.08 8.3 0.5 0.05 as 88 31 100 7.7 2.2 0.07 8.4 0.6 0.08 04/13 raw 45 47 11 13 0.13 ND ND 7.6 172.2 4.01 8.1 142.0 9.95 roc 100 100 100 8.1 0.1 0.01 8.5 0.3 0.04 ase 100 100 29 8.0 52.6 2.91 8.2 40.0 3.69 05/18 raw 50 50. ND 14 ND 7.5 264.2 5.13 rbc 100 100 7.9 62.5 3.03 ase 100 100 7.7 51.6 1.47 Notes: '100' indicates > 100 X ( i .e. non-toxic) "EC50-5" indicates Hicrotox EC50 aiter 5 ainutes "EC50-15" indicates Hicrotox EC50 after 15 ainutes "Total fnenol." indicates total phenolics "Total Extr. HC indicates total extractable hydrocarbons "before" indicates the beginning of Daphnia LC50 tests "after" indicates the end of Daphnia LC50 tests NH3-N = NHx-N/U + 10A(-pH)/Ka) Ka = 5.848 x 10A(-1C) (20* C) Source: £653 RAINBOW TROUT TOXICITY DATA Date LC5o NHx-N PH NH3-N Cu Zn Ni Hn fe (X) (ag/L) (ug/L) (ag/L) (ug/L) (•g/L) Ug/L) («g/L) 77/03/01 33 66 77/04/18 42 63 77/06/12 10 237 33/01/26 24 83 7.66 2.23 0.08 0.35 0.03 1.28 15.4 93/03/03 7 224 7.86 3.41 0.08 0.25 0.03 1.18 27.2 93/03/17 23 113 7.36 5.31 0.07 0.38 0.03 1.46 36.6 33/04/14 13 133 7.81 7.11 0.07 0.11 0.02 1.18 14.8 53/05/12 10 174.5 7.71 5.25 0.07 0.1 0.02 1.07 15.7 53/06/16 3 182 7.54 3.11 0.07 0.13 0.02 0.88 15.3 53/07/13 7 224 7.52 10.74 0.03 0.16 0.02 1.11 17.7 93/08/18 7 275 7.32 13.37 0.07 0.08 0.03 0.38 13.5 33/05/16 13 287 7.6 6.75 0.06 0.08 0.04 1.15 13.8 •33/10/13 12 277 7.34 13.37 53/11/19 13 160 7.73 5.04 53/12/28 13 164 7.65 4.32 54/01/27 24 57.2 7.53 1.55 54/02/05 13 171.5 7.54 3.53 54/03/03 13 144 7.7 4.24 54/04/13 13 183 7.65 5.41 54/07/13 7 222 7.56 4.77 54/12/14 13 161 7.44 2.64 Ka = 6.053E-10 (15'i) (for NHo-h Calculations) MICROTOX EC50 DATA 137 Daph Fish NHx Oate Saaple EC50-5 D-Conf EC50-15 O-Conf EC50-25 D-Conf EC50-35 D-Conf LC50 D-Conf LC50 D-Conf N 2259/N U> (Z) (Z) (Z) (Z) (Z) (Z) (Z) (Z) (Z) (Z) (Z) (•g/L) 02/09 raw 20.26 25.8 17.8 27.1 11.8 ? 13 8 171.5 13.2 rbc 51.6 49.3 27.2 15.2 20.0 16.1 71.8 31.5 ase 100 - 100 - 100 - 0.2 10966.0 03/09 raw 12.04 8.479 13.38 10.01 18.1 112.1 13 8 143.0 15.8 rbc 80.15 97 45 7 100 - 1.5 1531.5 as 88.2 28.4 31 85 100 - 2.2 1030.6 03/23 raw 49.82 99.93 50 large 162.4 13.9 rbc 100 100 0.2 10130.0 ase 100 too 38.8 58.2 asi 100 100 41.1 55.0 03/24 raw 32.95 20.9 26.93 5.71 168.6 13.4 rbc 100 100 1.3 1737.7 ase 100 100 37.1 60.8 asi 100 100 35.3 63.9 04/06 raw 7 24.4a 3.06 149.6 15.1 rbc 100 100 0.1 18825.0 ase 100 100 64.2 35.2 asi 100 100 65.8 34.3 04/07 raw 25.36 25.2 14.84 7.4 175.2 12.9 rbc 68 13 76 20 0.4 5145.8 ase 100 100 59.7 37.8 asi 100 100 65.2 34.7 04/13 raw 45.4 20 46.6 23.5 11 13 8 172.2 13.1 rbc 100 100 100 0.1 31375.0 ase 100 100 28.5 52.6 42.9 04/14 raw 44.2 39.9 25.9 174.9 12.9 rbc 77.7 57.7 90.9 150.2 47.3 47.8 ase 100 100 70.4 32.1 asi 100 100 82.3 27.5 04/20 raw 76 ? 83 7 175.5 12.9 rbc 100 100 32.2 70.2 ase-basic 63 63 104.8 21.6 ase-100 100 88.6 11 48.2 10.4 38 8.6 104.8 21.6 asi-basic 100 100 93.8 24.1 asi-100 100 100 93.8 24.1 04/21 raw 53.1 48.6 52.27 37.7 167.7 13.5 rbc 100 100 0.0 56475.0 ase-basic 91 95.5 83.8 26.9 ase-100 100 79.4 79 463 73.1 400.04 83.8 26.9 asi-basic 79 68 97.8 23.1 asi-100 100 100 89.4 105.8 69.7 40.1 97.8 23.1 05/18 raw 50 7 50 7 264.2 8.6 rbc 100 100 62.5 36.2 ase 100 100 51.6 43.8 33 66.0 34.2 Note: D-Conf" indicates 95Z confidence interval 

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