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Fixed- and real-time dairy manure treatment and experiments on digestion and phosphorus recovery Qureshi, Asif 2006

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FIXED- AND REAL-TIME DAIRY MANURE TREATMENT AND EXPERIMENTS ON DIGESTION AND PHOSPHORUS RECOVERY  by  Asif Qureshi  B.Tech., Indian Institute of Technology Kanpur, 2003  A THESIS SUBMITTED IN PARTIAL F U L F I L L M E N T OF THE REQUIRMENTS FOR THE DEGREE OF M A S T E R OF APPLIED SCIENCE in The Faculty of Graduate Studies (Civil Engineering) UNIVERSITY OF BRITISH C O L U M B I A May 2006  ©Asif Qureshi, 2006  ABSTRACT  A combined approach of biological treatment, solids digestion and nutrient recovery was tested on dairy manure. A total of three different sequencing batch reactors (SBRs) were studied. The first one, that employed mechanical mixing, was operated in three modes, in order to optimize nutrient (nitrogen and phosphorus) removals. The highest average removal efficiencies of 91% for NH -N, 59% for P0 -P and 80% for total COD were 4  4  achieved. Staining experiments suggested the coexistence of glycogen and phosphorus accumulating organisms. Anaerobic digestion of biosolids wasted from this reactor was able to produce a PO4-P concentration of 70 mg/L in the supernatant.  The second SBR employed gas-mixing, where the contents of the SBR were kept mixed by anoxic recirculation and air circulation in the anoxic and aerobic stages, respectively. The reactor showed interesting results, suggesting a relationship between nitrification and oxidation reduction potential (ORP). Little to no nitrification was observed when low ORP values of about -250 mV to -280 mV were encountered in the aerobic phase. The deterioration and re-establishment of nitrification appeared to be in relation to the ORP values being below or above ORP values, in the order of 0 mV.  The third pilot-scale SBR used real-time control strategies for controlling cycle times. It was designed to detect the end of nitrification, which coincides with the disappearance of ammonical-nitrogen (NH4-N) from the mixed liquor of the reactor. It was found that the reactor gave > 99% NH -N treatment efficiency for most of the study period, even when 4  ii  the operating conditions were not steady. The reactor, however, gave high (80-90%) orthophosphate-phosphorus (PO4-P) removals only when the feed conditions reached a relatively steady state. A pilot scale experiment, designed to recover phosphorus (as struvite, magnesium ammonium phosphate) in the supernatant obtained from acetate treatment of biosolids wasted from this SBR, was able to remove 82% of soluble PO4-P.  111  TABLE OF CONTENTS Abstract  ii  Table of Contents  iv  List of Tables  vii  List of Figures  viii  Acknowledgements  xiv  1. Introduction  1  2. Objective  6  3. Literature Review 3.1 Enhanced Biological Phosphorus Removal 3.1.1 PAO - GAO Competition 3.2 Simultaneous Nitrification and Denitrification 3.3 Previous Studies on Manure Treatment 3.4 Phosphorus Recovery as Struvite 3.4.1 Conditional Solubility Product 3.4.2 Supersaturation Ratio 3.4.3 pH  7 7 12 20 23 25 26 26 26  4. Materials and Methods 4.1. Experimental Methods 4.1.1. Manure Source 4.1.2. Mechanical Mixing SBR 4.1.3. Lab Scale Digester 4.1.4. Pilot Scale SBR 4.1.5. The P-release Tank and Struvite Crystallizer 4.1.6. Gas-Mixing SBR 4.2. Analytical Methods  29 29 29 29 31 31 33 35 37  5. Results and Discussions 5.1. Mechanical-mixing SBR 5.1.1. Mode A Soluble Chemical Oxygen Demand (s-COD) Total Organic Carbon (TOC) Ammonical Nitrogen (NH -N) Ammonia Removal and NO -N: implications for SND Orthophosphate P (P0 -P) Total Phosphorus (TP) and Total Kjeldahl Nitrogen (TKN) Track Study Profiles  38 38 38 38 43 45 47 51 54 57  4  x  4  iv  Lessons and Subsequent Modifications 5.1.2. Mode B... s-COD TOC Total Chemical Oxygen Demand (t-COD) NH -N NO -N P0 -P TP and TKN Track Study Profiles Lessons and Subsequent Modifications 5.1.3. Mode C s-COD TOC t-COD NH4-N NO -N PO4-P TP and TKN Track Study Profiles 5.1.4. Summary PAO-GAO Coexistence 5.2. Gas-mixing SBR s-COD TOC t-COD NH4-N NO -N PO4-P TP and TKN Track Study Profiles Summary 5.3. Pilot Scale SBR Summary Track Studies 5.4. Comparison of the three SBRs 5.5. Lab Scale Digester Potential for P recovery 5.6. Pilot Scale P-Recovery Experiment 4  x  4  x  x  59 59 59 61 62 64 65 67 68 70 72 72 72 73 75 76 76 78 79 84 85 87 90 90 91 93 94 96 99 100 103 105 106 119 119 123 125 125 127  6. Conclusions and Recommendations 6.1. Conclusions 6.2. Recommendations  131 131 132  7. References  134  v  Appendix A: Data for mechanical-mixing SBR  141  Appendix B: Data for gas-mixing SBR  158  Appendix C: Data for pilot-scale SBR  162  Appendix D: Data for crystallizer runs  168  vi  LIST OF TABLES Table 1.1. Nutrient balance of an average cow of 640 kg weight and producing 7760 kg of milk per year  3  Table 3.1. SND efficient and rates of nitrification and denitrification in an intermittently aerated SBR  23  Table 3.2. Phosphorus removal achieved in the UBC crystallizerfromdigester supernatant by various researchers at UBC  28  Table 4.1. Description of variations of anoxic/ anaerobic and aerobic cycle length times for the SBR  31  Table 5.1. Summary of results during mode A, mechanical-mixing SBR  85  Table 5.2. Summary of results during mode B, mechanical-mixing SBR  86  Table 5.3. Summary of results during mode C, mechanical-mixing SBR  86  Table 5.4. Summary of results for the gas-mixing SBR  105  Table 5.5. Summary of results for the pilot scale SBR  119  Table 5.6. Similarities in some basic characteristics of struvite and K-struvite  129  vii  LIST OF FIGURES Figure 1.1. A typical nitrogen budget for a Cornfieldusing manure as a fertilizer...  2  Figure 3.1. First reported excess phosphorus removal  8  Figure 3.2. Effect of aeration intensity on P uptake  8  Figure 3.3. Phoredox/ Modified Bardenpho process configuration  9  Figure 3.4. UCT process configuration  10  Figure 3.5. Acetate uptake profiles in anaerobic zone immediately after conversion from an aerobic process and after 6 weeks, in an acetate fed plant  11  Figure 3.6. Batch test results: a) control, b) glucose, c) peptone, d) acetate  14  Figure 3.7. COD and P04-P profiles of batch tests fed with acetate (a) and (c), and glucose (b) and (d) for different proportions of glucose in COD  15  Figure 3.8. P04-P concentrations in an SBR operated continuously in different pH conditions  18  Figure 3.9. Profile of substrate metabolism in an EBPR.  19  Figure 3.10. Oxygen and Nitrite/ Nitrate dynamics in an activated sludge flow with internal aerobic and anoxic zones  21  Figure 3.11. Impact of reactor DO on nitrogen species in an intermittently aerated SBR  22  Figure 3.12. An example solubility curve showing change in struvite solubility with pH  27  Figure 4.1. SBR Schematics  30  Figure 4.2. Typical parameter profiles in an anoxic-aerobic SND achieving SBR....  32  Figure 4.3. Schematics of the P-release reactor used to recover phosphorus from biosolids wasted from the pilot scale SBR  34  Figure 4.4. Basic flow diagram of the UBC pilot scale crystallizer  35  Figure 4.5. Gas-mixing SBR schematics  36  viii  Figure 5.1. Soluble-COD influent and effluent values, mode A  39  Figure 5.2. s-COD removals per cycle and s-COD removal efficiencies, mode A . . .  41  Figure 5.3. Correlation of s-COD removals per cycle with influent, mode A  41  Figure 5.4. Correlation of s-COD removals per cycle with effluent, mode A  42  Figure 5.5. Correlation of s-COD removal efficiencies with influent, mode A  42  Figure 5.6. Correlation of s-COD removal efficiencies with effluent, mode A  43  Figure 5.7. TOC influent and effluent values, mode A  44  Figure 5.8. Influent and Effluent TOC values' relation to respective s-COD values.  44  Figure 5.9. TOC removals per cycle and removal efficiencies, mode A  45  Figure 5.10. Influent and Effluent NH4-N values, mode A  46  Figure 5.11. NH4-N removals per cycle and removal efficiencies, mode A  47  Figure 5.12. Influent and Effluent NOx, mode A  48  Figure 5.13. NH -N reductions vs. NOx-N increments per cycle and corresponding SND efficiencies, mode A  50  Figure 5.14. Influent and Effluent P0 -P values, mode A  53  Figure 5.15. PO4-P removals per cycle and removal efficiencies, mode A  53  Figure 5.16. Correlation of PO4-P removals per cycle with influent P0 -P values..  54  Figure 5.17. Correlation of PO4-P removals per cycle with effluent PO4-P values..  54  Figure 5.18. Influent and Effluent TP values, mode A  55  Figure 5.19. TP removals per cycle and removal efficiencies, mode A  56  Figure 5.20. Influent and Effluent TKN values, mode A  56  Figure 5.21. TKN removals per cycle and removal efficiencies, mode A  57  Figure 5.22. Mode A NH -N, N O - N and P0 -P Track Study Profiles  58  4  4  4  4  x  4  ix  Figure 5.23. Influent and Effluent TOC values, mode B  60  Figure 5.24. s-COD removals per cycle and corresponding removal efficiencies, modeB  61  Figure 5.25. Influent and Effluent TOC values, mode B  62  Figure 5.26. TOC removals per cycle and corresponding removal efficiencies, mode B  62  Figure 5.27. Influent and Effluent t-COD values, mode B  63  Figure 5.28. t-COD removals per cycle and corresponding removal efficiencies  64  Figure 5.29. Influent and Effluent NFLj-N values, mode B  65  Figure 5.30. NFLj-N removals per cycle and corresponding removal efficiencies  65  Figure 5.31. Influent and Effluent NO -N values  66  Figure 5.32. NH -N reductions vs. NOx-N increments per cycle and corresponding SND efficiencies, mode B  66  Figure 5.33. Influent and Effluent P0 -P values, mode B  67  Figure 5.34. PO4-P removals per cycle and corresponding removal efficiencies, modeB  68  Figure 5.35. Influent and effluent TP values, mode B  69  Figure 5.36. TP removals per cycle and corresponding removal efficiencies, mode B  69  Figure 5.37. Influent and effluent TKN values, mode B  70  x  4  4  Figure 5.38. TKN removals per cycle and corresponding removal efficiencies, modeB  70  1  Figure 5.39. Mode B NH -N, N O - N and P0 -P Track Study Profiles  71  Figure 5.40. Influent and Effluent s-COD values, mode C  73  Figure 5.41. s-COD removals per cycle and corresponding removal efficiencies, mode C  73  4  x  4  x  Figure 5.42. Influent and Effluent TOC, mode C  74  Figure 5.43. TOC removals per cycle and corresponding removal efficiencies  74  Figure 5.44. Influent and effluent t-COD values, mode C  75  Figure 5.45. t-COD removals per cycle and corresponding removal efficiencies, mode C  75  Figure 5.46. Influent and Effluent NH -N values, mode C  76  Figure 5.47. NH4-N removals per cycle and corresponding removal efficiencies, mode C  77  Figure 5.48. Influent and Effluent NO -N values, mode C  77  Figure 5.49. NH -N reductions vs. NOx-N increments per cycle and corresponding SND efficiencies, mode C  78  Figure 5.50. Influent and Effluent PO4-P values, mode C  79  4  x  4  Figure 5.51. P0 -P removals per cycle and corresponding removal efficiencies, 4  mode C  79  Figure 5.52. Influent and effluent s-TP values, mode C  80  Figure 5.53. s-TP removals per cycle and corresponding removal efficiencies, mode C  80  Figure 5.54 Influent and effluent t-TP values, mode C.  81  Figure 5.55. t-TP removals per cycle and corresponding removal efficiencies, mode C  81  Figure 5.56. Influent and Effluent s-TKN values, mode C.  82  Figure 5.57. s-TKN removals per cycle and corresponding removal efficiencies, mode C  82  Figure 5.58. Influent and effluent t-TKN values, mode C  83  Figure 5.59. t-TKN removals per cycle and corresponding removal efficiencies, modeC .' Figure 5.60. Mode C NH -N, N O - N and PO4-P Track Study Profiles  83 84  4  x  xi  Figure 5.61. Results of PHA staining for intracellular PHA granules  88  Figure 5.62. Coccoid shape bacteria seen after Neisser staining  89  Figure 5.63. Bacteria showing positive Neisser staining  89  Figure 5.64. Influent and Effluent s-COD values, gas-mixing reactor  90  Figure 5.65. s-COD removals per cycle and removal efficiencies, gas-mixing reactor  91  Figure 5.66. Influent and effluent TOC, gas-mixing reactor  92  Figure 5.67. TOC removals per cycle and corresponding removal efficiencies, gasmixing reactor  92  Figure 5.68. Influent and effluent t-COD values, gas-mixing reactor  93  Figure 5.69. TOC removals per cycle and corresponding removal efficiencies, gasmixing reactor  94  Figure 5.70. Influent and effluent NH4-N, gas-mixing reactor  96  Figure 5.71. NH4-N removals per cycle and corresponding removal efficiencies, gas-mixing reactor  97  Figure 5.72. ORP pattern in the SBR during transition from nitrifying to nonnitrifying performance  97  Figure 5.73. ORP pattern in the SBR during a nitrifying performance, on 21 Augst  05  98  Figure 5.74. Influent and effluent NO -N values, gas-mixing reactor  98  Figure 5.75. Influent and effluent PO4-P values, gas-mixing reactor  99  x  Figure 5.76. PO4-P removals per cycle and corresponding removal efficiencies, gas-mixing reactor  100  Figure 5.77. Influent and effluent s-TP and t-TP values, gas-mixing reactor  101  Figure 5.78. s-TP and t-TP removals per cycle and corresponding removal efficiencies, gas-mixing reactor  101  Figure 5.79. Influent and effluent s-TKN and t-TKN values, gas-mixing reactor  102  xii  Figure 5.80. s-TKN and t-TKN removals per cycle and corresponding removal efficiencies, gas-mixing reactor  102  Figure 5.81. Track study profiles for various parameters, gas-mixing reactor  103  Figure 5.82. ORP and pH profiles for the track study in Figure 5.81  104  Figure 5.83. Influent and Effluent t-COD, pilot scale SBR  Ill  Figure 5.84. t-COD removals per cycle and corresponding removal efficiencies, pilot scale SBR  112  Figure 5.85. Influent and effluent NH -N, pilot scale SBR  113  4  Figure 5.86. NH4-N removals per cycle and corresponding removal efficiencies, pilot scale SBR  :  114  Figure 5.87. NH -N removals and effluent NO -N, pilot scale SBR  115  Figure 5.88. SND efficiencies, pilot scale SBR  116  Figure 5.89. Influent and effluent P0 -P values, pilot scale SBR  117  4  x  4  Figure 5.90. P0 -P removals per cycle and corresponding removal efficiencies, 4  pilot scale SBR  118  Figure 5.91. 8 Jul-05 track study parameter profiles for pilot scale SBR  120  Figure 5.92. 7 Oct-05 track study parameter profiles for pilot scale SBR  122  th  th  Figure 5.93. Anaerobic digester supernatant P0 -P and NH -N characteristics during the study Figure 5.94. Crystallizer effluent P0 -P and NH -N characteristics during the recovery experiment Figure 5.95. Crystallizer effluent PO4-P and NH -N characteristics during the experiment for synthetic supernatant 4  4  4  126  4  128  4  128  ACKNOWLEDGEMENTS  Working on this Master's thesis has been a great experience. However, this would not have been possible without the cooperation, support, and criticism of many people involved, directly or indirectly. Many thanks to my supervisors, Prof. K.V.Lo and Prof. D.S. Mavinic, who were available to me whenever I needed their help or guidance, especially in cases when the time frames were rather short.  Special thanks to Fred and Ping. Both of them have given me valuable inputs, and constructive criticism. Their ideas were very thought provoking. I enjoyed the field trips and outings at Agassiz, B.C and learned a lot from both while setting up the pilot plant at Agassiz.  Thanks to Paula and Susan who were invaluable to my research. Many thanks to my friends and colleagues at UBC, who have always, lend a supportive hand whenever I asked for. Thanks to Melissa, Maggie, Parvez, Wayne, Hemanth and Pattu. A special thanks to Yang. Yang helped me with sampling at the pilot plant in those hectic days, when I was running three SBRs, at different locations, at the same time. I would also like to thank Mr. Bill Kloop, and UBC Dairy Research Center, Agassiz, BC, for providing the dairy manure for this study.  Last but not the least, thanks to my family, who have been supportive throughout my life, and without whom, I could not have been able to attend IIT or UBC.  1. INTRODUCTION  Domestication and industrialization has led to a tremendous improvement in the quality of life of us humans. However, it has inevitably led to an enormous deterioration of our surroundings. We are now facing issues of air, water and soil pollution, and efforts have to be made to mitigate this adverse impact.  In any act of environmental management, a source of impact is first identified, and then strategies are devised for control of pollution from that source. The sources of pollution can be of point or non-point forms. Point-source pollution generally originates from the wastewater discharged in pipes through industrial establishments and from municipal wastewater treatment facilities. The basic sources may include domestic wastewater, storm  and  ground waters  infiltrated in the  conveyance  systems, commercial  establishments such as restaurants, and industrial facilities such as tanneries.  Non-point sources are spread over a wide area, and the extent and nature of pollutant loading depends on the particular land uses. Once the pollutant is on land, there is limited opportunity for repairing the damage to the environment. Surface run-off leads to pollution of surface waters: rivers, lakes, etc; and seepage leads to contamination of groundwater. Subsequent treatment can be very costly. A typical nitrogen budget for corn fields that use manure as a fertilizer is shown in Figure 1.1. As much as 30-70% of nitrogen can be lost to air or water, as a pollutant, e.g. dairy manure.  1  Every year, tons o f dairy manure are applied to crops in the fields, in order to take advantage o f the nutrients present. However, when the nutrients are i n excess, they find their way to various water bodies. Land spreading may lead to contamination o f receiving waters by nitrogen, phosphorus, pathogens and metals. Soon after the manure is spread, ammonia can escape into the environment. Soil microbes break down the nitrogen into simpler forms such as ammonium and nitrates, which, when in excess may migrate to the groundwater. The phosphorus content o f the soil can build up over time to a point when no additional phosphorus can be applied (without risking contamination). A t this point, the farmer must find another way to manage the manure: either to acquire more land or find other uses. Most likely, this manure ends up being a liability.  TOTAL Nitrogen Applied to Crop  300 lbs/acre  k  20.60%  mmMm \  Taken Up by Crop S y J J J E J * 5-15% Long Term Soil Storage  1 5  L  o  . s  u  3 5 %  o  A  i  r  A i r a n d  W a t e r  P o l l u t i o n  153 .5%  Lost from Root Zone  Figure 1.1. A typical nitrogen budget for a corn field using manure as a fertilizer (Chesapeake B a y Foundation, 2004)  Hofmann and K e m p (1996) estimated a production o f 132 billion kg o f manure for the year 1996. O f this, 19% o f manure was due to dairy cows. The Fraser Valley region in British Columbia is one o f the several regions i n Canada that produces manure in the excess o f 2000 kg/ hectare o f land. According to this study, cow manure contributed 16%  2  of the total nitrogen production of 783 million kilograms, and 13% of the total phosphorus production of 214 million kilograms.  A dairy cow, on an average, excretes most of its intake as waste and only a small portion of its yearly ingestion goes in the product (Table 1.1). An approach that prevents these excreted nutrients from reaching the environment must be adopted. Given the enormous amounts of nutrients, namely nitrogen (N) and phosphorus (P), it may not possible to remove the entire load by conventional biological treatment, and advanced treatment will be required. Moreover, it may be very worthwhile to reclaim these nutrients in a form that can be easily used by the farmers, and readily utilized by the plants/ crops.  Table 1.1. Nutrient balance of an average cow of 640 kg weight and producing 7760 kg of milk per year (Ministry of Agriculture and Food, B C , 1982)  Nutrient  Amount Ingested (kg/ year)  Production (kg/ year)  Amount Excreted (kg/ year)  Excretion to Ingestion ratio (%)  Nitrogen  164  48  116  71  Phosphorus  23  10  13  57  Enhanced biological phosphorus removal (EBPR) is useful in removing phosphorus amounts in excess of biological requirements; nitrogen removal will require a sequence of nitrification and denitrification/ or simultaneous nitrification and denitrification (SND). Over the past two decades, Sequencing batch reactors (SBRs) have gained significant research focus for treatment of low to high strength wastewaters. They are especially  3  useful in settings where space is limited, and offer a reasonably easy mode o f operation. The primary advantages o f S B R s have been recognized as follows:  i.  Equalization, primary and secondary clarification can be conducted in the same biological reactor,  ii.  N o chance o f short-circuiting,  iii.  Flexibility o f operation,  iv.  Reduced space requirements, and  v.  Cost savings by elimination o f clarifies, equalization tanks, etc.  More recently, it has been observed that carbon, nitrogen and phosphorus removals can all be achieved simultaneously i n an S B R (Holakoo et al,  2005). This has the  implications o f significant cost savings, since no extra carbon source w i l l be required for nitrification and denitrification (which is the case in conventional advanced wastewater treatment plants). Therefore, S B R s as such, present us with an ideal opportunity to treat the high strength wastes, while minimizing total costs.  A s far as nutrient utilization is concerned, a usable form, such as a palletized fertilizer w i l l have many advantages over manure as a source o f crop nutrients, some o f which are listed as follows:  i.  Fertilizers are more portable and easier to handle than manure, which is bulky and a nuisance,  4  ii.  Manure's nutrient content may vary over time and over different farms, making land loading control difficult, whereas a palletized fertilizer will have a known nutrient value, and  - iii.  The amount of loading can be controlled by using fertilizers.  The research work presented in this thesis attempted to combine the above-proposed approaches: manure treatment in a SBR to prevent environmental pollution, and nutrient reclamation  in  form  of  a  pelletized  or  crystal  based  fertilizer  -  struvite  (MgNH P04.6H 0). In addition, a comparison was made between lab-scale and pilot4  2  scale treatment reactors that used two different approaches of fixed-time and real-time control.  5  2. OBJECTIVES  The objectives of this thesis work were defined as:  i.  To evaluate the feasibility of sequencing batch reactor treatment of dairy manure,  ii.  To assess the nutrient removal capabilities of SBR treatment,  iii.  To analyze the nutrient content of supernatant obtained from lab scale digestion of wasted biosolids from the SBR,  iv.  To assess dairy manure treatment in a pilot scale SBR,  v.  Compare fixed- and real-time control strategies for SBR operation, and  vi.  Assess and demonstrate the application of struvite recovery, on released phosphorus, from the mixed liquor of dairy manure treatment plant.  6  3. LITERATURE REVIEW  The available literature on the topics relevant for this research is presented in the following sections 3.1, 3.2, 3.3 and 3.4.  3.1. Enhanced Biological Phosphorus Removal E B P R was first reported by Srinath et al. (1959) in India (Figure 3.1). Later, Alarcon (1961) reported rapid initial uptake o f phosphorus (P), when mixed liquor from an activated sludge process exhibiting E B P R was combined with raw sewage; and a backrelease o f phosphorus due to over-aeration. Feng (1962) found that inadequate aeration may adversely affect P uptake and may result in the release o f P in the liquor.  L e v i n and Shapiro (1965) noted that certain microorganisms were capable o f storing phosphorus Triphosphate  in poly-P  granules. Harold  (1966) suggested  the role o f  Adenosine  ( A T P ) in the poly-P mechanisms, and that the microorganisms having the  ability to store excess P had an advantage over the microorganisms that did not have this ability. Levin and Shapiro (1965) also found that P uptake was greater in batches receiving additional carbon substrate, than in control batches that received no extra carbon. In addition, they reported that P uptake was directly related to the intensity o f aeration at lower rates o f aeration, but that no improvement took place for higher rates (Figure 3.2). This finding was confirmed by Milbury et al. (1971), who stated that high P uptake was maintained i f dissolved oxygen (DO) was kept at a minimum o f 0.2 mg/L, above which there was no significant improvement in P uptake.  7  30  SS  S9  ffl  180  2W  380  360  Time in min — Rale of removal of phosphorus from sovage by activated sludge water soluble phosphorns (P); x x total phosphorus (P); 0 O min pcrmanganati; value.  Figure 3.1. First reported excess phosphorus removal (adapted from Srinath et al, i  1959)  r  Aerotien R o f e ( m u / » « c / l 5 0 0 m L ) * O-s^  I.SmM/L * u e c i n o t « + 0.5mM/L glueo«e added to »och bofeh  I  2 Time {hours}  Figure 3.2. Effect o f aeration intensity on P uptake (Levin and Shapiro, 1965)  Barnard (1976) pointed out that, in order for sludge to exhibit E B P R , it must be subjected to anaerobic conditions, such that P release occurs. H e suggested the design o f the Modified Bardenpho or Phoredox process (Figure 3.3) whereby an anaerobic zone was  8  added to the four compartments (anoxic-aerobic-anoxic-aerobic) of the Bardenpho process. The adverse effect of nitrates in the anaerobic zone to the P release mechanisms was noted.  Rabinowitz and Marais (1980) modified the Phoredox process, ensuring that no nitrates enter the anaerobic zone. They recycled the aerobic sludge and mixed liquor to the anoxic zone, and introduced an additional recycle to transfer sludge from the anoxic zone to anaerobic zone. The nitrate concentration in the anoxic and anaerobic reactors could thus be controlled by manipulating the recycle flow from aerobic reactor to the anoxic reactor. The process was termed as the 'UCT process' (Figure 3.4). Mixed Liquor Recycle Waste Flow  Anaerobic Reactor  Settler  O Influent  A Primary Anoxic Reactor  Aerobic Reactor  Secondary Anoxic Reactor  Effluent  Reaeration Reactor  Sludge Recycle  Figure 3.3. Phoredox/ Modified Bardenpho process configuration  9  Mixed Liquor Recycle  Mixed Liquor Recycle Waste Flow  Influent  Settler  Effluent •  Anaerobic Reactor  Anoxic Reactor  Aerobic Reactor  M  • Sludge Recycle  Figure 3.4. UCT process configuration Nicholls and Osborn (1979) developed a biochemical model which stated that the aerobic organisms responsible for EBPR survived in the anaerobic zone, due to their ability to store poly-P-hydroxybutyrate (PHB) in anaerobic conditions. The microorganisms stored the excess Ff produced in the oxidation of sewage as water insoluble PHB. In the aerobic +  zone, these ions are released as water in the aerobic tricarboxilic acid (TCA) cycle. Two mechanisms were identified: ATP formation from the energy derived from the breakup of poly-P chain, and the role of PHB formed as a sink for excess H and electrons. Later, +  Comeau et al. (1986) also proposed another version of a model for EBPR in which reducing power was supplied by the anaerobic operation of the TCA cycle. A different model was proposed by Aran et al. (1989), where the reducing power in the anaerobic conditions was provided by the utilization of glycogen.  The importance of a suitable substrate was stressed by Rensik et al. (1981) in their experiment, where the reactor was divided into anaerobic and aerobic compartments (5  10  each; all reactors in series), and was fed with acetate periodically. After six weeks of relatively non-existent P release/uptake and acetate uptakefromthe anaerobic zone, there was a visible acetate disappearance (Figure 3.5). Variability in the ratio of P release per unit of acetates removed has been attributed to factors such as utilization of intracellular glycogen instead of polyphosphates as a source of energy (Satoh et al., 1992) and influence of pH (Smolders et al., 1994; Chang and Hao, 1996; Jeon et al., 2001). Satoh et al. (1992) also stated that the glycogen metabolisms might be a factor leading to a deterioration of EBPR.  T — i — \ — i — r  1 2  3  4  5  REACTOR NUMBER Figure 3.5. Acetate uptake profiles in anaerobic zone immediately after conversion from an aerobic process and after 6 weeks, in an acetate fed plant (from Rensik et al., 1981)  11  3.1.1. PAO - GAO Competition  Traditionally, research has stressed that short chain fatty acids, namely acetates (common term used being volatile fatty acids, or VFAs) are responsible for triggering EBPR. Wentzel et al. (1991) suggested that carbon sources, such as glucose, are not taken up by bacteria, but are first converted to these short chain VFAs by non poly-P bacteria; the readily biodegradable portion of COD in raw sewage seldom consists of much acetate but rather simple carbohydrates and peptones. However, Carucci et al. (1994) used the same feed as by Wentzel et al. (1991) and observed dissimilar results. They used 8 L lab-scale SBR for their research, which, allowed them to study time profiles of various substrates, rather than space profiles of the continuous flow processes. They analyzed the process for two conditions of anaerobic times, with the longer anaerobic variation having a TKN/COD ratio of 17.8 (as against 9.3 for the shorter variation; total cycle length = 6 hrs) and a carbon feed of glucose + peptone. The DO was maintained at 2 mg/L in the aerobic cycle. Microorganisms in tetrad shapes of about 2pm were observed. These large coccoid cells stained Neisser positive on cell walls but negative in intracellular spaces. Cells with intracellular granules were lesser in number. The P content of the sludge was 3.5% for the first run, having a higher influent NO -N concentration. The content increased to x  4.9% with fewer influent nitrates. When the feed of glucose + peptone was modified to glucose only, the P uptake-release capacity of the plant decreased, and the P content decreased from 4.9% to 2.3% (Carucci et al, 1995). This capacity again increased when, by accident, the DO levels were very low for a period of three days (during which anaerobic conditions prevailed).  No poly-P-hydroxyalkanoate (PHA) inclusion took  place even after glucose disappearance. Their more important finding was the rapid  12  increase in PO4-P after addition of glucose, whereas the improvement with acetate addition was much lesser (Figure 3.6). They were not able to see any intracellular PHB inclusions after each test (Carucci et al, 1994).  It was concluded that their finding was not consistent with the current notion that relates acetate with proliferation of P mechanism and glucose (and GAO) with deterioration of the P mechanism. It was also concluded that competition was very high between PAOs and denitrifying organisms for substrates in the anaerobic cycle. Batch tests in Carucci et al. (1995) again revealed no intracellular PHB improvement after glucose disappearance, although the glycogen content increased with this disappearance. However, in tests with acetates as feed, there was a clear indication for correlation between acetates consumption and PHB development. Carucci et al. (1995) doubted the theory that poly-P hydrolysis was necessary to provide energy for P metabolisms. The fermentation products were not observed in anaerobic stages, and there was no anaerobic PHA production; even then, EBPR was observed. Randall et al. (1992) reported that anaerobic phase of SBRs did not acted as fermentation zones for glucose, probably because glucose was rapidly transformed to cells. Cech and Hartman (1993) observed GAOs in an SBR fed with glucose and acetates, and no EBPR was evident. A mechanism was suggested by Satoh et al. (1992) in which glycogen was used in anaerobic conditions, instead of poly-P, and PHA was synthesized without any reducing power. It was argued that, since the mechanisms had no energy deficit (on the contrary producing a net of one mole ATP), poly-P mechanisms were not required for survival, and the bacteria exhibiting this  13  mechanism will be capable of competing with PAOs for substrates in anaerobic/ aerobic systems.  Carucci et al. (1995) concluded that EBPR was possible even through glucose substrate, although possibly a large acclimization time was required with an extended period for anaerobic conditions. It seems though, that in their study, the onset of EBPR was merely by accident, where anaerobic conditions prevailed for three days; otherwise, the EBPR was absent for 5 months of continuous operation. However, it was rightly pointed out that more that one bacterium and more than one substrate might be responsible for EBPR, which, before that time, was primarily considered to be due to Acinetobacter species and acetate substrate. POvP (mgA.)  P0,-P (mgA.)  Time(h)  Time(h)  COD (mgA.)  Time (h)  Time(h)  Figure 3.6. Batch test results: a) control, b) glucose, c) peptone, d) acetate (from Carucci etal,  1994)  14  The effect of various substrate combinations on EBPR was studied by Tasli et al. (1997), who used a feed containing various proportions of Tryptone Soya Broth (TSB), glucose and acetate. It was observed that when acetate was excluded from the feed (COD maintained constant), the P removal from the system and the P content of the sludge decreased. In addition, as the glucose content of the feed increased, the P removal ability of the system decreased. When the glucose content was increased from 20% to 50% (acetate proportion was kept constant, though total COD increased when more glucose was added), the P release capacity of the system disappeared (Figure 3.7), even in batches fed with acetates.  Figure 3.7. COD and P04-P profiles of batch tests fed with acetate (a) and (c), and glucose (b) and (d) for different proportions of glucose in COD [20% in (a) and (b), and 50% in (b) and (d); P ,/COD = P eieased/COD , ] (Tasli et al, 1997) re  ut  r  uti ized  15  Cech and Hartman (1990) and Cech et al. (1993) observed that PAOs and GAOs coexisted in mixed liquor and that GAOs dominated the performance even though acetate was readily available to the biomass. However, the PAOs' domination started when acetate was made the only source of carbon.  Randall et al. (1997) studied three SBRs fed with substrate comprising of nutrient broth, yeasts, and nutrients; with two SBRs receiving doses of glucose and one receiving an equal amount of starch, for 5Vi years and reported that glucose fermentation in the feed jars prior to entering SBRs led to the production of VFAs, thus aiding in P removal. It was found that, with a 100% increase in the influent total phosphorus, significant improvement was observed in the P removal of the glucose fed reactors, whereas no EBPR was observed in the starch fed reactor. However, the systems had periods where there was no EBPR, even when the conditions were constant. These periods were of order of 100 days and 200 days for one of the glucose fed SBRs. Similar trend was observed in the other reactor, where in a period of 450 days, the P removal decreased significantly, from 18 mg/L to 7 mg/L. Bacteria Pseudomonas was identified most frequently in the glucose fed systems and was absent in starch fed system, due to the inability of Pseudomonas to hydrolyze starch. Acinetobacter was observed only once, in the starch system where no EBPR occurred throughout the study. Bacteria resembling GAOs were observed throughout the study. The authors argued that an increased activity of these bacteria might have led to the EBPR failure. In addition, they performed interesting statistical analysis, to suggest that the long-term P removal showed bounded oscillations. This implied that the population dynamics of the SBR system significantly affects the  16  performance of the system, and that this characteristic may be more obvious in SBR populations, due to constant temporal changes in the environment.  Many factors are believed to affect the kinetics and stoichiometry of EBPR. Smolders et al. (1994), for example, indicated that the ratio of P released/ HAc (acetic acid) taken up increases with an increase in pH. Romanski et al. (1997) studied the EBPR process with a view to observe its kinetics with different parameters. They were unable to find a convincing correlation between pH and P release, but found that the acetate consumption o  and P release kinetics increased with temperature in their tested range of about 12 C to 25 o  C. Liu et al. (1996) found that the acetate uptake rate increased linearly in the pH range 5.0 to 6.5, and then remained constant until 8.0, after which it started to decrease. P release rate, on the other hand increasedfrompH 5.0 to 8.0, after which it also started to decrease. Their findings regarding pH effects were partially confirmed by Filipe et al. (2001) who studied the effect of pH on anaerobic storage products and found that the stoichiometry of glycogen consumption and PHA accumulation was independent of pH in the range 6.5 to 8.0. Results obtained by Jeon et al. (2001) were, however, somewhat dissimilar to the ones obtained above. The amount of P release increased slowly at a pH of 8.0, but at a pH of 7.0 (which falls within the optimum range of the above studies), the P release disappeared. When pH control was lifted and pH reached about 8.4 in the anaerobic period, the P release picked up remarkably, and 100% P removal was obtained by the end of 30 days (Figure 3.8).  17  During the run with pH 7.0, it was found that acetate uptake occurred concurrently with glycogen consumption and PHA production. It was found that the amount of PHA produced was greater than the amount of acetate consumed. This excess production was attributed to glycogen metabolisms through glycolysis.  The P content of the sludge was  0.97% at the end of aerobic phase. The P release and glycogen decrease were 0.145 and 1.9 mM respectively, and it was inferred that the ATP and reducing equivalents required for PHA synthesis from acetates, were provided by glycogen degradation instead. The P release and glycogen consumption values changed to 2.85 mM and 0.7 mM when the pH increased to 8.4. It was inferred by the authors that, now, the required energy was derived from both poly-P and glycogen degradation.  pH 8,0  100  £  pH 8.4  j j  so Oi  pH 7.0  9  60  I  P  CL 40 Cf °-  anaerobic  p-  |  .b. 20 ^ W S J " g ) Q ^ i—,_, 0  -CD _,  SO  100  feed  C ;— 150  aerobio -TTT-, 200  2S0  fMf-^T 300  ~ 3S0  Time (day) Figure 3.8. P04-P concentrations in an SBR operated continuously in different pH conditions (Jeon et al, 2001)  Though the results regarding the effect of pH on EBPR were different by the above research, it was agreed that more energy is required to take up negatively charged ions as  18  the pH increases. That is, more poly-P degradation will be required to take up HAc (acetate ion being the negatively charged ion, CH3COO") with an increase in pH.  It appears from this review that both glycogen metabolism and poly-P metabolism may provide the energy in the anaerobic phase of a SBR. This suggests that there will be a coexistence of GAOs and PAOs, and the operational conditions will be the deciding factor for determining the dominant species. A typical profile of an EBPR sludge, with coexistence of GAOs, is illustrated in Figure 3.9.  Liu et al. (1997) studied the energy-based PAO-GAO competitions by feeding lab scale SBRs with a feed containing different P/C ratios. According to them, only a P limitation can give a valid reason for deterioration of EBPR. For example, for the reactor operating at a P/C ratio 20/100 gradually reduced to 2/100, the P composition of sludge decreased from above 12% to 2%. The authors argued that a P limitation will limit P inclusions in the cells and as a result the amount of anaerobic acetate uptake by PAOs will decrease. The growth of GAO will be promoted with eventual dominance.  Time  Figure 3.9. Profile of substrate metabolism in an EBPR (Mino et al, 1987) 19  3.2. Simultaneous Nitrification and Denitriflcation Nitrification and denitriflcation are two important steps for removal of nitrogen via conversion of ammonia to nitrogen gas. Nitrification is an autotrophic process where the relevant bacteria utilize inorganic carbon, ammonical nitrogen and oxygen to convert ammonical nitrogen to nitrates.  During denitriflcation, these nitrates are reduced to  nitrogen gas by heterotrophic bacteria, along with a utilization of organic carbon. Traditional methods of nitrogen removal have employed nitrification and denitriflcation as different steps occurring in different reaction chambers (or cells). This requires availability of an inorganic carbon source (alkalinity) in the nitrifying cell and the presence of an organic source of carbon in the denitrifying cell. While results have been satisfactory, there is the obvious disadvantage of space and carbon requirements that add to the cost of treatment.  A bypass has been discovered where nitrification and denitriflcation occurs in the same reactor, and essentially save the extra carbon requirements (Kuai and Verstraete, 1998). The concurrent occurrence of the two bioprocesses of nitrogen removal happens in conditions of low dissolved oxygen (DO) and is reported to save as much as 40% COD requirements compared to the conventional process. Turk and Mavinic (1989) have also reported high denitriflcation rates and low biomass yields for the process. Apart from chemical and technical advantages, the process has a lower energy consumption, as a result of lower oxygen requirements.  20  Dissolved Oxygen (DO) has been reported as the most important factor affecting SND removal efficiency. Under conditions of low DO, there is a mass transfer limitation in the biological floe and this creates an anoxic zone at the interior of the floe, where heterotrophs can denitrify using the nitrite that diffuses from the aerobic/anoxic divide to the center (Figure 3.10).  Figure 3.10. Oxygen and Nitrite/ Nitrate dynamics in an activated sludge flow with internal aerobic and anoxic zones (from Zeng et ai, 2003)  Zeng et al. (2003) found that the SND efficiency decreased with increasing DO. A DO of 0.5 mg/L produced negligible amounts (< 1.0 mg/L) of both NO2" or NO3", which increased as DO increased (Figure 3.11). 0.5 mg/L DO also gave the highest denitriflcation rates, along with reasonable nitrification rates, and the highest SND efficiency (Table 3.1).  N2O was identified as the major denitriflcation product. SND was postulated to occur via nitrite pathway, with an increased N2O production with increasing NO2" concentrations. Nitrogen removal was also accompanied by P uptake. In one of the earlier case studies on SND, Bertanza (1997) stressed a need for combined DO and ORP control strategies  21  for aeration control in a SND plant. He argued that ORP allows one to achieve better performance conditions, as it takes into account, along with oxygen, other parameters that affect SND: ORP is determined by 0 /OH" equilibrium as well as N0 7NH , N0 7NH +  2  3  4  2  + 4  and other similar equilibriums. He suggested optimum ORP values of 125 - 135 mV for achieving good N removal efficiencies, although it must be kept in mind that these results are for wastewaters considerably lower in strength, compared to agricultural wastewaters. DO=0Jmg/L  14 12  I>0=1.5mg/L  8  4  N(mg&)  N(mg/L) 4  Tim* (Ji) D0=2,5mg/L  N(mg/L)  Time (h) Figure 3.11. Impact of reactor DO on nitrogen species in an intermittently aerated SBR (from Zeng et al. 2003)  Helmer and Kunst (1998) reported nitrification and aerobic denitrification occurring in the same reactor at DO concentrations of 1.0 mg/L. Nitrogen loss occurred without any addition of organic substrate. It was postulated that certain heterotrophic organisms, such  22  as Thiosphaera pantrotropha or Nitrosomonus sp., might be able to nitrify and denitrify aerobically.  Table 3.1. SND efficient and rates of nitrification and denitriflcation in an intermittently aerated SBR (from Zeng et al, 2003) DO  0.5 mg/L  1.5 mg/L  2.5 mg/L  Nitrification Rate (mg-N/L/hr)  4.23  5.29  6.67  Denitriflcation Rate (mg-N/L/hr)  4.15  3.27  3.39  SND efficiency  98%  62%  51%  3.3. Previous Studies on Manure Treatment Most of the published literature using SBRs on agricultural manure has been on swine manure (Ra et al, 1997; Kim et al, 2004; Kishida et al, 2003; Maekawa et al, 1995; Liao et al, 1995; Lo et al, 2004; Chen et al, 2004; Poo et al, 2004). On the dairy side, literature published related to SBRs is mainly on dairy processing wastewater (milkprocessing industry wastewater; Goronszy, 1989; Eroglu et al, 1992; Kolarski and Nyhuis, 1995) and published researches on dairy manure (or screened dairy manure) treatment in SBR are limited. Li and Zhang (2001), for example, studied an integrated system, in which the anaerobic cycle was conducted in a different reactor, and the effluent of which was then fed to two aerated reactors. One reactor was fed continuously  23  and the other intermittently. Both aerated reactors were able to achieve high nitrogen removal (94%) although for denitriflcation additional carbon source was required. The soluble chemical oxygen demand (s-COD) and soluble total kjeldahl nitrogen (TKN) removal efficiencies were 90% and 88%, respectively. Total COD (t-COD) removal was about 60%. In addition, 30% less aeration time was required for the intermittently aerated reactor.  Whichard (2001) studied biological nitrogen removal on a dairy wastewater screened on 3 mm sieve size and demonstrated nearly 90% removal efficiency for ammonical + nitrite/ nitrate nitrogen and nearly 100% for ammonical nitrogen, for the reactor configuration used. The anoxic/ oxic SBR was fed from an anaerobically operated SBR and operated on a 24 hour cycle length. Removals of 73 - 88% for COD and nearly 80% for total suspended solids (TSS) were achieved. However, it was noted that nitrification failed several times during the study andfreshbiomass had to be added. The failure in nitrification was attributed to free ammonia inhibition at higher pH (around 8). He observed that nitrogen removal increased again when the pH was controlled below 7, along with the addition of new biomass. Reeves et a/.(http://www.ctic.purdue.edu/ Core4/nutrient/ManureMgmt/Paper33.html, last visited June 2005) however, fed their 3 L SBR with ammonia levels as high as 1700 mg/L and found very high removal rates (> 99%), at a pH between 8.8 and 9.0. They were using a high hydraulic retention time (HRT) of 10 days, which may explain the higher removal rates. It was acknowledged by them that their research was still in a startup period.  24  Lo and Liao (1995) compared the performance of a fixed film and conventional SBR and found better biochemical oxygen demand (BOD ), COD, ammonical-N and total solids 5  (TS) removals (~ 96%, 84%, 93% and 74% respectively) for a low organic loading of 0.69 g BOD /L reactor day, as compared to loadings of 1.38 and 2.45 g BOD /L reactor 5  5  day. They found that as the organic loading increased, the treatment efficiency decreased. The fixed film SBR under high loading maintained a consistent BOD removal (~ 60%), 5  whereas the conventional SBR did not give any steady performance.  The aforementioned studies have not investigated the removal of phosphorus as orthophosphates or total phosphorus (TP)fromthe wastewater in detail. Considering the possible advantages of dairy manure treatment and the presence • of high amounts of nitrogen and phosphorus, a major portion of the presented study investigated the feasibility of treatment of dairy manure in a SBR, with the aim being to study and optimize nitrogen and phosphorus removal, simultaneously.  3.4. Phosphorus Recovery as Struvite Struvite, or Magnesium Ammonium Phosphate (MgNH P0 .6H 0) has a fertilizer value 4  4  2  owing to its nitrogen and phosphorus content. A number of previous theses and papers have looked into basic and advanced concepts regarding struvite chemistry and formation (Fattah, 2004; Forrest, 2004; Huang, 2003; Britton, 2002; Adnan, 2002; Dastur, 2001).  The main factors that have been identified are conditional solubility product, temperature, pH and supersaturation ratio. An excellent coverage of the details can be found in  25  previous thesis on this topic conducted at UBC (Dastur, 2001). Only some basic concepts will be covered in this thesis, as their understanding will be essential.  3.4.1. Conditional Solubility Product  Traditional usage of solubility product K has been reported to be of less use as far as s p  struvite formation is concerned, due to the following reasons: K is accurate only for a s p  single pH and that the solubility of struvite is strongly influenced by pH. To alleviate this drawback, conditional solubility product was defined as the product of total concentrations of relevant ions, Mg , NFLt-NT and PO4 ", in the solutions, that is, P = 2+  3  s  [Mg ] 2+  .[NH -N ] +  total  4  .[P04 '] 3  total  total-  3.4.2. Supersaturation ratio  Supersaturation ratio (SSR) is defined as the ratio of conditional solubility product of a solution to the conditional solubility product of the solution at chemical equilibrium. P  Mathematically, SSR - — — . If supersaturation ratio is greater than one, then solution is supersaturated and struvite will precipitate. A SSR of 1.0 will imply equilibrium conditions and a SSR < 1.0 will mean under-saturated condition and no precipitation (Dastur, 2001).  3.4.3. p H  Crystal solubility and solution SSR is a function of pH. As can be seenfroman example result by Ohlinger (1999; Figure 3.12), the conditional solubility product of struvite at equilibrium is dependent of solution pH. Moreover, as pH increases, pP - decreases and s  eq  26  reaches a minimum value after which it starts to rise again. The point of minimum pP s  eq  is the point where most efficient precipitation can be obtained. However, the value of this pH is argued by many researchers, who have reported the value to be lower than 10; noting that those absolute values in the curve will depend on the solution in question, and only the nature and trend of the curve is reproducible.  pH  Figure 3.12. An example solubility curve showing change in struvite solubility with pH (adapted from Ohlinger, 1999)  At UBC, various researchers (Fattah, 2004; Forrest, 2004; Britton, 2002; Hui, 2003; Adnan 2002; Dastur, 2001) have studied the removal of phosphorus from digester centrate of a municipal sewage treatment plant and its recovery in the form of struvite, at pilot scale. A relatively high amount of phosphorus removal efficiency (70 - 90 %) from the centrate (both real and synthetic) were achieved. A summary of results obtained in previous research is presented in Table 3.2. Many of these studies have been able to recover this removed phosphorus in the form of visible struvite crystals, with sizes as high as 5 mm.  27  Based on these results, it was hypothesized that removal/ recovery of the phosphorus recovered from wasted solids of a SBR is possible and should be attempted. This formed the second part of this author's study. It must be mentioned at this point that, in the previous studies, the crystallizers were run on a continuous basis for a duration of several days. However, in the case of presented study, the amount of supernatant was insufficient for a continuous operation and hence the test was done on a batch basis, only.  Table 3.2. Phosphorus removal achieved in the UBC crystallizer from digester supernatant by various researchers at UBC  Researcher  Scale  Supernatant Source  Supernatant PO4-P range (mg/L)  Removal efficiency (%)  Fattah (2004)  Pilot  WWTP  40 -90  75--95  Forrest (2004)  Pilot  WWTP  10 -40  20--90  Britton (2002)  Pilot  WWTP  10 -70  40--90  Huang (2003)  Pilot  76-- 140  75 -95  Synthetic and WWTP Adnan (2002)  Pilot  Synthetic  48--220  20--98  Dastur (2001)  Bench  Synthetic  20 -80  40--90  28  4. MA TERIALS AND METHODS  4.1. Experimental Methods  4.1.1. Manure Sources  Two sources of manure were used. One manure source was a dairy farm located in Agassiz, British Columbia, Canada. Fresh manure was collected in barrels for transportation to the laboratory and then stored in buckets at 4°C.  The other manure source was from an anaerobic collection tank of another dairy farm at Agassiz. This manure was used to run a pilot scale SBR and was stored in a big storage tank near the biological nutrient removal wastewater treatment pilot plant at UBC. 4.1.2. Mechanical Mixing SBR  The setup consisted of a 14 L plexiglass reactor, to treat the screened and diluted fresh manure. The feed was prepared by diluting the manure 10 times with tap water and sieving the diluted manure through a 2 mm sieve, to remove coarse solids.  The sketch of the SBR is shown in Figure 4.1. The whole study consisted of three modes in which three variations of anoxic and anaerobic times were studied in series (Table 4.1); the last two variations were chosen based on the results of their respective preceding variations. The influent anoxic-feed time of 30 minutes, settling time of 1 hour 25  29  minutes and decant time of 5 minutes, was kept constant for all the three cycles. This gave the total cycle lengths of 12 hrs, 16 hrs and 14 hrs for study periods I, II and III, respectively. The reactor working volume was 10 L, and 2 L of wastewater was fed every cycle, resulting in HRTs of 2.5 days, 3.33 days and 2.92 days, respectively, for the three modes. The solids retention time (SRT), based on daily sludge wastage, and was controlled at 20 days. The mixed liquor suspended solids (MLSS) concentration was 8122 ± 1051 mg/L within the duration of the study, and the mixed liquor volatile suspended solids (MLVSS) concentration was 6439 ± 956 mg/L, producing a MLVSS/ MLSS ratio of 0.79 ± 0.04. Mode A lasted for 129 days (since January 2005 to April 8, 2005), mode B for about 40 days (April 9, 2005 to May 19, 2005), and mode C for 60 days (May 20, 2005 to July 20, 2005). All these durations correspond to two SRTs or more. The pH of the reactor ranged from 7.3 to 8.0.  Mixer Effluent  Feed Wastage to anaerobic digester  t  Air  Figure 4.1 SBR Schematics  30  Table 4.1. Description of variations of anoxic/ anaerobic and aerobic cycle length times for the SBR  Mode  Anoxic/ Anaerobic cycle length  Aerobic Cycle Length  A  3 hrs  7.5 hrs  B  5 hrs  9.5 hrs  C  5 hrs  7.5 hrs  4.1.3. Lab Scale Digester  500 mL of wasted sludge from SBR A was fed to an anaerobic digester every day. The digester was operated at an SRT of 40 days, at room temperature. The contents were kept completely mixed, with mixing at about 50 rpm. Initially, it was seen visually that a daily settling period of 3 to 4 hours did not remove substantial amount of solids from the supernatant. Consequently, a different philosophy was adopted. Sludge was added everyday, but decanting (and wasting) was done only after three batches (3 days) of feed. The mixer was stopped about 12-15 hours before the decanting time. This ensured better settling and more contact of the feed (the first two batches) with the digester sludge. On a larger scale process, however, this may not be necessary and centrifugation can address any solids settling problem. Sampling was done every time the supernatant was decanted until June 15, 2005 and once every week, thereafter.  4.1.4. Pilot Scale SBR  The feed was first fed to the anaerobic fermenter, at the head of the plant. From the fermenter, the feed was then pumped to the SBR during the SBR feed stage. The cycle  31  sequence in this SBR was the same as that in the lab-scale SBR: anoxic feed -> anoxic stage -> aerobic -> settle -> decant. The sludge wasting was not controlled volumetrically, but the approximate wastage per cycle was about 10 L. The feed pattern was rapid and lasted 1-3 minutes depending on the desired volumetric loading.  The cycle starts with a 1-3 minute feed depending on loading (A), followed by anoxic stage (Figure 4.2). The stage extends 15 minutes beyond the nitrate knee on the ORP curve, up to a maximum anoxic period of 75 minutes. The anoxic period is followed by aerobic stage (aeration commences at B). The airflow rate is controlled by a valve setting, so that the DO in the reactor is kept at a low value of 0.2-0.8 mg/L, in order to promote conditions for SND.  D  • P04-P • NOx-N • ORP  B Anoxic  Aerobic  -•— NH4-N -*-DO  Settle  Figure 4.2. Typical parameter profiles in an anoxic-aerobic SND achieving SBR  32  End of nitrification is detected by a DO elbow (C), which marks a sudden increase in the DO of the reactor. At this point, there is another change in the slope of the ORP curve. The program was set to continue the aeration 5 minutes past the DO elbow, to leave some residual DO in the SBR; this prevents the mixed liquor from going anoxic/ anaerobic during settling (starting at D). The first 30 seconds of decanting was recycled back to the anaerobic fermenter, to remove the low settling solids and scum, and to enhance the loading to the anaerobic fermenter. Thereafter, the effluent was decanted to the drain by gravity, until the low level was reached.  4.1.5. The P-release Tank and Struvite Crystallizer  The flow sheet of the P-release process is illustrated in Figure 4.3. The solids wasted from a pilot scale SBR treating dairy manure diluted with sewage were collected in a tank. From this tank, 70 - 75 L was transferred to the reaction tank every two days. 1000 mg/L sodium acetate was added to release the phosphorus in the solids. The contents in the reactor were mixed intermittently for 5 minutes, every 1 hour and 15 minutes. After one day, the mixer was stopped and the sludge allowed to settle without any intermittent mixing (daily wastage was not possible as settling was poor in four to five hours, and also since there was not enough sludge available everyday to fill the P-release tank completely). Then, on the second day, 40 to 45 L of supernatant was withdrawn to a separate supernatant collection tank and the remaining 30 L of solids were discharged to the drain. After about one month, when the total collected volume was about 400 L, about 200 L of collected supernatant was transferred to the crystallizer feed tank (so as to not  33  suck any solids that may have settled in the supernatant collection tank), to be tested in the crystallizer. Sodium Acetate Addition  180-liter Wasted solids collection tank 1200-liter Supernatant Collection Tank  90-liter P-release Reactor  Figure 4.3. Schematics of the P-release reactor used to recover phosphorus from biosolids wasted from the pilot scale SBR  The struvite crystallizer has been developed (since 1999) by researchers at the University of British Columbia (UBC). This crystallizer acts as a fluidized bed reactor. After 200 L of supernatant was collected, tests were done to determine PO4-P, NH4-N, suspended solids, ionic conductivity, pH and temperature of the feed. Magnesium and nitrogen source were added, based on the above-obtained results. The basic flow diagram of the crystallizer is shown in Figure 4.4.  34  Struvite Crystallizer (height: approx. 5.1 m)  400-liter Crystallizer Feed tank  54-liter Clarifier pH probe MgCI  NaOH  2  Feed Effluent  Recycle  Figure 4.4. Basic flow diagram of the UBC pilot scale crystallizer  4.1.6. Gas-Mixing SBR  No mechanical mixer was used in this SBR. In the aerobic stage, the reactor contents were kept mixed by the air supply and in the anoxic stage, contents were kept suspended by recirculating the headspace gas using a recirculation-pump (Figure 4.5). The reactor was operated at a total cycle length of 8 hrs, comprising of 10 minute anoxic feed (2.6 L per cycle), 3 hrs 15 minutes anoxic/ anaerobic react with headspace gas recirculation, 3 hrs 30 minutes of aerobic react and 15 minutes of headspace gas recirculation; this was followed by 45 minutes of settling, 10 minutes of decant and 5 minutes of idle stage durations. The 15 minutes of headspace gas recirculation, following the aerobic cycle, was done to consume as much headspace oxygen as possible, so that less oxygen is  35  present in the headspace during the anoxic/ anaerobic cycle. The air vent was 'ON' only during the aerobic cycle, to discharge the air out of the reactor.  The reactor MLSS concentration was 6137 ± 1355 mg/L and MLVSS concentration was 5674 ± 1282 mg/L, resulting in a MLVSS/ MLSS ratio of 0.92. The reactor SRT was targeted at 10 days, by wasting the appropriate amount of mixed liquor. However, there was a substantial solids loss in the effluent in the middle of the study (reasons discussed later) leading to an effective SRT of only 4.2 days for a period of about 20 days. The reactor working volume was 12 L, with 2 L of headspace. The pH of the reactor was not controlled but observed and it varied between 7.4 to 7.9, consistently.  pH  Air Vent  ORP  Effluent  = • 0 ^ 0 0 0 00  Wastage Recirculation Pump  Air Figure 4.5. Gas-mixing SBR schematics  36  4.2. Analytical Methods The influent and effluent from the SBR was monitored for COD, NO -N (=N0 -N+N0 " x  2  3  N), NH4-N, PO4-P, TP and TKN, about 3 to 6 times a week. Other parameters measured about once a week were influent TSS, MLSS and MLVSS. All the parameters except total COD and TSS/VSS, were analyzed for soluble fractions after filtering through a 0.45 um size membrane filter. Analyses were conducted in accordance with Standard Methods (APHA, 1995). Also, DO, pH and ORP profiles were monitored initially in the SBR, but due to electrical interference from the mechanical mixer, improper functioning of the probes was experienced, resulting in a suspension of their continuous use.  37  5. RESULTS AND DISCUSSIONS  5.1. Mechanical-Mixing SBR Different trial modes were studied. The alternative sequence of anoxic and aerobic conditions for the first trial yielded a mixed performance of the reactor in terms of COD, NH -N and PO4-P removal. The results are presented in the following sections. 4  5.1.1. Mode A  Soluble Chemical Oxygen Demand (s-COD)  To determine a trend in the values and remove the daily variability of treatment, a moving average, defined as the average of the value for that particular day and two previous days was used, and was plotted as continuous lines. The COD removals of the reactor are shown in Figure 5.1. The treatment appears to be stable and consistent over the duration of this mode. From January 29 2005 to February 5 2005, the SBR was run th  th  on feed from an anaerobic pit, where the farmers used to store the manure, as the fresh manure was exhausted. This manure, due to field constraints, was taken from the top portion of the pond and contained large quantities of straws and corns (visual observations only). The manure, after dilution and screening was relatively lower in strength, with the influent s-COD ranging from 1020 - 1260 mg/L. The effluent, however, remained near the higher side of the previous values, ranging 790 - 840 mg/L. After that,  38  the influent s-COD values had been consistent and ranged from 2600 to 3000 mg/L. From about 27 February 2005, the influent s-COD strength decreased to the range of th  1800 - 2400 mg/L. These sudden changes in ranges are a reflection of the preparation of feed batches from different/ same buckets in the fridge at different times. Some loss of COD, via biological activity was expected, even at 4°C.  8000 -i 7000 --  E  •  4000  Influent s-COD  •  Effluent s-COD  •A— Influent moving average  6000 =5, 5000 -I  •  -©— Effluent Moving Average  •  Figure 5.1. Soluble-COD influent and effluent values, mode A  The absolute removal or removal per cycle was initially highly variable, probably due to population acclimation issues, but later showed consistent trends (Figure 5.2) after the new feed was added on February 6 , 2005. The removal efficiency also showed similar th  consistency. Also, there was a small decreasing trend from February 10 , 2005 to 23 th  rd  February, 2005, with efficiencies decreasing from 67% to 58%. However, the efficiency rose again, to 68% by first week of March 2005. After a small dip in the second week, the efficiency increased again, to about 76% by March 22, 2005. Thereafter, the values  39  marginally decreased to about 68% - 70%. It was not so evident from visual analyses whether the changes in removal efficiency were a reflection of an increased absolute removal (due to a better quality effluent) or a stable effluent, with a more concentrated influent, thus translating to a higher removal efficiency. As such, regression analyses were undertaken.  From Figures 5.3 and 5.4, it appears that there is a good correlation (coefficient of correlation, R = 0.8508) between absolute removal and influent values, but very poor 2  correlation (R = 0.0817) exists between absolute removal and effluent values. This 2  suggests that the SBR was capable of producing a relatively stable effluent, in terms of soluble substrate, even if there were fluctuations in the influent values. This is in conformity with the 'equalization effect' of SBRs.  f  The removal efficiency is given by R%  Influent - Effluent ^ Q Q ^ X  Influent r x  V  _ Effluent^ Influent  xlOO  From the above equation, we see that higher removal efficiency may be the result of a better quality effluent, or a more concentrated influent, or a combination of both. Data analyses suggest that the removal efficiency was weakly correlated to both influent and effluent values (Figure 5.5 and 5.6). This may be due to the fact the both influent and effluent changed everyday, as opposed to one being constant and the other changing.  40  S  s-COD removal per cycle  Day  Figure 5.2. s-COD removals per cycle and s-COD removal efficiencies, mode A  Influent s-COD (mg/L)  Figure 5.3. Correlation of s-COD removals per cycle with influent, mode A  41  7000 6000  u u 0) Q. re  5000 „  4000 J  II  3000 2^,  a o o .3.000  Effluent s-COD (mg/L)  Figure 5.4. Correlation of s-COD removals per cycle with effluent, mode A  Figure 5.5. Correlation of s-COD removal efficiencies with influent, mode A  The information obtained from removal efficiency analyses is not so forthcoming, as compared to the information obtained from absolute removal analyses, which distinctly showed that the system was capable of delivering a relatively stable effluent, and an increase in loading was countered by an increase in substrate removals, for this trial mode.  42  100  T  80 -  >,  O c  60 -  tfc LU  20 -  o  0 -  . 2 o 40 -  Rem  H >  -20  |  -40 --  Effluent s-COD (mg/L)  Figure 5.6. Correlation of s-COD removal efficiencies with effluent, mode A  Total Organic Carbon (TOC)  Influent TOC values were as high as 1500 mg/L in the first two weeks of sampling, after which they reduced to between 400 and 600 mg/L (Figure 5.7). This change in concentration was not related to the change in the feed. In addition, the TOC values for this whole mode showed no relation to the s-COD of the influent. The correlation between influent s-COD values and influent TOC values was very weak (Figure 5.8). Similarly, the effluent TOC values were not correlated to the effluent s-COD values (Figure 5.8).  The removal efficiencies and removals per cycle are shown in Figure 5.9. For the entire mode as a whole, the removal efficiencies were 57.5 ± 14.0% and in steady state, the SBR was able to remove ~ 300 mg/L of TOC from the influent.  43  2000 1800 1600 1400 1200 E 1000 o 800 o 600 400 200 0 <ep'  •  Influent  •  Effluent  -A— Influent moving average -o— Effluent Moving Average *—A__ A \  •  +  -  A  • \  •  • • ^ £4-  o o • _r> B  0  •  -it—A—a» §  Q  —ESI Q =  A  ^  A^—A  ^  •  n  A—A  •  C*  m B  jjjj  1  ^  ^  A .  A  — KB nm —s  i  ^  .  A.  D  M  ©  1  y  ^ '  Figure 5.7. TOC influent and effluent values, mode A  120  3o>00  w  R = 0.064 2  •§•80 U  2 60  •  t 20 1000  2000  3000  4000  •  •  LU  Influent s-COD values (mg/L)  •  500  1000  1500  Effluent s-COD (mg/L)  Figure 5.8. Influent and Effluent TOC values' relation to respective s-COD values  44  • T O C removal per cycle -©—TOC removal per cycle moving average • Removal Efficiency - A — R e m o v a l Efficiency moving average  1600 1400  90  ~  N>' Day &  Figure 5.9. TOC removals per cycle and removal efficiencies, mode A  Ammonical Nitrogen (NH4-N)  The influent and effluent NH4-N values are shown in Figure 5.10. Until February 4 , th  2004, the influent NH4-N values were generally near the value of 200 mg/L, while the effluent NH -N was near the 150 mg/L mark. Between, January 18 to January 20 , the th  th  4  effluent values decreased considerably to about 10 mg/L, co-current with a drop of - 40 mg/L to the reactor from January 18 through January 20 , 2005. After a moderate th  th  period of low loading, bio-activity rose and larger quantities of ammonia in the loading were removed through nitrification and denitrification. It was seen that the removal efficiencies, from January 20 to February 10 (2005), were very high, about 90-95% th  th  (Figure 5.11). The absolute NH4-N removals were higher, compared to the rest of the period, and were about 100-200 mg/L. Apart from this period, the removals were always between 40-70 mg/L. The removal efficiencies were again higher in the period 3-10 March, although examination of removals per cycle indicates that there was no  45  improvement in the performance; rather, the influent concentration was lower than before. Confirmation is seen in the influent and effluent values (Figure 5.10), where the effluent values followed the same trend as the influent values in the latter part of the test period (after about 10 Feb-05). th  The relationship for SBR effectiveness, in terms of absolute removal, shows no significant correlation with either influent or effluent, meaning that the SBR did not produce a very stable effluent, regardless of the influent. This characteristic is expected, since the bacteria will only be able to remove a fixed amount of NH4-N, given the limited duration of aeration time. In a steady-state mode, the ammonia utilization rate of bacteria will be relatively constant; for a given air supply for a given period of time, the amount of absolute removal will be limited and bounded. This is exactly what was observed from the start of the experiment until about 20 Jan, 2005, and then again, from 20 Feb, 2005 th  th  until the end of this trial mode.  Figure 5.10. Influent and Effluent NH -N values, mode A 4  46  a Removal —o— Removal • Removal —A— Removal  250  >,  200  I  150  u  per Cycle per Cycle Moving Average Efficiency Efficiency Moving Average L 10O  re _ i  50 -H  Figure 5.11. NH -N removals per cycle and removal efficiencies, mode A 4  Ammonia Removal and nitrite/nitrates: implications for SND  Influent and effluent NOx-N values are shown in Figure 5.12. For the most part, the effluent values were not exceedingly high, usually maintaining values less that 10 mg/L after 8 Feb-05. However, in the period 15 Jan to 31 Jan-05, the effluent NO -N was th  th  st  x  predominantly above 15 mg/L. In order to assess the effect of SND, a modification of the definition of SND efficiency proposed by Zeng et al. (2003) was used. The original definition was given as, Efficiency  SND  =  Denitriflcation  _ NH (total) - NO 4  (accumulated)  x  Nitrification  NH (total) 4  Where: NH (total) was the concentration of NH -N at the onset of aerobic stage in the 4  4  mixed liquor and NO (accumulated) was the amount of NO -N appearing at a point when x  x  NH -N was depleted to zero concentration. Since the NH -N removal was 100% in their 4  4  47  experiments, the nitrification (inc. assimilation) accounted for the entire NH -N load. 4  Also, their calculations were based on three track studies only.  o> 5 0  Figure 5.12. Influent and Effluent NOx, mode A  In this thesis, a modified equation was used, which gives a rough estimate of SND efficiency from the influent and effluent NH -N, and effluent NO -N values. In the SBR 4  x  used in presented work, the effluent NH4-N was seldom 0 mg/L. Hence, the amount of NH4-N removed in the aerobic phase of each cycle was estimated as: NH4-N (removed) = {(2*[NH4-N] ent+8*[NH4-N]effl ent influ  U  -previous_cycle )/10}-[NH -N]efnuent -current_cycle4  For example, consider that NH4-N concentration at the end of any cycle was 10 mg/L. Out of the 10 L working volume, 2 L is decanted, so, 8 L of mixed liquor with an NH4-N concentration of 10 mg/L is left. In the next cycle, 2 L of influent, say with 30 mg/L of NH4-N, is added to the SBR. The resulting mixed liquor NH4-N concentration  48  , , 2x30 + 8x10 , . . , , _ __ will then be = 14 mg/L. It is assumed that N H 4 - N concentration remains /T  T  T  2+ 8 constant in the anoxic zone, and that there will be no NO -N present by the end of anoxic x  phase (i.e., complete denitrification in anoxic phase is assumed). If these assumptions hold, at the onset of the aerobic phase, the NH4-N concentration will be 14 mg/L and NOx-N concentration will be 0 mg/L. Suppose, at the end of aerobic phase, the NH4-N concentration is 4 mg/L and the NO -N concentration is 6 mg/L. These will be the NH -N x  4  and NO -N concentrations in the effluent, assuming no biological activity in the settling x  phase. So, out of 10 mg/L NH -N removed, 6 mg/L was converted to NO -N and the rest 4  x  (4 mg/L) was lost as a product of SND (probably N2O). Thus, the estimated SND (14-4)_6 efficiency will be — — — x l 0 0 = 40%. This (approximate) equation is used in the estimation of SND efficiency in this study. It must be kept in mind that the values will be approximate, as in some cases, some biological activity in the settling phase (leading to denitrification) is possible, giving higher than actual estimates of SND efficiency. On the other hand, if some organic nitrogen was hydrolyzed to ammonia in anoxic zone, a lower value will be estimated, using this equation. In case of a break in the sampling days, it was assumed that the effluent concentrations have not changed during the sampling break. This assumption will be particularly weak for long time intervals; however, for intervals of 1-3 day, such events of erratic behaviour are less likely to be missed. Thus, the SND efficiency values obtained should be only used as a rough estimate or indicator and not as a rigorous measure of SND, insitu.  49  As noted in Figure 5.13, the SND behaviour of the SBR was erratic in the initial period. It decreased from > 95% in the second week of Jan-05 to 43.6% by 28 Jan-05. However, th  when fresh new feed was used, after 5 Feb-05, the SND efficiency increased to the ~ th  90% level. The period 4 -19 Mar-05 saw much variation in SND efficiency, after which th  th  high efficiencies of > 90% were achieved.  m— N O x Increment — N H 4 - N reduction  Figure 5.13. NH -N reductions vs. NOx-N increments per cycle and corresponding SND efficiencies, mode A 4  Overall, the SND efficiency in this mode was 53.7 ± 103.3%. The large range was due to the fact that few values of SND efficiencies were < -300%. A negative SND efficiency can imply two causes: (a) excessive NO -N from the previous cycle, leading to x  incomplete denitrification and a consequent overestimation of NO -N production in the x  aeration phase, and (b) failure of nitrification, accompanied by incomplete denitrification in anoxic stage. If nitrification fails in a particular cycle, it will lead to a buildup of NH 4  N in the reactor; and, if there is relatively high NO -N in the SBR, a negative result will x  50  be obtained. Therefore, both reasoning imply some degree of incomplete denitriflcation. Basically, it characterizes a stage when the assumptions made for SND efficiency calculations are no longer valid. It is likely that these negative efficiencies will occur on days succeeding the days with higher than normal effluent NO -N values. One such x  example of cause (a) is the case of 18 Jan-05, where two values of -17.1 % and -399.0 th  % are measured on duplicates. Such low values of SND efficiency match with relatively higher NO -N values of 45.2 and 46.3 mg/L. While exorbitantly negative values may be x  an exaggeration, indication of incomplete denitriflcation can be inferred when SND efficiencies are negative. An example of cause (b) is on 11 Feb-05, where there appears th  to be a case of failed or severely compromised nitrification. The amount of NO -N from x  the previous day was only 4.36 mg/L, and the effluent NH -N was 9.28 mg/L. On 11  th  4  Feb-05, the influent NH -N was 133.6 mg/L. The combined mixed liquor concentration 4  will thus be (8*9.28 + 2*133.6)/10 = 34.1 mg/L. The effluent NH -N on this day was 4  33.7 mg/L. Thus, there was only a possible net reduction of 0.42 mg/L of NH -N. Given 4  that the effluent NO -N was 2.7 mg/L, on the assumption that denitriflcation was x  complete, little NH -N removal indicates a severely compromised nitrification process on 4  that date.  Orthophosphate P (PO4-P)  Figures 5.14 and 5.15 show the trends in influent and effluent P0 -P values and the 4  corresponding absolute mass removals and removal efficiencies. The initial removals after commencement of sampling were about 14-16 mg/L, with effluent P0 -P values of 4  51  12-15 mg/L. There was a sudden failure in PO4-P removal on January 27, 2005 when the removal per cycle values reached a low of 1.6 mg/L to 0.4 mg/L. It is interesting to note that the effluent values remained at the previous levels of ~14-19 mg/L, even though it was a case of influent PO4-P decreasing from 30-35 mg/L to 14-22 mg/L. Thus, a reduction in influent PO4-P concentration actually appeared to affect the P removal ability of the reactor. The period of time from the end of Jan-first week Feb 2005, was also one where a different feed source was used. This change in substrate composition, as well as substrate concentration, may have led to deterioration in the P removal process. When the influent PO4-P values again increased to above 30 mg/L, after 14 Feb-05, the th  effluent concentration remained nearly the same as before, and the removals per cycle increased again. This demonstrated the ability of the SBR to achieve relatively stable P0 -P levels in the effluent. Even with influent PO4-P values as high as 55 mg/L, the 4  effluent quality was not compromised. It is also possible that a high phosphorus loading, in fact, increased P removal efficiency, as is sometimes the case in EBPR processes. For example, it was pointed by Yagci et al. (2003) that the phosphorus releasing capacity of the biomass increased when the influent phosphorus concentration was increased, for a constant COD.  The period 8-12 March 2005 was another low performance period. Again, in this period there was a low influent loading observed. When the influent PO4-P increased above 40 mg/L, the effluent values actually decreased, to nearly 10-11 mg/L. That is, an improved performance was observed with increased phosphorus loading. It must also be noted, that  52  there was no corresponding increase in s-COD (the carbon substrate), when there was an increase in influent PO4-P.  P 0 4 - P removal per Cycle • P 0 4 - P Removal per Cycle Removal Efficiency • Removal Efficiency moving average  95  4  -1  qf>  y tf> ^  y  Da7  ^  ^  0/  9?  Figure 5.15. PO4-P removals per cycle and removal efficiencies, mode A  A strong correlation between absolute P0 -P removals and influent concentration 4  (rr>o.9) was observed, whereas there was a very weak correlation with effluent values  53  (Figures 5.16 and 5.17). This confirms the observation that there was increased removal performance, with an increasing influent PO4-P concentration.  U)  E u >« u o Q.  ">5 o E  O a.  -100 Influent P04-P (mg/L)  Figure 5.16. Correlation of PO4-P removals per cycle with influent PO4-P values  Effluent P 0 4 - P (mg/L)  Figure 5.17. Correlation of PO4-P removals per cycle with effluent PO4-P values  Total Phosphorus (TP) and Total Kjeldahl Nitrogen (TKN)  The values for TP and TKN were assessed for the soluble portions, only in this mode. The results are graphically presented in Figures 5.18 to 5.21. TP values show a similar trend, as P0 -P values. The average influent TP value was 38.1 ± 19.8 mg/L and the 4  54  effluent was 17.3 ± 6.7 mg/L. It can be recalled that the influent and effluent PO4-P values were 37.0 ± 13.8 mg/L and 16.6 ± 4.7 mg/L, respectively. It appears that the majority of soluble TP, was in fact, in the form of orthophosphates. The TP removal efficiency and mass removal per cycle were 45.5 ± 27.4% and 20.8 ± 17.4 mg/L, respectively. The daily variations of removals per cycle and removal efficiencies are shown in Figure 5.19. TKN influent and effluent concentrations and corresponding efficiencies are shown in Figure 5.20 and 5.21. The influent, effluent, removal per cycle and removal efficiency for the period were 144.6 ± 59.7 mg/L, 59.9 ± 50.0 mg/L, 83.3 ± 51.6 mg/L and 59.2 ± 26.1%, respectively. NH -N influent and effluent values of 128.8 ± 4  47.5 mg/L and 46.6 ± 45.2 mg/L suggest that most of the soluble TKN was in the form of NH4-N. After the initial period, it appears that the effluent TKN values increased after March 24, 2005, even though the influent was nearly the same.  100  Figure 5.18. Influent and Effluent TP values, mode A  55  Figure 5.19. TP removals per cycle and removal efficiencies, mode A  Figure 5.20. Influent and Effluent TKN values, mode A  56  —•— TKN Removal per Cycle  290  o, O  240  5>  190  ? o)  140  A  0 E,  1  fe/V  90 40  z  5&  <3  J  ^  rf  °f>  I  1  I  AA ,*  A4  •  ^  T\ TX  M  • m  \ \  ! ii T I % ^ Y /  1  f  \ ^  75 65 55  1 \  T  u c  0)  45  jjj  35  "5 o  5 • nihfa \ 2 /-15  |  5  *  i i i i i i II i i i i i i i ri i i i i i i i + I I I I I I i i i I I I I I u I- 5 I I I I M i I B  -10  ^  n  85  V  IT I  CL —I  95  —•—Removal Efficiency  AA  o>  ^  rf  $S JS <S <S <S ,<S ^ ^ ^ ^ J  <3  J  rf  rf  J  rf  J  rf  J  rf  J  J  ^ r f "6ay'  J  S  tf  J  J  J>' ^  rf  ,<S  J  ^rf Vrf J  «  tf  J  J  K * ' <f  ^  Figure 5.21. TKN removals per cycle and removal efficiencies, mode A  Track Study Profiles  Ammonia values showed the expected profile, increasing and then remaining steady in the anoxic stage, and then decreasing once aeration commenced (Figure 5.22). NO -N x  concentrations did not increase in the anoxic zone. At this point, it must be noted that due to the dilutions used while sampling, a presence of NO -N below a value of 2 mg/L x  cannot be confidently inferred.  It appeared that the NO -N values remained steady in the anoxic stage, and started to x  increase once the aerobic stage commenced. They rose above anoxic values, however, and remained low and stable, even while the ammonia was decreasing. This is a distinct indication of simultaneous nitrification and denitrification, where NH4-N decreased, while NO -N remained near stable, or increased very marginally. It was only after five x  hours of aeration that there was a change in the slope for the NO -N profile, as it x  increased at a faster rate than before. The amount of NH -N removal in the aerobic phase 4  57  was 28.8 - 19.2 = 9.6 mg/L. The approximate increase in NO -N values was 6.64 - 1.4 = x  5 mg/L, with the corresponding SND efficiency calculated to be = 47.9% (= [(9.6 - 5)/ 9.6]* 100). It can be recalled from an earlier section that the SND efficiency for mode A was about 53.7% ± 103.3%. The actual value obtained from this track study is 89% for the estimated average for the whole trial mode. However, some denitriflcation could be observed in the settling phase, which could introduce error in this calculation. Anoxic  K  #  K  #  Aerobic  .c£ 'b-  < .$>  fc-  <o-  <b-  V  Settle  < .$>  < .$>  <fcr  °r  ^N-  fy-  T i m e (hrs)  Figure 5.22. Mode A NH -N, NO -N and P0 -P Track Study Profiles (Mixed liquor concentrations expected after influent addition: NH -N = 38.9 mg/L, NO -N = 1.68 mg/L and P0 -P - 25.8 mg/L; please note the scales) 4  x  4  4  x  4  The P0 -P values indicated that there was a slight release of P in the anoxic period. The 4  values reached ~ 29 mg/L at the end of anoxic stage versus the 25.8 mg/L that would be  58  obtained after mixing of the influent. After the aerobic stage, the PO4-P decreased and reached 15.8 mg/L at the end of the cycle. This shows a P release-uptake phenomenon, although the extent of P-release was not as great as that observed in many good EBPR plants and the uptake was not complete either (for example, as compared to an anaerobic P release of > 50 mg/L, and almost complete aerobic uptake, achieved by Oehmen et al, 2006). However, it seems there is enough evidence to speculate that EBPR did occur in this system.  Lessons and Subsequent Modifications  As noted above, from the track study it was observed that there was a small release in the PO4-P in the anoxic phase. It was thought that an increase in the anoxic length might help in obtaining more release in the anoxic period. Similarly, NH -N values showed 4  incomplete nitrification. Thus, a larger aerobic duration was required to remove more NH -N from the mixed liquor. Consequently, the next phase was designed, with an 4  anoxic phase length of 5 hours and an aerobic phase length of 9.5 hours, for a total cycle length of 16 hours.  5.1.2. Mode B  s-COD  A very stable performance was experienced in this period. The effluent s-COD was had average values of 667 ± 1 1 7 mg/L, with removal efficiencies of 67.8 ± 6.0 % for an 59  influent of 2124 ± 472 mg/L. After 21 April, there was an increase in the influent st  loading and a corresponding increase in the effluent s-COD (Figure 5.23). Removals per cycle were also fairly constant (Figure 5.24), although there appears to be an increase in the removal capacity (as indicated by removal per cycle) after April 28, 2005. Correspondingly, there appeared to be a drop in the removal efficiencies from April 24  th  to 28 (due to higher influent values), followed by an increase (due to higher removals th  per cycle).  4000 3500  •  Influent s-COD Effluent s-COD  —sa— Influent moving average — S — Effluent Moving Average  «sr\  V d 2500 f 2000 — r j r i g u § 1500 1000 500 0 -  • •  — ^  *  / • • k ^ . t ^ ^ - r  -—•  ^  —  • »  <t  ^  ^  ^  ^  V  ^  V  ^  uT  J  Day  ^"  A  N  Figure 5.23. Influent and Effluent TOC values, mode B  60  •  s - C O D Removal per Cycle s - C O D Removal per Cycle moving average • Removal Efficiency — a — Removal Efficiency Moving Average  J$  &  ^  Day ^  ^  ^  ^  100 90 80 70 60 50 40 30 20 10 0 -10  ^  Figure 5.24. s-COD removals per cycle and corresponding removal efficiencies, mode B  TOC  During this period, the TOC in the influent decreased from over 600 mg/L to under 500 mg/L (Figure 5.25). The initial decreasing trend was similar to the decreasing trend observed in the influent s-COD curve. Figure 5.26 shows a trend of decreasing removal capacity and decreasing efficiency. A look at Figure 5.25 suggests that this was due to the decrease in the influent strength, and that the reactor essentially produced a similar quality effluent throughout the period. As a result, the removal efficiency decreased from as high as > 75% to ~ 50%.  61  >» u c  a> o  E  LU  "to > o E  O)  a:  • • -A— -©—  800 700 _  600  i  500 400  O  300  -ft— f t  A-  Influent Effluent Influent moving average Effluent Moving Average  • A •  B  •  i-o.  A • b  B  b  *~ 2 0 0 b  b  100 0  .5*>  ^  AT \  '  & IT  Dav •T? Day P  /  '  ^ IT  ^ <cT  .or  ^  Figure 5.25. Influent and Effluent TOC values, mode B  TVtfa/ Chemical Oxygen Demand (t-COD)  The influent t-COD in the initial stages of this mode was in the range of 3000-5000 mg/L, and the effluent concentration was below 1000 mg/L (Figure 5.27); the removal  62  efficiencies were in the range 75-85% (Figure 5.28). After 29  th  Apr-05, there was an  increase in the t-COD of the influent, with values rising to 7000-1000 mg/L. The effluent also rose to about 1900 mg/L and remained steady, thereafter. It was seen that the effluent quality was relatively steady, even though the influent loading was highly variable. This was confirmed by an observation of increased removals per cycle accompanied by an increase in influent concentrations. • •  Influent Effluent Influent Moving Average o—Effluent Moving Average  § 10000 0 9000 c 8000 § 7000 E 3 6000 w ro 5000 1 It 4000 3000 e 2000 3 1000 ? o w  I I T i l l — * 4 M H  rf rf rf rf rf rf rf rf rf rf ^ ^ N*>  n>  0?  ^  ^  ^  IT  <IT  ^ ^=T  rf*  ^  Day  Figure 5.27. Influent and Effluent t-COD values, mode B  63  16000  • t-COD Removal per Cycle -o—t-COD Removal per Cycle Moving Average • Removal Efficiency -A— Efficiency Moving Average  0)  75 o 14000 • >» O 12000 o a. ^ 0 0 0 0 >  o)8000  o ~6000 CH a 4000  o o  2000  5*  ^  ^  Day <cC  #  5*>  5*>  Of  Figure 5.28. t-COD removals per cycle and corresponding removal efficiencies  NH -N 4  As can be seen from Figure 5.29, excellent N H - N removals were obtained, with effluent 4  values even reaching <1 mg/L, essentially indicating complete N H 4 - N removals. The SBR maintained good removal capacity of around 100 mg/L, with 85-96% efficiencies (Figure 5.30).  64  180 W  0) 3  • Influent n Effluent -A— Influent -e—Effluent  160  « >  140  Z  NH4-N NH4-N N H 4 - N Moving A v e r a g e N H 4 - N Moving A v e r a g e  120  X  z  fflue  C  LU  A..  ^100 _j |> 8 0  ~A  60  w  •o e ro  40  +-t  c  20  q=  0  3 0)  c  </& vs"  J>  <<P /  ^ & ^  or  <<-&  v v$  ^ <$r ^  ^ ^ ^ ^ ^ •3^'  &  -v^'  Day  Figure 5.29. Influent and Effluent N H - N values, mode B 4  16 0 o >»  i  14 0  100  1  80  20  •  !00  O  u  60  80 ro -I  II  CH  60  • —o— • —a—  20 -1—i—i—i—i—i—i—i—i—i—i—h-  N H 4 - N Removal per Cycle N H 4 - N Removal per Cycle Moving Average R e m o v a l Efficiency R e m o v a l Efficiency Moving A v e r a g e  H—1—1—1—1—t—1—1—1—1—1—1—1—1—1—1—1—1—1—h-  4.'  o  -  20 0  ^ &  Day  Figure 5.30. N H 4 - N removal per cycle and corresponding removal efficiencies  NO -N x  The  system  efficiencies  demonstrated were  generally  good  nitrification capacity  above  80%, until  29  th  (Figure  5.31),  Apr-05 (Figure  and the S N D 5.32).  .1 o  £ in 4 0 ro >  •Mi  40  0  C  A slight  65  E o CH  deterioration of SND was observed in the period l -12 May-05, which was the result of st  th  increased effluent NO -N concentrations. However, the system again adapted and x  recovered nicely following 13 Apr-05. The overall SND efficiency in this mode was th  81.7 ±20.5%.  S  V  ^<f  ^ '  ^<f  .or &  .<cr &  <&  ^ '  ~\*r <p  v^'  „<?r « V^ Day  v^'  v^'  r<b">  v^'  ^  ^  K^'  K<b"  Figure 5.31. Influent and Effluent NO -N values x  </  <'  ;$r «s?  </  <'  ^ _^ s*.^ n  /'  <'  <'  \ ^  \ ^  x^? x»a ^ *$r *$r *sr * $ r ^ ^ ^ ^ ^ ^  ^ s*. ^ ^ ^ 0  ^'  ^ ' ^tr ^  Day  Figure 5.32. NH4-N reductions vs. NOx-N increments per cycle and corresponding SND efficiencies, mode B  66  P0 -P 4  The influent and effluent PO4-P concentrations are given in Figure 5.33. The influent values decreased from 50-70 mg/L to a near steady range of 28-36 mg/L. The effluent remained at levels 10-16 mg/L through most of the mode B. The system responded to the conditions of loadings, and stabilized once the loading became fairly constant. The removal per cycle values stabilized to ~20 mg/L, while the removal efficiency showed a gradual increasing trend, ranging between 60-70%. The overall influent and effluent values were 36.1 ± 14.4 mg/L and 13.2 ± 2.9 mg/L, respectively; the removals per cycle and removal efficiencies were 22.9 ± 14.8 mg/L and 59.3 ± 14.5%, respectively (Figure 5.34).  80  • Influent P 0 4 - P • Effluent P 0 4 - P •A— Influent P 0 4 - P moving average •e—Effluent P 0 4 - P moving average  •  Q) 3  0  ^  ^  ^  ^  Figure 5.33. Influent and Effluent PO4-P values, mode B  67  il P04-P • P04-P •A— P 0 4 - P •e— P Q 4 - P  80  o  70  5^  50  removal per cycle Removal Efficiency Removal per Cycle Moving Average Removal Efficiency Moving Average  100  re =J  > |>40  o ~~ 3 0 OH Q. 20 I  O  £L  10  0  t—f  n  i  i i  i  i  i i  i  i  i  i  i  i  II  i  i  i  0  Figure 5.34. PO4-P removals per cycle and corresponding removal efficiencies, mode B  TP and TKN  Effluent TP was in the range 15-20 mg/L most of the times, and was much less variable than the influent, that ranged from 30 to -55 mg/L (Figure 5.35). Mass removals per cycle showed a varying trend, and appeared to follow a similar trend as of the influent values. It is arguable that, with consistent effluent values, any change in the influent will be adequately reflected in the absolute mass removal values (Figure 5.36). The same was true for removal efficiencies that measured 58.4 ± 14.3%. The effluent TKN generally remained near 40 mg/L, while the effluent was more variable, 120-160 mg/L (Figure 5.37). The removal efficiency first decreased, then increased to 70-80% (Figure 5.38).  68  Figure 5.35. Influent and effluent TP values, mode B  Figure 5.36. TP removals per cycle and corresponding removal efficiencies, mode B  z c  Q) 3  E LU "D C  m c 3  280 260 240 220 200 180 160 140 120 100 80 60 40 20 0  Influent TKN -*— Effluent TKN  s£ </  <'  & </  5*> J?  8  J ?  #  9  ^  Figure 5.37. Influent and effluent TKN values, mode B  ^  ^ '  ^ '  ^ '  ^  v  v^'  K ^ '  Figure 5.38. TKN removals per cycle and corresponding removal efficiencies, mode B  Track study profiles  From the track study, it appeared that there was an increase in phosphorus release in the anoxic cycle (Figure 5.39). In the aerobic cycle, there was a clear uptake of PO4-P, as well. From a mass balance, it was determined that the mixed liquor PO4-P concentration, after addition of influent, would be 19.1 mg/L. However, the maximum PO4-P reached 70  within the anoxic stage was ~ 34 mg/L. This release of ~ 15 mg/L was significantly more than the -3.3 mg/L, released in mode A. However, there was still incomplete uptake of PO4-P in the aerobic stage. NH4-N values showed complete nitrification. It appeared that the nitrification started after about 1 hour of aeration; but there was almost complete removal of NH4-N by the end of the cycle. This indicated that there was a complete to near complete ammonia removal occurring in the SBR. Evidence for SND was also seen again. There appeared to be some air entrainment in the last hour of the anoxic cycle, which led to a small increase in NO -N and also a decrease in the PO4-P. Also, there x  appeared to be some NO -N at the start of the anoxic cycle, which may have delayed the x  P release, assuming that the bacteria responsible for P removal were not the "denitrifying PAOs". SND efficiency calculated on track study measurements was about 52.8% on average, which is lower than the estimated mode B SND efficiency, of 81.7 ± 20.5%. Anoxic  Aerobic  Settle  -•—ammonical-N -&— nitrate+nitrite-N -«— ortho-P  D)  E  z X  O X  z  Q-  # \-  # # <v - <v  Ix-  <$> <b- V  <b-  <b-  <§> #  o>-  #  x$> „.<$> x$> sfV£>•  Time (hrs)  Figure 5.39. Mode B NH -N, N O - N and P0 -P Track Study Profiles (Mixed liquor concentrations expected after influent addition: NH -N = 21.2 mg l" , NO -N = 4.9 mg f and PO4-P = 19.1 mg l" ; note the difference in scales) 4  x  4  1  4  1  x  1  71  Lessons and Subsequent Modifications  It appeared that the SBR was showing signs of enhanced P uptake, and it was thought that the presence of NO -N at the beginning of anoxic phase was a deterrent to P release. x  Therefore, it was decided to decrease the aeration phase length, in order to decrease the nitrification efficiency and consequently decrease the amount of NO -N going into the x  anoxic phase of the next cycle. The aeration length of the aerobic stage was reduced by 2 hours to 7.5 hours, which was identical to mode A, and achieved incomplete nitrification.  5.1.3. Mode C  s-COD  The s-COD value of the influent and effluent increased (2000 mg/L to 3000 mg/L and from ~ 1300 to 1700 mg/L, respectively) in the period 20 May-05 to 1 Jun-05. After th  st  10 Jun-05, the values decreased to near the previous levels (Figure 5.40). Removal per th  cycle values were very variable, and were in the range 700-1300 mg/L (Figure 5.41). As a result, the removal efficiencies were also variable, and ranged between 33-55% for most part of the study. 4 -12 Jul-05 was a period of low performance in terms of s-COD th  th  removal, where the removal efficiencies were as low as 15%, and the removals per cycle approximately 300 mg/L.  72  • Influent s-COD • Effluent s-COD —=— Influent moving average —=••— Effluent Moving Average  3500 •  3000 „ 2500 _j £ 2000 Q  •  /  n  1500  a  1000  >*  /  *  '  \ J m ^ ,'  W  \  —B-«~  s  MS.  * •  /--^ \ .  m  500 0  1  .<£  ^  •  ' •  •  •  1  .<£  ^  1  1  1  .<£  ^  1  1  ^  ^  ^  #  ^  $T  1  *  j£  &  <v'  *  1  r-+  J*  J*  *v  w  ,  ,  j$>  ^  ,y  1  •  j £  J o  N  Day  Figure 5.40. Influent and Effluent s-COD values, mode C a s - C O D R e m o v a l per C y c l e — 9 — s - C O D R e m o v a l per C y c l e Moving A v e r a g e • R e m o v a l Efficiency — — R e m o v a l Efficiency Moving A v e r a g e  2000  100  u  a*  1500  o. _ a  „  «  /  "  \  *  *  DC Q  O  *. 500  "  *  -  §  i - J ^ S ^ 50  |  f 30 o|  • ^ V - S ^ -  (0  J*  J*  J*  g>  J*  Ap  &  ^  &  ^  &  -60  /•Vfs./W  8  _  80  70 >«  2  r-  5 =5,1000  90  ^  r&  2 200 - 10  o |  -0 -10  *  ^  Figure 5.41. s-COD removals per cycle and corresponding removal efficiencies, mode C  TOC  TOC values were also variable, and were generally in 400-500 mg/L range (Figure 5.42). The period 3 -14 Jun-05 was a period where TOC removal was very low and rd  th  efficiencies were only in the order of 15-20% (Figure 5.43). It is possible that, owing to 73  the high t-COD loading, insoluble COD was solubalized to TOC, with the result being that the TOC value of the effluent remained the same, thought the system was still consuming carbon.  • • -A— -©—  800 700 _  600  "5)  500  E  Influent Effluent Influent moving average Effluent Moving Average •  400  o  300 200  •  n  S- ° -  flvi-o-'iv •  X  /V"  •  *  a  8  —*rvr  •  . • %£  ••/  A O .  •  O - o-o  A  • •  •  -A-  •  7/  <r  A  A  •  «-©  i  O-o—8 pa ™  •  •  •  100 0  ^  1  ^  1  ^  •  >  0  1  ^  •  ^  1  >S  ^ Day  1  ^  1  ^ T>'  1  ^  1  1  ^ <V*  ^ ^  Figure 5.42. Influent and Effluent TOC, mode C •  Removal per Cycle  Figure 5.43. TOC removals per cycle and corresponding removal efficiencies  74  t-COD  The influent t-COD was variable in this mode and the effluent ranged from 2400-4400 mg/L (Figure 5.44), suggesting highly variable treatment. As a result, the removal performance in terms of absolute mass or removal efficiency was also variable, as can be seen in Figure 5.45.  j?  20000  Q O 2 •£ J it •a £ "£ §  18000 16000 14000 12000 10000 8000 6000 4000 2000 0  •  * +k K 1  •  Influent Effluent Influent Moving Average Effluent Moving Averaqe  «  *  •  TBS" 1  1  1  1  1  1  1  1  1  rf>rf>rf>rf> ^ ^ ^ ^ « r ^ ^ ^ r ^ * ^rfrfrfrfrf A  N  1  A  -i  • • —A— —e—  A  ^  <^  <^  J* J* J* J*  ^  Day  1  1  v  ^  M^'^g  1  r  ^  I  1/  /  1  I  ^  1  ^  1  1  ^ ^ A <p $r  A / ^ A ^' * y N  s  Figure 5.44. Influent and effluent t-COD values, mode C 3 t - C O D Removal per Cycle - O — Removal per Cycle Moving Average # Removal Efficiency - A — R e m o v a l Efficiency Moving Average 0  20000  o  18000  O  16000  ©  14000 ^12000  > "a 10000 E S 8000 o> 6 000 oc  Q O  o  4000 2000  0  ^  rf  ^  J  <<>'  &  ^ ^ \ Day ^ %  ^ &  Figure 5.45. t-COD removals per cycle and corresponding removal efficiencies, mode C 75  ^  NH -N 4  Figures 5.46 and 5.47 show a clear deterioration in the NH4-N removal capacity of the SBR. Even though there was a decrease in the influent NH -N (from ~140 mg/L to 100 4  mg/L), the decrease in effluent concentration did not match it; the effluent values were very close to the influent values (Figure 5.46), while the removal efficiencies were only 8-25%, as the reactor reached a steady state. It was evident that the nitrification capacity of the reactor was severely compromised in this mode.  NOx-N  It can be seen that there were no nitrates in the effluent (Figure 5.48). All of the NH -N 4  removed was via SND, although it can be seen from NH -N data that the amount of 4  ammonia removed was lower. So, even a -100% SND efficiency (Figure 5.49) did not result in a good system performance, in terms of NH -N removal. 4  Figure 5.46. Influent and Effluent NH -N values, mode C 4  76  Figure 5.48. Influent and Effluent NO -N values, mode C x  77  Figure 5.49. NH4-N reductions vs. NOx-N increments per cycle and corresponding SND efficiencies, mode C  PO4-P  From Figure 5.50, it can be seen that the effluent PO4-P increased as the mode progressed. In the earlier part of the mode, an increase in effluent concentration can be attributed to the increasing influent concentration; later, even though the influent concentration decreased, the effluent concentration kept increasing, from 26 May-05 to 7 Jul-05. th  th  After that, the effluent concentration decreased slightly till 15 Jul-05, following which it th  started to increase again. The PO4-P removal per cycle decreased to as low as 2.2 mg/L on 27 Jun-05 (Figure 5.51). This was followed by a period of performance recovery, th  although by the end of study, the mass removals per cycle again started to decrease, to about 15 mg/L on 20 July-05. The removal efficiency dropped to as low as 9.5% on the th  same day of lowest removal per cycle, after which it recovered to reach ~ 35%, on 20  th  July-05.  78  =d  • Influent P04-P • Effluent P04-P -A—Influent P04-P moving average -e— Effluent P04-P moving average  60  G)  E  d  50  I  o 0. 3  !C LU •a  c re +-* c 0> 3  5  0  <P & & & &&  ^ ? ^  &&  &&  &&  &&  & c£  ^ rf' ^ rf' rf' rf' rf' rf' i> rf rf rf rf rf ^ J rf rf rf rf rf rf ^ * rf rf rf >& Day  Figure 5.50. Influent and Effluent PO4-P values, mode C P 0 4 - P Removal per Cycle • P 0 4 - P Removal per Cycle Moving Average • Removal Efficiency -e- - Removal Efficiency moving average  40 35  u o  95  30 25 20 15 10 5  ^  .0'  .0'  rf  $  Figure 5.51. PO4-P removals per cycle and corresponding removal efficiencies, mode C  TP and TKN  It also appeared that the effluent TP had increased in the later stages of the study, and that the removal per cycle decreased from ~ 38 mg/L to 15 mg/L resulting in a decrease in 79  removal efficiency from ~ 69% to 30% (Figures 5.52 and 5.53). Total TP values were highly variable too (Figures 5.54 and 5.55), the influent and effluent values being 122.6 ± 91.7 mg/L and 68.4 ± 81.4 mg/L, respectively; the removals per cycle and removal efficiencies were 54.2 ± 37.1 mg/L and 44.6 ± 25.1%, respectively.  100  g  90  a.  80  i  70  w  •  i r i T i u e n t s-1  r  -m- Effluent s-TP  60  c  50  0) 3  40  !t LU  •o 3 0 c re 2 0  •^•rO^kP"  10  e O)  =  \ f—•—•  ,  0  - rf rf rf rf  sT  rrf  N  rf*  j£  «r  j$> N  ^  j$> jj> rf  $> j$>  j$>  ^ ^  A  A  <£>  #  * v °>' ^  rf  Figure 5.52. Influent and effluent s-TP values, mode C 60  •s-TP Removal per Cycle • Removal Efficiency  E, 5 0 _Q) O >» U k_ O) Q.  40 30  re > o 20  E a> ct  10  I  0  $*> JP rf rf rf ^ rf* ^ ^ rf^rf  ^ <v r«T  w  IT n  tT  v  ^<v "y y  rf rf J?J? ^  V  KQ'  KTJ  MDay&  rf rf rf rf rf rf J> J> J> J> rf*  \  *  < b <v <\  Figure 5.53. s-TP removals per cycle and corresponding removal efficiencies, mode  80  500  • Influent t-TP  E  450  • Effluent t-TP  Q-  400  =S,  5  350  g 2  250  111  200  ™  100  300  150  S  "tor  50  3  c  0  ^  ^  ^  ^  ^  ^  ^  ^  5*>  &  #  #  Day  Figure 5.54. Influent and effluent t-TP values, mode C  •  160  TJ  140  O  120  •  t-TP Removal per Cycle  100  Removal efficiency  90  l-JOO  5  o, 8 0 o E E ^ 60 o> *  40 20  60  |  40  5  30  |  20  *  0  SP N  S  10  0  •N'  o  70 50  Q.  |T  80  5*>  5* 0>'Day  Figure 5.55. t-TP removals per cycle and corresponding removal efficiencies, mode C  The TKN removal performance deteriorated visibly, with the effluent TKN values being very close to the influent values (Figure 5.56). The s-TKN removal per cycle decreased from as high as 150 mg/L to as low as ~ 14 mg/L, by the end of the mode C. Removal efficiency values too decreasedfromas around 50% to a low of 9-10% (Figure 5.57).  81  Figure 5.56. Influent and Effluent s-TKN values, mode C  Figure 5.57. Absolute t-TP removal and corresponding removal efficiencies, mode C  The total TKN values were very random and variable (Figure 5.58). The influent concentration of 636 ± 3 3 1 mg/L decreased to 276 ± 1 1 5 mg/L giving removals per cycle of 360 ± 322 mg/L and removal efficiencies of 49 ± 22% (Figure 5.59).  82  o>  1600  • Influent t-TKN  ~  z  1400  • Effluent t-TKN  *  1200  Z  1000  I £  800 •  T3  600 400  -  200  c re  • •  .sP  •  •  •  •  •  IB  3  •  •  •  . . .  ° m  •  • i  0  vtfT  v O « ^  i  i  n  • i  cp cp cp v<^' > # ' v<^' ^ $r / / V  cp  /  n>'  Day  Figure 5.58. Influent and effluent t-TKN values, mode C  _1600 _i »1400  E  •  t-TKN Removal per Cycle  •  Removal efficiency  o  •  • •  •  •  600  200 0  ^  n  •  40 •  +  • • •  •  1  ^  H—h  • n sP  70  50  • •  •  0) 4 0 0 OH  80 — •  60  •  •  800  75  > o E  • •  o 1000  90  •  •  ]Tl200 a> a  100  •  30  n  20  >» u c Q)  *5  £  o  re > o E £  10 0  ^ Day  Figure 5.59. t-TKN removals per cycle and corresponding removal efficiencies, mode C  83  Track Study Profiles  Track study profiles confirmed little or no NH4-N removal (Figure 5.60). Little nitrification was also observed in the aerobic phase. The PO4-P value remained steady (except perhaps the erroneous point) in the anoxic phase and decreased somewhat in the aerobic phase. There was no significant P uptake, whatsoever, and the only uptake possible may have been due to cell growth. It clearly appeared that the P release-uptake capacity of the SBR had been compromised in this mode. The concept of SND efficiency in this case is meaningless, since almost no NH -N was removed in this phase. 4  Anoxic  Aerobic  Settle 42 38  - 34 - 30 26  Q. g  •4 O  - 22 - 18  I N  Time (hrs)  N^ -  <V-  NJ»-  14  ^  Figure 5.60. Mode C NH -N, NO -N and P0 -P Track Study Profiles (Mixed liquor concentrations expected after influent addition: NH -N = 91.4 mg l" , NO -N = 4.9 mg F and PO4-P = 32.8 mg l" ; note the difference in scales) 4  x  4  1  4  1  x  1  84  5.1.4. Summary  A summary of results obtained from all three modes for mechanical-mixing SBR is presented through Tables 5.1, 5.2 and 5.3. The mechanical mixing SBR demonstrated different degrees of removals for different modes. It was observed that the phosphorus accumulating organisms may have been subjected to competition from glycogen accumulating organisms. High NH -N removals and SND efficiencies were achievable 4  for mode B.  Table 5.1. Summary of results during mode A, mechanical-mixing SBR  :  Parameter  Influent (mg/L)  Effluent (mg/L)  Removal per cycle (mg/L)  t-COD  -  -  -  -  s-COD  2384 ± 5 0 3  840 ± 2 9 1  1537 ± 5 2 9  61.8 ± 16.4  TOC  718 ± 4 0 4  298 ± 1 2 9  433 ± 336  54.2 ± 19.8  NH4-N  129 ±47.5  46.6 ±45.2  82.2 ± 4 9 . 0  65.3 ±25.8  P04-P  37 ± 13.8  16.6 ± 4 . 5  20.1 ± 14.5  48.9 ±23.1  NOx-N  1.1 ± 1.5  8.2 ± 10.4  -  -  TP  38.1 ± 19.8  17.3 ± 6 . 7  20.8 ± 17.4  45.5 ± 27.4  TKN  145 ± 6 0  60 ± 5 0  83 ± 5 1  59.2 ±26.1  Removal Efficiency (%)  * ± values represent one standard deviation  85  Table 5.2. Summary of results during mode B, mechanical-mixing SBR*  Parameter  Influent (mg/L)  Effluent (mg/L)  Removal per cycle (mg/L)  Removal Efficiency  t-COD  6334 ± 2 6 5 8  1180±480  5154 ± 2 4 7 6  (%) 80.2 ± 5 . 8  s-COD  2124 ± 4 7 2  6 6 8 ± 117  1457 ± 4 3 7  67.8 ± 6.0  TOC  511±103  210±59  300±110  57.5 ± 14.0  NH4-N  103 ± 2 3 . 4  9.0 ± 8 . 6  93.7 ± 2 . 1  91.3 ± 7 . 6  P04-P  35.4 ± 14.3  13.0 ± 2 . 9  22.4 ± 14.6  58.9 ± 14.3  NOx-N  1.1 ± 0 . 4  3.8 ± 2 . 4  -  -  TP  51.1 ± 2 3 . 0  19.8 ± 7 . 0  31.3 ± 19.1  58.4 ± 14.3  TKN  155 ± 3 5  42 ± 26.5  113 ±46.5  70.5 ±23.5  * ± values represent one standard deviation Table 5.3. Summary of results during mode C, mechanical-mixing SBR*  Parameter  Influent (mg/L)  Effluent (mg/L)  Removal per cycle (mg/L)  t-COD  12575 ± 8206  3276 ± 742  9300 ± 7983  (%) 67.3 ± 14.0  s-COD  2236 ± 4 5 7  1281 ± 3 1 3  972 ± 358  42.9 ± 11.0  TOC  427±105  275 ± 76  155± 106  33.4 ±21.6  NH4-N  123 ±25.8  93.3 ±24.1  29.7 ±22.9  23.3 ± 17.1  PO4-P  34.3 ± 7.9  17.6 ± 4 . 1  16.6 ± 9 . 6  45.1 ± 19.1  NOx-N  1.1 ± 0 . 8  1.3 ± 2 . 3  -  -  TP  44.1 ± 9 . 7  24.0 ± 9 . 2  20.2 ± 9 . 1  45.4 ± 17.9  TKN  248 ± 87  171 ±59.6  75.0 ± 5 5 . 0  28.1 ± 17.9  Removal Efficiency  * ± values represent one standard deviation  86  PAO-GAO Coexistence  It can be seen from the three tables (5.1 to 5.3) that mode B gave the best results for all the parameters. This is due to the presence of both an EBPR population and a good nitrifying population. %P values obtained for the last week of mode B revealed a %P value of 2.60 ± 0.56% per MLVSS, whereas this value was 1.55 ± 0.17% per MLVSS for mode C. This clearly showed that the P uptake capacity developed in mode B was lost in mode C. It is reasonable to assume that in mode C, with such low values of %P per MLVSS, the P content of the biomass was associated with the cell structure. Thus, a %P composition greater that this value of 1.55 ± 0.17% per MLVSS will likely be associated with enhanced uptake.  A comparison of the track study profiles (Figures 5.22, 5.39 and 5.60) also shows that the P release in the anoxic stage of the cycle was about 15 mg/L, in mode B, after considering the effect of influent mixing; whereas, it was only about 3.3 mg/L in mode A, and was absent in mode C. The uptake in the aerobic cycle of mode B was incomplete, suggesting only a partial dominance of phosphorus accumulating organisms, which is consistent with the % P observations.  Photo micrographs obtained after poly-p-hydroxyalkanoate (PHA) staining (Figure 5.61) indicated the uptake of volatile fatty acids (VFA) as PHA granules. These micrographs were made on day 20 of mode C. The observation of coccoid shaped bacteria staining positively on cell walls (Figure 5.62), as well as bacteria staining positively in  87  intracellular spaces after staining with Neisser's Reagent (Figure 5.63), indicates the coexistence of glycogen accumulating organisms and phosphorus accumulating organisms in the mixed liquor. The relative activities of these two classes of organisms may have led to the different extents of PO4-P removals in the three modes. Since the micrographs were obtained on day 20 of mode C, a steady state was not yet achieved for this mode, and the bacteria were in transition from mode B to C.  Overall, the operation of this SBR demonstrated that advanced nutrient removal for dairy manure is possible, with relatively high efficiencies of COD, nitrogen and phosphorus removals.  Figure 5.61. Results of PHA staining for intracellular PHA granules  88  5.2. G a s M i x i n g R e a c t o r  s-COD  Within a week of the startup, the effluent s-COD was stabilized. The influent was more variable, averaging 1912 ± 423 mg/L (Figure 5.64). However, the s-COD removal per cycle was highly variable, and oscillated between 1500 mg/L and 300 mg/L (Figure 5.65). It was only after 13 Jul-05, that it became relatively stable and the amplitude of the th  variability decreased substantially. The removal efficiency also showed the same trend. The values for removal per cycle and removal efficiencies were 913 ± 400 mg/L and 46.4 ± 13.8%, respectively.  - • — Influent s - C O D  E,  a o  -m— Effluent s - C O D  w c a> 3  E  a> •a c ns +J  c a>  3 IP C  «  ^  Day ^  *  Figure 5.64. Influent and Effluent s-COD values, gas-mixing reactor  90  TOC  From Figures 5.66 and 5.67, it can be seen that both influent and effluent TOC were highly variable, and there was no steady state, as such, for the whole period. The values for influent and effluent were 588 ± 360 mg/L and 283 ± 1 0 3 mg/L, respectively, giving removals per cycle of 232 ± 1 8 8 mg/L and removal efficiencies of 43.2 ± 23.2%.  91  _1800  Influent T O C  !>1600  -•-Effluent TOC  ^T1400  0  5* rf  Day  A'  ^  ^  N>'  rf  ^  Figure 5.66. Influent and effluent TOC, gas-mixing reactor  1400  j  100  - Removal Efficiency  -  90  o 1000 a>  -  re •~800 > o £600 E  -- 6 0 -  50  -  40  4>  400  !' 30  O O  200  =- 7 0  CL  DC  80  ~~  §5, >» o c Effi  u 1200 >»  - T O C Removal per Cycle  o  -  20  re > o E  -  10  DC  "  0  n  0  0)  0)  rf  S  Day  Figure 5.67. TOC removals per cycle and corresponding removal efficiencies, gasmixing reactor  92  t-COD  The t-COD concentration was highly variable (Figure 5.68), even though the same procedures for feed preparation were maintained throughout the study. As a result, the influent to the reactor was 10625 ± 5350 mg/L, a very high concentration. The effluent through the reactor was less variable than the influent, at 3385 ± 986 mg/L, giving a removal per cycle value of 7240 ± 5404 mg/L and removal efficiency of 59.6 ± 25.6 mg/L (Figure 5.69). The removal was relatively good in terms of t-COD, but there was a period where the reactor performance was severely compromised (period 30 June - 6 July, 05).  j  25000  -•— Influent  E Q  20000  %  10000  TJ C  | 3 5=  =  5000  0  Day  Figure 5.68. Influent and effluent t-COD values, gas-mixing reactor  93  -A—t-COD Removal per Cycle  Figure 5.69. TOC removals per cycle and corresponding removal efficiencies, gasmixing reactor  NH -N 4  The influent NH -N values were relatively stable ranging from 180 - 200 mg/L mark. 4  However, the effluent NH4-N values increased dramatically after 22  nd  Jun-05 (Figure  5.70), and the NH -N removal, suddenly decreased from ~ 100% in 18 Jun to 22 Junth  nd  4  05, to less than ~ 30% (Figure 5.71). This sudden change could be due to two reasons: i.  On 22  nd  Jun-05, the plastic seal on the top of the reactor was replaced by a  rigid seal. This led to re-entrainment of the air left in pipes, into the SBR, leading to re-suspension of biomass. The TSS in the effluent increased, and it can be postulated that loss of TSS resulted in a shorter SRT (estimated to be ~ 4-5 days). This may have resulted in the loss of nitrifiers/ reduced activity of nitrifiers and lower removals.  94  ii.  The t-COD started to increase slightly after ~21 Jun-05. Increased loading s  may have led to a decrease in ORP and inhibiting nitrifier functionality. Figure 5.72 shows the sudden decrease in ORP from mid-June 22 , 2005. The nd  earlier limits of ORP were ~ -200 mV in the anoxic phase increasing to ~ 50 mV at the end of aerobic phase. This range then changed to ~ -380mV in the anoxic phase, to only -200 mV at the end of aerobic phase. The change in the NH4-N removal curve shows a striking match between the changes in the trends of two curves. The downside of this reasoning is that the SBR was probably still in start-up mode, and the hypothesis cannot be proven. Nevertheless, a correlation is obvious in the ORP and effluent NH -N curves. 4  In subsequent days, the air flow was increased in order to increase the amount of air going into the SBR and to raise the ORP and DO profiles. After 5 Aug-05, a decrease in th  effluent NH4-N was observed. Also, the removal per cycle and removal efficiencies had started to increase. On 21 Aug-05, the NH -N removal efficiency was 61.8%, indicating st  4  increased activity of nitrifiers. Interestingly, the OPR pattern for 21 Aug-05 showed > 0 st  mV and as high as ~ 120 mV ORP for the aerobic phase (Figure 5.73). The increasing ORP pattern in the anoxic stage indicated the presence of oxygen in the recirculation air. This reestablishment of nitrification strongly indicates that ORP is positively related to nitrification.  95  t  249  T  Figure 5.70. Influent and effluent  NH -N, 4  gas-mixing reactor  NO -N x  In conjunction with the N H 4 - N removal performance, it was confirmed from Figure 5.74 that there was little or no nitrification in the SBR, except for the first 4-5 days. The reasoning for this has already been discussed in the above section. After 5 Aug-05, th  NOx-N  were observed in the effluent, due to reestablishment of nitrification.  96  -1  -I  T  T  r  f  I  1  :  T  :  T  T  1  f  —  1- 0  T  Figure 5.71. NH4-N removals per cycle and corresponding removal efficiencies, gasmixing reactor 100  -500  T  -I  ,  ,  ,  0  1440  2880  4320  Time [minutes (mid-June 21 to mid-June 24, 2005)]  Figure 5.72. ORP pattern in the SBR during transition from nitrifying to non-nitrifying performance  97  98  P0 -P 4  The influent and effluent values, and corresponding removals per cycle and efficiencies are shown in Figures 5.75 and 5.76, respectively. After the first 4-5 days, the PO4-P removal capacity decreased drastically. This change occurred at the same time the NH4-N removal efficiency was compromised. Several reasons can be proposed: i.  the initial few days may account for the development of biomass and hence more phosphorus removal for cell requirements,  ii.  the loss of biomass due to re-suspension and subsequent degeneration of activity, or  iii.  insufficient air supply.  However, a failure in PO4-P removal was observed in the period 16 -21 Aug-05. This th  st  may have been due to the non-anaerobic conditions in the anoxic phase, due to the presence of oxygen in the recirculation air, as evidentfromORP pattern in Figure 5.73.  —•— Influent  Figure 5.75. Influent and effluent PO4-P values, gas-mixing reactor 99  TP and TKN  From Figures 5.77 and 5.78 it can be seen that the influent and effluent s-TP and t-TP values were highly variable. It was seen that the influent s-TP was 30.6 ± 3.6 mg/L; this compares very well with influent PO4-P of 27.8 ± 6.5 mg/L. Although the PO4-P and sTP measurements were not one-to-one, an indication of a close relationship is apparent. Similarly, the effluent s-TP of 13.8 ± 6.7 mg/L is very close to the effluent PO4-P of 11.8 ± 5.6 mg/L. Also, another observation is that the total TP was 114.1 ± 96.2 mg/L. This shows that less than ~ 25% of total phosphorus was in form of usable PO4-P. Similarly, < 30% of total TP was in form of soluble phosphorus. Thus, it appears that most of the phosphorus present in the dairy manure wastewater is in less usable forms (i.e., not in the form of PO4-P). From Figure 5.79, we see that the variability in s-TKN (256 ± 34 mg/L)  100  A t-TP influent x t-TP effluent • s-TP influent • s-TP effluent  450  40  T  _j  400 350  - 30  300  25 *wJ  c  - 20  200  LU T> 150 C  15  • •  ro 100  - 10  C a> 3  50  c  ~x~x~  0  - 5  X ^ X  _x_x_  &  &  V  >  V  HI  Influent and  c 250 u  s  •TP (m  =- 35 O)  -- 0  & Jp  & J> Jp  <T  <£ # # # # ^  v  v  ^  N  a>'  *  K  v  ^  ^ Jp Jp # Jp v ^ ^ ^ ^ ^ ^ ^ Day * ^ ' ^ ' *T 4 ' ^ ' <T A™. v  ^ «  #  v  v  Figure 5.77. Influent and effluent s-TP and t-TP values, gas-mixing reactor s-TP Removal per Cycle t-TP Removal per Cycle s-TP Removal Efficiency t-TP Removal Efficiency  •  TJ  c re  Q.  H•  oTd  o J? >« o E  A •  245 x  s  x  X  •  X  195  X  X X  145  1- Q . 0) L =  a "7 +J re > o  45  E a>  X  -5  A  A  ,  >  <?  ^  ^  s #  x  •  ^  v #  ^  IT  re  •  •  •  "7 to  >» o c .2 o  it  LU  75 > o E a>  - 2 0 DC  cp J>  j£ ^  0  = A = i =  & s  60  20  A  A  •-,  --  x  40  A •  DC  80  A A  ii B  --  a  X H •  X  X  •  95  100  ^  <o> Day  <P J> ^  ^  ^  ^  <P cp cp cp ^  N  W>  y>  ^  ^  #  Figure 5.78. s-TP and t-TP removals per cycle and corresponding removal efficiencies, gas-mixing reactor  101  was much less than t-TKN (492 ± 235 mg/L). However, these results are not conclusive, as only a few s-TKN samples were used. The effluent s-TKN and t-TKN values were 165 ± 60 mg/L and 224 ± 1 1 9 mg/L, respectively, giving removal efficiencies of 33.0 ± 26.0 % and 49.1 ± 30.7 %, respectively. Both removals per cycle and removal efficiencies were highly variable in the study period (Figure 5.80). t - T K N influent t - T K N effluent s - T K N influent s - T K N effluent  A x a •  250 ~  rf  J>  rf  rf  rf  rf  rf  rf  rf  rf  rf  rf  rf  rf  rf  rf  rf  rf  v> Day rfrfrfrfrf  n? ^  Figure 5.79. Influent and effluent s-TKN and t-TKN values, gas-mixing reactor A x • •  780 680 w J 580 of D> o E480 >» ~ ^ 5 380  1  t-TKN Removal per Cycle t - T K N removal efficiency s - T K N Removal per Cycle s - T K N removal efficiency  300 250 200 150  5 ~ 280 re -o  § 5180 |  80  -20  tn  o  °1  §  Z  g H  100 - ?  « re  _X-X—X •  v— XX * X  50 _x _ x  # ^ ^ ^ «^ / / / / / / /  /  |  Q> OS  0  Day  Figure 5.80. s-TKN and t-TKN removals per cycle and corresponding removal efficiencies, gas-mixing reactor  102  Track Study Profiles  Track study profile revealed very strange results. ORP and NO -N values in the anoxic x  period (A to B, fill at point A, Figure 5.81) suggested completely anaerobic conditions. Still, NH4-N and PO4-P decreased during the whole period. One explanation could have been the possibility of some residual air from the previous cycle, although it seems unlikely that with the headspace of ~ 3 L and a high organic loading, oxygen could have remained in the anoxic phase. A reduction of s-COD could be possible due to anaerobic denitrification (unlikely, since there were no nitrates at time zero), uptake of carbon substrates (possible), or anaerobic stabilization. The reduction of PO4-P can be due to bacterial requirements for cell metabolism, which needs air. Another possibility is the activity of denitrifying phosphorus accumulating organisms. - a - s C O D —•—NH4-N —&— P04-P - & - N O x -*-TOC  14:00 14:30 15:15 16:15 17:15 18:15 19:30 20:30 21:00 21:45 22:00  Time (hrs)  Figure 5.81. Track study profiles for various parameters, gas-mixing reactor  103  However, given the %P per MLVSS in the sludge, 1.43 ± 0.18 %, it is unlikely that there was any enhanced phosphorus uptake taking place. A decrease in ORP (Figure 5.82) suggests anaerobic conditions, and a decrease in pH could be due to hydrolysis and VFA production. Another more plausible explanation could be the stripping of ammonia due to high air flow. Given the high concentrations of NH4-N and the pH of 7.5-7.7, it is possible that some of the ammonia, which may also get produced as a product of hydrolysis, will escape from the SBR to the gaseous phase. This ammonia stripping will then lead to a pH decrease. This reason would be more consistent with the observed decreasing NH -N values in the anaerobic period. 4  x Q.  Figure 5.82. ORP and pH profiles for the track study in Figure 5.81  An increase in pH after start of aeration (point B) can be due to the effect of CO2 stripping. A continued decrease in NH4-N could be due to SND or more ammonia stripping. However, when there was a change in slope of ORP and pH curves, when the pH started to decrease, and ORP started to increase, there was a strange observation in  104  the profiles of all the parameters: all parameters, with the exception of NO -N started to x  increase. The author is not able to explain the cause of this observation. The increasing trend continued till point D, after which aeration was stopped and headspace gas recycling was initiated (to remove any oxygen that may be left in the headspace after the aeration phase). There was a slight decrease in parameter values. At point E, the recirculation was stopped, and the settling phase commenced and effluent was decanted at point E.  Summary  The results of the gas-mixing SBR are summarized in Table 5.4.  Table 5.4. Summary of results for the gas-mixing SBR*  Parameter  Influent (mg/L)  Effluent (mg/L)  Removal per cycle (mg/L)  Removal Efficiency  t-COD  10625 ± 5350  3385 ± 9 8 6  7240 ± 5404  59.6 ±25.6  s-COD  1912 ± 4 2 3  999 ± 280  913 ± 4 3 7  46.4 ± 13.8  TOC  588 ± 360  283 ± 103  232±188  43.2 ±23.2  NH4-N  186 ± 19.6  122 ±52.2  63.9 ± 4 6 . 4  35.4 ±27.3  P04-P  27.8 ± 6 . 5  11.8 ± 5.6  16.0 ± 9 . 7  53.5 ± 2 8 . 4  NOx-N  1.1 ± 0 . 8  4.4 ±7.5  -  -  s-TP  30.6 ± 3 . 6  13.8 ± 6 . 7  16.7 ±8.5  53.3 ±27.9  t-TP  114 ±96.3  41.8 ± 4 4 . 0  72.4 ±61.7  58.8 ±29.0  s-TKN  257 ±34.3  165.7 ±60.2  90.8 ±85.7  33.0 ±26.0  t-TKN  492 ± 235  224±119  269 ± 222  49.1 ±30.7  (%)  * ± values represent one standard deviation  105  5.3. Pilot Plant SBR The performance of the SBR was monitored in the period 20 June-05 to 7 October-05. The parameter variations are shown in Figures 5.83 through 5.90. For the initial two months, there were several incidents of feed failure or overloading leading to foaming. Before 20 June-05, the plant was operated by personnel from Vision Envirotech Ltd. As th  there were several breaks, and no big operational change was made (for example as in lab-scale SBR where anoxic-aerobic lengths were changed), the results of all the parameters are presented in one section only, which allows for easier analysis of data under the varying operational conditions.  The SBR was subjected to a high dairy waste overload on 25 May-05, and was then run th  on municipal wastewater to stabilize the process, until 10 July-05. The t-COD can be th  seen decreasing from > 900 mg/L to ~ 250 mg/L, and the corresponding effluent t-COD from ~ 357 mg/L to 55 mg/L (Figure 5.83). During this time, the removal efficiency can also be seen increasing from 50-60% to 90% (Figure 5.84). The influent NH -N also 4  decreased, owing to the municipal wastewater feed, with values gradually decreasing to 28-32 mg/L (Figure 5.85). The effluent NH -N was < 0.5 mg/L except for 23 and 24 rd  th  4  June-05 (possibly due to the fact that the SBR was still stabilizing from the dairy manure overload). Most of the time, high removal efficiencies of > 97% were observed (Figure 5.86). The effluent NO -N was 5-10 mg/L (Figure 5.87), and the SND efficiency was x  about >90 % from 20 -23 June, 05 and >80 % most of the time thereafter (Figure 5.88). th  rd  The influent P0 -P decreased from values as high as 22.8 mg/L to ~ 3.5 mg/L (Figure 4  5.89); however, the effluent P0 -P increased from < 1.0 mg/L to ~ 2.5 mg/L by 8 Jul-05, th  4  106  and reached a high of 6.03 mg/L on 4 Jul-05. This indicated that the P removal process was deteriorating in response to the changing conditions in the SBR. The corresponding P-removal efficiencies decreased from >95%, to as low as 30% by 8 Jul-05 (Figure 5. th  90).  From 10 July-05, the feed was mixed with dairy manure. An increase in influent t-COD th  can be seen. However, the t-COD in the period 18-23 July-05 was very low, which cannot be explained, as the t-COD should have increased. The effluent t-COD followed the trends of influent t-COD. The removal efficiency was relatively high till 18 July-05 th  (~ 76-88%), but after that, it appeared that the t-COD removal process was severely compromised, with removal efficiencies decreasing to 38-55%. With the addition of dairy feed, the influent NH -N started to increase, at first gradually (as the feed in the 4  pretreatment tank was becoming concentrated slowly), and then sharply in the later dates of 20-25 July, 05, where they reached as high as 129 mg/L. The effluent NOx-N increased marginally to values > 8 mg/L, thereby decreasing the SND efficiency slightly, to ~ 70%. The influent PO4-P appeared to increase as a result of dairy feed addition, from 3.3 -> 4.4 -> 13.3 mg/L. The effluent PO4-P was <0.5 mg/L, on all days, except one.  By 25 Jul-05, the reactor was severely foaming and hence the manure feed was stopped th  on July 26, 05, and the SBR was only fed with municipal wastewater. By 2 Aug-05, the nd  influent resembled a 'clearer' municipal wastewater and by 5 -6 Aug-05, the effluent th  th  was also visibly rid of dairy manure and was 'very clear'. The influent strength was around 300 mg/L (2 -10 Aug-05), although the effluent remained around 80-90 mg/L nd  th  107  (except the date of 4 Aug-05, when the influent was 855 mg/L and effluent was 295 mg/L). The stoppage of dairy feed led to a decrease in NH4-N values, to 25-26 mg/L which can be clearly seen in the Figure 5.85. A decrease in N H 4 - N loading led to a decrease in effluent NO -N, and an increase in SND efficiency. Attempts to bring back x  the SBR to a 'normal' state, however, compromised the P removal capacity of the reactor. The effluent PO4-P was in the range 6-7 mg/L, being 6.78 mg/L on 5 Aug-05, even with th  an influent value of 4.56 mg/L. The period 8 -l 1 th  th  Aug, 05 had influent PO4-P  characteristic of municipal wastewater (2.2-3.5 mg/L) and the SBR was producing effluent values < 1.0 mg/L, indicating that the process was stabilized.  There was no feed delivered (due to a system malfunction) to the pretreatment tank from 11 Aug-05 to 15 Aug-05, and the SBR was basically fed with the solids deposited at th  th  the bottom of the pretreatment tank. Visibly, the t-COD increased to 1720-2870 mg/L. The effluent was 115 mg/L and 102 mg/L for Aug 11 and 12, but increased to 4290 mg/L on 15 Aug-05. On the 15 , the feeding problem was fixed, and the influent on 16 th  th  th  returned to 290 mg/L, and the effluent to 130 mg/L. Period 16 -22 th  nd  August saw a  decrease in influent and effluent t-COD (290 to 100 mg/L, and 130 to 32 mg/L, respectively). Manure feed was started on 24 Aug-05 and stopped on 29 Aug-05, when th  th  the pump delivering municipal wastewater failed. The influent NH4-N remained almost constant during the whole period, with values of 22-28 mg/L for most of the time, increasing marginally to 34.1 mg/L when there was a feed failure. The effluent NO -N x  and SND efficiency were also consistent, mostly being in the range of 2-6 mg/L and. 8590%, respectively. The 12 of August showed a high influent P0 -P concentration (7.35 th  4  108  mg/L), although later PO4-P concentration for the period of no loading/ municipal loading remained mostly in the range 1-2 mg/L until 26 Aug-05, and 2-3 mg/L in period th  27 -30 Aug-05. However, on 29 Aug-05, there was severe failure of the EBPR process, th  th  th  and an effluent PO4-P of 17.5 mg/L was measured. This could have been due to the anaerobic release of P during the settling phase.  The manure-municipal mix was re-commissioned on 31 August, with a higher dilution, st  and subsequently the feed characteristics were more consistent than the overloaded period. Influent t-COD was more consistent, in the 400-700 mg/L range (barring 16  th  Sep-05 and 19 Sep-05, when the values were 190 mg/L and 3400 mg/L, respectively). th  The effluent was in the 100-200 mg/L range, giving removal efficiencies of 60-80% (except the 12 September and 16 September dates, when they were 43.4% and 98.1%, th  th  respectively). In general, it was observed that these removal efficiencies are lesser that the 80-95% efficiencies obtained on the same SBR, when run on municipal wastewater only, with the effluent t-COD being < 50 mg/L in almost all cases (Vision Envirotech data from 9-Mar to 24-Apr, 05; not presented in this thesis).  The influent NH -N was in the range 40-50 mg/L, except on the last sampled day, when it 4  was 31 mg/L. The effluent NH -N was almost always < 1.0 mg/L throughout the study 4  period (consistent with the results of Vision Envirotech International Ltd.), and the corresponding removal efficiencies were always > 99%, except on three occasions (Figure 5.80). The effluent NO -N increased to the range 9-16 mg/L and the SND x  efficiency was in the 70-80% range. The influent PO4-P was mostly in the range 5-6  109  mg/L and the effluent PO4-P was usually < 1.0 mg/L, although there were instances where it rose to values 1.2-1.6 mg/L. In general, the SBR maintained efficiency values of 80-90%, when the SBR did not face any operational problems, and was loaded largely with diluted manure.  110  Dairy feed stopped  Dairy feed started  eed iailure  Ee_ed_  -•—Influent t - C O D  started (muncipal)  -®— Effluent t - C O D  Heed (dairy + municipal)  F e e d failure  Feed started (dairy + municipal)  1 f  —^  SH—  mL  mm  fi  fi  rf  J* <b'  fi  > f i  fi fi fi ,fi rf ^ ^ rf erf rf #r rf % of  fi  Day  Figure 5.83. Influent and Effluent t-COD, pilot scale SBR  fi  fi  fi  rf  rf  #  rf <$  fi rf c  <£"  Figure 5.84. t-COD removals per cycle and corresponding removal efficiencies, pilot scale SBR  140 Dairy feed started  •  Dairy feed stopped  Feed f;M u r e eed started (muncipal)  120 -•-Influent NH4-N Feed (dairy + municipal)  100 E  -•—Effluent N H 4 - N  Feed failure  x  80  c  Feed started (dairy + municipal)  Q) it  a>  "D C (0  c a> 3  C  ^  5$>  & ^>  ^  &  ^  &  K  ^  JP ^  J>  ^  &  ^  &  ^  &  Day  Figure 5.85. Influent and effluent NH4-N, pilot scale SBR  ^  &  & <,  & ^  & 9  S  &  J? °  & 0  j£  100  120  + 90 100  Dairy feed  Feed  stopped—  -failure!  Feed -•— N H 4 - N Removal per Cycle  started (muncipal)  - « — R e m o v a l efficiency  Feed  70  o  (manure-+-  o  municipal)  E,  o >. O  80  60 Feed  i_ 0)  failure  Q.  To > o E a>  50  To  Feed (mamtrft anw* + ^ m u nnjcjoan* ^ •  DC  V /  40  • ^  30  T  V  1 DC  X  z  >,  o c .92 "o £ v  20  10  S$> #  .5$ ^  \& o , ^  JP  J  3  #  & ^  ^ *  ^  < ^  #  .$£ <<?  0°  .5$ O u  Day^ 1  Figure 5.86. NH4-N removals per cycle and corresponding removal efficiencies, pilot scale SBR  114  Dairy feed started  Dairy feed stopped •  A  F e e d failure -•-Effluent NOx-N - A — N H 4 - N m a s s removal  Feid started (m jncipal) Feed (manure + -mtmteipat}-  heed failure -Feedmanure + municipal) A * ^  1  ^  A  j  A  •  • •  - k -  1'  A  ••  • * — •  • ^ — • — * -  I fi fi rf rf rf rf rf fi fi fi v** K  A"  vO*  «*or  ^  *  ^  V -  S  V  &  ^  &  ^  <T  ^  <lT  ^  rf  Figure 5.87. NH4-N removals and effluent NO -N, pilot scale SBR x  rf ^ Day  fi  fi rf  rf  fi rf  rf  fi  rf  rf  fi  rf  fi  rf  ^  rf  ^  ^  rf o>'°  rf ^  Dairy feed stopped  Figure 5.88. SND efficiencies, pilot scale SBR  F e e d failure  Feed-failure-  started (muncipal)  Influent P 0 4 - P Effluent P 0 4 - P  Feed (dairy + mun cipal) Feed started (dairy "TTnonieipal)  Feed failure  4-^ g rf  fi  sy  fi  ^fi y  ^fi ^  ^fi  \-  j  ^fi &  <y n  ^fi  fi ^  <<f  fi ^  fi ^\>y  $r*  fi ^  <&r rJC Day  Figure 5.89. Influent and effluent PO4-P values, pilot scale SBR  fi cf' .<£  <ir  fi cf' erf  or ^  fi cf erf  rf  m•  fi cf  rf>  rf  •  fi cf  rf>  .fi  rf V  N  .fi  rf V  .fi o*  J* A'  \  x  J* ^  s& ^  \* o  /  ^ ^  ^  ^ ^  J> ^  ^  ^  J> ^  J? cf  JP cf  JP cf  JP cf  J> cf  qr  JP & ^P 0° 0° 0° K  NT  V  Day  Figure 5.90. PO4-P removals per cycle and corresponding removal efficiencies, pilot scale SBR  118  Summary  A summary of results for the pilot-scale SBR is presented in Table 5.5. Table 5.5. Summary of results for the pilot-scale SBR* Parameter  Influent (mg/L)  Removal per cycle (mg/L)  Effluent (mg/L)  #  #  Removal Efficiency  (%)*  #  t-COD 544 ± 609 212 ± 581 42.8 ± 20.9 NH4-N 3.1 ± 15.3 P04-P 6.2 ± 4 . 6 1.9 ± 3 . 0 NOx-N 0.3 ± 0 . 2 8.4 ± 5 . 0 * ± values represent one standard deviation Since the feed of the SBR changed and switched so many times from municipal to dairy wastes, the average of removal efficiency will not yield representative values. Similar caution is urged while reading and interpreting the influent and effluent values  #  Track Studies  Two track studies were undertaken. The first one was conducted on 8 July-05, when the feed th  was municipal and the SBR was stabilizing in the aftermath of manure overload. The parameter profile is presented in Figure 5.91.  The reactor was fed with 7 minutes of feed in the anoxic mode. After feeding, the mixed liquor NH4-N increased from 0.17 mg/L to 7.87 mg/L. The NH4-N values remained relatively stable in the anoxic phase, during which the ORP values decreased from 121 mV to -240.1 mV. PO4-P release was observed, with mixed liquor values increasing from 2.45 mg/L to 8.5-9.2 mg/L (the point at 0:15 hrs, 22.7 mg/L was possibly erroneous). A release of 6-7 mg/L when the influent was only 3.55 mg/L indicated that the biological population in the SBR was EBPR population, which exhibits PO4-P release. NO -N of 4.53 mg/L in the mixed liquor was quickly denitrified, x  possibly within 15 minutes, when the MLSS NO -N was less than 1.0 mg/L (0.92 mg/L). x  119  Nonetheless, denitrification was definitely complete by 30 minutes, as the 30-minute NO -N x  reading was 0.19 mg/L, which is essentially zero NO -N. x  Anoxic  200  Aerobic  Settle  24 22  150 100  j\  X  —  *  —  *  —  *  —  V—*—*—*—*—  ^  18  50  > Q.  0 -50  a. o -100 -150  —*—ORP —•—NOx-N  —IB— P04-P —A— DO  —X—pH  —•—NH3-N  E. o  - - 16 Q  14 12 10 Z -- 8  j ft~~m-—*—•—«  -200 A /  /  6  '—><~--X-HC^fc^——*— ~~~~^& 5t: ¥e  <  _ _ >V  -250  —• • flR  -300 Cy  20  & .<£ Co- c y Qy \ - \-  .<£  N-  .<£ \- <v - q>  /$> q> n;J  &  & . & .C? <b- 'b- " j - fc- tx-  B) Mr* vjy  & . & .c£ & t x ix- <5 <o?  V  /  4  CL I  o  ~ l 1 2 CL ^ 10  <§> <6  ?  Time (hr:min)  Figure 5.91. 8 Jul-05 track study parameter profiles for pilot scale SBR l  At the onset of aeration, the ORP started to increase rapidly. The DO increased to about 0.4 mg/L, and the NO -N started to increase gradually. However, it appeared that NH -N did not begin to x  4  decrease until about 30 minutes after the onset of the aerobic phase. Thereafter, the removal was gradual, and by the end of the aerobic phase, there was no NH -N left in the SBR. The ORP was 4  160.2 mV and the DO was 1.9 mg/L. During the aerobic phase, the mixed liquor NH -N 4  decreased from 7.7 mg/L to 0.21 mg/L, while the NO -N increased from 0.147 to 6.82 mg/L. x  Thus a 7.49 mg/L decrease in NH -N led to an increase of 6.67 mg/L of NO -N. Thus, only a 4  x  small percent of N removal was due to SND, about 10.9%. Interestingly, the DO was 0.4 to 0.6 for most of the aerobic phase, which is considered to be optimum for SND. However, SND was almost non-existent.  120  PO4-P removal started after 15 minutes of the aerobic phase, and by 3:45 hrs, there were 2.33 mg/L of PO4-P left in the SBR. The PO4-P curve was flattening with aerobic time and it seems unlikely that more PO4-P could have been removed from the SBR. This shows that, even though the SBR was exhibiting EBPR and its related characteristics, it may not be possible in some circumstances, that a complete P removal takes place. Also, on this particular day, the removal efficiency was only [(3.55-2.11)/3.55]*100 = 40.6%. Even at this low efficiency and low removal per cycle value (3.55-2.11) = 1.44 mg/L, it is seen that the biomass was exhibiting the phenomena characteristics of an EBPR sludge. So, it is possible that even with low % removals, the biomass in this system was capable of exhibiting EBPR.  The next track study was conducted on October 7 , 2005 when the reactor was fed with diluted th  dairy manure. At the time of this study, the dairy manure feed was almost finished, and the results here will correspond to an SBR that has been stabilized to the maximum extent possible, logistically. The parameter profiles are shown in Figure 5.92.  The SBR was fed for 8 minutes. The NH4-N value increased from ~ 0 mg/L to 9.61 mg/L within 20 minutes of the cycle. The pH increased, possibly due to the production of OH" from denitriflcation (Cheng et al, 2001). Denitriflcation was complete in about 39 minutes, with values decreasing from 8.52 mg/L to 0.18 mg/L. PO4-P release was observed, with values increasing to 6.26 mg/L within 20 minutes of the start of feed. This release occurred even when NO -N were x  present. After the onset of the aerobic phase, the NH -N started to decrease, and NO -N started to 4  x  increase. A look at these profiles shows that during the aerobic phase, NH -N decreased from ~ 4  9.38 mg/L to 0.14 mg/L and NO -N increased from 0.18 mg/L to ~ 9.98 mg/L. This indicates that x  121  all the NH -N in the mixed liquor was actually converted to NO -N, and hence, little or no SND 4  x  was occurring. This occurred even when the DO was 0.4 mg/L for most of the aerobic phase. The pH decrease, occurring in the aerobic phase, is attributed to alkalinity consumption, as a result of nitrification.  Time (hr:min)  Figure 5.92. 7 Oct-05 track study parameter profiles for pilot scale SBR  PO4-P uptake was more effective in this track study, as compared to the study on SBR using municipal wastewater as feed. From a concentration of 6.04 mg/L at the start of aerobic phase, the end concentration was 1.07 mg/L, and the effluent concentration was 1.01 mg/L. It is also seen from the trend of PO4-P curve that it had not yet flattened out, and more PO4-P removal could have been possible had there been more aeration time provided. Nevertheless, this SBR system showed a very good P0 -P removal capacity. 4  122  5.4. Comparison of the three SBRs The electrical interferences to the probes in the mechanical mixing SBR were absent in the gas mixing SBR and, hence, observations of ORP and pH profiles were possible. Interesting observations were made with regard to the nitrification capability of the gas-mixing reactor and the ORP profiles. The high strength loading to the SBR substantially lowered the ORP in the SBR and subsequently, no nitrification was observed. In the final days of the study, it was seen that a high ORP was reached at the end of the aerobic stage. The SBR was also seen to improve its nitrification capability. Therefore, it is postulated in this thesis that nitrification can be linked to ORP ranges, especially evident in the case of high strength wastes.  From the results obtained for the lab scale SBRs, we see that different parameters, namely NH -N 4  and PO4-P, were removed to different extents. It appears that there will be some particular cycle length at which the removal is optimum, and that this cycle length will be different for different types of wastewaters. Determination of an optimum cycle length, using fixed time strategies, will be iterative and time consuming, since at least two SRTs will be required to provide any conclusions with confidence. Also, in actual field trials, the loading to the SBR will vary and hence fixed-time strategy will not ensure optimum aeration. In other words, sometimes the mixed liquor may be under-aerated, and sometimes over aerated. Over-aeration in an SBR has many negative effects: more nitrates and DO will be present at the onset of the next anoxic/ anaerobic stage, thereby hampering the activity of phosphorus accumulating organisms. Moreover, overaeration may lead to depletion of intra-cellular carbon reserves, because of endogenous respiration by bacteria in the absence of a readily usable carbon source. A better way to treat the wastewater, of such high and variable strength, will be to utilize real-time control; in this scenario  123  dissolved oxygen (DO) and aeration lengths are controlled by electronic instrumentations and appropriate algorithms. Control o f D O w i l l ensure that the bacteria operated i n S N D mode, and controlling aeration length, based on D O changes, w i l l ensure that the mixed liquor is not over aerated.  The pilot scale S B R operated i n this study was able to provide excellent performance, once the operating conditions were stabilized. However, it must be noted the feed concentration for this pilot scale S B R was very low, compared to the lab scale S B R s . A l s o , this feed was significantly diluted with municipal wastewater, and the final strength was closer to municipal wastewater, than to a high strength wastewater. This loading characteristic could have implications when the performance o f this pilot scale S B R is compared to the lab scale S B R s . Nevertheless, the N H - N 4  removal was almost always > 97-99%, even when the S B R was overloaded. Thus, it is evident that the real-time strategy was successful in this research, in achieving complete nitrification, at least when the loading strength was closer to municipal wastewaters, rather than dairy manure.  124  5.5. Lab Scale Digester The digester was operated on the sludge wasted from the mechanical-mixing SBR. The phosphate concentration of the supernatant, in general, increased during the first 90 days of the study (Figure 5.93), but it appears that it stabilized around 70 mg/L. The initially observed lower values may be due to the fact that the digester was in start up mode. Also, the increased ambient temperature could have led to a better digestion performance and, thus, the higher values in the later stage. Another reason for increase in values from 50 mg-P/L during 9 Apr-05, to around 60-65 mg-P/L, th  may be due to the marginally increased P content in the sludge in period II. However, the orthophosphate concentration after this period remained around 70 mg-P/L, instead of decreasing during period III (since %P in sludge decreased). Ammonia values did not show any particular trend and, did in general, varied between 230 mg/L to 300 mg/L, while occasionally dropping to around 200 mg/L.  Potential for P recovery  The supernatant from the lab-scale digester shows that, for this partially treated (in terms of N and P) wastewater, the digester supernatant will contain both PO4-P and N H - N , which are essential to 4  struvite formation and recovery. Since the supernatant phosphate characteristics are within, and on the higher side of, the ranges already tested for recovery in the U B C crystallizer (Table 3.2), it was assumed that recovery from this digester supernatant was feasible.  125  Figure 5.93. Anaerobic digester supernatant PO4-P and NH -N characteristics during the study 4  126  5.6. Pilot Scale P-Recovery Experiments About 200 liter o f supernatant obtained from the P-release reactor (see materials and methods) was run i n the pilot scale crystallizer (Figure 4.4). The p H o f the supernatant was 8.04 prior to the experiment. This p H was maintained during the entire duration o f experiment, using a p H controller. The crystallizer was initially filled with tap water and replaced gradually by the feed supernatant. The initial PO4-P concentration for the experiment was 55 m g / L . From the results o f Fattah (2004), it was seen that big size crystals were obtained for a higher P: N molar ration (~ 1:6). Hence, the initial N H 4 - N concentration was increased from 15 m g / L to 172 m g / L , by the addition o f the appropriate amount o f ammonium chloride. The initial magnesium concentration was about 68 mg/L. This resulted in an M g : P : N molar ratio o f 1.6:1:6.9. The reactor recycle ratio was set for 6, in order to achieve high P removals.  The PO4-P concentration i n the effluent started to decrease within the first half hour and stabilized to around 10 m g / L , at about the fourth hour o f the experimental run (Figure 5.94).  Thus, a  removal efficiency o f 82% was achieved during the initial crystallization run. The analysis o f crystals obtained after the experimental run revealed that they were mostly in the form o f fines < 0.2 m m i n size, on average.  The struvite-recovery run gave some anomalous results for the N H - N profile. The N H 4 - N value 4  in the effluent increased with time, whereas the PO4-P values remained approximately constant. It was expected that the N H 4 - N profile would also remain fairly constant (for example, as shown in Figure 5.95 for a synthetic supernatant made from mixing ammonium chloride, potassium dihydrogen phosphate and magnesium chloride i n tap water; initial conditions were: PO4-P = 82  127  E, a. i o Q. 4-*  c a> 3  E LU  Time (hrs)  Figure 5.94. Crystallizer effluent PO4-P and NH -N characteristics during the recovery experiment 4  Effluent P 0 4 - P  10  - * - Effluent NH4-N  5  50 25  0  0 \  Time (hrs)  Figure 5.95. Crystallizer effluent PO4-P and NH -N characteristics during the experiment for synthetic supernatant. 4  mg/L, NH4-N = 210 mg/L, Mg = 181 mg/L, pH = 7.51; Mg:P:N = 2.8:1:5.8; recycle ratio = 3.5). One possible explanation is the replacement of N H from the crystal by K. Dairy wastewaters are 4  128  quite high in potassium levels, and it is possible that potassium started to replace NH3 in the crystals. The potassium ion is almost the same size as of N H  A  comparison of MgNH P0 .6H 0 4  4  2  ion, as well.  + 4  and MgKP0 .6H 0 4  2  is made in the Table  5.6  (http://www.mineralcollecting.org, last visited April 15, 2006 ). The basic similarities in cell lattice (a, b, and c; dimension b of struvite is similar to dimension c of K-struvite, and dimension c of struvite is similar to dimension b of K-struvite), and similarities in elemental sizes, make it very likely that potassium can replace ammonium in the struvite crystal lattice.  Table 5.6. Similarities in some basic characteristics of struvite and K-struvite Characteristic  Struvite  K-Struvite  Type  Biaxial (+)  Biaxial (+)  Rl Values  n =1.495, n =1.496  n =1.490, n =1.493  Molecular Weight  245.41 gm  266.47 gm  Cell Dimensions  a = 6.945, b = 11.208, c =  a = 6.892, b = 6.166,  6.1355,  c= 11.139  Optical Properties  a  p  a  p  This replacement would result in the formation of K-struvite (MgKP0 .6H 0). Thermphos 4  2  International, in the Netherlands, is already operating an installation for recovery of K-struvite  129  from calf manure, at Putten, Netherlands (Scope Newsletter # 57 - CEEP, 2004). NH -N is 4  required for formation of struvite, and K is required for formation of K-struvite. Further, there might be a strong possibility of K and N H +  + 4  replacing each other in the crystal lattice, depending  on their relative concentrations. Both forms of struvite are useful fertilizers and recovery of either or both will help in removing the nutrient load to the environment.  130  6. CONCL USIONS AND RECOMMENDA TIONS  6.1. Conclusions The discussions presented in previous chapters can be digested into the following conclusions: i.  Dairy manure treatment can be achieved with high efficiencies, provided the right anoxic-aerobic conditions are maintained. Treatment efficiencies, comparable to advanced treatment plants, can be achieved using a simpler SBR operational strategy.  ii.  Fixed-time control strategies were able to remove ~ 80% of total COD and > 65% of soluble COD. Real-time controlled treatment strategy was able to remove > 65% of total COD on consistent basis, once relatively stable conditions were established.  iii.  On fixed-time based strategies, NH -N removal of up to > 93% were achievable, while 4  on real-time control based strategies, consistent NH -N removals of > 99% were 4  achieved. iv.  The lab scale reactor, based on fixed-time strategy, was able to remove ~ 60% of P0 4  P from the influent. P0 -P removals of > 90% were achievable for the real-time 4  controlled pilot scale SBR. v.  A real-time control strategy is a better strategy for treatment of wastewater. Complete nitrification can be achieved on almost all occasions. This strategy provides optimum aeration and, hence, will also be suitable to develop an EBPR biological population.  vi.  ORP is speculated to be an important parameter, especially in the case of high strength wastewater treatment. If the ORP values are low, in order of -250 mV during aeration, nitrification will be severely compromised. ORP values above ~ 0-50 mV will be conducive for nitrifying bacteria.  131  vii.  The nitrogen and phosphorus concentrations in the digester were in the range already tested for struvite recovery; thus, it was concluded that struvite recovery from digestion of biosolids treating dairy manure should be possible. A pilot scale nutrient recovery process from the biosolids emanating from a pilot scale SBR revealed that struvite recovery was possible. PO4-P removal up to 82% was achieved.  6.2. Recommendations  From the lessons learnt in this study, the following recommendations are made for future research. Some of these recommendations are specific to dairy manure treatment or struvite recovery, while some are related to SBR studies, in general.  i.  Implement gas-mixing reactors, instead of mechanical mixing reactors for any study based on SBRs. Use of SBRs employing mechanical mixing are prone to interferences which, in some cases, are almost impossible to remove. Gas-mixing SBRs are not prone to such interferences. In addition, they may allow one to conduct proper mass balance-based studies. Having a single outlet on these reactors will facilitate measurement of escape gases, which, when integrated over time, will help in calculating the total amount of elements leaving the reactor. This will facilitate estimation of elemental consumption and production by the biomass, once the corresponding influent and effluent elemental concentrations are known.  ii.  Future studies on SBRs, even at lab scale should use real-time control. Such control systems will ensure speedy establishment of optimal conditions.  132  iii.  For research specific to dairy manure treatment, it is evident that real-time based control systems are the best means o f achieving high nutrient removals. Thus, future work should, i n detail, evaluate the performance o f the real-time strategy based S B R s , when fed with a more concentrated dairy manure than was used at the U B C based B N R pilot plant.  iv.  Results from the gas-mixing S B R suggest that, i n case o f higher loading and lower aeration, removal o f C O D and phosphorus is possible, while nitrification is inhibited. This property is especially useful for cases specific to dairy manure, or high strength animal wastewaters. The effluent from a treatment system performing similar to the gas-mixing S B R w i l l consist of lesser amounts of organics, while still being relatively rich i n nutrients, nitrogen and phosphorus. 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Thesis, Virginia Polytechnic Institute and State University, USA. Yagci, N., Artan, N., Cokgor, E.U., Randall, C.W., and Orhon, D. (2003) Metabolic model for acetate uptake by a mixed culture of phosphate- and glycogen-accumulating organisms under anaerobic conditions. Biotechnology and Bioengineering, 84(3), pp. 359-373. Zeng, R.J., Lemaire, R., Yuan, Z., and Keller, J. (2003) Simultaneous nitrification, denitrification, and phosphorus removal in a lab-scale sequencing batch reactor. Biotechnology and Bioengineering, 84(2), pp. 170-178.  139  LIST OF APPENDICES Appendix A: Data for Mechanical-mixing SBR Appendix B: Data for Gas-mixing SBR Appendix C: Data for Pilot-scale SBR Appendix D: Data for Crystallizer Runs  140  APPENDIX A: DA TA FOR MECHANICAL-MIXING SBR  Table A . l . Raw data for daily operation of mechanical-mixing SBR, s-COD, TOC and t-COD  s-COD Day  Absolute  Removal  Removal  Efficiency  (mg/L)  (%)  908  1513  62.5  835  1485  64.0  2675  810  1865  69.7  12- J a n - 0 5  2320  2160  160  6.9  13- Jan-05  4430  829  3601  81.3  Influent (mg/L)  Effluent (mg/L)  9-Jan-05  2420  9-Jan-05  2320  12-Jan-05  13- J a n - 0 5  2540  735  1805  71.1  14- J a n - 0 5  2025  920  1105  54.6  14-Jan-05  2920  1240  1680  57.5  18-Jan-05  1890  2390  -500  -26.5  18- J a n - 0 5  2180  1380  800  36.7  19- J a n - 0 5  1490  645  845  56.7  19- J a n - 0 5  1440  1290  150  10.4  20- Jan-05  610  643  -33  -5.3  20-Jan-05  760  570  190  25.0  25-Jan-05  6800  90.9  25- Jan-05 26- Jan-05  2640  26- Jan-05  t-COD  TOC  620  6180  460  -460  400  2240  84.8  800  2020  71.6  27- Jan-05  2680  800  1880  70.1  27- Jan-05  2750  675  2075  75.5  28- Jan-05  2920  650  2270  77.7  28-Jan-05  2920  580  2340  80.1  30-Jan-05  1080  790  290  26.9  30- Jan-05  1260  840  420  33.3  31- Jan-05  1020  790  230  22.5  Influent (mg/L)  Effluent (mg/L)  Absolute  Removal  Removal  Efficiency  (mg/L)  (%)  Influent (mg/L)  Effluent (mg/L)  Absolute  Removal  Removal  Efficiency  (mg/L)  (%)  141  31-Jan-05 8-Feb-05  2740  910  1830  66.8  9-Feb-05  2760  980  1780  64.5  10-Feb-05  2860  940  1920  67.1  11-Feb-05  2880  960  1920  66.7  12-Feb-05  2650  1060  1590  60.0  13-Feb-05  2760  980  1780  64.5  14-Feb-05  2520  1030  1490  59.1  1504  384  1120  74.5  16-Feb-05  2710  990  1720  63.5  1824  432  1392  76.3  17-Feb-05  2800  1130  1670  59.6  1320  560  760  57.6  19-Feb-05  2980  1400  1580  53.0  1320  384  936  70.9  1208  440  768  63.6  23-Feb-05  3040  1280  1760  57.9  1160  384  776  66.9  26-Feb-05  3110  1240  1870  60.1  496  232  264  53.2  27-Feb-05  2310  980  1330  57.6  648  312  336  51.9  28-Feb-05  2420  1000  1420  58.7  1336  520  816  61.1  1-Mar-05  2680  860  1820  67.9  528  176  352  66.7  2-Mar-05  2770  980  1790  64.6  480  480  100.0  3-Mar-05  2100  640  1460  69.5  4-Mar-05  2420  730  1690  69.8  584  584  100.0  5-Mar-05  2210  710  1500  67.9  496  240  256  51.6  7-Mar-05  1750  570  1180  67.4  432  208  224  51.9  8-Mar-05  2520  830  1690  67.1  464  176  288  62.1  10-Mar-05  1780  640  1140  64.0  472  240  232  49.2  20-Feb-05  12-Mar-05  2020  710  1310  64.9  400  200  200  50.0  15-Mar-05  2170  610  1560  71.9  480  168  312  65.0  17-Mar-05  2430  690  1740  71.6  432  208  224  51.9  18-Mar-05  2540  630  1910  75.2  656  192  464  70.7  19-Mar-05  2370  670  1700  71.7  400  160  240  60.0  20-Mar-05  1800  420  1380  76.7  400  208  192  48.0  21-Mar-05  2300  470  1830  79.6  984  368  616  62.6  22-Mar-05  2060  490  1570  76.2  344  120  224  65.1  24-Mar-05  2440  780  1660  68.0  344  312  32  9.3  360  424  -64  -17.8  808  592  216  26.7  26-Mar-05 28-Mar-05  1760  560  1200  68.2  30-Mar-05  1950  680  1270  65.1  2050  610  1440  70.2  4-Apr-05 6-Apr-05  480  184  296  61.7  608  200  408  67.1  8-Apr-05  2170  1060  1110  51.2  856  344  512  59.8  9-Apr-05  2990  660  2330  77.9  440  288  152  34.5  9-Apr-05  3000  690  2310  77.0  464  384  80  17.2  9-Apr-05  2990  570  2420  80.9  608  312  296  48.7  10-Apr-05  3240  780  2460  75.9  752  280  472  62.8  11-Apr-05  1900  670  1230  64.7  688  200  488  70.9  12-Apr-05  1820  680  1140  62.6  536  136  400  74.6  13-Apr-05  1940  600  1340  69.1  624  192  432  69.2  14-Apr-05  1860  600  1260  67.7  656  176  480  73.2  17-Apr-05  1890  630  1260  66.7  552  192  360  65.2  5480  940  4540  82.8  18-Apr-05  1960  600  1360  69.4  440  200  240  54.5  4720  1000  3720  78.8  19-Apr-05  2020  640  1380  68.3  464  152  312  67.2  2440  560  1880  77.0  20-Apr-05  1730  500  1230  71.1  512  184  328  64.1  4620  1030  3590  77.7  21-Apr-05  1570  360  1210  77.1  632  280  352  55.7  3510  540  2970  84.6  22-Apr-05  1640  580  1060  64.6  4400  1140  3260  74.1  23-Apr-05  3600  840  2760  76.7  512  176  336  65.6  24-Apr-05  1870  590  1280  68.4  480  192  288  60.0  2880  730  2150  74.7  25-Apr-05  1920  630  1290  67.2  368  200  168  45.7  3020  810  2210  73.2 82.2  1220  62.6  504  280  224  44.4  4890  870  4020  680  990  59.3  464  192  272  58.6  5610  860  4750  84.7  750  1030  57.9  5040  800  4240  84.1  2020  790  1230  60.9  528  168  360  68.2  4940  800  4140  83.8  1-May-05  2250  690  1560  69.3  480  184  296  61.7  14330  810  13520  94.3  2-May-05  2260  1070  1190  52.7  416  168  248  59.6  7500  1060  6440  85.9  3-May-05  2410  750  1660  68.9  472  176  296  62.7  8280  910  7370  89.0  4-May-05  1930  720  1210  62.7  344  216  128  37.2 8560  1090  7470  87.3  1970  640  1330  67.5  368  176  192  52.2  8140  1630  6510  80.0  5380  76.2  26-Apr-05  1950  730  27-Apr-05  1670  28-Apr-05  1780  29-Apr-05  6-May-05 7-May-05 8-May-05  2120  730  1390  65.6  408  288  120  29.4  7060  1680  496  152  344  69.4  9-May-05  1930  650  1280  66.3  8580  1980  6600  76.9  12-May-05  2300  580  1720  74.8  6480  1960  4520  69.8  13-May-05  2110  690  1420  67.3  8680  1820  6860  79.0  14-May-05  2470  710  1760  71.3  9720  1970  7750  79.7  15-May-05  1990  590  1400  70.4  6240  1420  4820  77.2  17-May-05  1870  640  1230  65.8  6900  1910  4990  72.3  20-May-05  2010  1280  730  36.3  408  288  120  29.4  8280  2850  5430  65.6  22-May-05  1950  1400  550  28.2  376  360  16  4.3  7920  3880  11560  74.9  24-May-05  2940  1280  1660  56.5  408  272  136  33.3  12000  2920  5000  63.1  143  26-May-05 27-May-05 28-May-05 29-May-05 30-May-05 31-May-05 1-Jun-05 3-Jun-05 4-Jun-05 5-Jun-05 8-Jun-05 9-Jun-05 10-Jun-05 12-Jun-05 13-Jun-05 14-Jun-05 16-Jun-05 18-Jun-05 19-Jun-05 20-Jun-05 22-Jun-05 24-Jun-05 25-Jun-05 27-Jun-05 28-Jun-05 30-Jun-05 1-Jul-05 2-Jul-05 3-Jul-05 4-Jul-05 5-Jul-05 6-Jul-05 7-Jul-05 8-Jul-05 10-Jul-05 12-Jul-05 13-Jul-05 15-Jul-05  2460 1660 2410 1950 3000 3130 3030 2730 2510 2600 2550 2470 3200 1680 1590 1870 2530 2280 2310 2140 2100  0 2500 1950 2330 1900 1810 1420 1830 1680 2170  1210 1110 1310 1270 1300 1560 1770 1720 1650 1650 1530 1600 1480 800 880 1000 1490 1350 710 990 1130  1900 1400 1250 1950 1110 1500 960 930 1030 990  1250 550 1100 680 1700 1570 1260 1010 860 950 1020 870 1720 880 710 870 1040 930 1600 1150 970  -1900 1100 700 380 790 310 460 900 650 1180  50.8 33.1 45.6 34.9 56.7 50.2 41.6 37.0 34.3 36.5 40.0 35.2 53.8 52.4 44.7 46.5 41.1 40.8 69.3 53.7 46.2  44.0 35.9 16.3 41.6 17.1 32.4 49.2 38.7 54.4  448 400 488 512 544 424 328 368 336 408 304  264 168 248 328 280 240 0 288 280 344 224  184 232 240 184 264 184 328 80 56 64 80  41.1 58.0 49.2 35.9 48.5 43.4 100.0 21.7 16.7 15.7 26.3  384 280 400 264 488 576 312 408 424 408 504 720 552 560 408 592  328 200 168 216 264 344 336 184 224 176 208 424 216 480 368 280  56 80 232 48 224 232 -24 224 200 232 296 296 336 80 40 312  14.6 28.6 58.0 18.2 45.9 40.3 -7.7 54.9 47.2 56.9 58.7 41.1 60.9 14.3 9.8 52.7  248 384  320 200  -72 184  -29.0 47.9  9880 15960 12080 16560 20440 37000 14320 9120 7560 8080 11040 8280 13880 12120 13520 16480 9200 16840 40920 18400 4480 5680 9520 7080 5080 3840 5380 6040 7560 7680 6700 13320  4220 3420 3100 3740 3240 3540 4380 4020 4380 4480 3760 3800 4020 3200 2980 3120 3560 3260 3300 3300 2660 2880 3180 3500 2440 2720 1570 1590 1820 3900 5720 3640 3560  7780 6460 12860 8340 13320 16900 32620 10300 4740 3080 4320 7240 4260 10680 9140 10400 12920 5940 13540 37620 15740 1600 2500 6020 4640 2360 2270 3790 4220 3660 1960 3060 9760  64.8 65.4 80.6 69.0 80.4 82.7 88.2 71.9 52.0 40.7 53.5 65.6 51.4 76.9 75.4 76.9 78.4 64.6 80.4 91.9 85.5 35.7 44.0 63.2 65.5 46.5 59.1 70.4 69.9 48.4 25.5 45.7 73.3  27120 5880 22000  1840 1900 2080  25280 3980 19920  93.2 67.7 90.5  144  16-Jul-05 17-Jul-05 19-Jul-05 20-Jul-05  1950 2070 2200 1840  730 1140 1190 1130  1220 930 1010 710  62.6 44.9 45.9 38.6  7800 7320 29360 20080  1460 5280 3120 3400  6340 2040 26240 16680  81.3 27.9 89.4 83.1  145  Table A.2. Raw data for daily operation of mechanical-mixing SBR, NH4-N, NO -N, SND efficiency, and PO4-P x  NH -N  NOx-N  4  Absolute  Removal  Removal  Efficiency  (mg/L)  (%)  140.8  57.6  139.0  49.8  153.6  40.8  190.4  154.2  36.2  13-Jan-05  196.0  136.0  13-Jan-05  190.4  146.6  14-Jan-05  210.4  133.6  14-Jan-05  211.2  18-Jan-05 18-Jan-05 19-Jan-05  Day  Influent (mg/L)  Effluent (mg/L)  9-Jan-05  198.4  9-Jan-05  188.8  12-Jan-05  194.4  12-Jan-05  PO4-P Absolute  Removal  Removal  Efficiency  (mg/L)  (%)  12.5  13.3  51.6  11.6  16.8  59.2  30.7  15.0  15.7  51.1  95.4  31.8  14.9  16.9  53.1  SND  Influent (mg/L)  Effluent (mg/L)  25.8 28.4  108.4  Influent (mg/L)  Effluent (mg/L)  29.0  0.25  0.42  26.4  0.46  0.54  99.3  21.0  0.35  0.64  Efficiency  (%)  19.0  0.47  0.78  60.0  30.6  0.27  0.42  99.4  29.4  15.6  13.8  47.1  43.8  23.0  0.32  0.57  22.8  29.6  15.1  14.5  48.9  76.8  36.5  0.30  1.44  95.6  54.0  13.6  40.4  74.7  129.6  81.6  38.6  0.27  1.55  93.4  53.5  13.5  40.0  74.7  152.0  96.0  56.0  36.8  0.59  45.20  -17.1  36.4  18.7  17.7  48.6  150.6  97.6  53.0  35.2  0.70  46.32  -389.9  39.3  18.3  21.0  53.4  39.0  9.3  29.8  76.2  2.72  21.96  74.9  21.8  8.1  13.6  62.7  19-Jan-05  41.3  11.2  30.0  72.8  2.74  22.56  -347.3  22.2  0.8  21.4  96.5  20-Jan-05  156.0  5.9  150.1  96.2  1.24  18.92  48.5  23.0  19.3  3.7  16.0  95.0  1.34  20.48  31.2  23.2  20.5  2.7  11.7  20-Jan-05  154.1  7.7  146.4  25-Jan-05  216.0  10.5  205.5  95.1  3.02  15.24  68.6  32.0  18.6  13.4  41.9  25-Jan-05  209.6  11.5  198.1  94.5  3.43  15.04  70.1  32.6  17.3  15.4  47.1  26-Jan-05  231.2  5.0  226.2  97.8  0.78  16.24  69.3  36.4  20.3  16.2  44.3  26-Jan-05  227.2  4.9  222.3  97.8  1.10  16.64  65.1  35.9  19.5  16.4  45.7  27-Jan-05  198.4  5.6  192.8  97.2  0.74  19.24  51.4  20.9  19.3  1.6  7.8  27-Jan-05  182.4  5.4  177.0  97.0  0.80  19.92  46.2  19.5  18.6  0.9  4.5 6.3  28-Jan-05  156.8  16.5  140.3  89.5  0.86  24.12  -21.2  15.9  14.9  1.0  28-Jan-05  157.6  19.4  138.2  87.7  1.09  24.40  8.0  14.5  14.1  0.4  2.8  30-Jan-05  85.6  1.8  83.8  97.9  0.72  18.68  41.6  25.0  14.7  10.3  41.3  30-Jan-05  81.1  2.2  78.9  97.3  0.76  19.36  -20.2  22.2  15.7  6.6  29.5  31-Jan-05  93.6  4.2  89.4  95.5  0.70  9.84  43.8  24.6  18.7  5.9  24.0  31-Jan-05  82.7  3.9  78.9  95.3  0.79  9.84  43.7  23.5  17.0  6.6  27.9  8-Feb-05  128.8  8.5  120.3  93.4  0.24  0.52  98.7  23.2  25.4  -2.2  -9.7  9-Feb-05  126.4  4.9  121.5  96.1  10.92  20.48  64.8  28.9  14.2  14.7  50.9  10-Feb-05  136.0  9.3  126.7  93.2  2.36  4.36  90.8  24.6  12.1  12.6  51.0  11-Feb-05  133.6  33.7  99.9  74.8  0.34  2.69  -406.1  27.2  23.4  3.8  14.0  12-Feb-05  129.6  36.2  93.4  72.0  0.39  1.68  92.2  24.0  21.6  2.4  10.2  13-Feb-05  139.2  29.4  109.8  78.9  0.42  2.53  92.3  28.4  22.4  6.0  21.1  14-Feb-05  146.4  91.2  55.2  37.7  0.45  0.24  99.5  58.0  24.9  33.1  57.0  16-Feb-05  140.0  99.2  40.8  29.1  0.21  0.29  95.7  55.2  24.4  30.8  55.8  17-Feb-05  129.6  109.6  20.0  15.4  0.74  0.30  89.9  49.2  24.3  24.9  50.7 44.9  19-Feb-05  120.8  78.0  42.8  35.4  0.81  0.45  101.1  38.5  21.2  17.3  20-Feb-05  116.8  62.2  54.6  46.7  0.90  8.96  65.7  36.3  15.7  20.6  56.7  23-Feb-05  100.8  43.4  57.4  56.9  0.55  10.52  62.4  36.9  21.4  15.5  42.1  26-Feb-05  36.0  17.6  18.4  51.1  0.32  0.74  98.3  27.4  12.5  14.9  54.3  27-Feb-05  106.4  63.8  42.6  40.1  0.44  0.90  101.6  55.2  20.2  35.0  63.5  28-Feb-05  103.2  47.8  55.4  53.6  0.16  0.96  96.6  53.2  17.2  36.0  67.7  1-Mar-05  106.4  48.6  57.8  54.4  0.48  0.53  99.5  2-Mar-05  99.2  44.2  55.0  55.4  0.34  0.76  97.1  53.6  17.4  36.2  67.5  3-Mar-05  91.2  19.0  72.2  79.2  0.35  4.04  89.4  46.0  16.8  29.2  63.4  4-Mar-05  105.6  13.4  92.2  87.3  1.26  2.53  94.5  42.2  16.2  26.0  61.6  5-Mar-05  83.2  25.9  57.3  68.8  0.89  1.70  44.6  55.0  19.8  35.3  64.1  7-Mar-05  74.2  22.0  52.2  70.3  0.51  1.13  95.5  29.5  19.3  10.2  34.7  8-Mar-05  76.3  4.2  72.1  94.5  1.39  16.24  48.2  27.4  20.5  7.0  25.4  10-Mar-05  73.0  3.3  69.7  95.5  1.91  9.12  50.9  29.4  17.1  12.3  41.8  12-Mar-05  75.9  4.9  71.1  93.6  2.13  3.78  87.2  30.0  17.7  12.3  41.1  15-Mar-05  80.0  20.4  59.6  74.5  1.94  1.65  44.1  37.2  19.2  18.0  48.4  17-Mar-05  114.4  56.3  58.1  50.8  1.92  12.48  161.7  38.6  21.1  17.4  45.2  18-Mar-05  110.4  49.6  60.8  55.1  1.58  18.24  5.0  51.2  20.7  30.5  59.5  19-Mar-05  116.0  44.8  71.2  61.4  2.69  2.67  100.1  50.2  14.2  36.1  71.8  20-Mar-05  105.6  35.8  1.29  1.82  97.5  55.5  12.8  42.7  76.9  103.8  81.8  69.8  66.1  21-Mar-05  97.6  32.0  65.6  67.2  2.06  1.46  84.0  15.3  68.7  22-Mar-05  107.2  51.3  55.9  52.2  2.11  1.46  84.5  41.0  16.8  24.2  59.0  24-Mar-05  108.0  52.7  55.3  51.2  1.10  0.86  102.4  37.6  11.2  26.4  70.2  26-Mar-05  112.0  69.6  42.4  37.9  1.12  1.46  106.7  40.2  11.0  29.2  72.6  28-Mar-05  118.4  57.6  60.8  51.4  1.42  1.60  99.2  50.1  11.8  38.2  76.4  1.31  1.25  100.3  50.4  15.1  35.3  70.0  108.2  72.8  30-Mar-05  108.0  44.8  63.2  58.5  4-Apr-05  103.3  52.3  51.0  49.3  0.56  0.21  40.4  11.0  29.4  6-Apr-05  108.9  60.5  48.3  44.4  0.41  0.25  105.2  41.2  11.6  29.6  71.8  8-Apr-05  98.5  15.1  83.4  84.7  0.28  1.41  97.9  42.8  12.8  30.0  70.1  9-Apr-05  111.3  15.4  95.8  86.1  0.27  2.12  90.2  73.2  9.4  63.8  87.2  0.27  1.18  96.5  49.2  17.0  32.2  65.4  0.23  1.42  95.5  73.2  9.4  63.8  87.2  90.2  76.0  12.1  63.9  84.1  94.9  73.6  11.5  62.1  84.3  9-Apr-05 9-Apr-05  112.1 112.1  9.0 3.3  103.0 108.8  91.9 97.1  10-Apr-05  121.2  3.6  117.6  97.0  1.46  3.74  11-Apr-05  94.5  7.0  87.4  92.6  0.44  1.20  12- Apr-05 13-Apr-05 14- Apr-05 17- Apr-05 18- Apr-05 19-Apr-05 20- Apr-05 21-Apr-05 22- Apr-05 23-Apr-05 24-Apr-05 25- Apr-05 26-Apr-05 27-Apr-05 28-Apr-05 29- Apr-05 1- May-05 2- May-05 3- May-05 4- May-05 7- May-05 8- May-05 9- May-05 12- May-05 13- May-05 14- May-05 15- May-05 17-May-05 20-May-05 22-May-05 24-May-05 26- May-05 27- May-05 28- May-05 29- May-05 30- May-05 31- May-05 1-Jun-05  104.1 108.9 112.1 94.5 85.7 88.1 62.5 58.1 97.7 92.1 86.5 80.9 93.7 77.3 82.5 75.9 100.1 104.1 116.1 110.5 93.7 96.1 121.7 134.5 150.5 146.5 153.7 142.5 137.7 159.3 131.3 161.7 149.7 156.9 166.5 164.9 159.3 121.7  1.7 10.7 16.5 18.3 18.9 17.1 5.4 4.9 0.2 3.6 2.3 2.1 2.2 3.0 7.7 4.3 3.2 1.1 1.0 0.1 0.5 10.9 18.3 37.9 21.7 12.9 7.9 9.7 109.7 120.1 112.9 72.6 74.2 81.7 110.5 116.1 123.3 128.1  102.3 98.2 95.5 76.2 66.8 71.0 57.1 53.2 97.5 88.5 84.1 78.8 91.5 74.3 74.7 71.6 96.8 103.0 115.0 110.3 93.1 85.1 103.4 96.6 128.8 133.6 145.8 132.8 28.0 39.2 18.4 89.0 75.4 75.2 56.0 48.8 36.0 -6.4  98.3 90.2 85.2 80.6 78.0 80.6 91.4 91.5 99.8 96.1 97.3 97.4 97.7 96.2 90.6 94.3 96.8 99.0 99.1 99.9 99.4 88.6 85.0 71.8 85.6 91.2 94.9 93.2 20.3 24.6 14.0 55.1 50.4 47.9 33.6 29.6 22.6 -5.3  1.34 0.97 1.69 1.40 1.26 1.37 1.41 1.31 1.48 1.45 0.87 1.26 0.62 1.39 1.28 1.19 1.38 0.93 0.74 0.99 1.11 0.92 1.26 0.53 0.70 1.40 0.77 0.62 1.50 1.23 0.53 0.59 0.92 1.28 1.02 1.54 1.00 0.54  3.98 1.28 1.36 3.10 1.37 2.05 1.27 1.22 3.10 3.98 3.58 4.08 5.60 4.28 2.22 3.49 7.36 7.24 5.16 7.04 5.64 7.68 9.76 9.40 4.04 2.50 3.60 4.16 1.24 1.22 0.64 0.82 1.06 0.80 0.74 1.21 1.48 0.60  89.3 97.5 102.3 87.7 99.1 95.3 101.0 100.5 92.2 77.0 88.4 81.1 72.1 81.9 94.9 83.8 46.2 63.0 78.2 72.9 80.3 70.3 53.6 -2.1 77.4 69.7 92.7 89.5 100.8 100.0 100.1 147.5 98.5 101.0 102.0 103.6 104.1 98.8  26.1 34.0 46.0 48.0 26.0 28.0 15.7 17.4 33.5 33.6 32.3 28.7 30.6 35.3 31.6 36.3 41.6 33.7 28.4 27.8 29.0 32.6 28.6 31.4 29.3 27.5 34.4 35.9 25.4 32.0 33.7 34.6 35.7 41.6 39.3 45.2 48.8 45.2  15.7 11.5 9.4 14.2 12.0 13.6 9.1 14.9 14.7 15.9 14.8 16.0 14.9 14.7 14.9 15.4 18.8 14.6 10.8 10.8 10.4 10.3 11.8 7.6 9.1 10.6 18.0 16.9 15.4 14.5 13.1 8.1 9.9 11.0 13.0 12.7 14.6 14.9  10.4 22.5 36.6 33.8 14.1 14.4 6.6 2.5 18.8 17.7 17.5 12.6 15.6 20.6 16.6 20.9 22.8 19.0 17.6 17.1 18.6 22.3 16.8 23.8 20.2 16.8 16.4 19.0 10.0 17.5 20.6 26.5 25.8 30.6 26.3 32.5 34.2 30.3  39.9 66.2 79.6 70.3 54.1 51.3 41.8 14.5 56.1 52.7 54.1 44.1 51.2 58.3 52.7 57.5 54.8 56.5 62.1 61.4 64.1 68.5 58.7 75.8 69.0 61.3 47.7 52.9 39.4 54.8 61.2 76.5 72.2 73.6 66.9 71.9 70.1 67.0  3-Jun-05  130.5  118.5  12.0  9.2  0.56  0.51  103.6  36.9  16.7  20.2  54.7  4-Jun-05  123.3  108.9  14.4  11.7  0.41  0.56  102.9  37.3  14.6  22.7  60.8  5-Jun-05  146.5  104.1  42.4  28.9  0.31  0.76  95.5  41.6  17.1  24.5  58.8  8-Jun-05  149.7  98.5  51.2  34.2  0.46  0.51  99.5  43.2  15.2  28.0  64.8  9-Jun-05  162.5  109.7  52.8  32.5  1.01  0.41  104.9  37.8  17.3  20.6  54.3  10-Jun-05  141.7  116.9  24.8  17.5  1.66  0.87  105.4  38.7  19.3  19.4  50.1  12-Jun-05  136.9  114.5  22.4  16.4  5.06  2.10  284.5  37.8  19.5  18.2  48.3  13-Jun-05  135.3  108.9  26.4  . 19.5  2.56  3.89  266.0  38.9  18.1  20.8  53.5  14-Jun-05  132.9  105.7  27.2  20.5  0.71  2.06  79.0  37.7  16.8  20.9  55.5  16-Jun-05  132.1  122.5  9.6  7.3  0.85  0.74  101.1  41.6  18.2  23.4  56.3  18-Jun-05  112.1  89.7  22.4  20.0  2.76  3.17  94.9  30.5  18.9  11.6  38.0  19-Jun-05  103.3  3.1  100.2  97.0  1.70  15.28  217.8  25.6  20.4  5.1  20.0  20-Jun-05  91.3  84.9  6.4  7.0  2.00  2.26  99.2  27.3  17.2  10.1  37.0  22-Jun-05  95.3  81.7  13.6  14.3  1.29  1.58  99.7  25.8  17.9  8.0  30.8  24-Jun-05  106.5  88.9  17.6  16.5  0.80  0.45  99.5  22.7  19.4  3.3  14.5  25-Jun-05  112.1  84.1  28.0  25.0  0.69  0.51  103.4  22.7  18.3  4.4  19.2  27-Jun-05  98.5  92.1  6.4  6.5  0.55  0.69  106.1  23.2  21.0  2.2  9.5  28-Jun-05  106.5  82.5  24.0  22.5  1.19  0.44  108.0  31.5  22.0  9.5  30.1  30-Jun-05  97.7  84.9  12.8  13.1  0.42  0.81  107.7  28.6  24.2  4.4  15.2  1-Jul-05  84.1  45.5  38.6  45.9  0.59  0.69  99.2  21.9  16.9  5.0  23.0  2-Jul-05  106.5  81.7  24.8  23.3  1.18  1.01  126.3  32.0  22.1  9.9  31.0  3-Jul-05  115.6  90.4  25.2  21.8  2.26  0.61  104.2  33.4  26.8  6.6  19.8  5-Jul-05  95.3  88.1  7.2  7.6  0.57  0.85  101.2  55.2  23.5  31.7  57.5  6-Jul-05  104.9  77.2  27.7  26.4  1.28  0.74  72.4  36.4  25.1  11.2  30.9  7-Jul-05  94.5  84.1  10.4  11.0  0.76  0.25  115.4  32.2  23.9  8.3  25.8  8-Jul-05  86.5  72.0  14.5  16.7  1.19  0.44  105.3  28.0  21.0  7.0  25.0  10-Jul-05  149.7  135.3  14.4  9.6  1.34  0.91  87.5  22.5  16.4  6.1  27.2  12-Jul-05  97.7  60.5  37.2  38.1  0.81  0.87  99.6  28.0  14.5  13.5  48.3 27.4  13-Jul-05  82.5  70.8  11.7  14.2  0.70  1.00  100.6  21.7  15.8  6.0  15-Jul-05  145.7  105.7  40.0  27.5  0.23  0.37  99.8  46.0  13.4  32.6  70.9  17-Jul-05  108.1  84.1  24.0  22.2  1.42  0.46  83.8  36.8  19.2  17.6  47.9  19-Jul-05  101.7  83.3  18.4  18.1  0.74  0.89  100.8  36.0  20.0  16.1  44.6  20-Jul-05  92.9  85.7  7.2  7.8  1.66  0.86  103.6  32.2  20.8  11.4  35.3  Table A.3. Raw data for daily operation of mechanical-mixing SBR, TP and TKN TKN  TP Day  9-Jan-05  Influent  Effluent  Absolute  Removal  Removal  Efficiency  (mg/L)  (mg/L)  (mg/L)  (%)  30.3  15.9  14.4  47.4  Influent  Effluent  (mg/L)  (mg/L)  Absolute  Removal  Removal  Efficiency  (mg/L)  (%)  9-Jan-05  31.6  15.1  16.5  52.2  229.2  172.8  56.4  24.6  12-Jan-05  29.2  15.7  13.5  46.3  230.4  183.2  47.2  20.5  12-Jan-05  31.1  15.0  16.1  51.7  236.0  194.0  42.0  17.8  13-Jan-05  50.4  13.8  36.6  72.5  232.0  164.8  67.2  29.0  13-Jan-05  50.6  14.3  36.2  71.7  254.4  154.0  100.4  39.5  14-Jan-05  40.8  19.4  21.4  52.5  244.0  164.0  80.0  32.8  14-Jan-05  41.5  18.2  23.3  56.1  182.4  136.4  46.0  25.2  18-Jan-05  20.9  8.0  12.9  61.8  182.4  138.4  44.0  24.1  18-Jan-05  20.0  8.0  12.0  60.0  54.8  31.8  23.0  41.9  19-Jan-05  23.2  17.8  5.4  23.1  55.3  35.1  20.2  36.5  19-Jan-05  21.8  21.5  0.3  1.5  182.8  29.0  153.8  84.1  20-Jan-05  30.0  19.8  10.1  33.8  195.2  31.0  164.2  84.1  20-Jan-05  31.8  22.2  9.6  30.2  220.8  37.6  183.2  83.0  25-Jan-05  21.0  19.4  1.7  8.0  276.0  37.9  238.1  86.3  25-Jan-05  19.7  19.4  0.2  1.2  218.4  218.4  100.0  26-Jan-05  10.6  10.0  0.6  5.6  218.4  42.6  175.8  80.5  26-Jan-05  15.2  15.5  -0.3  -2.1  62.0  56.0  6.0  9.7  37.8  38.2  -0.3  -0.8  27-Jan-05 27-Jan-05 28-Jan-05 28-Jan-05 30-Jan-05 30-Jan-05 31-Jan-05 31-Jan-05 8-Feb-05  11.8  14.4  -2.6  -22.4  91.2  13.0  78.2  85.8  9-Feb-05  11.8  12.0  -0.2  -1.4  102.4  9.6  92.8  90.6 84.3  10-Feb-05  20.2  14.4  5.8  28.9  82.4  13.0  69.4  11-Feb-05  20.6  15.5  5.0  24.5  77.3  15.8  61.4  79.5  12-Feb-05  10.9  8.0  2.9  26.5  107.2  19.1  88.1  82.2  Remarks  13-Feb-05  12.5  9.2  3.3  26.3  80.8  6.6  74.2  14-Feb-05  11.4  13.2  -1.8  -15.4  84.0  40.7  43.3  91.8 51.5  16-Feb-05  30.9  2.7  28.2  91.3  65.7  -3.8  69.5  105.8  17-Feb-05  30.0  29.3  0.7  2.4  81.6  141.6  -60.0  -73.5  19-Feb-05  27.9  11.8  16.1  57.6  105.6  135.2  -29.6  -28.0  20-Feb-05  38.1  11.8  26.2  68.9  105.6  -1.9  107.5  101.8  23-Feb-05  30.9  0.0  30.9  100.0  107.2  19.1  88.1  82.2  26-Feb-05  30.0  13.3  16.7  55.7  80.8  6.6  74.2  91.8  27-Feb-05  27.9  11.8  16.1  57.6  84.0  40.7  43.3  51.5  52.3  20.0  32.3  61.8  145.6  58.9  86.7  59.6  4-Mar-05  66.4  23.4  43.0  64.7  160.8  39.8  121.0  75.3  5-Mar-05  41.4  24.0  17.4  42.0  138.4  62.5  75.9  54.9  7-Mar-05  34.2  25.5  8.6  25.3  118.4  48.1  70.3  59.4  8-Mar-05  34.7  21.8  13.0  37.3  113.6  33.6  80.0  70.4  10-Mar-05  41.3  24.9  16.4  39.7  115.2  28.5  86.7  75.3  12-Mar-05  42.2  24.5  17.8  42.0  111.2  53.5  57.7  51.9  15-Mar-05  56.2  26.7  29.5  52.5  144.8  44.6  100.2  69.2  17-Mar-05  62.4  19.0  43.4  69.5  160.0  30.3  129.7  81.1  18-Mar-05  59.1  19.0  40.2  67.9  156.8  28.1  128.7  82.1  19-Mar-05  89.6  18.1  71.5  79.8  132.8  59.8  73.0  54.9  20-Mar-05  86.4  35.2  51.2  59.3  215.2  68.8  146.4  68.0  21-Mar-05  68.8  34.6  34.2  49.8  220.0  75.2  144.8  65.8  22-Mar-05  46.1  20.6  25.5  55.4  136.0  54.0  82.0  60.3  24-Mar-05  40.4  13.9  26.5  65.5  112.0  38.4  73.6  65.7  26-Mar-05  47.7  15.5  32.2  67.4  141.6  71.6  70.0  49.4  28-Mar-05  55.3  15.4  39.9  72.2  148.0  80.0  68.0  45.9  30-Mar-05  57.6  18.9  38.7  67.2  156.0  96.8  59.2  37.9  4-Apr-05  44.8  16.6  28.2  62.9  140.8  81.6  59.2  42.0  6-Apr-05  50.1  22.9  27.2  54.3  151.2  94.4  56.8  37.6  8-Apr-05  56.1  18.9  37.2  66.3  72.6  68.4  4.2  5.7  36.2  95.0  72.4  28-Feb-05 1-Mar-05 2-Mar-05 3-Mar-05  9-Apr-05  92.0  18.8  73.2  79.6  131.2  9-Apr-05  92.0  18.7  73.3  79.7  131.2  36.9  94.3  71.9  9-Apr-05  92.0  15.6  76.4  83.0  131.2  30.9  100.3  76.5  10-Apr-05  39.6  17.4  22.2  56.2  53.3  32.9  20.4  38.3  11-Apr-05  34.4  15.9  18.5  53.7  138.4  22.4  116.0  83.8  12-Apr-05  52.7  14.3  38.4  72.8  156.0  30.9  125.1  80.2  13-Apr-05  56.0  18.1  37.9  67.7  172.0  42.2  129.8  75.4  14-Apr-05  49.7  17.4  32.2  64.9  160.8  46.6  114.2  71.0  17-Apr-05  35.4  17.0  18.4  52.0  144.8  56.1  88.7  61.3  18-Apr-05  54.6  27.2  27.4  50.2  232.8  64.6  168.2  72.2  18-Apr-05  36.7  16.5  20.2  55.1  132.0  50.9  81.1  61.5  19-Apr-05  56.8  29.3  27.5  48.5  203.2  62.7  140.5  69.1  19-Apr-05  36.8  17.2  19.6  53.3  126.4  48.6  77.8  61.6  20-Apr-05  53.4  21.9  31.4  58.9  227.2  50.9  176.3  77.6  20-Apr-05  26.6  25.7  1.0  3.6  116.0  34.9  81.1  69.9  21-Apr-05  69.3  22.2  47.0  67.9  281.6  33.4  248.2  88.1  21-Apr-05  40.2  19.4  20.7  51.6  176.0  36.0  140.0  79.5  22-Apr-05  42.7  20.9  21.8  51.1  176.0  41.0  135.0  76.7  23-Apr-05  41.7  18.8  22.9  54.9  140.0  37.1  102.9  73.5  24-Apr-05  48.8  22.6  26.2  53.8  148.8  41.2  107.6  72.3  25-Apr-05  35.1  17.7  17.4  49.7  139.2  36.0  103.2  74.1  26-Apr-05  58.6  20.5  38.1  65.0  248.8  36.9  211.9  85.2  26-Apr-05  32.6  18.6  14.0  43.0  150.4  38.4  112.0  74.5  27-Apr-05  42.1  17.0  25.0  59.5  151.2  37.5  113.7  75.2  28-Apr-05  47.8  18.3  29.4  61.6  153.6  32.6  121.0  78.8  29-Apr-05  52.5  18.5  34.0  64.8  156.0  24.1  131.9  84.6  1-May-05  152.0  51.0  101.0  66.4  123.2  176.8  -53.6  -43.5  2-May-05  64.5  22.6  41.9  65.0  161.6  37.1  124.5  77.0  3-May-05  56.5  18.6  37.9  67.1  159.2  35.8  123.4  77.5  4-May-05  39.8  15.3  24.6  61.6  168.8  22.2  146.6  86.9  7-May-05  35.9  12.3  23.6  65.7  196.0  36.4  159.6  81.4  8-May-05  36.9  15.2  21.7  58.8  174.4  37.9  136.5  78.3  9-May-05  40.3  29.4  11.0  27.2  183.2  41.0  142.2  77.6  12-May-05  59.2  20.2  39.0  65.9  158.4  39.4  119.0  75.1  13-May-05  41.2  11.5  29.7  72.0  268.8  48.0  220.8  82.1  14-May-05  35.2  10.2  25.0  71.1  206.4  36.9  169.5  82.1  Total values  Total values  Total values  Total values  20-May-05  105.6  46.9  58.7  55.6  372.0  238.4  133.6  35.9  20-May-05  55.0  16.9  38.1  69.3  327.2  176.8  150.4  46.0  22-May-05  114.4  40.2  74.2  64.9  674.4  125.6  548.8  81.4  22-May-05  38.3  19.9  18.4  48.0  249.6  250.4  -0.8  -0.3  24-May-05  109.6  51.8  57.8  52.8  741.6  412.0  329.6  44.4  24-May-05  39.9  15.4  24.5  61.3  280.0  219.2  60.8  21.7  26-May-05  44.6  17.9  26.7  59.9  254.4  136.8  117.6  46.2  26-May-05  68.2  23.7  44.5  65.3  729.6  352.0  377.6  51.8  27-May-05  57.1  23.6  33.5  58.7  238.4  165.6  72.8  30.5  27-May-05  83.2  21.6  61.6  74.0  440.8  340.8  100.0  22.7  28-May-05  50.0  21.4  28.6  57.3  169.6  133.6  36.0  21.2  28-May-05  79.0  24.0  55.0  69.6  627.2  358.4  268.8  42.9  29-May-05  49.0  25.1  23.8  48.7  239.2  183.2  56.0  23.4  29-May-05  94.4  31.0  63.4  67.1  526.4  443.2  83.2  15.8  30-May-05  44.7  13.8  30.9  69.1  319.2  236.0  83.2  26.1  30-May-05  100.2  39.8  60.3  60.2  659.2  374.4  284.8  43.2  31-May-05  56.2  15.4  40.8  72.6  301.6  244.8  56.8  18.8  31-May-05  116.6  37.3  79.4  68.0  840.0  356.8  483.2  57.5 36.1  1-Jun-05  40.5  17.0  23.5  58.1  356.8  228.0  128.8  4-Jun-05  51.6  36.0  15.6  30.2  318.4  158.4  160.0  50.3  8-Jun-05  55.1  30.6  24.6  44.6  374.4  272.8  101.6  27.1  10-Jun-05  44.3  23.9  20.4  46.0  377.6  228.8  148.8  39.4  12-Jun-05  48.8  34.4  14.4  29.5  292.8  150.4  142.4  48.6  Total values  Total values  Total values  Total values  Total values  Total values  Total values  Total values  Total values  14-Jun-05  41.8  27.7  14.2  33.8  238.4  116.8  121.6  51.0  16-Jun-05  55.3  41.2  14.1  25.5  440.0  300.0  140.0  31.8  19-Jun-05  27.0  3.2  23.8  88.2  213.6  51.3  162.3  76.0  19-Jun-05  54.7  41.0  13.7  25.0  580.8  306.4  274.4  47.2  20-Jun-05  29.7  20.2  9.5  32.1  211.2  172.8  38.4  18.2  20-Jun-05  109.8  41.4  68.3  62.2  934.4  280.0  22-Jun-05  59.5  44.2  15.4  25.8  353.6  181.6  24-Jun-05  42.4  42.9  -0.5  -1.1  244.8  195.2  25-Jun-05  45.9  41.4  4.6  9.9  238.4  188.8  27-Jun-05  157.3  135.2  22.1  14.0  1036.8  496.8  28-Jun-05  432.0  360.0  72.0  16.7  1020.8  0.0  30-Jun-05  51.0  44.1  7.0  13.6  270.4  183.2  1-Jul-05  65.1  13.1  52.0  79.9  377.6  97.6  2-Jul-05  81.6  67.4  14.2  17.5  348.0  309.6  4-Jul-05  49.1  33.8  15.4  31.3  206.4  148.0  654.4  172.0  49.6  49.6  540.0  1020.8  87.2  280.0  38.4 58.4  70.0  Total values  48.6  Total values  20.3  Total values  20.8  Total values  52.1  Total values  100.0  Total values  32.2  Total values  74.2  Total values  11.0  Total values  28.3  6-Jul-05  57.4  46.9  10.6  18.4  153.6  161.6  -8.0  -5.2  8-Jul-05  35.3  22.7  12.6  35.6  161.6  118.4  43.2  26.7  10-Jul-05  41.6  25.7  15.9  38.3  140.0  124.8  15.2  10.9  12-Jul-05  182.4  38.4  78.9  1508.8  168.0  1340.8  88.9  144.0  Total values  Total values  12- J u ! - 0 5  25.0  19.2  5.8  23.3  106.4  13- J u l - 0 5  27.8  21.0  6.7  24.2  146.4  15-Jul-05  143.5  57.3  86.2  60.1  800.0  17-Jul-05  43.9  27.1  16.8  38.3  166.4  19- J u l - 0 5  120.2  53.2  67.0  55.7  921.6  2 0 -J u l - 0 5  38.9  23.8  15.0  38.7  152.0  Table A.4. %P/ M L V S S values for mode B Day  %P/ MLVSS  13- A p r - 0 5  2.16  14-A p r - 0 5  2.74  15- A p r - 0 5  2.84  1 6 -A p r - 0 5  3.33  18-Apr-05  1.94  Table A.5. %P/ M L V S S values for mode C Day  %P/ MLVSS  13-Jul-05  1.68  15-Jul-05  1.66  17-Jul-05  1.40  19-Jul-05  1.70  20-Jul-05  1.34  100.0  6.4  6.0  116.0  30.4  20.8  148.8  651.2  81.4  128.8  37.6  22.6  231.2  690.4  74.9  138.4  13.6  8.9  Total values  Total values  Table A.6. Raw data for track study, mode A  Table A.7. Raw date for track study, Mode B  Time  NH4-N  NOx-N  P04-P  Time  NH4-N  NOx-N  P04-P  (hrs)  (mg/L)  (mg/L)  (mg/L)  (hrs)  (mg/L)  (mg/L)  (mg/L)  Influent  100  2.76  49.2  Influent  99.2  2.952  33.52  0:00  23.68  1.228  19.92  0:00  1.696  5.44  15.52  0:30  24.8  0.892  21.36  0:30  23.68  2.216  27.2  1:00  26.4  1.116  25.72  1:00  20.8  3.68  31.6  1:30  1.276 1.168  24.08  20.96  3.96 2.84  28.32  25.08  1:30 2:00  20.48  2:00  28 30.4  2:30  29.6  1.408  29.12  2:30  21.76  1.872  34.08  3:00  29.6  1.408  29.12  3:00  21.76  1.872  34.08  3:30  28.8  1.82  24.76  3:30  20.8  2.096  31.52  4:00  28  2.452  30.24  4:00  20.48  3.488  30  4:30  27.2  1.632  24.6  4:30  19.92  3.432  28.16  5:00  26.4  1.488  22.96  5:00  20.88  4.792  31.2  5:30  26.4  1.532  23.4  5:30  20.08  3.792  28.88  6:00  24.8  1.248  23.68  6:00  20.08  4.768  30.48  6:30  24.8  1.108  26.8  6:30  19.04  3.832  27.28  7:00  22.4  1.492  23.48  7:00  18.72  5.64  30.16  7:30  24  1.392  23.52  7:30  18.24  4.184  29.68  8:00  23.2  1.72  26.28  8:00  16  6.272  23.84  8:30  24.8  2.308  21.76  8:30  16.16  6.952  27.44  9:00  20.8  3.32  22.24  9:00  12.96  5.296  25.44  9:30  18.4  4.4  22.4  9:30  13.2  4.048  25.2  10:00  18.8  5.28  20.68  10:00  12.48  5.36  25.76  10:30  19.2  6.64  20.92  10:30  10.16  7.08  22  11:00  18.4  8.44  20.64  11:00  8.88  6.984  24.32  11:30  17.6  5.2  17.92  11:30  4.432  3.864  15.92  12:00  17.6  4.2  15.24  12:00  5.624  .5.96  27.04  12:30  4.072  8.96  24.48  13:00  3.088  10.56  22.8  13:30  2.728  12.56  25.44  15:00  3.232  7.312  17.2  16:00  1.744  10.96  24.72  26.48  156  Table A.8. Raw data for track study, Mode C Time  NH4-N  NOx-N  P04-P  (hrs)  (mg/L)  (mg/L)  (mg/L)  Influent  116.4  2.264  33.4  0:00  85.2  5.52  32.64 26.64  1:00  91.6  2.624  2:00  84  1.472  42  3:00  94.8  1.648  31.64  4:00  95.6  1.312  30.04  5:00  87.6  1.84  30.48  6:00  89.2  5.12  28.28  7:00  84  0.992  24.76  8:00  84  2.38  24.92  9:00  88  4.6  25.92  10:00  88.8  2.168  26.88  11:30  90.4  1.732  28.72  12:30  86  5.8  27.88  14:00  91.2  0.612  26.8  Table A.9. Continued 16-Apr-05  272.0  19-Apr-05  260.0  54.8  22-Apr-05  217.5  40.1  P0 -P 4  25-Apr-05  292.6  55.4  (mg/L)  (mg/L)  28-Apr-05  200.9  62.9  1-May-05  317.3  63.1  15-Feb-05  292.6  34.1  4-May-05  251.2  70.0  18-Feb-05  288.5  34.4  7-May-05  284.0  66.8  21-Feb-05  216.2  38.2  10-May-05  288.4  55.4  172.6  60.7 57.6  Table A.9. Raw data for lab-scale digester Date  NH -N 4  52.8  24-Feb-05  267.7  34.6  13-May-05  27-Feb-05  283.7  16.7  16-May-05  300.4  2-Mar-05  281.6  15.7  19-May-05  277.4  58.1  5-Mar-05  221.9  19.7  22-May-05  299.2  69.2  8-Mar-05  255.5  23.0  25-May-05  222.3  62.2  292.8  70.0  11-Mar-05  177.6  22.7  28-May-05  14-Mar-05  210.2  13.8  31-May-05  281.6  70.4  17-Mar-05  245.6  12.8  3-Jun-05  260.8  66.8  20-Mar-05  308.0  26.4  6-Jun-05  283.2  64.4  38.2  9-Jun-05  289.6  70.4  12-Jun-05  229.3  66.4  299.2  69.2  23-Mar-05  211.8  26-Mar-05  276.4  35.8  29-Mar-05  204.8  43.0  15-Jun-05  1-Apr-05  71.6  50.6  24-Jun-05  74.0  4-Apr-05  191.0  40.2  30-Jun-05  69.9  7-Apr-05  204.8  43.0  6-Jul-05  70.0 83.0 84.0  10-Apr-05  301.7  49.9  12-Jul-05  13-Apr-05  274.1  59.8  21-Jul-05  APPENDIXBi DATA FOR GAS-MIXING SBR Table B.l. Raw data for daily operation, gas-mixing SBR, s-COD, TOC and t-COD s-COD Day  Influent (mg/L)  t-COD  TOC  Effluent (mg/L)  Absolute Removal (mg/L)  Removal Efficiency (%)  Influent (mg/L)  Effluent (mg/L)  Absolute Removal (mg/L)  Removal Efficiency (%)  18-Jun-05  680  304  376  377.7  19-Jun-05  208  192  16  7625.0  20-Jun-05  456  256  200  600.0  22-Jun-05  384  216  168  2095.2  Influent (mg/L)  Effluent (mg/L)  Absolute Removal (mg/L)  Removal Efficiency (%)  5280  1420  3860  73.1  10560  1220  9340  88.4  5760  1200  4560  79.2  16040  3520  12520  78.1 59.0  24-Jun-05  544  168  376  69.1  8000  3280  4720  25-Jun-05  560  312  248  44.3  15080  3720  11360  75.3  27-Jun-05  464  352  112  24.1  9520  3500  6020  63.2  28-Jun-05  760  264  496  65.3  18440  3800  14640  79.4  30-Jun-05  456  480  -24  -5.3  7600  4060  3540  46.6  1-Jul-05  992  456  536  54.0  4800  4040  760  15.8  2-Jul-05  896  416  480  53.6  4040  4180  -140  -3.5  7240  4260  2980  41.2  3-Jul-05  2640  1080  1560  59.1  5-Jul-05  1350  1050  300  22.2  7560  4120  3440  45.5  6-Jul-05  2380  1850  530  22.3  312  208  104  33.3  5800  5160  640  11.0  7-Jul-05  2110  910  1200  56.9  1584  256  1328  83.8  17040  4020  13020  76.4  8-Jul-05  1620  840  780  48.1  10320  3700  6620  64.1  10-Jul-05  1240  830  410  33.1  12-Jul-05  2340  820  1520  65.0  13-Jul-05  1780  860  920  51.7  15-Jul-05  1640  910  730  44.5  17-Jul-05  1770  920  850  48.0  19-Jul-05  2060  980  1080  52.4  20-Jul-05  2020  940  1080  53.5  272 248  192 168  80 80  29.4 32.3  9480  3220  6260  66.0  16440  3460  12980  79.0  9240  3100  6140  66.5  22200  3040  19160  86.3  18200  3340  14860  81.6  5120  3120  2000  39.1  158  Table B.2. Raw data for daily operation, gas-mixing SBR, NH4-N, NO -N, SND efficiency and PO4-P x  NH4-N Day  Influent (mg/L)  Effluent (mg/L)  NOx-N  Absolute Removal (mg/L)  Efficiency  Removal (%)  Influent (mg/L)  P O 4-P  Effluent (mg/L)  Influent (mg/L)  Effluent (mg/L)  Removal  Absolute Removal (mg/L)  Efficiency  47.9  (%)  18-Jun-05  192.1  16.2  175.8  91.6  2852.8  1485.4  261184.5  135988.2  125196.2  19-Jun-05  103.3  3.1  100.2  97.0  306.2  296.6  29717.3  28778.0  939.3  3.2  20-Jun-05  184.1  1.0  183.1  99.5  177.2  96.3  17630.5  9578.5  8052.0  45.7  22-Jun-05  187.3  -0.6  187.9  100.3  -112.7  -60.2  -11308.0  -6038.5  -5269.4  46.6  9379.0  4725.8  366723.4  184780.8  181942.6  49.6  24-Jun-05  198.5  120.9  77.6  39.1  25-Jun-05  182.5  141.7  40.8  22.4  5779.9  3167.7  129241.7  70831.3  58410.4  45.2  27-Jun-05  168.1  139.3  28.8  17.1  4010.8  2386.5  68730.4  40895.4  27835.0  40.5  28-Jun-05  188.1  152.1  36.0  19.1  5474.3  2910.9  104791.4  55721.2  49070.3  46.8  30-Jun-05  165.7  152.1  13.6  8.2  2068.1  1248.4  16977.6  10248.2  6729.4  39.6  2364.6  66208.8  36769.6  29439.2  44.5  1-Jul-05  180.1  152.1  28.0  15.6  4257.8  2-Jul-05  177.7  161.7  16.0  9.0  2586.6  1455.9  23294.5  13111.6  10183.0  43.7  3-Jul-05  190.8  141.2  49.6  26.0  7005.1  3670.8  182072.9  95410.0  86662.8  47.6  5-Jul-05  200.9  151.3  49.6  24.7  7502.7  3735.2  185266.5  92234.8  93031.7  50.2  6-Jul-05  206.5  156.9  49.6  24.0  7780.5  3768.4  186914.2  90531.1  96383.1  51.6  5726.4  2850.9  98069.8  48824.0  49245.8  50.2  7-Jul-05  200.9  166.5  34.4  17.1  8-Jul-05  182.5  159.3  23.2  12.7  3694.9  2025.0  46980.4  25747.7  21232.6  45.2  10-Jul-05  186.4  158.0  28.4  15.2  4488.1  2407.4  68369.3  36672.5  31696.8  46.4  12-Jul-05  188.1  155.3  32.8  17.4  5092.7  2707.9  88820.4  47228.8  41591.6  46.8  13-Jul-05  207.3  145.7  61.6  29.7  8972.9  4329.2  266679.6  128666.6  138013.0  51.8  6425.7  3277.3  136337.7  69537.4  66800.4  49.0  15-Jul-05  196.1  154.5  41.6  21.2  17-Jul-05  200.9  151.3  49.6  24.7  7502.7  3735.2  185266.5  92234.8  93031.7  50.2  19-Jul-05  206.5  156.9  49.6  24.0  7780.5  3768.4  186914.2  90531.1  96383.1  51.6  20-Jul-05  203.3  154.5  48.8  24.0  7537.8  3708.4  180969.9  89032.0  91938.0  50.8  5-Aug-05  197.7  144.9  52.8  26.7  7648.8  3869.6  204315.2  103364.9  100950.3  49.4  7-Aug-05  181.7  130.5  51.2  28.2  6679.8  3677.0  188261.6  103631.8  84629.8  45.0  10-Aug-05  191.3  135.3  56.0  29.3  7574.8  3960.4  221781.4  115955.6  105825.7  47.7  13-Aug-05  175.3  87.3  88.0  50.2  7679.2  4381.5  385574.0  219996.1  165577.9  42.9  16-Aug-05  184.1  108.9  75.2  40.9  8186.6  4447.7  334465.3  181711.4  152753.9  45.7  18-Aug-05  161.7  88.1  73.6  45.5  6481.5  4009.2  295080.6  182527.1  112553.5  38.1  182.5  69.7  112.8  61.8  7858.1  4306.7  485790.9  266239.3  219551.6  45.2  21-Aug-05  Table B . 3 . Raw data for daily operation, gas-mixing SBR, TP and TKN TP Day  Influent (mg/L)  Effluent (mg/L)  TKN  Absolute  Removal  Removal  Efficiency  (mg/L)  (%)  Influent (mg/L)  Effluent (mg/L)  Absolute  Removal  Removal  Efficiency  (mg/L)  (%)  Remarks  19-Jun-05  24.9  24.1  0.8  3.2  286.4  209.6  76.8  26.8  19-Jun-05  64.5  6.4  58.1  90.1  614.4  88.8  525.6  85.5  20-Jun-05  28.6  3.1  25.5  89.3  308.8  45.6  263.2  85.2  20-Jun-05  49.6  7.0  42.6  86.0  483.2  71.4  411.8  85.2  Total values  22-Jun-05  112.8  8.1  104.7  92.8  524.8  48.0  476.8  90.9  Total values  24-Jun-05  64.5  42.8  21.7  33.6  409.6  248.8  160.8  39.3  Total values  25-Jun-05  117.6  39.6  78.0  66.3  505.6  288.0  217.6  43.0  Total values  Total values  27-Jun-05  398.4  180.8  217.6  54.6  1017.6  352.0  665.6  65.4  Total values  28-Jun-05  56.2  44.4  11.8  20.9  328.0  202.4  125.6  38.3  Total values  30-Jun-05  69.4  35.2  34.2  49.3  390.4  314.4  76.0  19.5  Total values  1-Jul-05  31.0  33.0  -2.0  -6.4  259.2  303.2  -44.0  -17.0  Total values  2-Jul-05  134.7  36.3  98.4  73.0  447.2  335.2  112.0  25.0  Total values  64.9  Total values  12-Jul-05  104.0  36.5  67.5  64.9  104.0  36.5  67.5  12-Jul-05  31.8  14.4  17.4  54.7  218.4  187.2  31.2  14.3  13-Jul-05  31.8  14.2  17.5  55.2  243.2  181.6  61.6  25.3  15-Jul-05  81.0  34.0  47.0  58.0  476.8  300.8  176.0  36.9  17-Jul-05  31.0  13.5  17.5  56.4  232.8  173.6  59.2  25.4  19-Jul-05  200.0  38.8  161.2  80.6  838.4  318.4  520.0  62.0  Total values Total values  20-Jul-05  35.5  13.8  21.8  61.3  249.6  Table B.4. Raw date for track study, gas-mixing SBR Time  NH4-N  NOx  P04-P  TOC  s-COD  (mg/L)  (mg/L)  (mg/L)  (mg/L)  (mg/L)  Influent  191.6  1.632  42  796  2640  14:00  160  3.384  32.44  332  1850  360  1590  14:30  182.8  1.64  22.52  15:15  120.4  2.708  15.2  236  1150  16:15  115.6  2.436  13.6  236  1000  17:15  110.4  1.024  13.08  200  930  18:15  106.8  1.968  12.32  180  860  140  770 930  19:30  98  2.048  8.4  20:30  121.6  1.144  11.36  232  21:00  114  1.576  10.44  212  890  21:45  142  0.86  12.68  212  1080  22:00  102.4  0.588  9.88  148  910  Table B.5. %P/ MLVSS values for gas-mixing SBR Day  %P/ MLVSS  13-Jul-05  1.56  15-Jul-05  1.30  17-Jul-05  1.41  19-Jul-05  1.66  20-Jul-05  1.22  196.8  52.8  21.2  APPENDIX C: DATA FOR PILOT-SCALE SBR  Table C l . Raw data for daily operation, pilot-scale SBR, t-COD t-COD Day  Absolute  Removal  Removal  Efficiency  (mg/L) 560  (%) 61.0  225  343  60.4  243  338  58.2  188  143  43.2  425  208  218  51.2  29-Jun-05  390  168  223  57.1  4-Jul-05  260  150  110  42.3  5-Jul-05  215  85  130  60.5  6-Jul-05  250  65  185  74.0  7-Jul-05  268  85  183  68.2  8-Jul-05  250  55  195  78.0  11-Jul-05  563  53  510  90.7  12-Jul-05  358  65  293  81.8  13-Jul-05  430  103  328  76.2  14-Jul-05  660  80  580  87.9  15-Jul-05  880  130  750  85.2  18-Jul-05  293  175  118  40.2  20-Jul-05  190  115  75  39.5  22-Jul-05  145  88  58  39.7  23-Jul-05  125  78  48  38.0  24-Jul-05  770  345  425  55.2  26-Jul-05  430  103  328  76.2  27-Jul-05  430  103  29-Jul-05  515  193  323  62.6  1-Aug-05  410  243  168  40.9  2-Aug-05  333  78  255  76.7  3-Aug-05  325  90  235  72.3  4-Aug-05  855  295  560  65.5  9-Aug-05  293  103  190  65.0  10-Aug-05  310  83  228  73.4  11-Aug-05  1720  115  1605  93.3  12-Aug-05  2870  103  2768  96.4  15-Aug-05  1720  4290  -2570  -149.4  16-Aug-05  290  130  160  55.2  17-Aug-05  240  48  193  80.2  Influent (mg/L)  Effluent (mg/L)  20-Jun-05  918  358  22-Jun-05  568  23-Jun-05  580  24-Jun-05  330  27-Jun-05  438  28-Jun-05  19-Aug-05  140  45  95  67.9  22-Aug-05  100  33  68  67.5  24-Aug-05  133  30  103  77.4  162  25-Aug-05  173  83  90  52.2  26-Aug-05  125  75  50  40.0  29-Aug-05  50  160  -110  -220.0  30-Aug-05  240  65  175  72.9  31-Aug-05  280  63  218  77.7  12-Sep-05  190  108  83  43.4  14-Sep-05  650  156  494  76.0  16-Sep-05  710  130  580  81.7  19-Sep-05  3400  65  3335  98.1  21-Sep-05  501  156  345  68.9  23-Sep-05  482  102  380  78.8  25-Sep-05  605  200  405  66.9  27-Sep-05  523  165  358  68.5  28-Sep-05  520  198  323  62.0  30-Sep-05  420  125  295  70.2  4-Oct-05  540  185  355  65.7  Table C.2. ]R.aw data for daily operation, pilot-scale SBR, NH4-N, NO -r> , SND efficiency and P 0 - P 4  x  NOx-N  NH -N 4  Day  Influent (mg/L)  Effluent (mg/L)  Absolute  Removal  Removal  Efficiency  (mg/L)  (%)  PO4-P SND  Influent (mg/L)  Effluent (mg/L)  Efficiency  (%)  Influent (mg/L)  Effluent (mg/L)  Absolute  Removal  Removal  Efficiency  (mg/L)  (%)  20-Jun-05  73.0  1.6  71.4  97.8  0.2  5.6  92.4  22.8  0.5  22.3  98.0  22-Jun-05  67.9  0.5  67.4  99.3  0.2  5.6  90.6  19.5  0.4  19.1  97.8  23-Jun-05  58.2  28.4  29.8  51.2  0.2  5.6  99.8  11.9  0.5  11.4  95.9  24-Jun-05  56.5  22.1  34.4  60.9  0.2  5.6  82.8  13.2  0.3  12.9  97.9  0.2  9.3  97.6 68.8  27-Jun-05  40.1  0.2  39.9  99.4  0.2  5.6  82.1  9.5  28-Jun-05  39.9  0.2  39.7  99.6  0.2  5.6  78.9  5.7  1.8  3.9  29-Jun-05  32.0  0.2  31.8  99.4  0.2  5.6  81.6  5.2  2.1  3.0  58.7  4-Jul-05  31.4  0.3  31.1  99.2  0.2  9.9  69.0  3.7  6.0  -2.4  -64.3  5-Jul-05  30.4  0.3  30.1  99.2  0.1  6.2  79.6  6.2  2.8  3.5  55.3  5.1  82.3  4.2  2.0  2.3  53.3  6-Jul-05  28.2  0.2  28.0  99.4  0.1  7-Jul-05  28.5  0.2  28.3  99.4  0.0  5.3  81.6  3.5  2.4  1.1  31.6  8-Jul-05  30.6  0.2  30.4  99.4  0.1  4.5  85.4  3.6  2.5  1.1  31.0  12-Jul-05  30.7  0.9  29.8  97.1  0.1  9.4  68.7  3.3  0.0  3.3  98.7  13-Jul-05  32.5  0.9  31.6  97.2  0.1  11.2  64.7  4.5  0.1  4.4  97.9 98.2 97.8  14-Jul-05  38.5  97.4  0.1  11.0  71.7  5.5  0.1  5.4  0.9  31.1  97.1  0.1  8.8  72.0  4.4  0.1  4.3  0.2  27.2  99.3  0.0  7.4  72.7  3.8  3.2  0.5  14.3  48.9  0.2  48.7  99.6  0.1  9.0  81.7  9.4  0.3  9.1  96.5  63.0  0.3  62.7  99.5  0.1  17.2  72.8  10.1  0.1  10.0  98.7  8.5  4.8  35.9  39.5  1.0  15-Jul-05  32.0  18-Jul-05  27.4  20-Jul-05 22-Jul-05 25-Jul-05  129.0  110.0  19.0  14.7  0.9  1.5  96.5  13.3  29-Jul  118.0  0.5  117.5  1-Aug  85.3  0.3  85.0  99.6  1.1  15.7  87.5  16.0  1.5  14.5  90.8  99.6  0.9  9.9  89.3  17.4  6.5  10.9  62.6  2-Aug  63.6  0.2  3-Aug  50.7  0.1  63.4  99.6  0.5  16.6  74.6  8.0  6.0  2.1  25.6  50.6  99.8  0.5  12.1  77.1  10.0  6.2  3.8  38.2 16.8  41.5  99.9  0.4  9.4  78.3  8.1  6.8  1.4  0.1  33.1  99.7  0.3  9.1  73.3  4.6  6.8  -2.2  -48.7  1.0  26.9  96.6  0.4  3.7  87.5  3.6  1.0  2.6  72.4  26.7  0.1  26.6  99.8  0.3  4.4  84.6  2.3  0.6  1.7  74.3  10-Aug  24.5  0.0  24.5  100.0  0.5  3.7  86.7  3.1  0.7  2.5  78.6  11-Aug  25.4  0.0  25.4  100.0  0.2  3.1  88.7  3.4  0.8  2.6  76.9  12-Aug  51.9  0.0  51.9  99.9  0.9  2.5  96.8  7.4  0.3  7.1  96.3  4-Aug  41.6  0.1  5-Aug  33.2  8-Aug  27.9  9-Aug  15-Aug  24.8  0.2  24.6  99.0  0.2  3.1  88.2  2.1  0.3  1.8  16-Aug  26.1  0.0  26.1  100.0  0.3  3.8  86.5  2.4  0.9  1.6  84.2 64.4  17-Aug  27.0  0.0  27.0  100.0  0.3  3.4  88.6  1.2  0.6  0.6  47.3  19-Aug  26.0  0.0  26.0  99.9  0.3  3.6  87.3  2.0  0.4  1.6  79.4  22-Aug  27.1  0.1  27.0  99.5  0.2  2.8  90.4  1.9  0.9  1.0  51.2  24-Aug  22.2  0.2  22.0  99.2  0.3  2.9  88.6  1.0  0.4  0.7  65.4  25-Aug  23.7  0.2  23.5  99.3  0.3  3.4  87.2  0.6  0.3  0.3  47.4  26-Aug  26.3  0.2  26.1  99.4  0.3  1.2  96.4  1.0  0.2  0.8  84.4  29-Aug  28.5  0.3  28.2  98.8  0.3  24.6  13.7  2.6  17.5  -14.9  -583.6  30-Aug  28.3  0.2  28.1  99.5  0.3  4.5  85.2  2.1  0.1  1.9  93.0  31-Aug  34.1  0.2  33.9  99.4  0.4  7.0  80.7  3.0  0.1  2.8  95.5  12-Sep  42.6  0.2  42.4  99.5  0.5  16.0  63.4  5.4  0.7  4.6  86.1  14-Sep  49.6  0.2  49.4  99.7  0.5  13.6  73.5  5.9  0.5  5.4  91.6  16-Sep  50.6  0.2  50.4  99.6  0.6  16.3  68.8  7.1  1.6  5.5  77.9  18-Sep  47.2  0.2  47.0  99.5  0.2  14.1  70.4  6.8  0.4  6.4  94.6  19-Sep  46.5  0.1  46.4  99.7  0.3  13.9  70.7  5.7  1.2  4.5  78.4  21-Sep  47.8  0.3  47.5  99.4  0.5  9.3  81.4  5.0  1.5  3.5  70.0  23-Sep  43.2  0.1  43.1  99.7  0.2  14.2  67.4  5.2  1.0  4.2  81.2  25-Sep  45.8  0.1  45.7  99.7  0.9  9.6  81.0  5.9  0.5  5.4  92.1  27-Sep  41.3.  0.1  41.2  99.7  0.5  10.6  75.4  5.1  0.7  4.5  87.2  28-Sep  50.6  0.2  50.4  99.6  0.2  11.5  77.6  5.1  1.7  3.5  67.3  30-Sep  48.0  0.2  47.8  99.5  0.6  13.4  73.3  6.0  0.5  5.5  91.9  2-Oct  46.1  0.3  45.8  99.4  0.5  9.0  81.6  5.5  1.0  4.4  81.3  4-Oct  43.2  0.2  43.0  99.6  0.1  11.6  73.4  5.2  0.6  4.6  88.1  7-Oct  31.1  0.2  30.9  99.3  0.0  9.4  69.7  5.1  1.0  4.1  80.2  Table C.3. Raw data for track study, July 8, 2005 Time (hrs) Influent 0:00 0:15 0:30 0:45 1:00 1:15 1:30 1:45 2:00 2:15 2:30 2:45 3:00 3:15 3:30 3:45 4:00 4:15 4:30 4:45 5:00 5:15 5:30  NH4-N (mg/L) 30.6 0.17 7.87 7.55 7.88 7.7 7.71 7.73 7.59 7.12 6.37 5.45 4.49 3.6 2.55 1.66 0.728 0.21 0.18 0.232 0.233 0.239 0.266 0.206  NOx-N (mg/L) 0.0742 4.53 0.92 0.185 0.12 0.286 0.147 0.141 0.291 0.52 1.65 1.31 2.08 2.75 4.07 5.01 6.05 6.82 6.77 5.62 4.38 2.99 1.42 4.82  P04-P (mg/L) 3.55 2.45 22.7 8.49 8.73 8.95 9.26 9.47 7.41 6.23 5.4 4.26 3.55 3.29 2.89 2.67 2.5 2.33 2.29 2.36 2.28 2.15 2.11 2.17  ORP (mV)  DO (mg/L)  PH  Remarks  121 -142 -184.7 -213.8 -240.1 -188.5 25.8 116.4 106 113.5 118.1 113.6 108 121.7 125.4 155.7 160.2 102.5 107.3 113.7 110.9 110.9 115.4  0 0 0 0 0 0 0.4 0.4 0.4 0.5 0.6 0.5 0.6 0.6 0.6 1.7 1.9 0.1 0 0.1 0.1 0.1 0  6.6 6.6 6.6 6.6 6.6 6.6 6.6 6.2 6.7 6.6 6.5 6.5 6.4 6.4 5.8 6.3 5.6 6.3 6.1 6.3 6.5 6.5 5.2  Feed Anoxic  Air  Settling  Decant End  Table C.4. Raw data for track study, October 7, 2005  ,  Time  NH4-N  NOx-N  P04-P  DO (mg/L)  PH  Remarks  (hrs)  (mg/L)  (mg/L)  (mg/L)  Influent  31.4  0.00999  5.1  0:00  0.4063  8.52  1.13  0  6.4  Feed  0:15  9.61  1.99  6.26  0  6.6  Anoxic  0:20  9.93  0.825  5.9  0  6.8  0:39  9.38  0.18  6.04  0  6.95  1:15  8.42  1.48  4.08  0  6.9  1:35  6.94  2.49  3.24  0.4  6.9  1:55  5.7  4.02  2.49  0.4  6.8  2:15  4.24  5.61  1.98  0.4  6.8  2:35  2.88  7.07  1.62  0.4  6.7  2:55  1.09  9.3  1.36  0.1  6.7  3:15  0.14  9.98  1.07  0.7  6.6  3:35  0.171  9.83  0.96  -0.4  6.6  3:55  0.159  9.93  2.17  0  6.6  4:15  0.208  9.37  1.01  0  6.6  Air  Settling  Decant  APPENDIXD: DATA FOR CRYSTALLIZER RUNS  Table D.l. Crystallizer run for dairy manure supernatant _. . . T i m e (hrs:min) ______  0 0:30 1 1:30 2 2:30 3 3:30 4 4:30 5 5:30 6  NH4-N  P04-P  (mg/L)  (mg/L)  172  55.2 19.5 20.1 15.7 17 15 12 13.4 9.8 9.68 12.1 8.09 9.84  32.36  49.2 67.6 75.6 82.8 91.6 95.2 102.4 112.8 120.4 126.8 123.2  Table D.2. Crystallizer run for synthetic supernatant _. . . T i m e (hrs:min)  0 0:30 1 1:30 2 2 2:30 3  NH4-N  P04-P  (mg/L)  (mg/L)  210 141.5 152 164 164 169 170 163.5  82 36.9 35.2 25.1 22.7 22.6 21.8 19  168  

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