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Pilot scale phosphorus recovery from anaerobic digester supernatant Huang, Hui 2003

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PILOT SCALE PHOSPHORUS R E C O V E R Y F R O M ANAEROBIC DIGESTER SUPERNATANT by HUI HUANG B.A.Sc, Nanjing University of Chemical Technology, P. R. China, 1994 M . Sc., East China University Of Science And Technology, P. R. China, 1997 A THESIS SUBMITTED IN PARTIAL FULFILMENT OF THE REQUIREMENTS FOR THE DEGREE OF MASTER OF APPLIED SCIENCE in THE FACULTY OF GRADUATE STUDIES DEPARTMENT OF CIVIL ENGINEERNIG We accept this thesis as conforming to the required standard THE UNI V E R I T Y OF BRITISH COLUMBIA December 2003 © Hui Huang, 2003 Library Authorization In presenting this thesis in partial fulfillment of the requirements for an advanced degree at the University of British Columbia, I agree that the Library shall make it freely available for reference and study. I further agree that permission for extensive copying of this thesis for scholarly purposes may be granted by the head of my department or by his or her representatives. It is understood that copying or publication of this thesis for financial gain shall not be allowed without my written permission. Hui Huang December 16, 2003 Name of Author (please print) Date Title of Thesis: Pilot Scale Phosphorus Recovery From Anaerobic Digester Supernatant Degree: Master of Applied Science Year: 2003 ABSTRACT ABSTRACT In this study, the pilot-scale struvite crystallization process developed at UBC was operated continuously for recovering phosphate, in the form of struvite, from anaerobic digester supernatants from the Annacis Island Wastewater Treatment Plant and the Lulu Island Wastewater Treatment Plant. In addition, the process performance for a synthetic supernatant with high phosphate concentration (100-190 mg/L) was verified. Study results showed that the process was capable of removing more than 90 % of ortho-phosphate from both the synthetic supernatant and the digester supernatants. Approximately 90 % of removed phosphate was recovered as harvestable struvite crystals. The desired phosphate removal efficiency was achieved through controlling the inlet supersaturation (SS) ratio, operational pH and magnesium dosage in the supernatant. It was possible to reduce the effluent ortho-phosphate concentration to less than 5 mg/L through choosing optimal operational conditions. Chemical analysis of the recovered crystals showed very pure struvite (91.2 % and 94.1 % by weight for crystals produced from the Annacis supernatant and the Lulu supernatant, respectively.) with small amounts of calcium and carbonate, and traces of iron and aluminum. Most of recovered crystals were round, hard and larger than 2 mm in mean diameter over the course of the study. The crystal retention time in the reactor and the magnesium dosage in the supernatant were identified as two major factors affecting the size, density, hardness and morphology of recovered struvite crystals. Determination of the struvite solubility product (Ksp) showed that there were significant u ABSTRACT differences among Ksp values for the synthetic, Annacis and Lulu supernatants, due to combined effects from impurity ions and suspended solids, as well as other unknown factors. In this scenario, the conditional solubility product (Ps) was considered to be more useful than Ksp in operating the struvite crystallization process and predicting process performance. A cost analysis showed that the application of air stripping or a high magnesium dosage in the supernatant could not reduce the total chemical costs, since both Annacis and Lulu supernatants used in this study had a high pH value around 8.0. However, a further study on other anaerobic digester supernatants with low pH was recommended. Two struvite models developed by Britton and Potts, respectively, were used to predict the process performance and determine the operational parameters. Both were validated through comparing the predicted results with the actual operational data. The comparison showed that the former predicted the actual results with relatively high accuracy; however, the latter demonstrated a large deviation from the real results, probably caused by the Ksp value used in the model. in TABLE OF CONTENTS TABLE OF CONTENTS Page ABSTRACT ii TABLE OF CONTENTS iv LIST OF TABLES viii LIST OF FIGURES ix ACKNOWLEDGEMENTS , xii CHAPTER 1: INTRODUCTION 1 1.1 Annacis Island WWTP And Lulu Island WWTP 2 1.2 Previous Research At UBC 3 CHAPTER 2: RESEARCH OBJECTIVES 6 CHAPTER 3: BACKGROUND AND LITERATURE REVIEW 7 3.1 The Potential Driving Force For Phosphorous Recovery 7 3.1.1 Demand for sustainable phosphorus resources with high purity 7 3.1.2 Stringent nutrient discharge regulations 8 3.1.3 Problems met in WWTPs, especially those with BNR process 9 3.1.4 Economic impetus brought by phosphorus recovery ^ 1 1 3.2 Possible Recoverable Phosphorous Sources 13 3.3 Chemistry Of Struvite 14 3.3.1 Solubility product 15 3.3.2 Conditional solubility product 16 3.3.3 Factors affecting struvite solubility 17 3.4 Morphology Of Struvite Crystal 20 3.5 Current Phosphorus Recovery Studies 22 3.5.1 Phosphorus recovery methods 22 3.5.2 Phosphorus recovery processes 23 3.5.3 Pilot and full-scale struvite recovery 23 3.6 Modelling Application 27 iv TABLE OF CONTENTS C H A P T E R 4 : M A T E R I A L S A N D M E T H O D S 2 9 4.1 Supernatant Characteristics During The Study 29 4.1.1 Synthetic supernatant 29 4.1.2 Anaerobic digester supernatant 29 4.2 The Struvite Crystallization Process 30 4.2.1 Crystallization reactor 31 4.2.2 The external clarifier and recycle flow 35 4.2.3 Supernatant storage tanks and pumps 36 4.2.4 Magnesium feed tank and pump 37 4.2.5 pH control and sodium hydroxide dosing 37 4.3 Process Monitoring And Maintenance 38 4.4 Sample Collection, Storage And Preservation 40 4.5 Struvite Crystal Harvesting, Drying And Sieving 40 4.6 Crystal Quality Determination 41 4.6.1 Composition and purity 41 4.6.2 Density 4 2 4.6.3 Scanning electron microscope (SEM) examination 42 4.7 Struvite Solubility Determination 43 4.8 Analytical Methods 44 4.8.1 Ortho-phosphate and ammonia 44 4.8.2 Magnesium, calcium, aluminum and iron 44 4.8.3 Potassium 44 4.8.4 Carbonate • 44 4.8.5 pH 45 4.8.6 Conductivity 45 4.9 Terminology 45 4.9.1 Struvite solubility product (K s p) 45 4.9.2 Struvite conditional solubility product (Ps) 47 4.9.3 Supersaturation ratio 48 4.9.4 Recycle ratio 50 4.9.5 Crystal retention time 50 4.9.6 Mean crystal size 50 V TABLE OF CONTENTS 4.9.7 Removal efficiency for phosphate, ammonia and magnesium 51 4.9.8 Struvite recovery efficiency 52 CHAPTER 5: RESULTS AND DISCUSSION 53 5.1 Chemistry Of Struvite 53 5.1.1 Struvite solubility product (Ksp) 54 5.1.2 Temperature coefficient (0) and enthalpy (AH) 56 5.1.3 Conditional solubility product (Ps) 58 5.2 Performance Of The Struvite Crystallization Process 61 5.2.1 Phosphate removal efficiency 61 5.2.2 Effluent phosphate level 63 5.2.3 Ammonia removal efficiency 65 5.2.4 Struvite recovery efficiency 67 5.3 Controlling Parameters In The Struvite Crystallization Process 68 5.3.1 Supersaturation ratio (SS ratio) 68 5.3.2 pH 71 5.3.3 Magnesium dosage 72 5.4 Alternative Methods For Reducing Chemical Costs 74 5.4.1 Air stripping 74 5.4.2 Magnesium dosage 78 5.5 Characteristics Of Struvite Product 80 5.5.1 Purity and composition 81 5.5.2 Crystal Size 83 5.5.3 Factors affecting crystal mean size 85 5.5.4 Crystal density 87 5.5.5 Crystal hardness 89 5.5.6 Morphology 90 5.5.7 Crystal distribution in the reactor 99 5.6 Model Application In Process Control 101 5.6.1 Britton's model 101 5.6.2 Potts's model 106 CHAPTER 6: CONCLUSIONS 109 TABLE OF CONTENTS CHAPTER 7: RECOMMENDATIONS 112 CHAPTER 8: REFERENCES 114 APPENDIX A: CALCULATIONS FOR UPFLOW VELOCITES IN THE RACTOR 119 APPENDIX B: CALCULATIONS FOR REYNOLDS NUMBER IN THE REACTOR 120 APPENDIX C: INSTRUMENT OPERATIONAL PARAMETER DETAILS 121 APPENDIX D: K S p DETERMINATION DATA AND CALCULATIONS 122 APPENDIX E: OPERATING DATA FOR REACTOR A 139 APPENDIX F: OPERATING DATA FOR REACTOR B 173 APPENDIX G: CHEMICAL ANALYSIS OF STRUVITE CRYSTAL 200 APPENDIX H: MODEL RESULTS 211 vii LIST OF TABLES LIST OF TABLES Page Table 3.1: Side reactions in struvite formation 15 Table 4.1: Composition of the synthetic supernatant 29 Table 4.2: Supernatant characteristics of the Annacis Island WWTP 30 Table 4.3: Supernatant characteristics of the Lulu Island WWTP. 30 Table 4.4: Upflow velocities and Reynolds number in the different reactor sections 33 Table 5.1: Values of 9 and A H 57 Table 5.2: Comparison of theoretical struvite production and actual struvite recovery during the whole period of the study 67 Table 5.3: Chemical costs in the struvite crystallization process 79 Table 5.4: The results of crystal composition analysis 81 Table 5.5: Impurity content in crystal products 82 Table 5.6: Density of crystals produced in different supernatants 87 Table 5.7: Distribution of crystals with different size and density in the reactor 100 Table 5.8: Absolute error between the modeled and actual effluent phosphate concentration 105 Table 5.9: Chemical equilibria used in the Potts's model 106 Table 5.10: Comparison of the modeled and actual results 108 vii i LIST OF FIGURES LIST OF FIGURES Page Figure 4.1: Pilot-scale process layout 31 Figure 4.2: Pilot-scale crystallization reactor design 32 Figure 4.3: Injection port of the pilot-scale crystallization reactor 34 Figure 5.1: Struvite solubility products at 20 ° C 54 Figure 5.2: Struvite solubility product in Annacis supernatant at different temperatures... 56 Figure 5.3: Struvite solubility product in Lulu supernatant at different temperatures 57 Figure 5.4: Struvite pPs in different supernatants at 10°C 59 Figure 5.5: Struvite pPs in the Annacis supernatant at 15°C 59 Figure 5.6: Struvite pPs in different supernatants at 20°C 60 Figure 5.7: Phosphate removal efficiency for the synthetic supernatant 61 Figure 5.8: Phosphate removal efficiency for the Annacis supernatant 62 Figure 5.9: Phosphate removal efficiency for the Lulu supernatant 62 Figure 5.10: Effluent phosphate concentration for the synthetic supernatant 63 Figure 5.11: Effluent phosphate concentration for the Annacis supernatant 64 Figure 5.12: Effluent phosphate concentration for the Lulu supernatant 64 Figure 5.13: Percentage ammonia removal for the synthetic supernatant 65 Figure 5.14: Percentage ammonia removal for the Annacis supernatant 66 Figure 5.15: Percentage ammonia removal for the Lulu supernatant 66 Figure 5.16: Percentage phosphate removal under different in-reactor SS ratios 69 Figure 5.17: Percentage phosphate removal under different inlet SS ratios 69 Figure 5.18: The relationship between in-reactor SS ratio and inlet SS ratio 70 Figure 5.19: The relationship between the phosphate removal and magnesium dosage 73 LIST OF FIGURES Figure 5.20: The relationship between the pH change and aeration time 76 Figure 5.21: Chemical costs in the struvite crystallization process 79 Figure 5.22: The average crystal size harvested from the synthetic supernatant 83 Figure 5.23: The average crystal size harvested from the Annacis supernatant 84 Figure 5.24: The average crystal size harvested from the Lulu supernatant 84 Figure 5.25: The relationship between the crystal size and CRT 85 Figure 5.26: Relationship between crystal density and size 87 Figure 5.27: Relationship between crystal density and CRT 88 Figure 5.28: SEM images of crystals (D>4.75 mm) harvested from reactor A testing the Lulu supernatant on Nov. 10, 2002 91 Figure 5.29: SEM images of crystals (4.75 mm>D>2.83 mm) harvested from reactor A testing the Lulu supernatant on October 28, 2002 92 Figure 5.30: SEM images of crystals with different sizes harvested from reactor A testing the Lulu supernatant on Nov. 10, 2002 93 Figure 5.31: SEM images of crystals with different sizes harvested from reactor A testing the Annacis supernatant on Sept. 18, 2002. 94 Figure 5.32: SEM images of outside and inside structure of crystals (4.75 mm>D> 2.83 mm) harvested from reactor A testing the Lulu supernatant 96 Figure 5.33: SEM images of outside and inside structure of crystals (4.75 mm>D> 2.83 mm) harvested from reactor A testing the Annacis supernatant on Sept. 13, 2002 97 Figure 5.34: SEM images of outside and inside structure of crystals (4.75 mm>D> 2.83 mm) harvested from reactor A testing the synthetic supernatant 98 Figure 5.35: Distribution of crystals with different size and density in the reactor 100 Figure 5.36-A: Modeled and actual effluent phosphate concentration for reactor A testing the synthetic supernatant 102 LIST OF FIGURES Figure 5.36-B: Modeled and actual effluent phosphate concentration for reactor B testing the synthetic supernatant 103 Figure 5.37-A: Modeled and actual effluent phosphate concentration for reactor A testing the Annacis supernatant 103 Figure 5.37-B: Modeled and actual effluent phosphate concentration for reactor B testing the Annacis supernatant 104 Figure 5.38-A: Modeled and actual effluent phosphate concentration for reactor A testing the Lulu supernatant 104 Figure 5.38-B: Modeled and actual effluent phosphate concentration for reactor B testing the Lulu supernatant 105 XI ACKNOWLEDGEMENTS ACKNOWLEDGEMENTS I would like to acknowledge the assistance, support and encouragement from the following people and organizations, without whom, this research would not have been possible: • Dr. D. S. Mavinic, my supervisor, for his unwavering support and encouragement through the course of my work; • Frederic Koch, the manager of the UBC Environmental Engineering Pilot Plant, for his continuous technical direction and support; • Ali Adnan and Ahren Britton, the former graduate students in this research group, for introducing their conclusions to me and giving good suggestions for my work; • Daniel Potts, for his work in developing the struvite crystallization model; • Paula Parkinson, for her help with analytical work, chemicals and instruments provision; • Susan Harper, for her lab direction and technical advice; • Ping Liao, the team partner, for his help with struvite solubility determination; • Mary Mager, the technician of Metal and Material Engineering Department, for her help with SEM examination work; • GVRD and BC Hydro, for their generous funding of this research project. xii To My loving daughter—Tina who was born during this endeavor INTRODUCTION CHAPTER 1 INTRODUCTION Phosphorus is an important element and essential to life itself. Used extensively by mankind, natural phosphorus reserves are facing depletion. In addition, due to the lower quality of present phosphorus rock, the sustainable phosphorus resource is in high demand for modern industry and agriculture. However, the release of phosphorus to surface waters due to human activities, and its consequent contribution to eutrophication, have led to increasing concern about water quality and phosphorus removal technologies. The technologies of removing phosphorus from domestic and industrial wastewater have been under development since the 1950s. At present, there are two established methods of phosphorus removal — chemical precipitation and biological removal. The latter is in increasing application but some operational problems arise in those wastewater treatment plants installed with biological phosphorus removal system, such as phosphorus release in sludge digestion and excess sludge produced. The most serious problem is the struvite encrustation in the piping and equipment of anaerobic digestion and postdigestion process, resulting in a high cost of maintenance. This problem is met not only in the plants with biological phosphorus removal system but also in secondary wastewater treatment plants with an anaerobic digestion process. In these scenarios, the best solution is phosphorus recovery, in which the phosphorus in wastewater is removed in the form of a simple inorganic salt that can be separated easily and has utility for recycling in industrial and agricultural applications. Considerable worldwide research has been undertaken into phosphorus recovery techniques. However, most research has been at l INTRODUCTION bench and pilot-scale stage, and little has been implemented on a full-scale basis [15]. In this study, a pilot-scale struvite crystallization process was tested for the recovery of phosphorus, in the form of struvite (MgNIl4PCV6H20), from anaerobic digester supernatants. The process was designed and developed in the Civil Engineering Department of the University of British Columbia (UBC), Canada. The tested anaerobic supernatants came from the Annacis Island Wastewater Treatment Plant (WWTP) and the Lulu Island Wastewater Treatment Plant, in Vancouver, Canada, since both plants are experiencing serious struvite accumulation problems and are interested in this innovative and sustainable waste management technique. 1.1 Annacis Island WWTP And Lulu Island WWTP The Annacis and Lulu Island Wastewater Treatment Plants are two secondary wastewater treatment plants operated by the Greater Vancouver Regional District of the Province of British Columbia, Canada. The Annacis Island Wastewater Treatment Plant serves the Fraser Valley Sewerage Area. It was opened in 1975 with only primary treatment and extended to secondary treatment in 1997. Currently, it serves a population of about 850,000. The Lulu Island Wastewater Treatment Plant was opened in 1973, provided primary treatment and extended to secondary treatment in 1999. Now it serves a population of about 159,000 [1]. Both plants consist of physical treatment, including screening, grit removal and primary sedimentation, and biological treatment, including trickling filters, solids contact and secondary clarification. Their sludge managements have three processes: sludge thickening, anaerobic digestion (which is performed respectively through thermophilic anaerobic digesters in the Annacis WWTP and mesophilic anaerobic digesters in the Lulu WWTP) and biosolids dewatering [1]. Due to the releases of magnesium, ammonia and phosphorus during the anaerobic digestion process, the struvite fouling and encrustation occur in digestion and 2 INTRODUCTION post-digestion processes, which plague the plants continuously. It is recently estimated that the total phosphorus in the municipal wastewater treated by the Annacis WWTP and the Lulu WWTP reach 637.5 tonnes/year and 119.3 tonnes/year, respectively; these amounts of phosphorus enter into the Fraser River un-recovered [2]. Implementation of phosphorus recovery process in these two WWTPs could provide a method not only to solve their struvite encrustation problem, but also recover a large amount of phosphorus for further commercial use. 1.2 Previous Research At UBC Since 1999, the study of phosphorus recovery has been carried out in the Civil Engineering Department of UBC. During the first two years, synthetic supernatant was used as feed in bench-scale experiments using jar tests. Preliminary results led to the basic understanding of struvite formation and its equilibrium chemistry. A bench-scale struvite crystallization reactor was designed and built up. The test results of this reactor showed that its performance was satisfactory in terms of phosphorus removal efficiency, but the struvite crystals produced were poor in quality (Fred Koch, Environmental Engineering Pilot Plant, UBC, pers. comm.). In 2001, Mahazareen Behram Dastur continued the bench-scale study based on the results of previous works. She used synthetic supernatant as feed and the phosphorus strength ranged.from 20 to 170 mg/L. The operating pH was identified as the crucial controlling parameter. However, the phosphorus removal efficiency in her study was lower than 50 % and brittle struvite crystals were harvested. Also the reactor was found to be fouled and plugged easily by struvite accumulation [3]. 3 INTRODUCTION The results from this bench-scale study revealed the limitations in small size reactor, so the reactor was scaled up to approximately 20-25 L in volume. From May of 2001 to May of 2002, the pilot-scale studies were conducted both at the UBC Environmental Engineering Pilot Plant and the Penticton Advanced Wastewater Treatment Plant, Penticton, B.C., Canada. Graduate student, Ali Adnan, still used synthetic supernatant as feed but the phosphorus strength ranged from 47 to 220 mg/L. His results showed that over 90 % of phosphorus in the synthetic supernatant was removed and 81 % of removed phosphorus was recovered in the form of struvite. The quality of harvested struvite crystals was good, with a mean diameter of 2-3 mm [4]. Another graduate student, Ahren Britton, also conducted the pilot-scale study at the Penticton Advanced Wastewater Treatment Plant. He tested the performance of the struvite crystallization process for the real anaerobic digester supernatant and the phosphorus strength was from 37 to 70 mg/L during the period of his test. Approximately 80 % of phosphorus removal efficiency was achieved and about 90 % of removed phosphorus was recovered in the form of struvite. However, the quality of struvite crystals produced was not very high, since they were brittle and the mean sizes ranged from 0.5 to 1.8 mm in diameter [5]. Both Adnan and Britton's work provided a new method to control the performance of the struvite crystallization process, besides through changing the operating pH. They found that the supersaturation ratio in the reactor was crucial to phosphorus removal and that it was determined through using the conditional solubility product curve as a criterion. Britton developed a model to predict the process performance under designed operational conditions and its veracity was verified using the data from Britton and Adnan [4,5]. Although a high efficiency of the UBC struvite crystallization process, in phosphorus recovery, has been proven to some extent, further study is needed since its application to the real anaerobic digester supernatant did not achieve as high a performance as that for the synthetic supernatant. The window for various operating parameters is still not entirely and clearly 4 INTRODUCTION understood. In addition, the process performance is seriously affected by supernatant characteristics, so that it is necessary to apply this process to other anaerobic digester supernatants with high phosphorus strength, suspended solids or impurity ions. Therefore, this study was conducted in order to explore the uncertainties present in the previous studies and develop more pilot-scale knowledge about this struvite crystallization process and possible full-scale implementation. 5 R E S E A R C H O B J E C T I V E S CHAPTER 2 RESEARCH OBJECTIVES The purpose of this study was to verify the efficiency of the UBC struvite crystallization process for different anaerobic digester supernatants, in terms of phosphorus removal and recovery. The results of this study would provide the criteria of controlling the struvite crystallization process for the further full-scale study, aimed at real anaerobic digester supernatant. The objectives of this study were defined as follows: 1. To better understand the chemistry of struvite formation using anaerobic digester supernatant; 2. To determine operational parameters that would allow successful performance (i.e. achieve 90 % phosphorus removal) for treating the anaerobic digester supernatant from two GVRD wastewater treatment plants: the Annacis Island WWTP and the Lulu Island WWTP; 3. To optimize struvite growth conditions for producing crystals with good quality, i.e. with high purity, hardness and appropriate size (>2 mm in diameter); 4. To try alternative means to reduce chemical costs in process operation; 5. And, to verify the veracity of two struvite crystallization models. 6 BACKGROUND AND LITERATURE REVIEW CHAPTER 3 BACKGROUND AND LITERATURE REVIEW 3.1 The Potential Driving Force For Phosphorous Recovery Phosphorus is an element indispensable for all living organisms. Since the natural source of phosphorus is scarce, there is intense competition between life forms, both on land and in aquatic systems. Due to a lack of gas phase, the only natural source of phosphorus comes from the weathering of phosphate-containing rocks [6]. As early as in the late seventeenth century, the importance of phosphorus was widely recognized. For the modern society, the development of industry and agriculture lead to a huge demand for phosphorus sources. Due to the non-renewal of the natural phosphorus source, more concern is now focusing on the recovery of phosphorus. 3.1.1 Demand for sustainable phosphorus resources with high purity For the phosphate industry and fertilizer industry, the phosphorus source comes from phosphate rock, which is the collective of calcium phosphate with various forms. Although the phosphate rocks are present throughout the Earth's crust, most of them are low in phosphate content. The high-grade rocks only occur in several regions, such as United State and China [6]. For those countries, such as Japan, having insufficient phosphate reservoir, the phosphorus recovery is a practical way for securing a sustainable phosphorus supply. According to United States Geological Survey in 1996, around 38 million tonnes of 7 BACKGROUND AND LITERATURE REVIEW phosphate (expressed as P2O5) are extracted each year globally. The known global phosphate reserves are 3600-8000 million tonnes [6]. Another investigation shows that, based on the current consumption rate, the present world reserves of phosphate maybe will be exhausted within the next 50-100 years [7]. However, this is not the only concern for the phosphorus resource; the more immediate concern is the decreasing quality of phosphate rocks. It is found that the content of metallic contaminants in rocks is increasing steadily, such as cadmium, uranium, nickel, chromium, copper and zinc [6]. These impurities are unacceptable in end products for detergent, food additives, fertilizer and so on. In these scenarios, searching for sustainable phosphorus resources, with a high purity, is an urgent problem facing all industries related to phosphorus. 3.1.2 Stringent nutrient discharge regulations Phosphorus is one of the limiting nutrients in most freshwater systems and its concentration is considered to be a measure of the biological productivity or trophic state of the freshwaters. The level of phosphorus has a close relationship with algal growth and eutrophication. Since the phosphorus inputs from point sources, such as municipal sewage effluents, are more amenable to control than from non-point sources, more stringent discharge regulations have been imposed on phosphorus concentration. In 1991, the Europe Urban Waste Water Treatment Directive required the wastewater treatment plants, which serving a population greater than 10,000 and discharging effluent into potentially nutrient-sensitive surface waters, to remove phosphorus from their effluent discharges. As a result, approximately 48 percent of the European population is subject to phosphorus removal requirement since 1991 [8]. In Canada, some regions are phosphorus sensitive and the phosphorus concentration in municipal effluents entering these regions has a stricter limit. For example, the municipal discharge of Penticton, B.C., has a special low total phosphorus limit of 0.25 mg/L [5]. Generally, the current effluent discharge limit on total phosphorus ranges from 2 to 0.1 mg/L in North America [9]. 8 BACKGROUND AND LITERATURE REVIEW In order to achieve the low phosphorus limit in effluent discharge, the phosphorus removal technology, especially the biological nutrient removal process (BNR), is increasingly applied around the world. The application of BNR in wastewater treatment provides the enriched phosphorus stream for phosphorus recovery; the latter is a practical solution for problems arising in wastewater treatment plants, especially those with BNR processes. 3.1.3 Problems met in WWTPs, especially those with BNR processes One of the main driving forces for studying phosphorus recovery techniques is related to several serious problems plaguing the secondary wastewater treatment plants, especially those that are designed for BNR processes. These problems can be solved or alleviated through recovering phosphorus in the form of phosphate salt from streams rich in phosphorus. Phosphorus re-release during sludge digestion Currently, many new or expanded wastewater treatment plants are designed for the BNR process, or even the enhanced biological phosphorus removal process (EBPR). However, overall phosphorus removal may prove more difficult because of its re-release during either sludge handling or anaerobic digestion. In a conventional activated sludge plant, bacteria use enough phosphorus to satisfy their basic metabolic requirements, resulting in 20-40 % of phosphorus removal [10]. For the EBPR process, bacteria accumulate phosphorus in excess of normal metabolic requirement, leading to the phosphorus content of activated sludge reaching values of up to 7 % [8]. During sludge digestion, especially anaerobic digestion, much of the stored polyphosphate in the sludge is re-released to a different extent and at different rates, depending on operational conditions. It was reported that sludge liquors can contain levels of phosphorus up to 100 mg/L, when anaerobic conditions and readily biodegradable COD were present [11]. 9 BACKGROUND AND LITERATURE REVIEW With the centrate or filtrate from sludge dewatering (so-called sidestream), the released phosphorus is usually recycled back to the plant inlet, thus increasing the phosphorus load to the treatment system. In this way, most of the phosphorus is only recirculated and not removed. Jardin found that under the conditions of EBPR plants studied, the phosphorus-feed-back occupied up to 40% of the incoming phosphorus [12]. Some plants reported additional phosphorus loads of up to 100 % [13]. Moreover, the release of ammonium nitrogen in anaerobic digestion also causes an extra load to the head of the WWTP. Since the efficiency of the BNR process relies on the BOD 5: P and BOD5: N ratios, the additional phosphorus and nitrogen loads caused by re-release can deteriorate the whole BNR process. Struvite accumulation Another major problem met in wastewater treatment plants is struvite (MgNFLJGy 6H2O) accumulation. As early as in 1960's, the Hyperion Treatment Plant in the City of Los Angeles found the struvite deposit in the underflow line of its secondary digester. Since then, a number of WWTPs around the world reported the occurrence of struvite accumulation on pipe walls and equipment of anaerobic digestion and postdigestion processes [14]. The struvite deposits are hard and difficult to dislodge, causing damage to pumping equipment, reducing plant capacity and even plugging sludge pipes. Remediation is often impractical, and when possible, is costly in terms of labor, materials and system downtime. It was reported that the annual costs for a med-size treatment plant (25 MGD) related to struvite accumulation, exceeded 100,000 US dollars [15]. Accumulation of struvite is closely related to the anaerobic digestion of wasted sludges. Besides phosphate, magnesium and ammonium also are released as the result of sludge degradation, and under certain conditions, these constituents combine together to form struvite. For wastewater treatment plants with the BNR process, removing more phosphorus results in a 10 BACKGROUND AND LITERATURE REVIEW greater concentration of phosphate, ammonium and magnesium in wasted sludge, thus resulting in a higher possibility to form struvite. Through phosphorus recovery, in the form of struvite, in a separated process, this unintentional struvite encrustation problem in undesirable locations can be reduced or even eliminated. Additional sludge produced due to phosphorus removal In order to achieve a low phosphorus concentration in effluent, the enhanced BNR process (EBPR) or physico-chemical process is widely applied. Both have the effect of increasing the sludge production in wastewater treatment plants. Paul estimated the excess sludge production in EBPR and chemical precipitation process [16]. His results showed that the excess sludge production for the EBPR process was around 3 g of total solids for each gram of phosphorus removed and for the chemical precipitation process, this value was 5-7 g TS/g P [16]. The excess sludge brought along a high cost in sludge handling and management. A phosphorus recovery technique provides a feasible way to solve this problem. Recovering phosphate, in the form of struvite, removes phosphate from the sludge, as well as ammonium and magnesium, leading to a significant reduction in sludge volume. Through model examination, Woods found that the phosphorus recovery could reduce sludge volumes by up to 30 percent, compared with EBNR, and up to 49 percent, compared with chemical precipitation [8]. For the conventional biological wastewater treatment plants, the percentage sludge reduction reached could be 11-49 % [8]. It was also reported in England that phosphorus recovery reduced biosolids production by 2-8 % of dry weight and, if the biosolids were incinerated, the ash production would be reduced by 12-48 % [17]. 3.1.4 Economic impetus brought by phosphorus recovery Through recent studies on phosphorus recovery techniques, it is considered that the economic impetus behind it comes from the cost reduction in sludge management and the huge n BACKGROUND AND LITERATURE REVIEW potential market value for recovered phosphorus products. This technique can turn a sludge problem into a saleable material, which will be of benefit to both industry and society. Cost reduction in sludge management As mentioned above, by recovering phosphorus instead of accumulating it into biosolids or chemical precipitates, sludge generation can be reduced. Therefore, the implementation of phosphorus recovery can lead to a considerable reduction in sludge handling costs. Paul estimated that the excess production of sludge in phosphorus removal costed 15 million Euros every year in France [16]. Even 10 % of sludge reduction achieved through phosphorus recovery will bring a huge saving for France's wastewater treatment plants. The study of phosphorus recovery performed in the Penticton Advanced WWTP showed that the cost saving in sludge handling was at least CAD $120 per day [5]. The capital input and daily operational cost can be covered by the saving in sludge disposal. It was estimated that the capital payback period could to be as low as 3 to 5 years, if the Crystalactor process by DHV Water BV (Netherlands) was implemented [8]. It is predicted that in coming years, the cost of sludge disposal will rise significantly, because of limitations to agricultural spreading of sludge; these include contamination of sludge with chemicals and heavy metals, geographical concentration of sludge production near cities, opposition of rural residents and, specifications in food companies and supermarkets quality requirements for farmers [8]. As sludge disposal costs increase, phosphorus recovery alternatives will become more economically viable and more attractive. Market value of recovered phosphorus products Since the phosphorus is recovered in an inorganic form, such as calcium phosphate, magnesium phosphate and struvite, these crystallized products are appropriate for direct use in either agriculture or phosphate industry. The value of recovered phosphorus products will be 12 BACKGROUND AND LITERATURE REVIEW higher than that of phosphate rocks, because of their higher purity and low heavy metal content. For example, the struvite recovered is a good fertilizer that can release nutrient contents slowly, avoid fertilizer burn and be applied directly for agricultural spreading. It also can be used as other industrial products through further treatments, such as cleaning products, chemicals and fire retardants [18]. Therefore, the potential market for recovered phosphorus products is huge and attractive. Currently, the market value of recovered phosphorus product is different around the world, depending on its usage. In Australia, the suggested value for struvite is from $198 to $330 US dollar per tonne and in Japan, it has reached as high as $1885 US dollar per tonne [15]. At full scale, struvite recovered from wastewater by Unitika Ltd, Japan, is currently being sold to fertilizer companies for US $ 150-200 per tonne. The Unitika Ltd claims that its recovered struvite contains almost no hazardous materials and exhibits equivalent or better fertilizer effectiveness than conventional chemical fertilizers [19]. Currently, the products are currently being evaluated by the European fertilizer industry and foreign markets outside of Japan [6]. 3.2 Possible Recoverable Phosphorus Sources There are two major sources of phosphorus available for recovery: human sewage and animal manures. The former is considered as the most promising source for phosphorus recovery, since most of it has been collected and treated in municipal wastewater treatment plants. In the UK, about 40 million tonnes of domestic sewage are generated every year and this stream contains approximately 45,000 tonnes of phosphorus [6]. In Canada, total phosphorus in municipal sewage is estimated to be about 23,000 tonnes per year and in the Province of British Columbia, the total phosphorus in sewage is about 3048 tonnes per year [20]. However, not all of human sewage is amenable for recovery. It is estimated that approximately 62 percent of total phosphorus in human sewage can be recovered [2]. 13 B A C K G R O U N D A N D LITERATURE REVIEW The bigger contributor to potential recoverable phosphorus source is animal manure, since it has a higher phosphorus content. In the UK, 150 million tonnes of farm animal waste are generated each year and in terms of the phosphorus content, it is equivalent to approximately 200,000 tonnes of phosphorus [6]. A recent report has shown that in the Province of British Columbia, the total phosphorus generated by all livestock is about 18,981 tonnes per year [2]. However, it should be noted that the difficulty in collection of animal manure also leads to low phosphorus recoverability from this source. Comparing these two potential sources for phosphorus recovery, human sewage attracts more interest, since it is the direct contaminant source for eutrophication in freshwater systems. In addition, the wide application of BNR in municipal wastewater treatment plants provides an enriched phosphorus stream for recovery, making this technique more technologically and economically feasible. Whereas, for animal manures, the number of specific phosphate removal techniques is still very limited, even in Europe where manure treatment is advanced [2]. However, since it is now widely accepted that the transfer of phosphorus from agricultural soils to surface waters also presents a major cause of eutrophication, the application of animal manure to agricultural land will be more tightly controlled in the future. This will help to drive the application of phosphorus recovery in animal manure treatment [21]. 3.3 Chemistry Of Struvite Struvite (MgNHUPO^^O, MAP) is a white crystalline substance consisting of equal molar amounts of magnesium, ammonium and phosphate, as well as six waters of hydration. Struvite forms according to the general reaction shown in equation (1). M g 2 + + N H 4 + + P 0 4 3 +6H 2 0 — MgNH4P04-6H20 (1) However, this equation is a simplification of the chemistry involved in the struvite precipitation. It has been accepted that some side reactions are related to the struvite formation, which are 14 BACKGROUND AND LITERATURE REVIEW shown in Table 3.1 [15]. Table 3.1: Side reactions in struvite formation MgOFf -—• M g 2 + + OH' M V «—• H+ + NH3 H3PO4 -—• H + + H 2P0 4" H 2P0 4" - — - H + + HPO4 2" HPO4 2" — H+ + P043" MgH 2 P0 4 + Mg2 + + H 2P0 4" MgHP0 4 M g 2 + + HPO4 2" MgP0 4" M g 2 + + P0 4 3" H 2 0 — H + + OH 3.3.1 Solubility product The chemistry of struvite, with regard to phosphorus recovery from wastewater, is closely linked with struvite solubility, so that it becomes a key issue in the performance of the phosphorus recovery process. The solubility of struvite can be described by the thermodynamic solubility product, defined as K s p . It represents the product of the activities of the precise species involved in the equilibrium of struvite. If the effective concentrations of magnesium, ammonium and phosphate in solution exceed the equilibrium solubility of struvite, the struvite will be formed. If those concentrations are lower than the equilibrium solubility, then the struvite in solution will dissolve. Generally, the determination of Ksp involves two methods: dissolution or formation of struvite precipitate in distilled water under some controlled conditions, such as a constant temperature, a constant mixing energy applied to the solution, carefully adjusted pH and conductivity [22-26]. The formation of struvite is carried out through adding chemical reagents to provide magnesium, ammonium and phosphate ions. The dissolution test uses struvite precipitates formed in advance and lets them dissolve. The value of Ksp will be obtained after analyzing the left solution. In order to get a thermodynamic constant applicable for any 15 BACKGROUND AND LITERATURE REVIEW conditions, all potential reactions that could affect the speciation of each compound must be accounted for in the calculation. It also requires accurate values for dissociation constants and solubility products for all related compounds. Extensive studies on Ksp value have been conducted. However, until now, there has not been a universal agreement on this value. Published values of Ksp at 25 °C range from 7.94 X 10"15 to 3.89X 10"10, i.e. values of pKsp (negative log of Ksp) range from 9.41 to 14.10 [3]. The reasons for poor agreement among reported values include different mixing conditions and assumed times to reach equilibrium used in these studies [23]. Some studies neglected the effect of ionic strength or ionic activity, such as Borgerding et al. [25], while, others considered it, such as Ohlinger et al. [22]. In addition, the uncertainty about the chemical species and side reactions selected for the calculation can also cause large variation. Some researchers assumed that different forms of phosphate were involved in the formation of struvite, while others did not think so [15]. Recent research undertaken by Bouropoulos et al. considered reactions between magnesium and ammonium, which most studies did not include in their calculations [26]. Many studies on struvite solubility showed that the measured value of Ksp decreased with the increasing pH and it only was accurate for a specific pH value [4, 5, 15, 23]. Whereas, theoretically, the thermodynamic solubility product of a compound can be applied at any pH or any other conditions except temperature [27]. This uncertainty is also cause for concern in determining Ksp. 3.3.2 Conditional solubility product Due to the uncertainties and complexities in the determination of Ksp value, the conditional solubility product (Ps) is developed to describe the struvite solubility under specific conditions. Ps represents the product of the measured total concentrations of magnesium, ammonium and phosphate. Ps is an approximate surrogate for real Ksp, since the effects from 16 B A C K G R O U N D A N D L I T E R A T U R E R E V I E W ionic strength and side reactions are not considered in the calculation [15]. However, since only the measurements of magnesium, ammonium, phosphate and pH are required, the determination of Ps value is simpler and more accurate than that for Ksp, thus leading to more application in the operation of a struvite crystallization process. It should be noted that Ps is only accurate for a certain experimental condition and will vary with pH, ionic strength of solution and temperature. Any variation in water chemistry will result in a difference in Ps value. Therefore, the Ps value should be determined again if conditions changes or different wastewaters are used. The definition of Ps is selected for practical purposes. Plotting Ps values at equilibrium vs pH establishes the struvite solubility limit curve [22]. This curve can be used easily to determine the struvite saturation condition of a wastewater by comparing the Ps value for that wastewater with the solubility limit value. If the Ps value is higher than the limit, then it is clearly illustrated that struvite will precipitate from this wastewater. 3.3.3 Factors affecting struvite solubility Stumm and Morgan found that the solubility of many salts was not governed by the solubility product alone because other equilibria besides the solubility equilibrium occur in solution [28]. With respect to struvite, the side reactions (listed in Table 3.1) will increase or decrease its solubility. The apparent effects are the dependence of struvite solubility on pH and the presence of other ions in solution such as calcium, carbonate and acetate. Temperature affects the struvite solubility through thermodynamics. pH It is generally accepted that struvite solubility depends heavily on pH. [22-28]. Some studies showed that the struvite solubility decreased as pH increased within the pH range expected in wastewater treatment (6.0-8.0) and the minimum solubility occurred at pH 10.3 [22]. Buchanan et al. reported the minimum solubility point of pH 9.0 [29]. The reported pH with the 17 BACKGROUND AND LITERATURE REVIEW minimum struvite solubility ranges from 8.0 to 10.7. The difference in struvite solubility among these works results from the selection of different Ksp values [22]. * The decrease in apparent struvite solubility in an alkaline medium is a consequence of side reactions accompanying with the solubility equilibrium; these include the reaction of magnesium with water to produce hydroxo complexes and the acid-base reactions of ammonium and phosphate [28]. These side reactions and speciation of the components caused are pH dependent and respectively affect the struvite solubility in different pH ranges [29]. Therefore, the net effect of these side reactions causes the struvite solubility to decrease with the increasing pH value. Temperature Some researchers found that the struvite solubility was affected by temperature significantly [25]. The effect of temperature on solubility shows a steady increase in solubility with increasing temperature, followed by a steady decline in solubility over the range 10-65 °C [15]. It was reported that the struvite solubility increased to a maximum at 20°C [30]. The same study conducted by Aage et al. found that maximum solubility was at 50 °C. It also found that at a high temperature, the structure of struvite crystals changed, which inevitably affected its solubility [15]. The Ksp of struvite is also temperature dependent. Burns et al. determined the Ksp values at different temperatures and the data showed that the Ksp value increased with the increasing temperature in the range from 25 °C to 45 °C. They also calculated that the enthalpy of the struvite formation was 24.23 KJ-mor1 [24]. Therefore, the struvite formation in solution is an endothermic reaction. 18 BACKGROUND AND LITERATURE REVIEW The enthalpy is an important parameter for predicting the Ksp value at different temperatures. If a Ksp value at a particular temperature is not known, it can be estimated from the published enthalpy value according to equation (2). Alternatively, the unknown enthalpy of the equilibrium reaction can be calculated using equation (3) [27]. dlnKsp - A H (2) dT RT 2 In Ksp r^ } = - A H x T 1 - T 2 (3) Ksp(xi) R TlxT2 where T=temperature, K=273.15+°C AH=enthalpy of the reaction, J/mol R=ideal gas constant, 8.314J/mol-K (1.99 cal/mol-K). Since most wastewater treatment processes, including struvite crystallization, are carried out at or near the ambient temperature, the quantity A H / ( R T i T 2 ) in equation (3) can be assumed to be a constant for all practical purposes. Therefore, equation (3) can be rewritten as equation (4) as in the following [9]. Ksprr2)_ = 9 ( T 2 _ T 1 ) (4) Ksp (Tl) where 0 is the temperature coefficient. Impurity ions Struvite solubility is also affected by the presence of impurity ions in solution. The magnesium, ammonium and phosphate ions will form complexes with each other or with other species present in the solution, tending to increase the solubility [28]. For example, magnesium will combine with phosphate to form MgH2P04+, MgHPC»4 and MgPCV. Phosphate will form Ca3(PC»4)2 with calcium. Also, the presence of impurity ions will affect the ionic strength of a solution, which will affect struvite solubility because the electrostatic interactions of ions in solution reduce their activities or effective concentrations. Related studies found that the 19 BACKGROUND AND LITERATURE REVIEW presence of organic acids, carbonate, acetate and calcium would increase the struvite solubility [22, 30, 31]. In summary, the net effect of pH, temperature, impurity ions and any unknown factors will change the struvite solubility. Among these factors, the influence of pH is dominant, so that in the anaerobic digestion process that normally performs under a high pH, the suppression of struvite solubility will occur easily, leading to struvite precipitation [25]. 3.4 Morphology Of Struvite Crystal It is difficult to generalize the morphology of struvite crystals since it varies as widely as the surrounding conditions, under which they grow. It is accepted that individual struvite crystal is orthorhombic in shape. The crystal internal structure consists of regular PO43" tetrahedral, distorted Mg(H20)62+ octahedral and NFLt+ groups which are all held together through hydrogen bonding [32]. The crystal habit of struvite is variable from equant, wedge shaped, short prismatic to thick tubular, depending on the growth conditions [30]. Generally, the factors effecting the morphology of struvite crystal include supersaturation level, phosphorus concentration, molar ratio of Mg:P, impurities in the solution, crystal retention time in the reactor, pH, temperature and kinetic factors. Abbona and Boistelle reported that the developing crystal habit depended on the supersaturation of the solution [32]. They found that very high levels of supersaturation would promote the formation of bidimensional and tridimensional twinned crystals. As supersaturation decreased, crystal habit altered from a tubular formation to an increasing elongation [32]. The effect of supersaturation level on morphology is performed through its effect on nucleation rate. It was found that a high supersaturation resulted in high primary nucleation rate. In this scenario, struvite crystals were typically X-shaped or dendritic, due to preferential growth along one 20 BACKGROUND AND LITERATURE REVIEW crystal axis. Crystals growing slowly tended to be tubular or prismatic resulting from balanced growth along all the crystal axes [32]. The supersaturation level in the solution also has a visible effect on the size of struvite produced. It was reported that the high supersaturation would lead to formation of tiny crystals [33]. Some researchers have found that the size of struvite crystals was affected by the influent phosphorus concentration and molar ratio of Mg:P in the solution. Abe reported that, for high influent phosphorus concentrations, struvite was generated instantaneously near the inlet of the injection port and did not grow larger [34]. Hirasawa et al. found that Mg/P molar ratio affected the properties of produced crystals. The crystals were agglomerated at Mg/P molar ratio 2, resulting in large crystals. When Mg/P molar ratio became 4, the shape of crystals became needlelike and in addition, fine crystals were observed [35]. Another study showed that aggregation maybe was favored at higher magnesium concentrations [36]. The presence of impurities in a crystallization system can have a radical effect on crystal growth, nucleation, macrostep formation, agglomeration and the uptake of foreign ions in the crystal structure. It is found that different impurities have different effects on the crystal growth; some impurities can suppress growth entirely, some might enhance growth, and some might exert a highly selective effect, acting only on certain crystallographic faces [37]. The effect of impurities can be classified as thermodynamic effects (change of solubility) and kinetic effects (suppressing or accelerating crystal growth of certain or all faces) [38]. For example, the organic ligands, such as acetate and citrate, have been shown to bind to active growth sites of new-formed nuclei, resulting in inhibition to crystal growth [39]. Retention time is also important in determining the crystal size. Typically, a size maximum is reached after a certain time, after which prolonged retention time results in a decrease in size [30]. 21 BACKGROUND AND LITERATURE REVIEW Some studies showed that pH value and temperature of the solution influenced struvite formation and morphology highly, because the crystal growth changed with the changing pH and temperature [38, 40]. In addition, kinetic factors applied to struvite crystallization system affect the morphology of crystals. Ohlinger et al. found that the mixing energy was primarily responsible for controlling struvite growth rate and crystal habit [41]. Another study found that the crystal size decreased with increasing specific power input to the reactor. This was due to a strong increase in the nucleation rate caused by increasing specific power input, which led to the reduced crystal growth [42]. Since all of these external factors will combine together to affect the final morphology and size of struvite crystals, the reported sizes of struvite produced in pilot or full-scale crystallization process are quite different. Munch and Barr reported that their crystal had a volume median size of 0.11 mm [43]. The full-scale struvite crystallization process used by Kurita Water Industries in Japan is generally operated to achieve crystal size of 2.0-3.8 mm [43]. Abe reported the size of struvite produced by crystallization process in Seibu Treatment Plant of Fukuoka City, Japan, was greater than 2 mm and the growth rate in size was 0.061-0.173 mm/day [34]. 3.5 Current Phosphorus Recovery Studies 3.5.1 Phosphorus recovery methods Potential methods for recovering phosphorus from wastewater or animal waste include calcium phosphate (hydroxyapatite, HAP) crystallization, struvite (MAP) crystallization and membrane or ion exchange technology, followed by crystallization. Most current studies focus on the crystallization process of HAP or MAP. It is unclear whether HAP or MAP recovery is 22 BACKGROUND AND LITERATURE REVIEW better; however, MAP recovery may be preferable because its recovery process is simple and removes ammonium as well as phosphate, thus leading to easy application of MAP as fertilizer [8]. 3.5.2 Phosphorus recovery processes Currently, most phosphorus recovery studies are in the research or development stage and few have been implemented on a full-scale basis. A number of different processes for recovering phosphorus as either HAP or MAP are summarized and critiqued by Stratful et al. [10]. These processes include DHV Crystalactor ®, which has been implemented as a full-scale system at the Geestmerambacht, Netherlands since 1994, Unitika Phosnix process, the Kurita fixed bed crystallization column, the Rim-Nut ion exchange process and the CSIR fluidized bed crystallization process. 3.5.3 Pilot andfull-scale struvite recovery Fluidized bed reactor A common process used for struvite recovery is the fluidized bed reactor. The reactor consists of a standard columnar reactor with a cone-shaped bottom. In order to maintain the pellet bed in a fluidized state, the influent wastewater is pumped in an upward direction or a blower is used to force air into the base of the reactor [11, 14, 18, 19, 34, 43, 44]. The reactor commonly is filled with a seed material to support the struvite crystal growth. The seed materials used include quartz and silica sands, minerals, magnesia clinker, pumice, clays and struvite produced in advance [15]. Performance Extensive studies have been conducted on struvite recovery. Generally, the performances of pilot or full-scale struvite crystallization processes used by different studies are quite 23 BACKGROUND AND LITERATURE REVIEW satisfactory, in terms of phosphorus removal ratio. In Japan, several full-scale MAP processes have been installed and operated since 1995. The MAP process in Fukuoka City achieves 80 % of phosphate removal efficiency even with the high phosphate concentration of 245 mg/L in the influent. Also, the struvite grain size produced is greater than 2 mm [34]. Another full-scale MAP process, with a capacity of 500 m3-d_1, was in operation at the Shimane Prefecture Lake Shinji East Clean Center in 1998. The minimum removal rate of phosphate reached 90 % and the total phosphorus in the effluent ranged between 0.3-0.6 mg/L [19]. In Italy, Battistoni et al. set up the pilot-scale MAP crystallization process and their results showed that, in the low range of phosphate concentration between 30 to 60 mg/L, 81 % of phosphate removal could be achieved [45]. The phosphate removal in the study of Munch and Barr achieved 94 % for an anaerobic digester sidestream with the phosphate concentration of 61 mg/L [43]. The pilot-scale MAP crystallization process of UBC has achieved 90 % of phosphate removal from synthetic supernatant, with the phosphate concentration from 47 to 220 mg/L; the struvite crystals produced has a size greater than 2 mm [4]. When this process was applied to treat the anaerobic digester supernatant in the Penticton Advanced WWTP in Canada, about 80 % of the phosphate was removed from the digester supernatant and some recovered crystals had mean diameters of 1.8 mm [5]. Controlling parameters Generally, the struvite precipitation is achieved through changing pH or constituent concentration in the solution [15]. Since anaerobic digester supernatant contains ammonium much in excess of the amount needed, there is no need for optimization of its concentration. Therefore, pH and the magnesium concentration become two important controlling parameters in the struvite crystallization process. Suggested pH values for struvite crystallization are mostly between 8 and 9 [4, 19, 34, 43, 46]. Most studies change the operational pH through adding base, commonly in the form of 24 BACKGROUND AND LITERATURE REVIEW Ca(OH)2, NaOH or Mg(OH)2. Purely as a means of pH adjustment, NaOH has been suggested as the more effective chemical. However, dosing with a magnesium-based chemical has its distinct advantage over others, because the supersaturation of the solution is increased so that the required pH is reduced. Another method of pH adjustment is aeration of solution. Aeration strips carbon dioxide, resulting in an increase in pH. The MAP process in Fukuoka City uses a combination of air stripping and addition of NaOH to accomplish the required pH value of 8.2 [34]. The MAP process at the Shimane Prefecture Lake Shinji East Clean Center adds Mg(OH)2 for pH adjustment to 8.2-8.8, as well as NaOH dosing and air stripping [19]. Some studies showed that the chemical costs of a struvite crystallization process mainly came from the addition of base to raise the pH, so that the attempt to develop processes without chemical addition has been made [11, 45, 46]. In these processes, pH adjustment is achieved totally through aeration. Battistoni et al. used air stripping to increase the solution pH to the appropriate value for struvite precipitation and obtained the combination product of struvite, calcium phosphate and calcium carbonate [11, 47]. Suzuki et al. found that the pH of the swine wastewater was raised to approximately 8.5 with continuous aeration and a large part of the phosphate was removed through forming struvite and HAP [48]. Besides increasing pH, another method to initiate struvite crystallization is to increase the magnesium concentration. The magnesium ion is a limiting factor for struvite crystallization, so that excess magnesium is required to remove all the available phosphate from solution. The increasing concentration of magnesium also promotes the driving force of crystallization. Some researchers found that the presence of magnesium in excess increased the percentage phosphorus removal [49, 50]. A recent study revealed that the phosphate removal ratio increased with an increase in Mgp ratio and this increase was much more pronounced at low pH values [43]. The previous research at UBC showed that the Mgp molar ratio was at least 1.3:1, in order to achieve high phosphorus removal [3]. 25 BACKGROUND AND LITERATURE REVIEW In order to reduce the chemical cost brought by magnesium dosage, seawater is used as a source of magnesium ions. Kumashiro et al. developed a new MAP system and substituted seawater for the chemicals. The struvite crystals produced were quite pure and cheap [44]. Other notable controlling parameters include turbulence, phosphorus loading in the reactor and recycle ratio. Turbulence controls the growth rate of struvite crystals [23]. The phosphorus loading affects the maximum capacity of the reactor and phosphorus removal efficiency indirectly. The recycle is applied to the reactor in order to dilute the strong wastes and obtain an appropriate phosphorus concentration in the reactor [34]. For different struvite recovery processes and treated wastewaters, the values of these controlling parameters are variable. It is difficult to generalize the optimal values. Therefore, the determination of specific controlling parameters should be conducted for the specific case. Other applications of struvite recovery Struvite recovery is not confined to municipal wastewater treatment system; other waste streams offer opportunities for struvite recovery. Altmbas et al. recovered struvite from raw landfill leachate, which was anaerobically pre-treated by UASBR [51]. Suzuki et al. and Burns et al. studied on the phosphorus removal from the swine wastewater and swine waste slurries, respectively, through struvite crystallization [48, 52]. Also, struvite has been successfully recovered from calf manure and abattoir wastes [15, 53]. Struvite recovery also can be applied to remove ammonia, as well as phosphate from digester supernatant. Ammonia is often present in much higher concentration than phosphate and magnesium in the supernatant, so that phosphoric acid and magnesium are added in order to remove over 90 % of the ammonia [50, 54]. 26 B A C K G R O U N D A N D LITERATURE REVIEW 3.6 Modelling Application In order to predict the struvite precipitation in sludge digestion process and intentional struvite crystallization process, a number of chemical equilibrium based models and kinetic based models have been developed. The crucial issue of struvite modelling is how the chemistry of struvite is calculated by the modelling package and how laboratory based research compares with the struvite precipitation in real cases. Struvite version 3.1, a commercially available computer model was developed by R.E. Loewenthal and I. Morrison of the University of Cape Town, South Africa. This model is based on the chemical equilibrium, involving ionic equilibria and ion activity coefficients [15]. Some studies use this model to predict the struvite precipitation potential of wastewater tested [55, 56], Doyle et al. found that the model prediction compared well with the real precipitation; however, at higher pH values (8.5), the model under-predicted struvite precipitation [56]. MLNEQL+ is a computer model program for the computation of chemical equilibria in aqueous systems. It performs iterative analyses using an internal thermodynamic database and specified constituent concentration values to calculate equilibrium concentrations of all considered complexes [29]. Some researchers use this model to determine the theoretical solubility product of struvite. Ohlinger et al. set up struvite solubility limit curves at different pH vales using this model and predicted the struvite formation in digestion [22]. Musvoto et al. developed a three phase (aqueous/solid/gas) mixed acid/base kinetic model that reported to be a more applicable method of modelling reactions that occur in water and wastewaters [57, 58]. This model involves kinetic reactions, including forward and reverse dissociation processes of the weak acid/base species, precipitation of various magnesium and calcium phosphates and carbonates, and stripping of C 0 2 and NH3. They claimed that the 27 BACKGROUND AND LITERATURE REVIEW kinetic system modeled physical and chemical processes more accurately than equilibria-based model. However, further calibration is needed for wider application. Some models are developed for describing the process of phosphorus precipitation. They are divided into models based on primary nucleation mechanism that is caused by pure supersaturation and models based on secondary nucleation mechanism, in which nucleation and growth take place on preexistent seeds [18]. Battistoni et al. developed an empirical double saturational model, which was based on the secondary nucleation mechanism. This model has the physical meaning that, not only the operating pH, but also the contact time characterize the process performances. It has been verified through long-term operation of a pilot-scale fluidized bed reactor [18, 47]. Generally, using a modelling program, a series of scenarios can be quickly evaluated, such as different chemical compositions and sudden pH changes in process operation. Through model prediction, the treatment strategies can be determined and reviewed. Therefore, the study on modelling application in struvite recovery has a serious meaning for the wastewater treatment industry. 28 MATERIALS AND METHODS CHAPTER 4 MATERIALS AND METHODS 4.1 Supernatant Characteristics During The Study 4.1.1 Synthetic supernatant In the first phase of this study, the synthetic supernatant, containing ammonium and phosphate, was used as influent for testing the process. The detailed composition of the synthetic supernatant during the test is shown in Table 4.1. Table 4.1: Composition of the synthetic supernatant Parameters P0 4-P 1 mg/L) NH4 -N (mg/L) N: P ratio (molar) Reactor A Reactor B Reactor A Reactor B Reactor A Reactor B Maximum 152.6 188.2 733.0 923.7 12.7 13.4 Minimum 102.9 102.9 589.9 589.9 10.3 9.6 Average 136.7 143.7 682.8 710.8 11.1 11.1 4.1.2 Anaerobic digester supernatant In the second and third phases of this study, the anaerobic digester supernatants from the Annacis Island WWTP and the Lulu Island WWTP were tested. Since this study was conducted in the Environmental Engineering Pilot Plant of UBC, the supernatants from these two wastewater treatment plants were trucked there every two or three weeks and stored in the tanks. The trucked supernatants were taken from different centrifuge wells at different times. In addition, the commercial truck used for transportation was not cleaned completely in advance, with leftover sludge or wastewater from the last usage being present. This interfered with the quality of the tested supernatants. For these reasons, the supernatant characteristics were not 29 *1 MATERIALS AND METHODS constant during the period of this study, as shown in Table 4.2 and 4.3. Table 4.2: Supernatant characteristics of the Annacis Island WWTP Parameters PH Suspended solids (mg/L) Conductivity (ps/cm) Alkalinity (mg/L) P0 4-P (mg/L) Maximum 4000 141.1 Minimum 3850 128.43 Average 8.0 500 6200 3925 132.75 Parameters NTLt-N (mg/L) N: P ratio (molar) Mg (mg/L) Ca (mg/L) Maximum 1084.51 18.68 7.18 42.10 Minimum 1000.80 16.25 5.50 19.39 Average 1050.20 17.51 6.04 30.75 Table 4.3: Supernatant characteristics of the Lulu Island WWTP Parameters pH Suspended solids (mg/L) Conductivity (us/cm) Alkalinity (mg/L) PO4-P (mg/L) Maximum 8.2 300 2216 95.06 Minimum 8.0 200 1958 72.21 Average 8.1 250 5600 2087 84.06 Parameters NH4-N (mg/L) N: P ratio (molar) Mg (mg/L) Ca (mg/L) Maximum 1107.39 32.28 6.37 45.55 Minimum 879.01 22.26 4.22 22.98 Average 988.79 26.28 5.28 34.27 4.2 The Struvite Crystallization Process The pilot-scale struvite crystallization process, developed in the Civil Engineering Department of the University of British Columbia (UBC), included the crystallization reactor, external clarifier, feed pump, recycle pump, supernatant storage tank, magnesium feed tank and sodium hydroxide dosing tank. Figure 4.1 shows the layout of the process set up in the UBC Environmental Engineering Pilot Plant. 30 MATERIALS AND METHODS Effluent Effluent 1: Supernatant storage tank; 2: Magnesium feed tank; 3: Sodium hydroxide dosing tank; 4: Crystallization reactor A; 5: Crystallization reactor B; 6: External clarifier A; 7: External clarifier B Figure 4.1: Pilot-scale process layout There were two process setups in the Pilot Plant, which were named as A and B, respectively. These two processes had different reactors (A and B) and external clarifiers, but they used the same supernatant storage tank, magnesium feed tank and sodium hydroxide dosing tank. 4.2.1 Crystallization reactor The design of the crystallization reactor is shown in Figure 4.2. The crystallization reactor was a fluidized bed reactor, with four sections of increasing diameter from the bottom to the top. These four sections were one harvest zone, two reaction zones (I and II) and one top clarifier zone. Their inside diameters were 4.0 cm, 5.2 cm, 7.7 cm and 20.2 cm, respectively. The total height was 509.7 cm for reactor A and 520.7 cm for reactor B. Finally, the total liquid volumes for reactor A and B were 28.1 L and 24.5 L, respectively. 31 MATERIALS AND METHODS Top clarifier, 1D=202 mm Reaction zone II, ID=77 mm Reaction zone I, ID=52 mm pH control probe Harvest zone, ID=40 mm. Injection port MgCl2 Effluent Clarifier Sludge NaOH Supernatant Recycle Figure 4.2: Pilot-scale crystallization reactor design The purpose for the reactor design of increasing the diameter from the bottom to the top was to create decreasing upflow velocities in the reactor, so as to classify the fluidized particles along the reactor by sizes. Therefore, only the largest and heaviest crystals would be found in the harvest zone and the washing-out of the fine particles with the effluent would be avoided. The influent came into the reactor from the bottom and was completely mixed with the recycle fluid at the injection port. The effluent exited from the top clarifier to the external clarifier and then was discharged to the sewer. During the whole period of this study, the total upflow rate for both reactors was controlled from 3000 to 6800 mL/min and the HRT was 4.1-9.4 minutes for reactor A and 3.6-8.2 minutes for reactor B. The calculated upflow velocities and Reynolds numbers in the different sections are listed in Table 4.4. The detailed calculations are in Appendix A and B. 32 MATERIALS AND METHODS Table 4.4: Upflow velocities and Reynolds number in the different reactor sections Reactor sections Upflow rate (mL/min) Upflow velocity (cm/min) Reynolds number Harvest zone 3000-6800 238-541 1783-4041 Reaction zone I 142-320 1371-3108 Reaction zone II 64-146 926-2099 Top clarifier 9-21 353-800 The reactor was built using transparent PVC pipes with different diameters and lengths, which were connected by standard Schedule 40 or Schedule 80 PVC fitting. So, through the transparent reactor, the behavior of the struvite crystals in the reactor was monitored and the height of the collapsed crystal bed was recorded. The injection port There were four streams entering the bottom of the reactor, which were the supernatant influent, the recycle fluid, the magnesium chloride solution and the sodium hydroxide solution. In order to ensure that these streams were completely mixed, the injection port was designed at the bottom of the harvest zone. Figure 4.3 shows the cross section of the injection port. The injection port was made of stainless steel and was assembled to the reactor through a quick release connector. A ball valve at the bottom was used to shut down the entering streams from the influent and recycle. The harvest zone The harvest zone was designed for collecting the produced struvite crystals and also for cleaning the injection port. For each reactor, this part had an internal diameter of 4.0 cm and was 106 cm in length. The volume was about 1.3 L. There were two ball valves located at the top of the harvest zone and the top of the injection port; these were used to isolate the harvest zone when harvesting. 33 MATERIALS AND METHODS To the bottom of the reactor D=2.4 mm MgCl2 feed D=2.4 mm NaOH dosing D=12.7mm Supernatant Figure 4.3: Injection port of the pilot-scale crystallization reactor The reaction zone Above the harvest zone, there were two reaction zones with different diameters and lengths; one was reaction zone I, located at the bottom, and the other was reaction zone II, located at the top. During the operation of the reactors, the reaction zones were regions for crystal growing and expanding. The internal diameters of these two zones were 5.2 cm and 7.7 cm, respectively. For reactor A, the reaction zone I had a length of 108 cm and held a volume of 2.3 L. The reaction zone II had a length of 250 cm and held a volume of 11.5 L. As for reactor B, the length and volume for the reaction zone I were 276 cm and 5.9 L, and 93 cm and 4.3 L for the reaction zone II. Between zones I and II, a ball valve was equipped for separation. The top clarifier Above the reaction zone was the clarifier zone, with a nominal diameter of 20.2 cm and a 34 MATERIALS AND METHODS length of 45.7 cm, for both reactors. The volume was about 13 L. The purpose of the top clarifier was to prevent the fine struvite crystals from escaping the reactor. Since the upflow velocity in this zone was only from 9 to 21 cm/min in this study, most of fine crystals would settle by gravity. Two side outlets for the overflow were located in the top clarifier; one was set at 40.6 cm water depth and carried the overflow from the reactor to the external clarifier. This outlet was connected to the external clarifier by a vertical transparent PVC pipe, with an inside diameter of 2.5 cm, and a flexible tube, with an inside diameter of 3.1 cm. The other outlet was placed 2.5 cm higher than the lower outlet. It was connected to the external clarifier through a LDPE tube, with an outside diameter of 1.27 cm. This outlet could be used if the lower outlet were plugged. 4.2.2 The external clarifier and recycle flow The overflow from the crystallization reactor was carried to the external clarifier through recycle tubing. In the external clarifier, the fine struvite crystals washed out from the reactor and the suspended solids in the supernatant would settle out. The external clarifier also acted as a tank to store the effluent and recycle some portion of the effluent back to the injection port. The external clarifier was made of clear acrylic plastic. It was rectangular with the surface dimension of 36.5 cm by 40 cm and had a square pyramidal bottom with a slope of 45°. Its approximate volume was 54 L. A side outlet for the final effluent was used to keep the water level with 30.5 cm in side depth. The final effluent was carried to the sewer drain using LDPE tubing, with an outside diameter of 1.27 cm. A 3-way valve was equipped at the starting point of the effluent drain line, in order to be used for collecting the effluent sample and measuring the flowrate. Another side outlet was placed 15 cm below the water surface. The recycle flowed back to the injection port through this outlet. The LDPE tubing, having an outside diameter of 1.27 cm, was used to 35 MATERIALS AND METHODS connect this outlet with the injection port. The recycle was pumped by a Moyno Model 500 322 progressive cavity pump, with a 1/2 HP motor and a digital speed controlling panel. A sludge drain valve was equipped on the bottom of the external clarifier; this was used to remove the sludge accumulated during the reactor operation. 4.2.3 Supernatant storage tanks and pumps The supernatants used in this study included the synthetic supernatant and real anaerobic digester supernatant. The real digester supernatant came from the Annacis Island WWTP and the Lulu Island WWTP. The synthetic supernatant was made through dissolving the chemical reagents in tap water. The reagent salts used were commercial grade magnesium chloride, diammonium hydrogen phosphate and ammonium chloride. The anaerobic digester supernatants from the Annacis Island WWTP and the Lulu Island WWTP were carried to the Pilot Plant by trucks and were stored in two tanks, with an approximate volume of 19,000 L. These two storage tanks were equipped with an overflow port and a drain valve. The supernatant was pumped to the reactor through a pipeline, located 30 cm above the tank bottom. Therefore, most of the suspended solid in supernatant could be settled out and prevented from entering the reactor. A 3-way value was placed at the beginning of the pipeline for collecting samples. The synthetic supernatant without magnesium content was made in a mixing tank and then pumped to a storage tank, with a volume of 3,888 L. The supernatant was pumped to the reactor from the tank bottom and mixed with magnesium feed in the injection port; this produced the synthetic supernatant with the desired contents of phosphate, ammonia and magnesium. The piping from the storage tanks to the reactors was arranged in order to let both reactors feed from the same line, so that the supernatant used in both reactors was exactly the same. The piping used LDPE tube, with an outside diameter of 1.27 cm. Each reactor was 36 MATERIALS AND METHODS equipped with a pump for delivering the supernatant. The pump used was Moyno Model 500 331 progressive cavity pump, with a 1/2 HP motor and a digital speed controlling panel. 4.2.4 Magnesium feed tank and pump The magnesium feed was made through dissolving the commercial grade magnesium chloride in tap water. The solution was stored in a tank, with a volume of 1,400 L, and pumped to the injection port using a MasterFlex L/S variable speed peristaltic pump, with a standard pump head. The tube used in the pump was neoprene tube, with 0.63 cm in outside diameter. Both reactors used the same magnesium feed tank but each of them was equipped with an individual pump system, in order to apply different magnesium feeding speed for producing different magnesium concentrations in the process. The piping for connecting the magnesium feed tank with the injection port was a LDPE tube, with 0.63 cm in outside diameter. 4.2.5 pH control and sodium hydroxide dosing The pH control system is very important for the operation of the whole crystallization process because the desired supersaturation condition in the reactor is highly pH dependent, thus directly affecting the phosphate removal. Therefore, each reactor had an individual pH control system, in order to provide strict pH monitoring and apply different operating pHs in each reactor. In this study, the pH within the reactor was monitored through a Cole Parmer, double junction, in-line pH probe, located at the top of the harvest zone (shown in Figure 4.2). According to the difference between the real pH in the reactor and the set pH, the pH pump control system pumped the sodium hydroxide solution into the reactor at a constant rate. This control system could control pH within ±0.1 units. Also, the pH in the external clarifier was monitored using an Oakton continuous pH monitor equipped with an Oakton gel filled, epoxy body pH probe. In practice, the pH reading at the top of the harvest zone was slightly higher or 37 MATERIALS AND METHODS lower (0.1 pH units) than the pH reading in the external clarifier. The pH in the reactor was adjusted using sodium hydroxide solution. The industrial grade sodium hydroxide was dissolved in tap water to make a solution and then was stored in a tank, with a volume of 1,400 L. The tubing between the sodium hydroxide storage tank and the injection port was a LDPE tubing, with 0.63 cm in outside diameter. 4.3 Process Monitoring And Maintenance Before running the process, both reactors were seeded in order to overcome the time lag of the nucleation period. The struvite crystals formed in the previous experiments were used as seed. The volume of seed added was approximately 6 L. No seed was needed during the period of continuous process operation, since the reactors were self-seeded by the fine struvite crystals formed. During the operation of the crystallization process, several operating parameters were monitored and recorded daily. For both reactors, the influent and effluent samples were collected, filtered, stored and analyzed using the methods described in Section 4.4 and Section 4.8. The pH readings in the reactor and in the external clarifier were recorded in order to check whether the difference was present. The water temperature was measured using a thermometer and recorded, since the solubility of struvite is temperature dependent. Then, the effluent flow rate, the total combined flow rate in the down pipe from the reactor to the external clarifier, and the magnesium feeding rate were measured and monitored. All these flow rates were measured using a graduated cylinder and stopwatch. Given 1 or 2 minutes, the total volume of the flow was collected and recorded, so that the flow rate was obtained. The solution levels in storage tanks for supernatant, magnesium chloride solution and 38 MATERIALS AND METHODS sodium hydroxide solution were recorded daily, in order to calculate the usage of each solution according to the difference from the previous day's reading. When the new solution was made, the mass of reagent and the volume of tap water added were recorded. On harvesting day, the reactors were shut down and struvite crystals inside were allowed to settle for about an hour. The collapsed volume of crystal bed was recorded; then the crystals were harvested as described in Section 4.5. Maintenance work was performed every day when the synthetic supernatant was tested, since the plugging problem caused by struvite accumulation was frequently observed. For the Annacis and Lulu supernatants, maintenance was performed only on the harvesting day. The maintenance work included cleaning of the injection port, top clarifier, external clarifier and calibrating pH probes. After the reactors were stopped, the injection ports were removed from the reactors and cleaned using a thin welding rod. The acid was used to wash the accumulated struvite out if the fouling was severe inside. The sludge, including the fine struvite crystals and suspended solid in digester supernatant, accumulated in the bottom of top clarifiers and external clarifiers, and it was removed. Then, the clarifiers were washed using tap water. The pH probes in the reactors and in the external clarifiers were calibrated using the standard pH 7 and pH 10 buffer solutions. The calibration procedure followed the manufacturer's instruction for two-point calibration. After calibration, the probes were verified by measuring the pH of a same solution and ensuring the difference among pH readings within 0.1 pH units. Once the maintenance was finished, the reactors were restarted and the operational parameters were adjusted to the desired set points, if needed. 39 MATERIALS AND METHODS 4.4 Sample Collection, Storage And Preservation Every day, the influent and effluent samples were collected at least once. The influent samples for supernatants were collected from the storage tank and ones for the magnesium feed were collected from the magnesium feed tank. The effluent samples were collected directly from the external clarifier. All the samples were filtered using Fisher Brand G6 filter papers, with a nominal pore size of 1.5 microns, in order to remove suspended solids and fine struvite particles. Samples for [PCVPJtotai and [NEf4-N]t0tai measurement (influent and effluent) were collected in small test tubes and the sample volume was about 5 mL. The concentrated sulfuric acid was added so as to decrease the sample pH lower than 2, in order to preserve samples. Samples for metal measurement (influent and effluent) were collected in plastic centrifuge tubes and the sample volume was around 30 mL. Concentrated nitric acid was added to preserve samples. All samples were stored at 4°C until analysis. The analysis was completed within USEPA recommended times [59]. 4.5 Struvite Crystal Harvesting, Drying And Sieving On harvest day, struvite crystals were collected from the harvest zone of the reactor. Firstly, the supernatant feed, recycle and chemical feed flows were shut down and the crystals were allowed to settle for about an hour. After the settling was complete, the ball valve at the top of the harvest zone was closed to isolate the harvest zone from the rest part of the reactor. Then, the injection port section was removed from the reactor and the crystals dropped into a container by gravity. Tap water was used to flush out the remaining crystals from the top of the harvest zone and rinse the harvest zone. After the harvest was complete, the injector port section was assembled again, the isolation valve was opened and the process was restarted. 40 MATERIALS AND METHODS After crystals were harvested from the reactor, tap water was used to wash the harvested crystals. The clean crystals were spread over the drying rack, which was made of a wooden frame supporting a plastic window screen. Then, the crystals were dried for at least 24 hours by a ceramic heater fan blowing warm air over them. It should be noted that the expulsion of some ammonia or water molecules from the struvite crystal matrix would occur, if the heating temperature was set too high. Once the drying procedure was done, the dried crystals were collected and screened using W.S.Tyler sieves. The sieves used were with nominal sieve sizes of 4.75 mm, 2.83 mm, 2 mm, 1 mm and 0.5 mm. A plastic pan was used to collect the portion of crystals with diameters of less than 0.5 mm. Through this procedure, the harvested crystals were separated into six size fractions: 0-0.5 mm, 0.5-1 mm, 1-2 mm, 2-2.83 mm, 2.83-4.75 mm and greater than 4.75 mm. In the end, the crystals in each size fraction were weighed using an analytical balance and some crystal samples in each size fraction were collected for further analysis. 4.6 Crystal Quality Determination The quality of the harvested struvite crystals tested in this study included the composition, purity, density and, inside and outside morphology. Since it was impossible to check all crystals produced, only selected samples were involved in the quality determination. It was assumed that the selected crystal samples were representative. 4.6.1 Composition and purity The composition and purity of the crystals grown from real digester supernatants were determined through testing the crystal samples. No crystals grown in the synthetic supernatant were tested because the chemical reagents with high purity were used in the synthetic supernatant; thus almost pure struvite crystals were expected to be produced in the process. 41 MATERIALS AND METHODS The crystal samples collected from the Annacis and Lulu supernatants, respectively, were dissolved in a 0.5 % nitric acid solution. For each sample analyzed, approximately 0.03 g of crystals were dissolved in 50 ml of 0.5 % nitric acid solution. The magnetic stirrer was applied to accelerate the crystal dissolution. The crystal solution was sit for 24 hours to ensure the complete dissolution, and then the solution was analyzed for magnesium, ammonia, ortho-phosphate, as well as calcium, aluminum, iron, potassium and carbonate. 4.6.2 Density In this study, there were two methods to measure the density of the harvested crystals. One was measuring the mass of the dry crystals harvested from the harvest zone using an analytic balance. The value of the dry weight of crystals divided by the volume of the harvest zone was regarded as the density of the harvested crystals. However, this "density" was not the real density but only a surrogate, since the true volume of dry crystals was not used in this calculation. Another method was used to measure the real density. All the crystals existed in the reactor was drained and dried. The dried crystals were measured for the total mass and volume. The density of the crystals was calculated through dividing the mass by the volume. Since this method needed to drain the whole reactor, it was tested only after the whole study had been completed. 4.6.3 Scanning electron microscope (SEM) examination In order to study the morphology of the struvite crystals produced from the crystallization process, the SEM examination was performed in the lab of Materials and Metals Engineering Department of UBC. Before the test, the crystal samples were glued to a small steel plate and were put into the machine. The crystals were cut using a small knife if the inside structure was observed. The SEM used was the HITACHI S-3000N unit and the operation 42 MATERIALS AND METHODS procedure followed the manufacturer's manual. . 4.7 Struvite Solubility Determination The struvite solubility curve is crucial for the operation of the struvite crystallization process. This curve was developed using the bench-scale crystallizer. For the synthetic supernatant, the Annacis supernatant and the Lulu supernatant, their respective struvite solubility curves were determined separately. The struvite crystals produced in different supernatants were used for solubility curve determination of different supernatants. Since the struvite solubility is highly temperature dependent, the curves at temperatures of 10°C, 15°C and 20°C were determined. The apparatus used for determining the solubility of struvite was a six-station paddle stirrer (Phipps and Bird). Each stirrer was inserted into a square jar. About 10 grams of struvite crystals and 1.5 liters of the supernatant being tested were added to each square jar, which was immersed in a constant temperature bath at the desired temperature. The paddle stirrers were set to operate at 70 ± 1 RPM. In order to determine the struvite solubility over a pH range between 6 and 9, the pH in each jar was adjusted using dilute hydrochloric acid or sodium hydroxide solution. Since the previous research at UBC found that the equilibrium was reached 24 hours after the pH was changed (Ping Liao, Department of Chemical and Biological Engineering, UBC, pers. comm.), the apparatus was left to equilibrate for at least 24 hours before analysis. When the equilibrium was complete, the pH and conductivity in each jar were measured. The solution samples for magnesium, calcium, ammonia and ortho-phosphate were collected, filtered, stored and analyzed later. 43 MATERIALS AND METHODS 4.8 Analy t ica l Methods 4.8.1 Ortho-phosphate and ammonia Ortho-phosphate and ammonia samples were analyzed together, using flow injection analysis on a LaChat QuikChem 8000 instrument. These analyses included influent and effluent samples from the operation of the process, samples from the crystal composition analysis and struvite solubility determination experiments. The measurement procedure followed the manufacturer's manual. The instrument operational parameters can be found in Appendix C. 4.8.2 Magnesium, calcium, aluminum andiron The analysis for magnesium, calcium, aluminum and iron was performed by flame atomic absorption spectrophotometry, using a Varian Inc. SpectrAA220 Fast Sequential Atomic Absorption Spectrophotometer. The samples for magnesium and calcium analysis included influent and effluent samples from the operation of the process, samples from the crystal composition analysis and struvite solubility determination experiments. The samples from the crystal composition analysis also were analyzed for aluminum and iron. The measurement procedure followed the manufacturer's manual. Instrument operational parameters can be found in Appendix C. 4.8.3 Potassium Potassium analysis was performed on the samples from the crystal composition analysis. This analysis used the same instrument as for the magnesium analysis described above, but using atomic emission spectrophotometry. Instrument operational parameter can be found in Appendix C. 4.8.4 Carbonate The carbonate analysis was performed on the samples from the Annacis and Lulu 44 MATERIALS A N D M E T H O D S supernatants, and the samples from the crystal composition analysis. In this analysis, it was assumed that all the inorganic carbons existed in the form of carbonate. The analysis instrument used the Shimadzu Total Organic Carbon Analyzer TOC-500IC. The measurement procedure followed the manufacturer's manual. 4.8.5 pH Field pH measurements were performed using the Oakton continuous pH monitors described in Section 4.2.5. Laboratory pH measurements were performed using a Beckman 044 pH Meter, equipped with an Oakton epoxy body pH electrode (WD-35801-00). All pH meters were regularly calibrated by the two-point method, using buffer solutions of pH 7 and pH 10. The calibration procedure followed the manufacturer's manual. 4.8.6 Conductivity Conductivity was measured using a Hanna Instruments FH9033 multi-range conductivity meter. The samples performed conductivity measurement included influent and effluent samples from the operation of the process and samples from struvite solubility determination experiments. The measurement procedure followed the manufacturer's manual. 4.9 T e r m i n o l o g y In order to let readers understand the content of this study more easily and clearly, the following terms and definitions related to the struvite process are described. 4.9.1 Strwitt solubility product (Ksp) The solubility product of struvite (K s p) defined in this study is the product of the ionic activities of the precise species involved in the equilibrium of struvite, as shown in equation (5). K s p={Mg 2 +}{NH4 +}{P0 4 3-} (5) 45 MATERIALS AND METHODS where the {} brackets indicate ionic concentration in moles per liter, corrected for activity. The calculation of K s p value included the speciation of analytically measured concentrations using published acid and base dissociation constants, as well as an adjustment for activity. The concentration of ion can be adjusted for activity through using equations (6) and (7). Firstly, the ionic strength of the solution was determined based on conductivity measurements using the conversion factor described in equation (6) [60]. where n is the ionic strength and EC is the measured electric conductivity with unit of//S/cm. Then, the Guntelberg approximation of the Debye-Huckel equation, as shown in equation (7), was applied to calculate the activity coefficients for each species of interest [27]. where, y and z are the activity coefficient and ionic charge for the species of interest, respectively. The measured concentrations for total soluble ortho-phosphate, ammonia and magnesium involve several other species except PO43", N H / and Mg 2 + , as shown in equations (8) to (10). Therefore, the related acid and base dissociation constants were used into equations (11) to (19) to solve for the individual concentration of interest. The dissociation constants at 25°C are described in equations (11) to (19) (Daniel Potts, Department of Civil Engineering, UBC, pers. comm.). ,u=1.6 x 10"5 EC (6) log y = 0.5z2Ju (7) T-P0 4 = [H3PO4] + [H2PCV] +[HP042"] + [P043"] (8) T-NH 3 = [NH3] + [NH 4 +] (9) T-Mg = [Mg2 +] +[MgOH+] (10) 46 MATERIALS AND METHODS [H2P04"][H+]/[H3P04] = 7.08 x 10'3 (11) [HP042"][H+]/[F£P04'] = 6.31 x 10"8 (12) [P043"][H+]/[HP042"] = 2.95 x i f / 1 3 (13) pS^][H^/rNH4+] = 5.01 x 10"10 (14) [Mg2+][OH-j/rMgOFf] = 2.75 x 10'3 (15) [Mg2 +] H2P04"]/[MgH2P04+] = 0.355 (16) [Mg2+][HP042"]/[MgHP04] = 1.23 x 10"3 (17) [Mg2+][P043"]/[MgP04"] = 1.58 x lO'5 (18) [H+][OFr]= 1 x if/ 1 4 (19) where the [ ] brackets indicate ion concentration in moles per liter, without correction for activity. The ion concentration without correction for activity can be converted into the concentration by multiplying with the activity coefficient discussed above. The K s p also can be defined as equation (20), once the speciation for interested ion and correction for activity have been done. K Sp=(aMg 2 +yMg 2 + [T-Mg])(aNH4 +7NH4 + [T-NH3 ])(apo4 3 "YP04 3 "[T-P0 4 ]) (20) where, a = free ion concentration of interest total dissolved species concentration 4.9.2 Struvite conditional solubility product (Ps) In this study, the struvite conditional solubility product did not consider the speciation of interested ions and correction for ionic activity. It is defined as the product of the analytical results for the total soluble magnesium, ammonia and ortho-phosphate, as described by equation (21). It also can be described by equation (22). Ps provides a quick way to determine the supersaturation condition for the process operation. 47 MATERIALS AND METHODS PS= [Mg]total [NH4-N],otol [P04-P]total Ps= Ksp 2 + 2 + + + 3- 3-ttMg YMg 0.NH4 Y N H 4 CL?04 J?04 (21) (22) 4.9.3 Supersaturation ratio In this study, the supersaturation ratio (SS ratio) was used as an indicator for struvite precipitation potential. Theoretically, the SS ratio of a solution at equilibrium is equal to 1. A solution with a value of SS ratio greater than 1 is in the supersaturated condition with struvite and struvite will be formed. In contrast, a solution with a SS ratio less than 1 is undersaturated and struvite in the solution will dissolve. The supersaturation ratio is defined as the ratio of the conditional solubility product in a solution to the equilibrium conditional solubility product, under the given conditions, shown as in equation (23). SS ratio = P s/P Seq (23) Inlet supersaturation ratio The inlet supersaturation ratio describes the hypothetical supersaturation condition of the solution. It is not really present in the reactor since it only considers the flows of supernatant, magnesium feed and sodium hydroxide dosing; it also assumes that these flows would mix to form an influent with the pH value same as that in the reactor. However, in effect, the supernatant is mixed with the recycle before magnesium feed and sodium hydroxide dosing entering. Therefore, the inlet SS ratio is a hypothetical value for estimating the driving force for the crystallization reaction. The inlet SS ratio can be calculated using equation (24). Inlet SS ratio=Ps.iniet/Ps e q (24) 48 MATERIALS AND METHODS where Ps.i„iet is the conditional solubility product of the solution consisting of supernatant, magnesium feed and sodium hydroxide dosing, in proportions equal to those entering the reactor. In-reactor supersaturation ratio The in-reactor supersaturation ratio describes the real supersaturation condition and governs the crystallization process. It can be applied to separate the precipitation reaction and the crystallization reaction because the high in-reactor SS ratio will lead to excess nucleation, which is the characteristic of a precipitation reaction. The in-reactor supersaturation ratio can be calculated using equation (25). In-reactor SS ratio=Ps.reactor/Ps e q (25) where Ps.reactor is the conditional solubility product of the solution consisting of supernatant, recycle stream, magnesium feed and sodium hydroxide dosing, in proportions equal to those entering the reactor. Effluent supersaturation ratio The effluent supersaturation ratio describes the degree of reaction completion. Theoretically, the effluent SS ratio should be equal to 1 if the crystallization reaction reaches equilibrium. However, due to the effect of operational conditions, such as insufficient retention time in the reactor and exclusion of ammonia from the recycle stream, the reaction will not be 100% complete and the effluent SS ratio will not be 1. The effluent supersaturation ratio can be calculated using equation (26). Effluent SS ratio=Ps.effleunt/Ps e q , (26) where Ps.effleunt is the conditional solubility product of the effluent at given conditions. 49 MATERIALS AND METHODS 4.9.4 Recycle ratio The recycle ratio is defined as the ratio of the recycle flow to the total influent flow that includes the flow from the supernatant, magnesium feed and sodium hydroxide dosing. It is used to control the in-reactor supersaturation ratio by diluting the feed with treated effluent. The recycle ratio can be calculated using equation (27). Recycle ratio = Qr/Qi„ = (Qt-Qin)/Qi„ (27) where: Q r = the recycle flow; Q t = the total combined flow through the reactor, including the influent flow and the recycle flow; Q i n = the influent flow (or the effluent flow). 4.9.5 Crystal retention time The crystals need sufficient time in the reactor to reach to a desired size. In this study, the crystal retention time (CRT) was developed to estimate the crystal age, which is the amount of days a harvested crystal spending in the reactor. It was determined by measuring the volume of the settled crystal bed in the reactor at the time of each harvest, and then calculating the approximate number of days that had past until that volume of crystals was removed from the reactor. For example, if the measured volume of the crystal bed was 6.5 L, and 1.3 L of crystals were harvested from the reactor every two days, then the CRT would be 10 days. But for the harvest with an irregular interval, the CRT was counted from the harvest day to the estimated day that crystals in the recorded bed volume began to grow. It was noted that the CRT calculation started from the date after the seed volume had been removed from the reactor. 4.9.6 Mean crystal size The mean crystal size is used to describe the size of harvested crystals and calculated from the result of the sieve analysis. The crystals that were of less than 0.5 mm were assumed to 50 MATERIALS AND METHODS be 0.25 mm in diameter, the 0.5-1 mm crystals were assumed to have a diameter of 0.75 mm, the 1-2 mm crystals were assumed to have a diameter of 1.5 mm, the 2-2.83 mm crystals were assumed to have a diameter of 2.4 mm, the 2.83-4.75 mm crystals were assumed to have a diameter of 3.8 mm, and the crystals that were greater than 4.75 mm were assumed to have a diameter of 4.75 mm. Based on this assumption, the mean crystal diameter by mass was calculated using equation (28). Dm e a„ = (Ml x0.25 + M2x0.75 + M3 x 1.5 + M4x2.4 + M5x3.8+ M6x4.75)/M (28) where: D m e a n = Mean Crystal Diameter (mm); M l = mass of crystals with diameter less than 0.5 mm; M2 = mass of crystals with diameter from 0.5 to 1; M3 = mass of crystals with diameter from 1 to 2 mm; M4 = mass of crystals with diameter from 2 to 2.83 mm; M5 = mass of crystals with diameter from 2.83 to 4.75 mm; M6 = mass of crystals with diameter greater than 4.75 mm; M = M1+M2+M3+M4+M5+M6. 4.9.7 Removal efficiency for phosphate, ammonia and magnesium The removal efficiencies for phosphate, ammonia and magnesium were calculated using equations (29), (30) and (31), respectively. P removal (%) = ( [ P 0 4 - P ] i (Qs)- [ P 0 4 - P ] e (Qe)V ( [ P 0 4 - P ] ; (QO) * 100 (29) N removal (%) = ([NH4-N], (QO- [NH4-N] e (Qe)V ([NH4-N] i (Qi)) * 100 (30) Mg removal (%) = ([Mg] { (Q,)+[Mg]f (Qf)- [Mg] e (Qe)V ([Mg] s (Q;)+ [Mg]f (Qf)) x 100 (31) where: [ P 0 4 - P ] 1, [NH4-N] 1, [Mg] i = concentrations of P 0 4 - P , NFI4-N and Mg in the feed supernatant; [ P 0 4 - P ] e, [NH4-N] e, [Mg] e = concentrations of PO4 -P, NH4 -N and Mg in the effluent; 51 MATERIALS AND METHODS [Mg]f= concentration of Mg in the magnesium feed; Qi = the flow of the feed supernatant; Q e = the flow of the effluent; Qf = the flow of magnesium feed. 4.9.8 Struvite recovery efficiency The struvite recovery efficiency describes the degree of the removed phosphate converting to the form of struvite. It was calculated by using equation (32). Recovery (%) = Mass of harvested struvite crystals * 100 Theoretical mass if all the removed phosphate converted to struvite form (32) Theoretically, the removed phosphate should be 100 % converted to the struvite in the designed crystallization reaction. However, due to the fine particles present that cannot be completely harvested, and also due to the mass loss in the process of harvesting, drying, transferring and sieving, the recovery efficiency would be lower than 100 %. 52 RESULTS AND DISCUSSION CHAPTER 5 RESULTS AND DISCUSSION From June 2002 to December 2002, two pilot-scale UBC struvite crystallization processes (described in Section 4.2) were operated continuously for recovering phosphorus, in the form of struvite, from anaerobic digester supernatants from two GVRD municipal wastewater treatment plants-the Annacis Island WWTP and the Lulu Island WWTP. Before the anaerobic supernatants were tested, a synthetic supernatant was used to simulate the real one and to find the possible optimal range of operational conditions. Through six months of the crystallization process operation, the main result was that the process was successful in recovering phosphorus in the form of struvite from the anaerobic digester supernatants. The struvite crystal products harvested from the process were high in purity and hardness with average sizes of over 2 mm in diameter. It showed promise for scale up and application to other anaerobic digester supernatants from different sources. 5.1 Chemistry Of Struvite Struvite chemistry is crucial for anticipating the struvite precipitation potential of a known digester supernatant and for controlling struvite formation in an intentional struvite crystallization process. In this study, the solubility of struvite was regarded as a baseline for determining operational parameters and ensuring complete crystallization. A number of studies on struvite solubility reported a very wide range of solubility values, due to different testing methods and conditions, as well as different calculations used, for which there is not a universal 53 RESULTS AND DISCUSSION standard until now [3, 23]. In addition, the struvite solubility is affected by some factors, such as pH, temperature, impurity ions, and other unknown factors [22-31]. Therefore, it is necessary to determine the struvite solubility that would be expected in this study's testing conditions for the supernatants used. The detailed data and calculations are listed in Appendix D. 5.1.1 Struvite solubility product (Ksp) Three sets of experiments were conducted using the procedure described in Section 4.7; one to determine the struvite solubility product (Ksp) in the synthetic supernatant, and others to determine the struvite Ksp value in the anaerobic digester supernatants. Figure 5.1 shows the negative logarithm of Ksp values for the synthetic, Annacis and Lulu supernatants at 20 °C. 12.00 1 1 1 1 1 1 1 1 1 ' 5 5.5 6 6.5 7 7.5 8 8.5 9 9.5 pH • Synthetic • Annacis A Lulu Synthetic Annacis Lulu Figure 5.1: Struvite solubility products at 20°C It can be seen from Figure 5.1 that the values of struvite solubility products in the three different supernatants were highly pH dependent. They varied significantly over a pH range 54 RESULTS A N D DISCUSSION from 5.5 to 9. For the Annacis supernatant, the Ksp value increased from 4.46><10"14 to 6.04xl0"13, when the pH increased from 5.62 to 8.77. For the Lulu supernatant, the Ksp value increased from 2.92xl0"14 to 4.66xl0'13, when the pH increased from 5.89 to 9.02. For the synthetic supernatant, it varied from 8.08xl0"15 to 1.06xl0"13, when the pH varied in the range of 5.50 to 8.70. This changing trend of Ksp with varying pH was consistent with results of both Britton and Adnan when they tried to determine the struvite Ksp value in the distilled water, tap water, synthetic supernatant and digester supernatant from the Penticton Advanced WWTP [4, 5]. In addition, other researchers also found this pattern in their previous works [22, 28, 29]. Thermodynamically, there should be a single value of struvite solubility product that could apply to all solutions, given that the activity and reaction of each chemical species present could be known accurately. Unfortunately, there are too many unknown compounds present in the digester supernatant, thus making it difficult to determine the activities of individual compounds accurately. On the other hand, there is considerable uncertainty over the actual reactions that will occur in the supernatant. These unknown species and reactions, which may compete with the struvite formation, will affect the solubility product determination. In addition, the Ksp values for different supernatants were not the same even at the same pH, as shown in Figure 5.1. It can been seen that the Ksp value for the Annacis supernatant was the highest, while the Ksp value for the synthetic supernatant was the lowest. This means that the struvite is more soluble in the Annacis supernatant than in the Lulu supernatant and the synthetic supernatant. This can be explained in two ways. One is that the higher ionic strength of the Annacis supernatant increases the struvite solubility, since the electrostatic interaction of ions in solution will reduce their real activities or effective concentrations [22]. The other possible reason is that there are more impurity ions, such as carbonate, present in the Annacis supernatant, thus inhibiting the precipitation of struvite and increasing solubility significantly. 55 RESULTS A N D DISCUSSION 5.1.2 Temperature coefficient (0) and enthalpy (AH) The temperature coefficient and enthalpy are two important parameters in the thermodynamics of struvite equilibrium. They reflect the effect of temperature on the equilibrium reaction and solubility product. In this study, the struvite solubility products at different temperatures were determined and the data are shown in Appendix D. Under different temperatures, the struvite solubility product is different. The Ksp value will increase with the increasing temperature [24]. Figures 5.2 and 5.3 show the Ksp values at different temperatures in the Annacis and Lulu supernatants, respectively. It can be seen that the Ksp value for the Annacis supernatant increased 167 % when temperature increased from 10°C to 20 °C and the Ksp increment for the Lulu supernatant was about 87 %. 13.80 13.60 13.40 13.20 a. 13.00 ^ 12.80 12.60 12.40 12.20 12.00 ft 5 5.5 6 6.5 7 7.5 8 8.5 pH 9.5 • 10 °C • 15 °C A20°C Figure 5.2: Struvite solubility product in the Annacis supernatant at different temperatures 56 RESULTS A N D DISCUSSION 13.80 13.60 13.40 13.20 $ 13.00 a. 12.80 12.60 12.40 12.20 • • -f>" cr • 10°C rJ20°C 5 5.5 6 6.5 7 7.5 8 8.5 9 9.5 pH Figure 5.3: Struvite solubility product in the Lulu supernatant at different temperatures The values of temperature coefficient and enthalpy in different supernatants are shown in Table 5.1. The corresponding equations used are listed in Section 3.3. Since the enthalpy calculated is positive, the struvite formation in solution is an endotherrnic reaction. Table 5.1: Values of 0 and A H Supernatant Temperature fC) Ave. pKsp Ave. Ksp 0 Ave. 0 A H (KJ/mol) Ave. A H Annacis 10 13.20 6:35xl0"14 15 13.04 9.06xl0-14 1.07 48.22 20 12.84 1.46xl0"13 1.10 1.085 67.02 57.62 Lulu 10 13.30 4.98xl0"14 20 13.02 9.53xl0"14 1.07 1.07 44.79 44.79 Theoretically, the value of struvite 0 and A H should be the same for different solutions. 57 RESULTS A N D DISCUSSION Similar to the same reasons that had been given for different Ksp values in different supernatants, the measured 0 and A H values for different supernatants were not identical. In engineering application of struvite crystallization process, temperature is an unavoidable factor that will affect the struvite solubility. Therefore, it is necessary to obtain the struvite Ksp at different temperatures. The 0 can be used as a valuable and easy parameter to predict the Ksp values at different temperatures from a known value. It should be noted that the value of 0 itself could vary with temperature, so that caution must be used in selecting appropriate values for 0 for different temperature ranges. 5.1.3 Conditional solubility product (Ps) In order to overcome the uncertainties and complexities associated with the determination of Ksp value, conditional solubility product (Ps) was used to describe the struvite solubility and monitor the struvite crystallization process in this study. Since the determination of Ps only includes the measurement of total concentrations of the three species involved in the struvite formation, it is simpler and more accurate to develop an equilibrium curve of Ps than that of Ksp. Since the struvite crystallization process was operated outdoor and the effect of ambient temperature should be considered (which decreased from 20°C in summer to lower than 10°C in winter), the equilibrium curves of conditional solubility product for the three supernatants at different temperatures were determined; these are shown in Figures 5.4 to 5.6, respectively. 58 RESULTS A N D DISCUSSION 4.5 5 5.5 6 & 6.5 7 7.5 8 8.5 5 y =-0.13 x2 +3.04 x-8.52 " S ^ . R2 = 0.99 y =-0.3lx2 +5.75 x- 18.39^'^> Cu R2 = 0.99 L l ^ ^ ! * ^ ! : r . . D 5 6 6.5 7 7.5 8 8.5 9 9.5 pH • Annacis supernatant • Lulu supernatant Annacis supernatant Lulu supernatant Figure 5.4: Struvite pPs in different supernatants at 10°C 8.5 5.5 6 6.5 7 7.5 8 8.5 9 9.5 pH • Annacis supernatant Annacis supernatant Figure 5.5: Struvite pPs in the Annacis supernatant at 15°C 59 RESULTS AND DISCUSSION 8.5 9 I 1 1 1 . 1 5 6 7 8 9 10 pH • Synthetic supernatant • Annacis supernatant A Lulu supernatant Synthetic supernatant Annacis supernatant Lulu supernatant Figure 5.6: Struvite pPs in different supernatants at 20°C The operation of the crystallization process for the synthetic supernatant was conducted in June, July and August when the ambient temperature was around 20 °C, so that the Ps curve (as shown in equation (33)) developed at 20 °C was used to evaluate the struvite saturation condition. pPs=-0.23 pH 2+4.37pH-12.57 (33) The operation for the Annacis supernatant was conducted in September when the ambient temperature was dropped to 15 "C and for the Lulu supernatant, the temperature in October to December was about 10TJ, or even lower. Consequently, the pPs curves developed at 15°C and 10°C were used for the Annacis supernatant and the Lulu supernatant, respectively. Equations (34) and (35) describe the polynomial curves for the Annacis supernatant at 15°C and for the Lulu supernatant at 10"C, respectively. pPs= -0.14 pH2+3.21 pH-9.34 (34) 60 RESULTS A N D DISCUSSION pPs= -0.31 pH2+5.75 pH-18.39 (35) 5.2 Performance Of The Struvite Crystallization Process In this section, performances of the crystallization process for the synthetic supernatant and the anaerobic digester supernatants were discussed. During the study, two crystallization processes (A and B) were operated under different conditions, such as pH, supersaturation ratio and magnesium dosage, from which the corresponding process performances were compared. The detailed operational data collected during the study are listed in Appendixes E and F for A and B, respectively. 5.2.1 Phosphate removal efficiency Figures 5.7 to 5.9 show the phosphate removal efficiency for the synthetic supernatant, the Annacis supernatant and the Lulu supernatant, respectively. S 60.0 | 50.0 13 40.0 | 30.0 8 20.0 P H 10.0 0.0 I 1 1 1 1 1 3-Jun-02 18-Jun-02 3-Jul-02 18-Jul-02 2-Aug-02 17-Aug- l-Sep-02 02 Date • Reactor A • Reactor B Figure 5.7: Phosphate removal efficiency for the synthetic supernatant 61 RESULTS A N D DISCUSSION o C3 2 o 100.0 95.0 90.0 85.0 80.0 75.0 70.0 . 4 0 D • Q 0 fi • • 5 • * a • • » • • l-Sep-02 • • • 8 • 6-Sep-02 ll-Sep-02 16-Sep-02 21-Sep-02 Date • Reactor A • Reactor B Figure 5.8: Phosphate removal efficiency for the Annacis supernatant 'o > o B 22 100.0 95.0 90.0 85.0 80.0 75.0 70.0 65.0 60.0 nrfer • 21-Sep-02 ll-Oct-02 31-Oct-02 20-Nov-02 10-Dec-02 30-Dec-02 Date • Reactor A • Reactor B Figure 5.9: Phosphate removal efficiency for the Lulu supernatant 62 RESULTS A N D DISCUSSION It can be seen that 90 % or even higher phosphate removal efficiency was achieved easily for these three supernatants, with different phosphate strengths. Some data in Figures 5.7 and 5.9 displayed removal ratios lower than 90 %; this was caused by operational conditions that were not optimal. 5.2.2 Effluent phosphate level Through the struvite crystallization, the phosphate concentration in the effluent was decreased to a relatively low level, depending on the removal efficiency achieved. As shown in Figures 5.10 to 5.12, the phosphate concentrations in the effluents for these three supernatants were reduced to below 10 mg/L, when 90 % of phosphate removal ratio could be achieved. It was possible to lower the phosphate level to 5 mg/L, if optimal operative conditions were chosen. 80.00 70.00 3 60.00 3 50.00 0.00 13-Jun- 23-Jun- 3-M-02 13-Jul- 23-Jul- 2-Aug- 12-Aug- 22-Aug-02 02 02 02 02 02 02 Date • Reactor A * Reactor B Figure 5.10: Effluent phosphate concentration for the synthetic supernatant 63 RESULTS A N D DISCUSSION 20.00 18.00 16.00 14.00 12.00 fl 10.00 o c 8.00 6.00 4.00 2.00 0.00 • • -r> • • • • * • • • — • ^ • l-Sep-02 5-Sep-02 9-Sep-02 13-Sep-02 17-Sep-02 21-Sep-02 Date • Reactor A • Reactor B Figure 5.11: Effluent phosphate concentration for the Annacis supernatant ! o 1 14.00 12.00 10.00 8.00 6.00 4.00 2.00 0.00 % - q ^ - r i r J -re • rP -T£fl3_ 21-Sep-02 ll-Oct-02 31-Oct-02 20-Nov-02 10-Dec-02 30-Dec-02 Date • Reactor A • Reactor B Figure 5.12: Effluent phosphate concentration for the Lulu supernatant 64 RESULTS A N D DISCUSSION 5.2.3 Ammonia removal efficiency The struvite crystallization process can remove and recover ammonia in the digester supernatant at the same time that phosphate is recovered in the form of struvite. Consequently, the ammonia recovery through struvite crystallization offers an alternative technique for the treatment of high ammonia containing wastewater [50, 54]. In this study, the ammonia concentrations in the testing supernatants were much higher than phosphate. Since the removal of ammonia should be equal with phosphate in molar amounts during the formation of struvite, the ammonia removal was relatively low in the process. Figures 5.13 to 5.15 show the percentage ammonia removal when the synthetic, Annacis and Lulu supernatants were tested, respectively. 30.0 25.0 o o 20.0 * 8 15.0 S 10.0 5.0 0.0 • • • 0 3 vU • -• m 13-Jun-02 28-Jun-02 13-M-02 28-Jul-02 12-Aug-02 Date o Reactor A • Reactor B Figure 5.13: Percentage ammonia removal for the synthetic supernatant 65 RESULTS A N D DISCUSSION 25.0 es 20.0 15.0 1 10.0 o 6 (D £ 5.0 • • • • • 9 0.0 l-Sep-02 5-Sep-02 9-Sep-02 13-Sep-02 17-Sep-02 21-Sep-02 Date • Reactor A o Reactor B Figure 5.14: Percentage ammonia removal for the Annacis supernatant 20.0 0 S * •a > o S 15.0 10.0 ^ 5.0 0.0 • 0 • TTJ d ? 0 • d i n 0 D • 21-Sep-02 ll-Oct-02 31-Oct-02 20-Nov-02 10-Dec-02 30-Dec-02 Date • Reactor A • Reactor B Figure 5.15: Percentage ammonia removal for the Lulu supernatant 66 RESULTS A N D DISCUSSION From the operational data, it can be seen that the average ammonia removal efficiencies were only 7.1 % for the synthetic supernatant, 5.6 % for the Annacis supernatant and 3.6 % for the Lulu supernatant. With the increasing ammonia to phosphate molar ratio in the supernatant, it is more difficult to achieve high ammonia removal efficiency, due to the effect of excessive ammonia. The ammonia ions in excess will compete with each other in formation of struvite, thus causing lower ammonia combination ratio in struvite than expected. 5.2.4 Struvite recovery efficiency The main purpose of this study was to recover the phosphate from supernatant in the form of struvite. Therefore, the main issues included, not only the phosphate removal ratio, but also the recovery efficiency. Theoretically, 100 % of the removed phosphate will transfer to the struvite in the designed reaction. However, in the operation of a real process, some precipitated struvites in the form of fine particles did not reach a target size that could be harvested, and would exit with the effluent. In this way, the phosphate remained in the effluent without recovery. In order to evaluate how much the removed phosphate was, in fact, being recovered, the struvite recovery efficiency of the process was calculated and presented in Table 5.2. Table 5.2: Comparison of theoretical struvite production and actual struvite recovery during the whole period of the study Reactor A Reactor B Total seed struvite added (Kg) 2.16 2.93 Total struvite harvested (Kg) 26.59 23.88 Struvite left in the reactor (Kg) 7.18 6.12 Total struvite recovered (Kg) 31.61 27.07 Theoretical struvite production (Kg) 36.75 33.13 Struvite recovery efficiency (%) 86.0 81.7 As shown in Table 5.2, the struvite recovery efficiency reached 86.0 % and 81.7 % for reactor A and B, respectively. The lower recovery efficiency in reactor B was due to the fact that the reactor was overloaded with crystals, so that some fine particles exited the reactor not 67 RESULTS A N D DISCUSSION recovered. The main error in this recovery efficiency calculation came from the operation time. In calculation of theoretical struvite production, the operation time was estimated to be 24 hours a day, whereas, in fact, it was only 22 hours a day. The process was shut down for at least 2 hours a day for harvesting crystals, cleaning the injection port, making chemical solutions and so on. If corrected for operation time, then the struvite recovery was close to 93.8 % and 89.1 %, respectively. In addition, the mass of struvite recovered did not include the loss of struvite particles during the process of harvesting, drying, transferring and sieving. The struvite accumulation on the wall of the reactor and external clarifier aggravated the loss. Therefore, the recovery efficiency will be higher than expected if all these losses are collected. In conclusion, most of the removed phosphate was successfully recovered in the form of harvestable struvite product in this study. 5.3 Controlling Parameters In The Struvite Crystallization Process In this study, the performance of the struvite crystallization process was controlled through several operational parameters, such as supersaturation ratio, pH and magnesium dosage. Among them, the supersaturation ratio is the most accurate parameter to predict the process performance, since it takes into account the four main constituents in struvite equilibrium — concentrations of phosphate, ammonia, magnesium ions, and pH. Since the purpose of struvite crystallization in this study was recovering phosphate, the phosphate removal efficiency was used as the criteria to evaluate the process performance. The data and results discussed in this section were for the process operation testing the synthetic supernatant. The detailed data are listed in Appendix E and F. 5.3.1 Supersaturation ratio (SS ratio) In this study, there were two supersaturation ratios that could be used as controlling parameters; in-reactor SS ratio and inlet SS ratio. Figures 5.16 and 5.17 show the percentage 68 RESULTS A N D DISCUSSION phosphate removal under different in-reactor SS ratios and inlet SS ratios, respectively. > O S <u s-a, t*> o PH 100 0 95 0 90 0 85 0 80 0 75 0 70 0 65 0 60 0 55 0 50 0 0.0 • • 1.0 2.0 3.0 In-reactor SS ratio 4.0 5.0 ° Reactor A • Reactor B Figure 5.16: Percentage phosphate removal under different in-reactor SS ratios > o S <u i _ <L> a, C O O H3 PH 100.0 95.0 90.0 85.0 80.0 75.0 70.0 65.0 60.0 55.0 50.0 0.0 4 CD • • • -10.0 20.0 30.0 40.0 50.0 Inlet SS ratio • Reactor A • Reactor B Figure 5.17: Percentage phosphate removal under different inlet SS ratios 69 RESULTS A N D DISCUSSION From these two figures, it can be seen that, with the increasing in-reactor SS ratios and inlet SS ratios, the phosphate removal efficiency gradually increased. The increasing trend of phosphate removal with the inlet SS ratios was more pronounced than that with the in-reactor SS ratios. As shown in Figure 5.18, there was somewhat of a linear relationship between the in-reactor SS ratio and inlet SS ratio under the approximately same pH and recycle ratios. The correlation lines for reactor A and B had different slopes because their respective set pH and recycle ratios were different. Although the trend was less definite due to low R 2 value, theoretically expected trends did appear. With the increasing of inlet SS ratio, the in-reactor SS ratio increased proportionally. However, this relationship was not shown in Britton and Adnan's data, due to the fact that they used either a variable pH or recycle ratio [4, 5]. 5.0 4.5 4.0 •2 3 5 £ 3.0 in S 2.5 § 2.0 h 1.5 1.0 0.5 0.0 0.0 y = 0.06 x + 1.14 R z = 0.32 y = 0.02 x+1.38 R z = 0.11 10.0 20.0 30.0 Inlet SS ratio 40.0 50.0 • Reactor A * Reactor B • Reactor A - - - Reactor B Figure 5.18: The relationship between in-reactor SS ratio and inlet SS ratio 70 RESULTS A N D DISCUSSION Theoretically, the in-reactor SS ratio, considering the effect of the effluent recycle, describes the actual saturation condition in the process, whereas the inlet SS ratio is only a hypothetical value to estimate the influent potential for the crystallization reaction. For this reason, it would be better to use the in-reactor SS ratio as the operational parameter to control the process performance. However, it can be seen that the data in Figure 5.16 scattered in a wide range, meaning the low precision. Since the in-reactor SS ratio is a function of eight parameters that are pH, recycle ratio, influent concentrations of phosphate, ammonia and magnesium, and effluent concentrations of phosphate, ammonia and magnesium, a slight inaccuracy in measurement of each parameter will bring a high error in the value of in-reactor SS ratio. In addition, it is difficult to predict the effluent concentration in advance. Since the measurement of the inlet SS ratio, containing only four parameters (i.e. pH, influent concentrations of phosphate, ammonia and magnesium), is more accurate than the in-reactor SS ratio and there is a correlation between these two SS ratios, it is more practical to select the inlet SS ratio as controlling parameter. In this case, it is assumed that the effluent reaches the equilibrium and its SS ratio is equal to 1. In this study, the inlet SS ratio is recommended to be as a main operating parameter to control the performance of the crystallization process. It is noted that the optimal inlet SS ratio for the process performance is specific for the corresponding recycle ratio because different recycle ratio will lead to different phosphate removal. Generally, it is considered that the inlet SS ratio should be higher than 20, in order to achieve 80 % of phosphate removal. 5.3.2 pH As known, the solubility of struvite varies with pH. When the concentrations of Mg 2 + , PO43" and NHj + in the supernatant are fixed, the struvite formation is controlled only by the pH. For this reason, pH can be used as a parameter to control the process performance. If the other 71 RESULTS AND DISCUSSION operational conditions, such as the molar ratio of Mg 2 + : PO43": NrL;+ and recycle ratio are set invariably, the percentage of phosphate removed would vary with the operating pH. This has been proven in Britton and Adnan's work [4, 5] and is also in agreement with the results of other researchers [23, 38, 43, 49]. Although this controlling method is simple and direct, it is not accurate for the supernatant with high daily variation in composition. 5.3.3 Magnesium dosage In this struvite crystallization process, the concentrations of phosphate and ammonia were determined by the initial composition of influent supernatant and did not change during the process operation. Therefore, in the four constituents of the inlet SS ratio, what can be changed to achieve a desired phosphate removal are the operating pH and magnesium dosage in the supernatant. When pH is set the same, the increasing magnesium dosage would increase the phosphate removal proportionally. This result can be seen from Figure 5.19. Figure 5.19 shows the linear relationship between the phosphate removal and the magnesium dosage in the supernatant. The study of Katsuura also showed that the phosphorus removal ratio increased with an increase in Mg:P ratio; he found that this increase was much more pronounced at low pH values (pH of 8.0) compared to high pH values (pH of 9.0) [61]. Consequently, even at a low pH, the high phosphate removal efficiency still can be achieved through increasing the magnesium dosage. Since there was a 0 to 0.2 unit of difference between the real pH in the reactor and the set operating pH, some data scatter was evident. 72 RESULTS AND DISCUSSION 100.0 95.0 90.0 O H O PH X 85.0 > o s •£ 75.0 80.0 70.0 65.0 60.0 55.0 50.0 0.0 y = 7.41 x +69.06 1.0 2.0 3.0 Mg:P molar ratio 4.0 5.0 o Reactor A •Reactor A Figure 5.19: The relationship between the phosphate removal and the magnesium dosage Similar to pFL the magnesium dosage is an easy and quick controlling parameter in daily process operation. For the supernatant with a low pH, adding more magnesium, instead of increasing pH, can increase the process performance; this gives an alternative way to reduce the chemical cost since, according to one study, the cost of sodium hydroxide for increasing pH occupied a large part of the entire chemical cost [46]. Having the same shortcoming as pH, controlling through magnesium dosage is only adequate for the supernatant with a relatively stable composition. In addition, the high magnesium added in the supernatant will increase the magnesium level in the effluent. Therefore, for treatment plants that pump this effluent back to the head of the plant, the magnesium level in the whole treatment system will be increased; this aggravates the unintentional struvite formation in the facilities, such as pipelines and pumps. In a full-scale process, control of the magnesium dose rate is recommended using on-line effluent measurements, in order to avoid struvite formation in the digester or post-digestion system. 73 R E S U L T S A N D D I S C U S S I O N 5.4 Alternative Methods For Reducing Chemical Costs Operation costs for the struvite recovery process mainly come from two sources; chemical costs and labor costs. Labor costs include the labor-hour requirements for daily monitoring operational parameters of the process, periodical cleaning of the injection port, harvesting, drying and packing the struvite crystals, and facilities maintenance. This part of costs is relatively stable for a mature process, so it was not discussed in this study. Some researchers indicate that the most significant portion of the operational costs come from the chemical costs [46]. The purpose of this section, then, was to find a practical method of reducing the chemical costs by comparing this part of the cost under different operational conditions. In this study, the chemical costs included the dosage of magnesium chloride and sodium hydroxide. Moreover, the latter is much more expensive than the former in the commercial market. Therefore, the discussion focuses on the methods of reducing the usage of sodium hydroxide. The money unit for cost calculation is Canadian dollars. 5.4.1 Air stripping Carbon dioxide is always present in anaerobic digester supernatant. It stays in the acid-base equilibrium with carbonate and bicarbonate ions in the digester supernatant, which is described by equation (36). C0 2 (gas)+H 2 O^H 2 C03^HC03+H + ^C03 2 "+2H + (36) From equation (36), it can be seen that when more C 0 2 dissolves into solution, the pH value will decrease; otherwise pH will increase. Based on this principle, some researchers have introduced air stripping into the digester supernatant for driving out C0 2 , thus increasing the pH value [11, 45-48]. As discussed in Section 5.3.2, the phosphate removal would also be increased through raising the operating pH value. Therefore, the desired phosphate removal can be achieved through air stripping, instead of adding a large amount of sodium hydroxide. Kazuyoshi et al. found that the pH of the swine wastewater was increased to approximately 8.5 74 R E S U L T S A N D D I S C U S S I O N from 7.0, with continuous aeration for 3 hours; in addition, a large part of the phosphate was removed through forming struvite and HAP [48]. Before the digester supernatants from the Annacis Island WWTP and the Lulu Island WWTP were trucked to the Pilot Plant, field samples of these two supernatants were collected and analyzed. The analysis results showed that the pH value of the Annacis supernatant was already 8.36, whereas the pH of the Lulu supernatant was only 7.68. This meant that there was less C O 2 left in the Annacis supernatant. Therefore, in this air stripping study, only the Lulu supernatant is discussed. The test of air stripping was performed in one beaker with a volume of 2 L. The air was input into the supernatant in the beaker through an air stone and the used flowrate was 1392 mL/min. Figure 5.20 shows the increasing pH of the Lulu supernatant in 1000 mL volume, with the increasing time used for aeration. In this figure, the bottom line is for the field sample collected at the Lulu Island WWTP and the upper one is for the supernatant trucked to the Pilot Plant and actually used in the struvite recovery process. It can be seen that the slopes of two lines were nearly the same even though there were different initial pH values; this meant that the same air amount needed for increasing one unit of pH was required for both samples. The testing supernatant in the struvite recovery process had the initial pH of 7.97, quite different from the field sample. The reason for this difference was unknown. The following discussion on cost was based on data collected during the process operation using the supernatant with a pH value of about 8. 75 R E S U L T S A N D D I S C U S S I O N 0 20 40 60 80 100 120 140 Aeration time (min) —•— Sample from supernatant tested in the reactor —o— Field sample from the Lulu Island WWTP Figure 5.20: The relationship between the pH change and aeration time From the operational data collected from reactor B, listed in Appendix F, the phosphate removal ratio reached 90 % when the operating pH was set to 8.2. It can be seen from Figure 5.20 that the aeration time for increasing the pH of 1000 mL supernatant from initial value of 7.97 to 8.2 was about 15 minutes. Therefore, a total of about 20.9 L of air was applied to 1 L of Lulu supernatant. However, this air volume did not take into effect of the recycle effluent. Since the recycle ratio in this process operation was about 5, it was estimated that total air volume needed for increasing the pH in the reactor (i.e. including the influent and the recycle flow) to 8.2 would be 6 times this volume (i.e. 125 L). From the operational data, it was found that the NaOH amount required for increasing the operating pH value in the reactor to 8.2 (to form struvite) was in the range of 0.15-0.20 g for per liter of the Lulu supernatant. Based on the estimation that the NaOH price is $0.5/Kg [5], the NaOH cost would be $7.5><10~5-lxl0"4 The energy cost of aeration is difficult to estimate, since it is related to the type of blower chosen and the electric power used. If the blower with an air 76 RESULTS A N D DISCUSSION flow rate of 600 m /min and 500 KW of power was used, the estimated energy cost for inputting 125 L of air would be $8.7><10"5 based on electric cost of $0.05/KW-hr. This cost would be lower or higher, if different blowers were chosen. Although the aeration cost and NaOH cost are comparable, air injection will change the hydrodynamics in the reactor, thus having an effect on process performance and crystal growth. In addition, extra capital will be required for installing aeration facilities. Therefore, using air stripping, instead of adding NaOH, to increase pH does not appear to be economical in terms of cost reduction. However, Battistoni et al. removed phosphate from anaerobic liquors by means of external continuous aeration, without the addition of chemicals [11, 18, 45, 47]. In their studies, aeration was more economical than adding chemicals. The estimation of chemical costs conducted in the Penticton Advanced WWTP showed that the cost of NaOH for producing one kilogram of struvite was around $0.41 [5], whereas for the Lulu supernatant, the NaOH cost was only $0.18/Kg struvite. The difference comes from the fact that the initial pH and concentrations of Mg 2 + , PO43" and NH4+ of different supernatants were quite different. Comparing supernatants from Penticton to Lulu, it was found that the greatest difference came from the supernatant initial pH, which resulted in a big difference in the struvite saturation state of the supernatant. Since the pH of the Penticton supernatant was only 7.1 and un-saturated with struvite, a large amount of NaOH was added to increase the pH, in order to drive the supernatant to a supersaturation state for struvite formation. In addition, the buffer effect of carbonate in the supernatant made the usage of NaOH higher. On the other hand, the amount of CO2 present in the Penticton supernatant with pH value of 7.1 was high and the effect of air stripping would be prominent. The same phenomenon was seen in the studies of Battistoni et al. [11, 18, 45, 47]. However, the Lulu supernatant already had a pH of approximately 8.0 and was close to the struvite saturation state, so that a pH increment of only 0.2 units would result in the supernatant supersaturation. Also, the buffering effect from carbonate, at a higher pH, was marginal. Therefore, the usage of NaOH for the Lulu supernatant was low and it was not necessary to 77 RESULTS A N D DISCUSSION apply aeration for reducing the NaOH cost. In conclusion, using air stripping to reduce chemical costs of the struvite crystallization process is not recommended for supernatants with a high pH of 8, like the Annacis and Lulu supernatants. However, for the Penticton supernatant and other supernatants with a pH around 7, air stripping still may be an appropriate choice in terms of cost saving. 5.4.2 Magnesium dosage As discussed in Section 5.3.3, the magnesium dosage improved the phosphate removal of the struvite crystallization process. In other words, without changing other operational conditions, it was possible to achieve the purposed phosphate removal by increasing the magnesium concentration in the supernatant. This approach provides another method to control the process, which means running the process using a high magnesium dosage in place of the high operating pH, but without a compromise in phosphate removal. In addition, the price of magnesium chloride in the market is much cheaper than that of sodium hydroxide. Therefore, it is possible to reduce the chemical costs of the process, if more magnesium is added at the lower operating pH. The chemical cost analysis for sodium hydroxide and magnesium chloride was based on calculated usage of sodium hydroxide and magnesium chloride in reactor B running the Lulu supernatant during the period of December 6-20 , 2002, which was shown in Appendix F. The phosphate removal efficiencies were kept higher than 90 % and it was assumed that 90 % of removed phosphate converted to the form of struvite. Table 5.3 shows the chemical costs for sodium hydroxide and magnesium chloride, when the process was operated for the Lulu supernatant under different Mgp molar ratios. It is noted that these calculated chemical costs are specific for the supernatant used and the operational conditions chosen in this study. The data for the Penticton supernatant was obtained from Britton's work [5]. The prices of sodium 78 RESULTS A N D DISCUSSION hydroxide and magnesium chloride were estimated to be $0.5/kg and $0.2/Jcg, respectively [5]. Table 5.3: Chemical costs in the struvite crystallization process Supernatant Mgp $Total Chem./ $ NaOH/ NaOH/Total $ MgCl 2/ MgCl2/Total molar ratio Kg MAP Kg MAP Chem. (%) Kg MAP Chem. (%) Penticton 1.3 0.62 0.41 66.1 0.21 33.9 Lulu 1.3 0.44 0.18 40.9 0.26 59.1 1.8 0.51 0.15 29.4 0.36 70.6 2.5 0.62 0.14 22.6 0.48 77.4 3 0.66 0.08 12.1 0.58 87.9 3.5 0.74 0.03 4.1 0.71 95.9 0.8 0.7 0.6 •f 0.5 1 0.4 3 0-3 0.2 0.1 0 A A A • A • • • • • i • • 1.5 2 2.5 3 Mg:P molar ratio 3.5 • NaOH cost • MgC12 cost A Total chemical cost Figure 5.21: Chemical costs in the struvite crystallization process From Table 5.3 and Figure 5.21, it can be seen that the total chemical costs did not decrease, as expected, when using a high magnesium dosage. The costs increased because the cost of magnesium chloride increased dramatically, even though the cost of sodium hydroxide dosage decreased. Comparing the costs for the Penticton supernatant and the Lulu supernatant 79 RESULTS AND DISCUSSION under the same magnesium dosage in Table 5.3, it is found that the magnesium costs in the two supernatants were close to each other, whereas the costs of sodium hydroxide were quite different. This can be explained by the facts discussed in the previous section. The Penticton supernatant had a low pH value and it needed a large amount of NaOH dosage to raise 1.4 units of pH, in order to get 80 % of phosphate removal [5]. However, for the Lulu supernatant, increasing 0.2 units of pH could achieve 90 % of phosphate removed. Therefore, for the Lulu supernatant, the proportion of NaOH cost occupied in the total chemical cost was less than 50 %. In this scenario, the increment of magnesium cost brought by high magnesium dosage was higher than the savings in NaOH cost. For the Penticton supernatant and other supernatants with a pH around 7, it still is possible to reduce the chemical cost through increasing the magnesium dosage, since their NaOH usage occupied a high proportion of total costs. Some researchers even report the NaOH cost as high as 97 % of total chemical costs [46]. Therefore, the possibility of using high magnesium dosage to reduce the chemical costs is worth studying for other supernatants with a low pH value. 5.5 Characteristics Of Struvite Product In this study, another important objective was to produce satisfactory struvite crystals, in addition to achieve high phosphate removal. Struvite characteristics depend on its future applications. If using struvite as agricultural fertilizer, it is required to be of high purity, without heavy metal ions and pathogens. If it is used for the river or lake fertilization, purity is not important, but the struvite crystal cannot be too large or hard, otherwise it will settle down to the bottom of river and release phosphate too slowly. However, the large and hard product has benefits in handling, such as harvesting, cleaning, packing and transporting, and reduces the handling loss. Therefore, in this study, the targeted qualities of product were purer than 90 % and larger than 2 mm in diameter. 80 RESULTS A N D DISCUSSION 5.5.1 Purity and composition In order to exam the purity and composition of the crystals harvested during the study, some crystal samples harvested form the struvite crystallization process, using the Annacis and Lulu supernatants, were analyzed. For the Annacis supernatant, 20 samples with different size fraction (>4.75 mm, >2.83 mm, >2 mm, >1 mm and >0.5 mm) were chosen from three dates and two reactors. For the Lulu supernatant, 25 samples with different size fraction (>4.75 mm, >2.83 mm, >2 mm, >1 mm and >0.5 mm) were chosen from three dates and two reactors. The detailed analysis data are shown in Appendix G. Table 5.4 shows the average analysis results of crystal purity and composition. From the results, it can be concluded that the crystal products were high-purity struvite. The purity of crystals produced from the Lulu supernatant was a little higher than the Annacis supernatant, which can be explained by the fact that the Annacis supernatant had higher suspended solid concentration and more impurity ions than the Lulu supernatant. Table 5.4: The results of crystal composition analysis Crystals from the Annacis Supernatant Composition by mass (%) Mean value of analysis Standard deviation Theoretical value for pure struvite Mg 9.7 0.8 9.9 NH4 -N 4.9 0.3 5.7 PO4-P 11.5 0.7 12.6 Struvite 91.2 3.0 100.0 Crystals from the Lulu Supernatant Composition by mass (%) Mean value of analysis Standard deviation Theoretical value for pure struvite Mg 9.9 0.6 9.9 N H 4 -N 5.0 0.3 5.7 PO4-P 11.9 0.4 12.6 Struvite 94.1 2.6 100.0 Table 5.5 shows the average results of the crystal analysis for impurities, with detailed 81 RESULTS A N D DISCUSSION data listed in Appendix G. The main impurities were calcium ion and carbonate as expected, since there were, on average, 30.8 mg/L of Ca and 471 mg/L of carbonate (calculated in inorganic carbon) present in the Annacis supernatant and 34.3 mg/L of Ca and 251 mg/L of carbonate (calculated in inorganic carbon) present in the Lulu supernatant. Since the solubility product of CaC03 is 5xl0"9, there should be some C a C 0 3 formed in the struvite products. Fe3(P04)2 also has a very low solubility product, so that some of Fe 3(P04)2 would be present in these products, depending on the iron concentration in the supernatant. From Table 5.5, it can be seen that the total measured impurities in crystals from the Annacis supernatant only occupied 5.03 % of total mass and for crystals from the Lulu supernatant, impurities were 3.37 % of total mass. The proportion of tested struvite and impurities in total mass was 96.2 % for the Annacis crystals and 97.5 % for the Lulu crystals. Both were lower than 100 %, so that there must be some unknown ions or solids present in products. During the analysis of products, it was found that a few fibrous residues were left in the solution dissolving products. Those residues could compensate for the mass difference mentioned above. No further analysis for those residues was done and it was estimated that they were suspended solids emanating from the supernatant. Table 5.5: Impurity content in crystal products Crystals from the Annacis Supernatant Crystals from the Lulu Supernatant Content by Mean value Standard Content by Mean value Standard mass (%) of analysis deviation mass (%) of analysis deviation Ca 1.22 0.50 Ca 1.34 0.35 Fe 0.03 0.02 Fe 0.03 0.02 Al 0.02 0.01 Al 0.01 0.01 K * * K * co32- 3.76 5.46 co32- 1.99 3.88 Total 5.03 Total 3.37 * Most K analyses were below the detection limit of the method used. 82 RESULTS A N D DISCUSSION 5.5.2 Crystal Size Figures 5.22 to 5.24 show the mean size in diameter of crystal products harvested during the whole period of the study. It can be seen that the harvested crystals' size could be controlled to greater than 2 mm in diameter, under appropriate operational conditions. During the study, for reactor A, the average crystal sizes harvested from the synthetic supernatant, the Annacis supernatant and the Lulu supernatant were 2.6 mm, 2.9 mm and 3.0 mm, respectively. For reactor B, the average crystal sizes harvested from these supernatants were 2.0 mm, 1.9 mm and 2.3 mm, respectively. These results meant that in this study, the characteristics of the influent supernatant had no significant effect on the size of produced crystals, if the process was operated under optimal conditions. The difference in crystal size from reactor A and reactor B was due to different CRTs and magnesium dosages applied in this operation. 3.5 3.0 £ 2.5 <u •3 2.0 c 0 > cn u 1.5 1.0 0.5 0.0 <> « • • • * • • • _ • A • n • [ 13-Jul-02 23-Jul-02 2-Aug-02 12-Aug-02 22-Aug-02 Date • Reactor A • Reactor B Figure 5.22: The average crystal size harvested from the synthetic supernatant 83 RESULTS A N D DISCUSSION 3.5 ^ 3.0 J , 2.5 •§ 2.0 U 1 1.5 1 1.0 U 0.5 0.0 • • • • • • • • • • > 1 1 1 l-Sep-02 6-Sep-02 ll-Sep-02 16-Sep-02 21-Sep-02 Date • Reactor A • Reactor B Figure 5.23: The average crystal size harvested from the Annacis supernatant N on u 4.0 3.5 3.0 2.5 2.0 1.5 1.0 0.5 0.0 16-• • a • Sep-02 l-Oct-02 16-Oct-02 31-Oct-02 15-Nov-02 30-Nov-02 Date • Reactor A • Reactor B Figure 5.24: The average crystal size harvested from the Lulu supernatant 84 RESULTS A N D DISCUSSION 5.5.3 Factors affecting crystal mean size It has been found that the two important factors affecting the harvested crystal size are the CRT and the SS ratio in the reactor [17, 19, 56]. In this study, no significant relationship between the crystal size and the SS ratio in the reactor was found. The effects of the CRT and magnesium dosage on the crystal size were significant and discussed in this section. In the discussion, the assumption was made that the characteristics of influent supernatant had no significant effect on the crystal size, based on the result obtained in previous section. Crystal retention time (CRT) The crystal retention time is an important factor in determining the final size of the harvested crystals. The crystal needs sufficient time in the reactor to grow and aggregate up to a desired size, provided that the good operational conditions of the process are achieved. Figure 5.25 shows the changing trend of the crystal size with the CRT. The data for crystal products harvested from the synthetic, Annacis and Lulu supernatants were combined together. N CU s 13 -4—» C/) U 4 3.5 3 2.5 2 1.5 . 1 0.5 0 10 15 CRT (days) 20 v = 0 04x4-2.35 R 2 = 0.30 ^ s * t * -t a n n n J I - * • " • a ...a-----rj • i y = 0.06 x+ 1.36 • R 2 = 0.35 i i i 25 • Reactor A o Reactor B • Reactor A Reactor B Figure 5.25: The relationship between the crystal size and CRT 85 RESULTS A N D DISCUSSION As expected, it can be seen from Figure 5.25 that the longer the CRT, the larger the crystal would get. For reactors A and B, which were operated under different conditions (i.e. reactor A used a higher magnesium dosage in the supernatant than reactor B), the average increasing rate of the crystal size with the CRT were 0.04 mm and 0.06 mm per day of CRT, respectively. Since there were several other factors, except CRT, that would affect the crystal size, such as process performance, phosphorus concentration, operating pH, supersaturation level, and harvesting frequency, the crystal sizes under the same CRT were not exactly the same. Therefore, the increment in the crystal size, with the increasing CRT, was variable (with low R 2 value) and the increasing rate was different under different operational conditions. Magnesium dosage From Figure 5.25, it is also shown that the size of crystals harvested from reactor A was larger than reactor B. Both reactors achieved similar phosphate removal efficiency under different operational conditions. The significant difference between reactor A and reactor B in operational conditions was the magnesium dosage in the supernatant. For reactor A, the magnesium addition was around 3:1 molar ratio to phosphate concentration, while for reactor B, the magnesium was approximately 1.3:1 to phosphate. Therefore, it could be concluded that the high magnesium dosage had a benefit to the crystal growth and aggregation, leading to the large final size. This result was also found in previous studies. Hirasawa et al. found that Mg/P molar ratio affected the properties of produced crystals. The crystals were agglomerated when Mg/P molar ratio was 2, resulting in large crystals [35]. The lower increasing rate of the crystal size, for higher magnesium dosage (0.04 mm/day of CRT) than that for low magnesium level (0.06 mm/day of CRT), was caused by other unknown factors, other than CRT and magnesium level. 86 RESULTS A N D DISCUSSION 5.5.4 Crystal density In this study, the density of the harvested crystal was not measured directly. The "density" used in this section was the value of the total dry weight of crystals removed from the harvesting section of the reactor divided by the volume of reactor harvest zone. So, this "density" was a surrogate of the real density. Table 5.6 shows the average densities of crystals harvested from the synthetic, Annacis and Lulu supernatants during the entire period of the study. Table 5.6: Density of crystals produced in different supernatants Supernatant Synthetic Annacis Lulu Reactor A Reactor B Reactor A Reactor B Reactor A Reactor B Density (g/L) 490 410 563 455 600 514 700 650 600 550 500 >> +J 450 C 400 <U Q 350 300 250 200 Y= 122.15 x+ 197.02 R 2 = 0.25 t * * *f J C ™ ^^^^ y = 86.97x + 270.72 R 2 = 0.28 i i i i 1 1.5 2 2.5 3 Size (mm) 3.5 • Reactor A • Reactor B • Reactor A Reactor B Figure 5.26: Relationship between crystal density and size It was found that the density of synthetic crystals was lower than that of Annacis crystals, and the density of Lulu crystals was highest. In addition, the crystal density from reactor A was 87 RESULTS A N D DISCUSSION higher than reactor B. These phenomena coincided with the increase in the crystal size. From Figures 5.22 to 5.24, it can be seen that the crystal size increased slightly from the synthetic supernatant to the Annacis supernatant and then, to the Lulu supernatant. Also, the crystal size in reactor A was generally higher than that in reactor B. This observation meant that there was a relationship between the crystal size and density, as shown in Figure 5.26. For both reactors, a correlation between size and density existed obviously but the R 2 value was relatively low. As two important factors affecting the final size of harvested crystals, CRT and magnesium dosage, also have obvious effects on the crystal density, as shown in Figure 5.27. It can be seen that the crystal density increased with the increasing CRT. The long CRT benefits crystal aggregation, leading to high density. Since reactor A used the higher magnesium addition (Mg:P=3:l molar ratio) than reactor B (Mg:P=1.3:l molar ratio), the high magnesium dosage is also conducive to high crystal density, as shown in Figure 5.27. 800 700 ^ 600 & 500 I 400 -a 1 300 u 200 100 0 5 10 15 20 25 CRT • Reactor A • Reactor B Reactor A Reactor B Figure 5.27: Relationship between crystal density and CRT 88 RESULTS A N D DISCUSSION In the above discussion, the density used was not the real crystal density. After the study had been completed, the real crystal density was determined, following the method described in Section 4.6.2. The tested density of struvite crystals was 1.15 g/mL, whereas the reported struvite density is approximately 1.7 g/mL [14]. The difference comes from the error in the rough method for density determination in this study. 5.5.5 Crystal hardness The crystal density also can be exhibited in the way of hardness. The higher the density, the harder the crystal is. In this study, the crystal hardness was not measured using a specific test. The harvested crystals were crushed in the fingers and the strengths used were compared, in order to have a qualitative idea of crystal hardness. After trying to crush the crystals harvested from reactors A and B, running different supernatants under different operational conditions, the differences in crystal hardness were found. In general, the characteristics of the influent supernatant had no significant effect on the crystal hardness. Under similar operational conditions, such as SS ratio, CRT and magnesium dosage, the produced crystals from different supernatants had similar hardness levels. In addition, the crystal hardness increased with the increasing CRT and magnesium dosage. For example, it was easy to crush the crystals produced under the CRT shorter than 10 days, while for those with the CRT longer than 18 days, it was very hard to crush using only one's fingers. Comparing the crystal harvested from reactor A and reactor B, it was found that the crystal from reactor A, using a high magnesium dosage, was a little harder than that from reactor B, with a low magnesium dosage in the influent. However, it should be remembered that these were qualitative assessments only, based on one person's assessment. 89 RESULTS AND DISCUSSION 5.5.6 Morphology In this study, struvite crystals with various size, density and hardness were harvested. In order to understand how these external qualities would change with the crystal morphology, the outside and inside structures of crystal samples were observed under the scanning electron microscope (SEM). In general, the harvested crystals during the entire study were round and with satisfactory hardness. They were not easy to break apart in the process of harvesting, drying, sieving and transportation. The tested crystals were chosen for different size and hardness. Figure 5.28 shows the outside appearance of the struvite product harvested from the Lulu supernatant and with the CRT of 18 days. This crystal product is very hard and round. It can be seen that, for the most part, the crystal surface is smooth and monolithic but with fine anomalistic stripes; some small areas are also coarse. Under the 300x magnification, the smooth surface part is made up of tightly agglomerated brick-like crystals, as shown in Figure 5.28-B. At the same magnification, it can be seen that the coarse surface part also consists of tightly aggregated orthorhombic brick-like and rod-like crystals, as shown in Figure 5.28-C. Some fine needle-like crystals can be found inside. When using 3000* magnification to observe this coarse part, the aggregation of brick-like and rod-like crystals can be seen clearly, which is shown in Figure 5.28-D. Comparing these four SEM images, it is concluded that the surface of the entire crystal is an aggregation of fine brick-like and rod-like crystals. The abrasion in the fluidized bed reactor rounds off the tips of these fine crystals, so that the whole surface looks round only with fine stripes. It can be expected that the surface of the crystal product will be rounder and smoother after a longer retention time in the reactor. 90 RESULTS A N D DISCUSSION Fig.5.28-A: Outside appearance magnified at 18X Fig. 5.28-B: Smooth surface magnified at 300X Fig. 5.28-C: Coarse surface magnified at 300X Fig. 5.28-D: Coarse surface magnified at 3000X Figure 5.28: S E M images of crystals (D>4.75 mm) harvested from reactor A testing the Lulu supernatant on Nov. 10, 2002 After cutting the hard crystal product harvested from the Lulu supernatant and with the C R T of 16 days, the inside vision was observed. Figure 5.29-A shows the cross section of the 91 RESULTS A N D DISCUSSION cut crystal at 50x magnification. It can be seen that the inside core consists of an agglomeration of fine crystals; however, in the core, the aggregation looks much looser and aggregated crystals looks much smaller than the edge part. A t the edge part, the aggregation of fine crystals is very tight and solid, resembling a one-piece rock with scrapes. Close examination at the 300x magnification in Figure 5.29-B reveals the inside core of the cut particle. It can be seen that the loose aggregation o f brick-like and rod-like crystals is dominant. Some needle-like crystals and tightly crystal aggregation, like the edge part, are also found. The S E M analysis of the crystal inside structure shows that the big struvite particle is the tight aggregation of uncountable fine crystals. In the core, the aggregation is loose and appears weak in structure strength. During the period of retention in the reactor, the abrasion caused by the surrounding upflow fluid and collision with other particles make the loose aggregation tighter and tighter, so that the edge part grows in strength and makes the whole particle difficult to break apart. Fig. 5.29-A: S E M image magnified at 5OX Fig. 5.29-B: S E M image magnified at 300X Figure 5.29: S E M images of crystals (4.75 m m > D > 2 . 8 3 mm) harvested from reactor A testing Lulu supernatant on October 28, 2002 92 RESULTS A N D DISCUSSION Fig. 5.30-A: Crystal with D>4.75 mm Fig. 5.30-B: Crystal with 4.75 mm>D>2.83 mm Fig. 5.30-C: Crystal with2.83 mm>D>2 nun Fig. 5.30-D: Crystal with2 mm>D>l mm Fig. 5.30-E: Crystal with 1 mm>D>0.5 mm Figure 5.30: SEM images of crystals with different sizes harvested from reactor A testing the Lulu supernatant on Nov. 10, 2002 93 RESULTS A N D DISCUSSION Figures 5.30 and 5.31 show the outside appearances of the struvite crystals from the different size fractions collected in one harvest, which grew in the Annacis and Lulu supernatants, respectively. The operational conditions for producing theses crystals were similar. Fig. 5.31-A: Crystal with D>4.75mm Fig. 5.31-B: Crystal with 4.75 mm>D>2.83 mm Fig. 5.31-C: Crystal with 2.83 m m > D > 2 mm Figure 5.31: S E M images of crystals with different sizes harvested from reactor A testing the Annacis supernatant on Sept. 18, 2002 94 RESULTS A N D DISCUSSION Figures 5.30 and 5.31 reveal that the outside structure of crystals is not affected significantly by the characteristics of the influent supernatant, provided that the operational conditions were the same. In addition, the appearances of large and small crystals in one harvest are similar, which means that, after sufficient retention time in the reactor, the abrasion in the reactor makes crystal outside structure monolithic. The interesting image is the image of the crystal in the size fraction of 0.5 mm shown in Figure 5.30-E. It looks like a broken piece of larger crystal, since its structure is similar to that of the edge part shown in Figure 5.29. This image shows that the aggregation occurs from the center of the crystal outwards. Meanwhile, the inside structures of struvite products harvested from the Lulu and Annacis supernatants were analyzed, which are shown in Figures 5.32 and 5.33, respectively. The operational conditions for producing theses crystals were similar. These images reveal that the characteristics of the influent supernatant have no significant effect on the inside structure of crystals. Since the inside and outside structures of the crystals will determine the crystal qualities, such as size, hardness and density, it can be concluded that, under appropriate operational conditions, the effect of the supernatant composition on these crystal qualities is minor. 95 RESULTS A N D DISCUSSION Fig. 5.32-A: Outside appearance, harvested on Nov. 9, 2002 Fig. 5.32-B: Inside structure, harvested on Nov. 9, 2002 Fig. 5.32-C: Outside appearance, harvested on Oct. 28, 2002 Fig. 5.32-D: Inside structure, harvested on Oct. 28, 2002 Figure 5.32: S E M images of outside and inside structure of crystals (4.75 mm>D>2.83 mm) harvested from reactor A testing the Lulu supernatant 96 RESULTS A N D DISCUSSION Figure 5.33: S E M images of outside and inside structure of crystals (4.75 mm>D>2.83 mm) harvested from reactor A testing the Annacis supernatant on Sept. 13, 2002 Figure 5.34 shows the outside and inside structures of crystals harvested from the synthetic supernatant. The C R T was 10 days for the crystal in Figures 5.34-A and 5.34-B, and 10.5 days for the crystal in Figures 5.34-C and 5.34-D. Comparing these images with all o f the above figures, it is found that the surfaces of crystals in Figure 5.34 are coarse, porous and not as smooth as others. This was caused by the short CRT of only around 10 days. The crystals in Figures 5.28 to 5.33 had the C R T longer than 15 days. The longer the CRT, the smoother and rounder the crystal surface became. In Figures 5.34-A and 5.34-B, the struvite product grew under low magnesium dosage (Mg:P molar ratio=1.3:l) and the one in Figures 5.34-C and 5.34-D was produced using high magnesium dosage (Mg:P molar ratio=3:l). Their outside structures have no striking difference. While looking at the inside structure, the struvite product in Figure 5.34-B has many needle-like fine crystals inside and the aggregation of crystals appears loose. On the contrary, the tightly-packed brick-like and rod-like crystals are dominant inside the product in Figure 5.34-D. This difference in crystal aggregation supports the discussion in a study conducted by Bouropoulos et al. that the high magnesium concentration wi l l favor struvite crystal aggregation 97 RESULTS A N D DISCUSSION [26]. Also, due to this difference, the crystal product in Figures 5.34-A and 5.34-B is much softer than that in Figures 5.34-C and 5.34-D. Fig. 5.34-A: Outside appearance, harvested on July 15, 2002 Fig. 5.34-B: Inside structure, harvested on July 15, 2002 111 Fig. 5.34-C: Outside appearance, harvested on July 29, 2002 Fig. 5.34-D: Inside structure, harvested on July 29, 2002 Figure 5.34: S E M images of outside and inside structure of crystals (4.75 mm>D>2.83 mm) harvested from reactor A testing the synthetic supernatant 98 RESULTS A N D DISCUSSION From the analysis results of SEM images, it was concluded that the supernatant characteristics had a. minor effect on the morphology of struvite crystals. In our struvite crystallization process, the inside of the crystal products had typical individual orthorhombic shape. The crystal aggregation occurred at the same time that the crystal formed and it was dominant in crystal size enlargement. It has been accepted that aggregation takes place, parallel to crystal growth, as an important size enlargement mechanism of reactive crystallization or precipitation processes. After the nucleus has formed, it may grow in two ways; it can either stick together with another particle and create an agglomerated particle or grow alone. With high supersaturation, aggregation dominates over crystal growth [62], which explains why aggregation was dominant in crystals produced in the Annacis and Lulu supernatants, compared to the synthetic supernatant, because the process operated for the Annacis and Lulu supernatants had higher in-reactor SS ratio. In addition, aggregation will make crystals pack tightly, leading to high hardness. Therefore, the struvite products harvested in this study were of large size and hardness. 5.5.7 Crystal distribution in the reactor Since the fluidized bed reactor used in this study was ladder shaped, with increasing diameter from the bottom to the top, the velocities of the upflow fluid in the different sections of the reactor were different. It was expected that the crystals with different size would stay in the different sections so that the biggest crystals always could be harvested from the bottom part of the reactor. In order to prove this expectation and also understand the size distribution of crystals in the reactor, reactor A was drained after the crystals had settled down for an hour. The crystals were collected one volume by one volume from the bottom to the top of the reactor. Table 5.7 and Figure 5.35 show the mean size and density of crystals collected from the different sections of the reactor. 99 RESULTS A N D DISCUSSION Table 5.7: Distribution of crystals with different size and density in the reactor The section of the reactor Crystal mean size (mm) Crystal density (g/L) 0-1.3 L 2.79 631.5 1.3 L-2.6L 2.65 655.1 2.6 L-4.1 L 2.20 612.3 4.1 L-5.6L 1.83 607.0 5.6L-6.8L 1.52 574.8 6.8L-8.1 L 1.25 554.3 8.1L-10.7L 0.61 .. 548.2 3.00 2.50 &> 2.00 N <U S 13 1.00 -4-» C O £ '0 .50 0.00 1.3 2.6 4.1 5.6 6.8 8.1 10.7 Reactor section volume (L) <D T 3 13 Size —•—Density Figure 5.35: Distribution of crystals with different size and density in the reactor From Figure 5.35, it can be seen that the crystal size and density decreased from the bottom to the top of the reactor and the harvest zone had the biggest and heaviest crystals. An interesting phenomenon is that the crystal size and density collected from 4.1 L to 10.7 L decreased significantly, though the diameter of the reactor A from the height of 214cm (at this height, the volume from the bottom to this point was 3.6 L) to the height of 464 cm (at this 100 RESULTS A N D DISCUSSION height, the volume from the bottom to this point was 15.1 L) was uniform. This meant that the big and heavy crystals would still stay in the lowest section of the reactor, even in the reactor with uniform diameter. Thus, it seems that the ladder design of the reactor was not significant in classifying crystals in the reactor, by size and weight. However, the harvest zone is still recommended to have a small diameter, to prevent the fine particles from staying in this zone. The hydraulic characteristics in the reactor are not clearly understood, which is very important for monitoring the movement and distribution of crystals in the reactor. Therefore, further study on the hydraulics in the reactor is strongly recommended, for determining the final reactor design in full scale. . . . . 5.6 Model Application In Process Control In this study, two models could be used to set the operational parameters in advance. One was developed by Britton [5] and the other was developed by Potts [63]. Generally, Britton's model was applied to predict the effluent magnesium, ammonia and ortho-phosphate concentrations in order to check whether the expected removal efficiency was achieved, under chosen operational conditions. Potts's model was not used during the process operation; however, it was validated using the study results. 5.6.1 Britton's model [ 5 ] This Struvite Equilibrium Model uses the conditional solubility product (Ps) to describe the struvite equilibrium state in solution and it dose not consider the effect from other side reactions. The model assumes that magnesium, ammonia and ortho-phosphate are removed in equimolar amounts. The general equation in the model is equation (37). [Mg2+];n, [P043"]in, and [NH 4 +]in represent the concentrations of magnesium, ammonia and ortho-phosphate in the mixed influent to the reactor; A represents the molar reduction of Mg 2 + , P0 4 3" and N H 4 + . Through solving A , the resulting effluent concentrations are predicted as the combined influent 101 RESULTS A N D DISCUSSION concentrations minus A . ( [ M g 2 + ] m - A)([P0 4 3 "],n- A ) ( [ N H 4 + ] i n - A)=Ps e q (37) Since the value of Ps is case specific, it is necessary to generate the Ps e q curve for certain supernatant. In this study, three different supernatants were tested so that the Ps e q curves used for the synthetic supernatant, Annacis supernatant and Lulu supernatant were equations (33), (34) and (35), respectively. Figures 5.36 to 5.38 show the comparison of the measured and modeled effluent concentrations for ortho-phosphate, when testing the synthetic, Annacis and Lulu supernatants, respectively. All of these graphs showed quite good correlation between the actual and predicted results. The average absolute error and relative absolute error are listed in Table 5.8. The detailed model calculations and the analysis of the model results can be found in Appendix H. 50.00 Date —•—Actual EffluentPredicted Effluent Figure 5.36-A: Modeled and actual effluent phosphate concentration for reactor A testing the synthetic supernatant 102 RESULTS A N D DISCUSSION c o c co o C o o O PH 50.00 45.00 40.00 35.00 30.00 25.00 20.00 15.00 10.00 5.00 0.00 13-Jul-02 23-M-02 2-Aug-02 Date 12-Aug-02 22-Aug-02 • Actual Effluent •Predicted Effluent Figure 5.36-B: Modeled and actual effluent phosphate concentration for reactor B testing the synthetic supernatant G O c CD o c o o '->* o PH 14.00 12.00 10.00 8.00 6.00 4.00 2.00 0.00 l-Sep-02 6-Sep-02 ll-Sep-02 Date 16-Sep-02 21-Sep-02 • Actual Effluent • Predicted Effluent Figure 5.37-A: Modeled and actual effluent phosphate concentration for reactor A testing the Annacis supernatant 103 RESULTS A N D DISCUSSION oo a o o o c o o O PH 20.00 18.00 16.00 14.00 12.00 10.00 8.00 6.00 . 4.00 2.00 0.00 l-Sep-02 6-Sep-02 • ll-Sep-02 16-Sep-02 21-Sep-02 Date • Actual Effluent —o— Predicted Effluent Figure 5.37-B: Modeled and actual effluent phosphate concentration for reactor B testing the Annacis supernatant i—I o o e o o O P H 10 00 9 00 8 00 7 00 6 00 5 00 4 00 3 00 2 00 1 00 0 00 fit IS 16-Sep-02 l-Oct-02 16-Oct-02 31-Oct-02 15-Nov-02 30-Nov-02| Date -•— Actual Effluent Predicted Effluent Figure 5.38-A: Modeled and actual effluent phosphate concentration for reactor A testing the Lulu supernatant 104 RESULTS A N D DISCUSSION c o o a o o O PM 16.00 14.00 12.00 10.00 8.00 6.00 4.00 2.00 0.00 21-Sep-02 ll-Oct-02 31-Oct-02 20-Nov-02 10-Dec-02 30-Dec-02 Date • Actual Effluent —o—Predicted Effluent Figure 5.38-B: Modeled and actual effluent phosphate concentration for reactor B testing the Lulu supernatant Table 5.8: Absolute error between the modeled and actual effluent phosphate concentration Supernatant Synthetic Annacis Lulu Reactor Reactor Reactor Reactor Reactor Reactor A B A B A B Average absolute 2.61 3.45 0.79 1.77 0.79 1.04 error (mg/L) Relative absolute 15,0 21.7 21.9 21.9 16.1 16.9 error * (%) * Relative absolute error calculates the error between the predicted effluent phosphate concentration by model and the actual effluent phosphate concentration in process operation. Besides phosphate, the modeled effluent results for ammonia and magnesium matched closely with the actual results, as shown in Appendix H. Since some experimental errors were present during the study, such as errors in reading pH and measuring concentrations of Mg 2 + , PO4 3" and N H 4 + , the model over-predicted or under-predicted the real results. However, this 105 RESULTS A N D DISCUSSION difference was acceptable and would be reduced through using more precise test methods. 5.6.2 Potts's model [63 ] The Potts's model can be used to determine the required operating pH according to the desired recycle ratio, or to determine the required recycle ratio according to the desired operating pH. This model uses the solubility product (Ksp) to describe the equilibrium state of the struvite and includes the effect from other side reactions. It also considers the effect of the ion activity. A list of the chemical equilibria considered is shown in Table 5.9. Table 5.9: Chemical equilibria used in the Potts's model [63] MgOH + «—• M g 2 + + OH' N H 4 + H + + N H 3 H3PO4 " H + + H 2PQ 4" H 2P0 4" " H + + HP0 4 2" HPQ 4 2 ' •>—» H + + PQ 4 3 ' MgH 2 PQ 4 + - • M g 2 + + H 2 PQ 4 ' MgHPQ 4 -—" Mg 2 + + HPQ 4 2 ' MgPOV » M g 2 + + PQ 4 3 ' H 2Q " f f + OFf MgNH 4PO 46H 20 " Mg 2 + + NH 4 + + PQ 4 3 '+6H 2Q The input parameters are concentrations of magnesium, ammonia and ortho-phosphate, and the conductivity in the influent. By using the Excel's Solver tool to balance the chemical equilibria mentioned above, the predicted operating pH or recycle ratio could be found. Also, based on these operating conditions, the expected removal percentage of the ortho-phosphate can be calculated. Although the Ksp value for the struvite should be singular, regardless of the supernatant characteristics, the test results in this study showed that there were different struvite Ksp values for different supernatants; this has been discussed in Section 5.1.1. In addition, the process was 106 RESULTS A N D DISCUSSION run for different supernatants under different ambient temperatures. Therefore, the pKsp values used in the model were 13.62 for the synthetic supernatant at 20°C, 13.04 for the Annacis supernatant at 15°C and 13.30 for the Lulu supernatant at 10°C. Since the Potts's model was not used during the process operation, its validity was checked using the study results. The operation results of running the synthetic supernatant, the Annacis supernatant and the Lulu supernatant were input to this model, respectively. Comparing the predicted values by model with the real ones, it was found that there was a large difference between them, especially for the Annacis supernatant and the Lulu supernatant. Some examples of comparison are listed in Table 5.10. Not all of the results were listed in this thesis, since the errors between other predicted results and their respective actual results were in the same range as those of the listed examples. From Table 5.10, it can be seen that the required recycle ratio predicted by this model is much higher than the value in actual application, for similar phosphate removal efficiency. The main reason for this huge error is the value of Ksp used in the model. Since there were too many uncertainties and complexities present in the determination of Ksp value, the measured Ksp value had a relatively high deviation from the actual value. The measurement of Ps value was simpler and more accurate than Ksp, so that the predicted results by Britton's model were closer to the actual data obtained and the relative errors were low (15 %-22 %). Therefore, it is recommended that the Britton model be used to control the struvite crystallization process, until a more accurate method of determining Ksp is developed. 107 RESULTS A N D DISCUSSION Table 5.10: Comparison of the modeled and actual results The synthetic supernatant The input parameters The actual result The model result Relative absolute error* (%) Mg=316.7mg/L; NH4-N=571.6mg/L; PO4-P=101.6mg/L; Cond.=3000 us/cm; pH=7.2 Recycle ratio=10.9; P removal=94.0 % Recycle ratio=24.1; Premoval=92.1 % 121 Mg=128.8 mg/L; NH4-N=604.5 mg/L; P04-P=122.8 mg/L; Cond.=3000 us/cm; pH=7.6 Recycle ratio=9.7; P removal=92.9 % Recycle ratio=26.0; P removal=96.7 % 168 The Annacis supernatant The input parameters The actual result The Model result Relative absolute error (%) Mg=307.7 mg/L; NH4-N=851.2mg/L; PO4-P=109.0 mg/L; Cond.=6000 us/cm; pH=8.0 Recycle ratio=6.1; P removal=96.0 % Recycle ratio=29.0; P removal=98.9 % 375 Mg=163.5 mg/L; NH4-N=958.1 mg/L; P04-P= 123.0 mg/L; Cond.=6000 us/cm; pH=8.35 Recycle ratio=8.9; P removal=95.2 % Recycle ratio=64.3; P removal=99.2 % 622 The Lulu supernatant The input parameters The actual result The Model result Relative absolute error (%) Mg=242.4 mg/L; NH4-N=896.3 mg/L; PO4-P=80.4 mg/L; Cond.=5600 us/cm; pH=7.9 Recycle ratio=5.7; P removal=96.3 % Recycle ratio=75.8; P removal=99.6 % ' 1230 Mg=100.3 mg/L; NH4-N=973.2 mg/L; P04-P=87.3 mg/L; Cond.=5600 us/cm; pH=8.2 Recycle ratio=7.0; P removal=94.3 % Recycle ratio=103.0; P removal=99.6 % 1371 * Relative absolute error calculates the error between the predicted recycle ratio by model and the actual recycle ratio used in process. 108 CONCLUSIONS CHAPTER 6 CONCLUSIONS Based on the results from this pilot-scale study on phosphorus recovery from anaerobic digester supernatant at the Environmental Engineering Pilot Plant at UBC, the following conclusions can be drawn: • The pilot-scale struvite crystallization process developed at UBC was effective in removing and recovering phosphate from the anaerobic digester supernatants of the Annacis Island Wastewater Treatment Plant and the Lulu Island Wastewater Treatment Plant, as well as the synthetic supernatant (with 100-190 mg/L of the ortho-phosphate concentration); • Over 90 % of ortho-phosphate in the supernatants was successfully removed and around 90 % of removed phosphate was recovered after harvesting, drying and screening operations. The ortho-phosphate concentration in process effluent could easily be lowered to 5 mg/L; • The inlet supersaturation (SS) ratio, operational pH and magnesium dosage in the supernatant were considered to be effective controlling parameters for obtaining desired phosphate removal efficiency. With high inlet SS ratio, or high operational pH, or high magnesium dosage, the high phosphate removal was achieved; • A preliminary solubility product determination for the produced struvite crystals gave significantly different results for the synthetic supernatant, Annacis supernatant and Lulu supernatant. The struvite crystals had higher solubility in the Annacis supernatant than in the Lulu supernatant and synthetic supernatant, due to higher impurities and suspended solid concentrations; • Struvite formation is an endothermic reaction. The tested temperature coefficient and enthalpy were 1.07-1.09 and 44.79-57.62 KJ/mol for different supernatants; 109 CONCLUSIONS • The application of air stripping or a higher magnesium dosage in the supernatant was not economical for reducing the chemical costs in struvite recovery from the Annacis supernatant and the Lulu supernatant, due to a high initial pH value around 8.0; • The produced struvite crystals were easily separated from the process, and were composed of very pure struvite (i.e. the purities were 91.2 % and 94.1 % for crystals produced in the Annacis supernatant and the Lulu supernatant, respectively.) with small amounts of calcium and carbonate, and traces of iron and aluminum. Most of harvested crystals were round, hard and larger than 2 mm in mean diameter, over the course of the study; • The size, density and hardness of produced struvite crystals were affected by the crystal retention time in the reactor and the magnesium dosage in the supernatant. The longer the crystal retention time, the larger, heavier and harder crystals became. The high magnesium dosage (Mg:P=3:l) in the supernatant resulted in larger, heavier and harder crystals, compared to low magnesium dosage (Mg:P=1.3:l); • The SEM analysis showed that the supernatant characteristics had no significant effect on struvite crystal qualities (i.e. size, density and hardness). The produced struvite crystals were aggregation of numerous fine crystals and, high retention time and magnesium dosage promoted aggregation; • The study on crystal distribution in the reactor showed that the present reactor design of decreasing diameter from the top to the bottom did not have a significant effect on classifying crystals in the reactor by size and weight; • The Struvite Equilibrium Model developed by Britton [5], to predict effluent magnesium, ammonium and ortho-phosphate concentrations, was used to control the struvite crystallization process. The predicted results matched the actual data very well; no CONCLUSIONS • The Struvite Crystallization Model developed by Potts [63], to determine the operational parameters, was verified using operational data, and the predicted results showed a large deviation from the actual results. The reason for the error maybe came from the fact that there was no accurate value of calculating struvite solubility product that could be used in the model; • Finally, the present determination of struvite solubility product included many uncertainties and complexities, so that the conditional solubility product was more useful in operating the struvite crystallization process and predicting process performance. i l l RECOMMENDATIONS CHAPTER 7 RECOMMENDATIONS Based on the experience gained from pilot-scale study on phosphorus recovery from anaerobic digester supernatant, the following recommendations are made: • The curve of struvite conditional solubility product vs pH is recommended for application as a criterion in operating the struvite crystallization process. The corresponding curve should be determined for different supernatants, due to the effect of supernatant characteristics; • The possibility of using air stripping of carbon dioxide or high magnesium dosage in the supernatant, as a means to reduce process chemical costs, should be further explored, especially for those anaerobic digester supernatants with a relatively low pH; • It was noticed in this study that the upflow rate of the fluid in the reactor had an effect on the crystal size, but there were no sufficient data to support this observation. 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Department of Civil Engineering, University of British Columbia, Canada. 118 APPENDIX A APPENDIX A CALCULATIONS FOR UPFLOW VELOCITES IN THE REACTOR Upflow velocity = Flow rate Cross-sectional area Flow rate range: 3000-6800 mL/min The corresponding upflow velocities are listed in Table A. Table A: Upflow velocities in different reactor sections Reactor sections Nominal diameter Cross-sectional area Upflow velocity (cm) (cm2) (cm/min) Harvest zone 4 12.6 238-541 Reaction zone I 5.2 21.2 142-320 Reaction zone II 7.7 46.6 64-146 Top clarifier 20.2 320.5 9-21 119 APPENDIX B APPENDIX B CALCULATIONS FOR REYNOLDS NUMBER IN THE REACTOR The following equation [1] was used to calculate the Reynolds numbers: Reynolds number= p x V x D where: p = Mass density of the fluid, kg/m3 V = Average velocity of the fluid, m/s D = Diameter, m u = Viscosity of the fluid, N-s/m2 At a temperature of 25°C, the values of p and p are 997 kg/m3 and 8.9xl0"4 N-s/m2. Flow rate range: 3000-6800 mL/min The corresponding Reynolds numbers in different sections of the reactor are listed in Table B. Table B: Reynolds numbers in different reactor sections Reactor sections DxlO 3 V x l 0 J Reynolds number (m) (m/s) Harvest zone 40 40-90 1783-4041 Reaction zone I 52 24-53 1371-3108 Reaction zone II 77 11-24 926-2099 Top clarifier 202 1.6-3.5 353-800 [1] Metcalf and Eddy, Inc. (1991) Wastewater engineering: treatment, disposal, and reuse. Third Edition. McGraw-Hill, Inc., New York., U.S. A. 120 APPENDIX C APPENDIX C INSTRUMENT OPERATIONAL PARAMETER DETAILS Table C - l : Instrument operational parameters for flame atomic absorption spectrophotometer Element Analyzed Magnesium Iron Calcium Aluminum Potassium Concentration Units mg/L mg/L mg/L mg/L Mg/L Instrument Mode Absorbance Absorbance Absorbance Absorbance Emission Sampling Mode Autonormal Autonormal Autonormal Autonormal Autonormal Calibration Mode Concentration Concentration Concentration Concentration Concentration Measurement Mode Integrate Integrate Integrate. Integrate Integrate Replicates Standard 3 3 3 3 • ' 3 Replicates Sample 3 3 3 3 3 Wavelength 202.6 248.3 nm 422.7 nm 309.3 nm 766.5 nm Range 0-100 mg/L 0-10 mg/L 0-60 mg/L 0-20 mg/L 0-10 mg/L Flame Type N 2 0 / C 2 H 2 A i r / C 2 H 2 N 2 0 / C 2 H 2 N 2 0 / C 2 H 2 A i r / C 2 H 2 Calibration Algorithm New Rational New Rational New Rational New Rational New Rational Table C-2: Instrument operational parameters for flow injection analysis. Ion Analyzed P0 4-P N H 3 - N Concentration Units mg/L Mg/L Range 0-100 mg/L 0-100 mg/L Temperature 63°C 63 °C Method Ammonia Molybdate Phenate Reference 1 2 1: LaChat Instruments Methods Manual for the QuikChem Automated Ion Analyzer (1990). QuikChem method number 10-115-01-1Z 2: APHA, AWWA, WPCF (1995). Method 4500-NH3-F. Phenate Method. In Standard Methods for the Examination of Water and Wastewater, 19 edition. American Public Health Association, Washington, D.C. 121 APPENDIX D A P P E N D I X D K S P D E T E R M I N A T I O N D A T A A N D C A L C U L A T I O N S 122 od i> r-»' r- r-' I--' oo oo r-' r-~ r~ NO' g 'si1 NO r o o t-- i a m * h oo r-' r--' r-- NO NO oo r-- r-- r- NO' >n - ^ • ^ • r - o ' o o o o o ' r f ^ H m o O N N D o o o c N o o i n r o ^ H O ^ r - ; i n NO NO r-~ t-- P - i n NO' r - t~- oo oo 2 J f ON o ON ON •*}- i ON CN O O 0 0 Tl-oo CN r o r o ON —i i n ON o • — i f -2 ON ON ON o d o d 2 ON oo o o o t> 60 8r ^-i CN • — i T j - ^ v o O N T t t N t ^ v O • < 3 - i n i n i n i n i n r o - 3 - i n i n i n N O co i n s o g «5I E Z "ill —i, r - o o i n ON o o CN o o o CN CN O TJ- r o r o O CN o o o i— t—- r— o o o o o o o r -X QH o 0 0 NO O t--C N IT) '—1 r o r o i n o t> c--' CN CN o o i n r o CN ' 1 ON i n i n NO i n ON '—1 r-- r -NO o d r o I •*' r-- i n CN CN NO m i n i n i n m o i n t-- ON r o o CN ON NO r o r o 0 0 i n CN o OO • * CN ON o d CN <ri CN ON NO X 0 CN o O O o O O CN CN CN CN CN CN r-- NO OO ON NO 0 0 CN i n NO NO t> ON O NO m T J - T)- t -» ON CN 0 0 r o cN NO o o OO 0 0 r o i n o i n r o r o r o ON o CN CN ON r o r o CN O o O r - r -o o O o o O o o CN NO 0 0 •* NO CN o_ OO r o r»" O r o r o i n 0 0 r o r o CN >n i n CN CN r o • 3 - ON </-> >n NO r o r o ON i—i o r o CN O i n NO CN o o O CN CN CN CO o o d o o o 0 0 CN r o '•g f O o CN / O a. ^ I-1 to GO O > OO J2 Tt o P H X 60 00 i 2 o o P H 2 "ggl 5? •? 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RPM pKsp Units °C mg/L mg/L mg/L mS/cm @ 25°C Annacis supernatant 6.37 10 112.06 1125.13 293.00 9000 70 12.46 IOC 6.64 10 66.44 1066.88 194.63 8400 70 12.41 7.19 10 36.79 1036.25 111.00 7800 70 12.10 8.09 10 3.98 1024.88 92.00 6400 70 12.03 8.27 10 2.86 988.38 85.75 6000 70 12.01 9.09 10 0.81 904.00 77.88 6000 70 11.85 5.97 10 233.57 1158.88 453.63 9500 70 12.67 6.74 10 71.74 526.19 158.00 8400 70 12.62 7.61 10 10.28 1008.75 88.50 7500 70 12.22 8.22 10 3.80 985.31 85.44 7000 70 12.00 8.63 10 1.09 952.88 82.00 6500 70 12.14 9 10 1.18 819.88 74.88 6000 70 11.83 Annacis supernatant 7.5 15 42.06 969.43 86.31 9100 70 12.16 15C 6.44 15 100.44 1194.90 217.98 8600 70 12.77 7.9 15 8.99 984.12 79.30 7500 70 12.32 5.98 15 327.18 1533.93 407.56 10300 70 12.76 8.27 15 3.32 919.36 75.80 6400 70 12.36 9.06 15 1.97 904.31 72.30 5700 70 11.84 6.95 15 86.34 1008.69 136.42 8500 70 12.33 6.33 15 136.85 1264.76 219.31 9600 70 12.87 7.82 15 10.28 1001.32 81.50 7800 70 12.35 8.18 15 3.80 985.31 75.60 6700 70 12.38 8.3 15 3.09 980.84 75.30 6000 70 12.31 8.9 15 1.18 919.13 79.90 6500 70 12.20 Annacis supernatant 7.1 20 32.80 1102.28 687.81 9700 70 12.31 20C 6.3 20 208.32 1376.31 371.66 10700 70 12.78 7.97 20 8.74 1239.80 120.15 7000 70 12.29 5.64 20 810.75 1673.30 1241.95 13400 70 12.88 6.2 20 251.62 1427.99 471.90 10000 70 12.74 8.28 20 7.39 1102.05 122.74 7700 70 12.12 7.89 20 11.05 1076.06 648.43 7800 70 11.90 6.22 20 167.77 1338.93 350.76 10500 70 13.03 7.95 20 30.46 1208.80 31.05 7100 70 12.32 5.62 20 891.40 1759.23 1290.73 13600 70 12.84 6.12 20 320.78 1448.94 465.60 11500 70 12.82 8.77 20 9.90 1027.90 26.63 7600 70 12.16 Lulu supernatant 6.33 10 118.04 1035.79 295.41 8000 70 12.50 IOC 6.46 10 86.76 1014.94 235.42 7800 70 12.51 7.25 10 15.75 982.92 110.22 7500 70 12.39 6.83 10 38.35 998.51 150.96 7600 70 12.45 127 Lulu supernatant 20C 7.95 10 3.22 956.29 ' 89.65 6500 70 12.32 8.88 10 0.92 839.45 87.51 5500 70 11.95 6.09 10 211.10 1107.79 392.68 9400 70 12.58 6.04 10 246.67 1130.28 432.06 9600 70 12.56 6.69 10 59.88 1020.00 176.15 8200 70 12.43 7.19 10 19.01 994.87 107.25 7800 70 12.40 8.23 10 2.92 946.78 87.66 6600 70 12.09 9.05 10 2.85 760.08 89.66 5500 70 11.34 5.94 10 345.10 1207.02 600.60 10700 70 12.47 6.1 10 208.87 1188.35 457.32 10000 70 12.49 6.79 10 45.43 773.12 162.91 8500 70 12.56 7.25 10 12.43 1010.28 106.33 8200 70 12.52 8.02 10 5.04 934.78 96.20 7100 70 12.06 8.86 10 2.00 515.32 92.78 4900 70 11.78 6.5 20 151.34 827.05 308.04 10000 70 12.87 6.7 20 78.56 871.05 206.81 8500 70 12.91 7.4 20 15.07 832.73 110.11 8000 70 12.92 8.06 20 6.65 751.70 97.59 6800 70 12.59 8.25 20 4.36 810.51 96.54 6200 70 12.52 9.02 20 2.47 792.90 93.53 5800 70 12.08 6.2 20 270.97 833.44 452.93 10000 70 12.96 6.53 20 111.73 894.56 255.45 9000 70 12.95 7.32 20 15.81 850.70 109.46 7500 70 12.97 8.22 20 3.57 831.28 94.88 6500 70 12.65 8.46 20 2.88 817.61 95.94 5900 70 12.48 9.01 20 2.50 757.53 93.51 6200 70 12.12 5.89 20 354.40 988.74 590.73 10200 70 13.21 6.24 20 147.91 918.28 313.53 9100 70 13.21 7.19 20 17.90 878.05 114.84 7700 70 13.05 8.19 20 3.35 857.19 95.65 7000 70 12.72 8.67 20 2.56 806.15 95.30 5700 70 12.34 8.99 20 3.53 720.71 95.13 6300 70 12.01 128 Mg 2 + NH 4 + P04 3" H + OH- MgOH+ NH 3 ( a q ) H 3 P0 4 H2P04" HP042" MgH2P( log!) -log{ } -log{ } -log{ } -log{ } -log{ } -log{ } -log{ } -log{ } -log{ } -log{ i 2.93 1.23 9.30 6.37 8.15 8.62 4.65 6.63 2.31 3.19 4.93 3.15 1.25 9.01 6.64 7.88 8.57 4.40 7.15 2.57 3.17 5.40 3.39 1.26 8.44 7.19 7.33 8.26 3.86 8.23 3.10 3.15 6.18 4.34 1.26 7.43 8.09 6.43 8.31 2.96 9.92 3.89 3.04 7.91 4.47 1.28 7.26 8.27 6.25 8.26 2.79 10.29 4.08 3.05 8.23 5.02 1.37 6.47 9.09 5.43 7.99 2.06 11.96 4.92 3.08 9.62 2.61 1.22 9.84 5.97 8.55 8.70 5.04 5.97 2.05 3.33 4.35 3.11 1.56 8.95 6.74 7.78 8.43 4.60 7.39 2.70 3.21 5.50 3.94 1.27 8.01 7.61 6.91 8.39 3.45 9.06 3.50 3.14 7.13 4.37 1.29 7.34 8.22 6.30 8.21 2.85 10.22 4.06 3.08 8.11 4.91 1.31 6.92 8.63 5.89 8.33 2.47 11.03 4.46 3.07 9.05 4.85 1.40 6.57 9.00 5.52 7.91 2.19 11.79 4.85 3.09 9.39 3.36 1.30 8.15 7.50 6.84 7.71 3.42 8.90 3.49 3.22 6.49 2.97 1.20 9.25 6.44 7.90 8.38 4.38 6.82 2.46 3.25 5.07 4.01 1.29 7.69 7.90 6.44 7.95 3.01 9.63 3.82 3.15 7.46 2.48 1.10 9.83 5.98 8.36 8.35 4.74 6.01 2.12 3.37 4.24 4.42 1.32 7.28 .8.27 6.07 7.99 2.67 10.34 4.16 3.12 8.21 4.63 1.39 6.48 9.06 5.28 7.42 1.95 11.90 4.93 3.10 9.20 3.04 1.28 8.66 6.95 7.39 7.94 3.94 7.76 2.90 3.18 5.58 2.85 1.19 9.50 6.33 8.01 8.36 4.47 6.74 2.50 3.40 4.98 3.95 1.28 7.77 7.82 6.52 7.98 3.08 9.48 3.74 3.15 7.33 4.36 1.29 7.38 8.18 6.16 8.03 2.72 10.17 4.08 3.13 8.08 4.44 1.29 7.24 8.30 6.04 7.99 2.61 10.39 4.18 3.11 8.25 4.87 1.36 6.62 8.90 5.44 7.82 2.08 11.56 4.75 3.08 9.26 3.69 1.25 7.70 7.10 7.07 8.23 3.60 7.27 2.29 2.40 5.57 2.71 1.15 9.24 6.30 7.87 8.05 4.31 6.41 2.23 3.15 4.54 4.05 1.19 7.37 7.97 6.20 7.72 2.67 9.56 3.71 2.95 7.35 2.16 1.08 9.96 5.64 8.53 8.16 4.90 5.15 1.63 3.21 3.39 2.62 1.13 9.31 6.20 7.97 8.06 4.39 6.18 2.10 3.12 4.32 4.14 1.26 7.05 8.28 5.89 7.50 2.43 10.17 4.01 2.94 7.74 4.22 1.25 6.74 7.89 6.28 7.97 2.82 8.69 2.92 2.24 6.73 2.79 1.17 9.39 6.22 7.95 8.21 4.40 6.33 2.23 3.22 4.61 3.43 1.20 8.01 7.95 6.22 7.12 2.71 10.13 4.30 3.57 7.33 2.12 1.06 9.98 5.62 8.55 8.14 4.90 5.12 1.62 3.21 3.33 2.53 1.14 9.47 6.12 8.05 8.05 4.47 6.11 2.11 3.20 4.23 3.93 1.33 7.22 8.77 5.40 6.80 2.01 11.81 5.15 3.60 8.68 2.89 1.26 9.35 6.33 8.19 8.62 4.72 6.56 2.29 3.21 4.86 3.02 1.27 9.22 6.46 8.06 8.62 • 4.59 6.82 2.42 3.20 5.12 3.76 1.28 8.35 7.25 7.27 8.57 3.82 8.32 3.13 3.12 6.57 3.37 1.28 8.81 6.83 7.69 8.60 4.23 7.52 2.75 3.16 5.80 4.43 1.29 7.59 7.95 6.57 8.54 3.13 9.66 3.77 3.06 7.89 4.96 1.38 6.61 8.88 5.64 8.14 2.28 11.47 4.65 3.01 9.29 2.66 1.24 9.68 6.09 8.43 8.63 4.94 6.17 2.14 3.29 4.48 2.59 1.23 9.73 6.04 8.48 8.61 4.98 6.07 2.09 3.29 4.37 3.19 1.27 8.97 6.69 7.83 8.56 4.36 7.26 2.63 3.18 5.50 3.68 1.28 8.45 7.19 7.33 8.55 3.87 8.24 3.10 3.16 6.47 4.48 1.30 7.31 8.23 6.29 8.31 2.86 10.22 4.05 3.06 8.21 4.47 1.44 6.43 9.05 5.47 7.48 2.17 11.80 4.81 3.00 8.96 2.47 1.21 9.79 5.94 8.58 8.59 5.05 5.83 1.94 3.25 4.10 2.68 1.21 9.60 6.10 8.42 8.64 4.90 6.12 2.07 3.22 4.44 3.32 1.39 8.85 6.79 7.73 8.59 4.39 7.44 2.71 3.16 5.71 3.88 1.28 8.38 7.25 7.27 8.68 3.81 8.35 3.15 3.15 6.71 4.26 1.31 7.50 8.02 6.50 8.30 3.07 9.78 3.82 3.05 7.76 4.62 1.58 6.59 8.86 5.66 7.82 2.51 11.39 4.58 2.97 8.88 2.84 1.37 8.97 6.50 7.67 7.98 4.33 6.75 2.37 3.08 4.80 3.10 1.34 8.80 6.70 7.47 8.04 4.10 7.17 2.59 3.11 5.28 3.81 1.36 8.08 7.40 6.77 8.05 3.42 8.55 3.27 3.09 6.67 4.15 1.41 7.36 8.06 6.11 7.73 2.80 9.82 3.88 3.03 7.61 4.32 1.38 7.15 8.25 5.92 7.71 2.58 10.17 4.04 3.01 7.96 4.56 1.47 6.37 9.02 5.15 7.18 1.91 11.70 4.80 2.99 8.96 2.59 1.37 9.33 6.20 7.97 8.02 4.62 6.20 2.12 3.14 4.30 2.95 1.33 8.99 6.53 7.64 8.06 4.26 6.85 2.44 3.13 4.99 3.77 1.35 8.17 7.32 6.85 8.09 3.48 8.41 3.21 3.10 6.57 4.41 1.37 7.20 8.22 5.95 7.83 2.60 10.13 4.03 3.02 8.03 4.50 1.38 6.92 8.46 5.71 7.68 2.38 10.58 4.24 2.99 8.33 4.57 1.49 6.39 9.01 5.16 7.19 1.94 11.69 4.80 3.01 8.96 2.46 1.30 9.78 5.89 8.28 8.21 4.86 5.72 1.95 3.28 4.00 2.82 1.32 9.39 6.24 7.93 8.22 4.54 6.39 2.27 3.24 4.68 3.72 1.33 8.32 7.19 6.98 8.17 3.60 8.16 3.09 3.12 6.41 4.45 1.36 7.24 8.19 5.98 7.90 2.62 10.08 4.01 3.03 8.05 4.54 1.41 6.71 8.67 5.50 7.51 2.19 10.99 4.44 2.99 8.58 4.42 1.51 6.40 8.99 5.18 7.07 1.97 11.65 4.78 3.00 8.79 130 IgHP04 MgP04" li Yi 72 Y3 pKw pKMgOH pKN pKPl •log{ } -log{ } Ionic St. @T°C @T°C @T°C @T°C 3.34 7.55 0.1440 0.729 0.282 0.058 14.52 2.46 9.78 2.06 3.54 7.48 0.1344 0.734 0.291 0.062 14.52 2.46 9.78 2.06 3.77 7.16 0.1248 0.74 0.301 0.067 14.52 2.46 9.78 2.06 4.60 7.09 0.1024 0.756 0.327 0.081 14.52 2.46 9.78 2.06 4.74 7.06 0.0960 0.762 0.336 0.086 14.52 2.46 9.78 2.06 5.31 6.81 0.0960 0.762 0.336 0.086 14.52 2.46 9.78 2.06 3.16 7.77 0.1520 0.724 0.275 0.055 14.52 2.46 9.78 2.06 3.54 7.38 0.1344 0.734 0.291 0.062 14.52 2.46 9.78 2.06 4.30 7.27 0.1200 0.744 0.306 0.07 14.52 2.46 9.78 2.06 4.67 7.03 0.1120 0.749 0.315 0.074 14.52 2.46 9.78 2.06 5.20 7.15 0.1040 0.755 0.325 0.08 14.52 2.46 9.78 2.06 5.17 6.75 0.0960 0.762 0.336 0.086 14.52 2.46 9.78 2.06 3.75 6.79 0.1456 0.728 0.28 0.057 14.34 2.49 9.62 2.09 3.40 . 7.50 0.1376 0.732 0.288 0.061 14.34 2.49 9.62 2.09 4.33 6.97 0.1200 0.744 0.306 0.07 14.34 2.49 9.62 2.09 3.03 7.59 0.1648 0.717 0.265 0.05 14.34 2.49 9.62 2.09 4.71 6.98 0.1024 0.756 0.327 0.081 14.34 2.49 9.62 2.09 4.91 6.39 0.0912 0.766 0.344 0.09 14.34 2.49 9.62 2.09 3.40 6.98 0.1360 0.733 0.289 0.061 14.34 2.49 9.62 2.09 3.42 7.63 0.1536 0.723 0.273 0.054 14.34 2.49 9.62 2.09 4.28 7.00 0.1248 0.74 0.301 0.067 14.34 2.49 9.62 2.09 4.67 7.03 0.1072 0.753 0.321 0.078 14.34 2.49 9.62 2.09 4.72 6.96 0.0960 0.762 0.336 0.086 14.34 2.49 9.62 2.09 5.13 6.77 0.1040 0.755 0.325 0.08 14.34 2.49 9.62 2.09 3.23 6.62 0.1552 0.722 0.272 0.053 14.17 2.53 9.46 2.12 2.99 7.19 0.1712 0.714 0.26 0.048 14.17 2.53 9.46 2.12 4.13 6.66 0.1120 0.749 0.315 0.074 14.17 2.53 9.46 2.12 2.50 7.36 0.2144 0.695 0.233 0.038 14.17 2.53 9.46 2.12 2.87 7.17 0.1600 0.72 0.268 0.052 14.17 2.53 9.46 2.12 4.21 6.43 0.1232 0.741 0.302 0.068 14.17 2.53 9.46 2.12 3.60 6.20 0.1248 0.74 0.301 0.067 14.17 2.53 9.46 2.12 3.15 7.42 0.1680 0.716 0.262 0.049 14.17 2.53 9.46 2.12 4.13 6.68 0.1136 0.748 0.313 0.073 14.17 2.53 9.46 2.12 2.47 7.34 0.2176 0.693 0.231 0.037 14.17 2.53 9.46 2.12 2.86 7.24 0.1840 0.708 0.251 0.045 14.17 2.53 9.46 2.12 4.66 6.39 0.1216 0.743 0.304 0.069 14.17 2.53 9.46 2.12 3.31 7.56 0.1280 0.738 0.297 0.065 14.52 2.46 9.78 2.06 3.44 7.56 0.1248 0.74 0.301 0.067 14.52 2.46 9.78 2.06 4.10 7.43 0.1200 0.744 0.306 0.07 14.52 2.46 9.78 2.06 3.75 7.50 0.1216 0.743 0.304 0.069 14.52 2.46 9.78 2.06 4.72 7.35 0.1040 0.755 0.325 0.08 14.52 2.46 9.78 2.06 5.20 6.90 0.0880 0.768 0.349 0.093 14.52 2.46 9.78 2.06 3.17 7.66 0.1504 0.725 0.276 0.055 14.52 2.46 9.78 2.06 3.11 7.65 0.1536 0.723 0.273 0.054 14.52 2.46 9.78 2.06 3.59 7.48 0.1312 0.736 0.294 0.064 14.52 2.46 9.78 2.06 4.06 7.45 0.1248 0.74 0.301 0.067 14.52 2.46 9.78 2.06 4.76 7.11 0.1056 0.754 0.323 0.079 14.52 2.46 9.78 2.06 4.69 6.23 0.0880 0.768 0.349 0.093 14.52 2.46 9.78 2.06 2.94 7.58 0.1712 0.714 0.26 0.048 14.52 2.46 9.78 2.06 3.12 7.60 0.1600 0.72 0.268 0.052 14.52 2.46 9.78 2.06 3.70 7.49 0.1360 0.733 0.289 0.061 14.52 2.46 9.78 2.06 4.24 7.57 0.1312 0.736 0.294 0.064 14.52 2.46 9.78 2.06 4.52 7.08 0.1136 0.748 0.313 0.073 14.52 2.46 9.78 2.06 4.80 6.52 0.0784 0.777 0.365 0.104 14.52 2.46 9.78 2.06 3.06 7.06 0.1600 0.72 0.268 0.052 14 17 2.53 9.46 2.12 3.33 7.13 0.1360 0.733 0.289 0.061 14 17 2.53 9.46 2.12 4.03 7.13 0.1280 0.738 0.297 0.065 14 17 2.53 9.46 2.12 4.31 6.75 0.1088 0.752 0.319 0.077 14 17 2.53 9.46 2.12 4.46 6.71 0.0992 0.759 0.332 0.084 14 17 2.53 9.46 2.12 4.69 6.17 0.0928 0.764 0.341 0.089 14 17 2.53 9.46 2.12 2.86 7.15 0.1600 0.72 0.268 0.052 14 17 2.53 9.46 2.12 3.21 7.18 0.1440 0.729 0.282 0.058 14 17 2.53 9.46 2.12 4.00 7.18 0.1200 0.744 0.306 0.07 14 17 2.53 9.46 2.12 4.57 6.84 0.1040 0.755 0.325 0.08 14 17 2.53 9.46 2.12 4.62 6.66 0.0944 0.763 0.339 0.088 14 17 2.53 9.46 2.12 4.70 6.19 0.0992 0.759 0.332 0.084 14 17 2.53 9.46 2.12 2.87 7.47 0.1632 0.718 0.266 0.051 14 17 2.53 9.46 2.12 3.19 7.45 0.1456 0.728 0.28 0.057 14 17 2.53 9.46 2.12 3.97 7.28 0.1232 0.741 0.302 0.068 14 17 2.53 9.46 2.12 4.61 6.92 0.1120 0.749 0.315 0.074 14 17 2.53 9.46 2.12 4.66 6.49 0.0912 0.766 0.344 0.09 14 17 2.53 9.46 2.12 4.55 6.06 0.1008 0.758 0.33 0.082 14 17 2.53 9.46 2.12 pKP2 pKP3 pKMgl pKMg2 PKMg3 Mg in Nin P in Mg 2 + @T°C @T°C @T°C @T°C @T°C mol/L mol/L mol/L mol/L 7.25 12.48 0.32 2.78 4.68 4.61E-03 8.03E-02 9.46E-03 4.14E-03 7.25 12.48 0.32 2.78 4.68 2.73E-03 7.62E-02 6.28E-03 2.44E-03 7.25 12.48 0.32 2.78 4.68 1.51E-03 7.40E-02 3.58E-03 1.34E-03 7.25 12.48 0.32 2.78 4.68 1.64E-04 7.32E-02 2.97E-03 1.39E-04 7.25 12.48 0.32 2.78 4.68 1.18E-04 7.06E-02 2.77E-03 9.96E-05 7.25 12.48 0.32 2.78 4.68 3.35E-05 6.45E-02 2.51E-03 2.84E-05 7.25 12.48 0.32 2.78 4.68 9.61E-03 8.27E-02 1.46E-02 8.86E-03 7.25 12.48 0.32 2.78 4.68 2.95E-03 3.76E-02 5.10E-03 2.66E-03 7.25 12.48 0.32 2.78 4.68 4.23E-04 7.20E-02 2.86E-03 3.73E-04 7.25 12.48 0.32 2.78 4.68 1.56E-04 7.03E-02 2.76E-03 1.35E-04 7.25 12.48 0.32 2.78 4.68 4.47E-05 6.80E-02 2.65E-03 3.82E-05 7.25 12.48 0.32 2.78 4.68 4.87E-05 5.85E-02 2.42E-03 4.16E-05 7.23 12.43 0.36 2.83 4.72 1.73E-03 6.92E-02 2.79E-03 1.55E-03 7.23 12.43 0.36 2.83 4.72 4.13E-03 8.53E-02 7.04E-03 3.72E-03 7.23 12.43 0.36 2.83 4.72 3.70E-04 7.03E-02 2.56E-03 3.23E-04 7.23 12.43 0.36 2.83 4.72 ' 1.35E-02 1.10E-01 1.32E-02 1.24E-02 7.23 12.43 0.36 2.83 4.72 1.36E-04 6.56E-02 2.45E-03 1.17E-04 7.23 12.43 0.36 2.83 4.72 8.08E-05 6.46E-02 2.33E-03 6.79E-05 7.23 12.43 0.36 2.83 4.72 3.55E-03 7.20E-02 4.40E-03 3.15E-03 7.23 12.43 0.36 2.83 4.72 5.63E-03 9.03E-02 7.08E-03 5.20E-03 7.23 12.43 0.36 2.83 4.72 4.23E-04 7.15E-02 2.63E-03 3.71E-04 7.23 12.43 0.36 2.83 4.72 1.56E-04 7.03E-02 2.44E-03 1.35E-04 7.23 12.43 0.36 2.83 4.72 1.27E-04 7.00E-02 2.43E-03 1.08E-04 7.23 12.43 0.36. 2.83 4.72 4.87E-05 6.56E-02 2.58E-03 4.10E-05 7.21 12.39 0.41 2.87 4.76 1.35E-03 7.87E-02 2.22E-02 7.50E-04 7.21 12.39 0.41 2.87 4.76 8.57E-03 9.83E-02 1.20E-02 7.50E-03 7.21 12.39 0.41 2.87 4.76 3.60E-04 8.85E-02 3.88E-03 2.85E-04 7.21 12.39 0.41 2.87 4.76 3.34E-02 1.19E-01 4.01E-02 2.96E-02 7.21 12.39 0.41 2.87 4.76 1.04E-02 1.02E-01 1.52E-02 8.93E-03 7.21 12.39 0.41 2.87 4.76 3.04E-04 7.87E-02 3.96E-03 2.42E-04 7.21 12.39 0.41 2.87 4.76 4.55E-04 7.68E-02 2.09E-02 2.00E-04 7.21 12.39 0.41 2.87 4.76 6.90E-03 9.56E-02 1.13E-02 6.15E-03 7.21 12.39 0.41 2.87 4.76 1.25E-03 8.63E-02 1.00E-03 1.18E-03 7.21 12.39 0.41 2.87 4.76 3.67E-02 1.26E-01 4.17E-02 3.26E-02 7.21 12.39 0.41 2.87 4.76 1.32E-02 1.03E-01 1.50E-02 1.17E-02 7.21 12.39 0.41 2.87 4.76 4.07E-04 7.34E-02 8.60E-04 3.85E-04 7.25 12.48 0.32 2.78 4.68 4.86E-03 7.39E-02 9.54E-03 4.35E-03 7.25 12.48 0.32 2.78 4.68 3.57E-03 7.25E-02 7.60E-03 3.20E-03 7.25 12.48 0.32 2.78 4.68 6.48E-04 7.02E-02 3.56E-03 5.68E-04 7.25 12.48 0.32 2.78 4.68 1.58E-03 7.13E-02 4.87E-03 1.40E-03 7.25 12.48 0.32 2.78 4.68 1.32E--04 6.83E-02 2.89E-03 1.13E-04 7.25 12.48 0.32 2.78 4.68 3.76E-•05 5.99E-02 2.83E-03 3.11E-05 7.25 12.48 0.32 2.78 4.68 8.69E--03 7.91E-02 1.27E-02 7.96E-03 7.25 12.48 0.32 2.78 4.68 1.01E--02 8.07E-02 1.39E-02 9.31E-03 7.25 12.48 0.32 2.78 4.68 2.46E -03 7.28E-02 5.69E-03 2.20E-03 7.25 12.48 0.32 2.78 4.68 7.82E -04 7.10E-02 3.46E-03 6.94E-04 7.25 12.48 0.32 2.78 4.68 1.20E -04 6.76E-02 2.83E-03 1.03E-04 7.25 12.48 0.32 2.78 4.68 1.17E -04 5.43E-02 2.89E-03 9.64E-05 7.25 12.48 0.32 2.78 4.68 1.42E -02 8.62E-02 1.94E-02 1.29E-02 7.25 12.48 0.32 2.78 4.68 8.59E--03 8.48E-02 1.48E-02 7.78E-03 7.25 12.48 0.32 2.78 4.68 1.87E--03 5.52E-02 5.26E-03 1.67E-03 7.25 12.48 0.32 2.78 4.68 5.11E--04 7.21E-02 3.43E-03 4.54E-04 7.25 12.48 0.32 2.78 4.68 2.07E--04 6.67E-02 3.11E-03 1.77E-04 7.25 12.48 0.32 2.78 4.68 8.23E--05 3.68E-02 3.00E-03 6.62E-05 7.21 12.39 0.41 2.87 4.76 6.23E--03 5.90E-02 9.95E-03 5.33E-03 7.21 12.39- 0.41 2.87 4.76 3.23E--03 6.22E-02 6.68E-03 2.76E-03 7.21 12.39 0.41 2.87 4.76 6.20E--04 5.95E-02 3.56E-03 5.25E-04 7.21 12.39 0.41 2.87 4.76 2.74E--04 5.37E-02 3.15E-03 2.24E-04 7.21 12.39 0.41 2.87 4.76 1.79E--04 5.79E-02 3.12E-03 1.44E-04 7.21 12.39 0.41 2.87 4.76 1.01E-•04 5.66E-02 3.02E-03 8.00E-05 7.21 12.39 0.41 2.87 4.76 1.11E--02 5.95E-02 1.46E-02 9.68E-03 7.21 12.39 0.41 2.87 4.76 4.60E-•03 6.39E-02 8.25E-03 3.97E-03 7.21 12.39 0.41 2.87 4.76 6.51E--04 6.07E-02 3.53E-03 5.51E-04 7.21 12.39 0.41 2.87 4.76 1.47E-•04 5.93E-02 3.06E-03 1.19E-04 7.21 12.39 0.41 2.87 4.76 1.19E--04 5.84E-02 3.10E-03 9.43E-05 7.21 12.39 0.41 2.87 4.76 1.03E-•04 5.41E-02 3.02E-03 8.20E-05 7.21 12.39 0.41 2.87 4.76 1.46E--02 7.06E-02 1.91E-02 1.31E-02 7.21 12.39 0.41 2.87 4.76 6.09E-•03 6.56E-02 1.01E-02 5.42E-03 7.21 12.39 0.41 2.87 4.76 7.36E--04 6.27E-02 3.71E-03 6.29E-04 7.21 12.39 0.41 2.87 4.76 1.38E-•04 6.12E-02 3.09E-03 1.13E-04 7.21 12.39 0.41 2.87 4.76 1.05E--04 5.76E-02 3.08E-03 8.32E-05 7.21 12.39 0.41 2.87 4.76 1.45E-•04 5.15E-02 3.07E-03 1.16E-04 134 N H 4 + P0 4 3" H + OH- M g O H + N H 3 ( a q ) H3PO4 H 2 P C V HP0 42 " mol/L mol/L mol/L mol/L mol/L' mol/L mol/L mol/L mol/L 8.03E-02 8.74E-09 5.86E-07 9.75E-09 3.27E-09 2.26E-05 2.36E-07 6.68E-03 2.30E-03 7.61E-02 1.57E-08 3.12E-07 1.80E-08 3.68E-09 4.01E-05 7.05E-08 3.68E-03 2.31E-03 7.38E-02 5.40E-08 8.72E-08 6.34E-08 7.35E-09 1.39E-04 5.86E-09 1.08E-03 2.33E-03 7.21E-02 4.58E-07 1.07E-08 4.93E-07 6.43E-09 1.10E-03 1.20E-10 1.72E-04 2.77E-03 6.90E-02 6.37E-07 7.05E-09 7.41E-07 7.14E-09 1.61E-03 5.13E-11 1.10E-04 2.64E-03 5.59E-02 3.97E-06 1.07E-09 4.90E-06 1.35E-08 8.62E-03 1.11E-12 1.57E-05 2.49E-03 8.27E-02 2.65E-09 1.48E-06 3.91E-09 2.74E-09 9.19E-06 1.08E-06 1.22E-02 1.70E-03 3.75E-02 1.81E-08 2.48E-07 2.27E-08 5.04E-09 2.49E-05 4.09E-08 2.69E-03 2.12E-03 7.17E-02 1.42E-07 3.30E-08 1.66E-07 5.44E-09 3.57E-04 8.79E-10 4.23E-04 2.38E-03 6.89E-02 6.12E-07 8.04E-09 6.71E-07 8.22E-09 1.41E-03 6.00E-11 1.17E-04 2.62E-03 6.46E-02 1.50E-06 3.10E-09 1.71E-06 6.13E-09 3.42E-03 9.28E-12 4.61E-05 2.59E-03 5.20E-02 3.10E-06 1.31E-09 3.98E-06 1.60E-08 6.52E-03 1.61E-12 1.86E-05 2.39E-03 6.88E-02 1 23E-07 4 35E-08 1 99E-07 2 70E-08 3 83E-04 1 26E-09 4 47E-04 2 16E-03 8.53E-02 9 32E-09 4 96E-07 1 72E-08 5 74E-09 4 15E-05 1 53E-07 4 69E-03 1 94E-03 6.93E-02 2 97E-07 1 69E-08 4 89E-07 1 50E-08 9 88E-04 2 33E-10 2 03E-04 2 31E-03 1.09E-01 2 98E-09 1 46E-06 6 09E-09 6 25E-09 1 81E-05 9 70E-07 1 05E-02 1 61E-03 6.35E-02 6 46E-07 7 10E-09 1 13E-06 1 34E-08 2 16E-03 4 59E-11 9 21E-05 2 33E-03 5.33E-02 3 70E-06 1 14E-09 6 86E-06 4 99E-08 1 13E-02 1 25E-12 1 53E-05 2 30E-03 7.19E-02 3 53E-08 1 53E-07 5 56E-08 1 58E-08 1 14E-04 1 73E-08 1 71E-03 2 28E-03 9.03E-02 5 86E-09 6 47E-07 1 35E-08 6 00E-09 3 37E-05 1 83E-07 4 42E-03 1 47E-03 7.07E-02 2 55E-07 2 04E-08 4 08E-07 1 42E-08 8 35E-04 3 34E-10 2 43E-04 2 33E-03 6.85E-02 5 32E-07 8 78E-09 9 20E-07 1 24E-08 1 88E-03 6 73E-11 1 10E-04 2 31E-03 6.75E-02 6 66E-07 6 58E-09 1 20E-06 1 36E-08 2 48E-03 4 09E-11 8 73E-05 2 32E-03 5.73E-02 3 03E-06 1 67E-09 4 81E-06 2 00E-08 8 31E-03 2 73E-12 2 34E-05 2 55E-03 7.84E-02 3 77E-07 1 10E-07 1 19E-07 8 16E-09 2 50E-04 5 37E-08 7 11E-03 1 45E-02 9.82E-02 1 20E-08 7 02E-07 1 90E-08 1 25E-08 4 90E-05 3 86E-07 8 19E-03 2 74E-03 8.64E-02 5 69E-07 1 43E-08 8 48E-07 2 57E-08 2 12E-03 2 77E-10 2 62E-04 3 54E-03 1.19E-01 2 93E-09 3 30E-06 4 28E-09 9 93E-09 1 27E-05 7 06E-06 3 37E-02 2 67E-03 1.02E-01 9 49E-09 8 77E-07 1 50E-08 1 21E-08 4 07E-05 6 56E-07 1 10E-02 2 85E-03 7.50E-02 1 30E-06 7 08E-09 1 75E-06 4 31E-08 3 71E-03 6 77E-11 1 32E-04 3 77E-03 7.53E-02 2 70E-06 1 74E-08 7 14E-07 1 44E-08 1 52E-03 2 05E-09- 1 63E-03 1 90E-02 9.56E-02 8 23E-09 8 42E-07 1 58E-08 8 58E-09 3 97E-05 4 71E-07 8 28E-03 2 29E-03 8.43E-02 1 33E-07 1 50E-08 8 11E-07 1 01E-07 1 97E-03 7 34E-11 6 64E-05 8 62E-04 1.26E-01 2 81E-09 3 46E-06 4 09E-09 1 04E-08 1 27E-05 7 65E-06 3 49E-02 2 66E-03 1.03E-01 7 56E-09 1 07E-06 1 27E-08 1 26E-08 3 38E-05 7 83E-07 1 11E-02 2 51E-03 6.36E-02 8 76E-07 2 29E-09 5 40E-06 2 13E-07 9 74E-03 1 57E-12 9 43E-06 8 27E-04 7.39E-02 6 78E-09 6 34E-07 8 77E-09 3 26E-09 1 92E-05 2 73E-07 6 94E-03 2 09E-03 7.24E-02 8 95E-09 4 68E-07 1 18E-08 3 26E-09 2 54E-05 1 50E-07 5 15E-03 2 08E-03 7.00E-02 6 42E-08 7 56E-08 7 .25E-08 3 .62E-09 1 52E-04 4 79E-09 1 .01E-03 2 .47E-03 7.12E-02 2 26E-08 1 .99E-07 2 .76E-08 3 .37E-09 5 .88E-05 3 03E-08 2 .42E-03 2 .27E-03 135 6 . 7 5 E - 0 2 3 1 9 E - 0 7 1 4 9 E - 0 8 3 5 8 E - 0 7 3 7 9 E - 0 9 7 4 8 E - 0 4 2 1 7 E - 1 0 2 2 5 E - 0 4 2 6 5 E - - 0 3 5 . 4 7 E - 0 2 2 6 2 E - 0 6 1 7 2 E - 0 9 2 9 9 E - 0 6 9 3 3 E - 0 9 5 2 4 E - 0 3 3 3 8 E - 1 2 2 9 3 E - 0 5 2 7 9 E - 0 3 7 . 9 1 E - - 0 2 3 7 8 E - 0 9 1 1 2 E - 0 6 5 1 4 E - 0 9 3 2 5 E - - 0 9 1 1 6 E - 0 5 6 7 7 E - 0 7 1 0 1 E - - 0 2 1 8 5 E - - 0 3 8 . 0 7 E - - 0 2 3 4 2 E - 0 9 1 2 6 E - 0 6 4 5 9 E - 0 9 3 3 7 E - - 0 9 1 0 5 E - • 0 5 8 4 4 E - 0 7 1 1 3 E - • 0 2 1 8 5 E - - 0 3 7 . 2 8 E - - 0 2 1 6 8 E - 0 8 2 7 7 E - 0 7 2 0 2 E - 0 8 3 7 6 E - - 0 9 4 3 2 E - • 0 5 5 4 7 E - 0 8 3 2 0 E - - 0 3 2 2 3 E - - 0 3 7 . 0 9 E - - 0 2 ' 5 3 4 E - 0 8 8 7 2 E - 0 8 6 3 4 E - 0 8 3 8 0 E - - 0 9 1 3 4 E - - 0 4 5 7 9 E - 0 9 1 0 6 E - • 0 3 2 3 1 E - - 0 3 6 . 6 2 E - - 0 2 6 2 3 E - 0 7 7 8 1 E - 0 9 6 8 3 E - 0 7 6 5 1 E - • 0 9 1 3 9 E - • 0 3 6 0 4 E - • 1 1 1 2 0 E - • 0 4 2 6 9 E - • 0 3 4 . 7 5 E - - 0 2 3 9 6 E - 0 6 1 1 6 E - 0 9 4 4 2 E - 0 6 4 2 8 E - - 0 8 6 7 4 E - • 0 3 1 5 8 E - - 1 2 2 0 3 E - • 0 5 2 8 5 E - - 0 3 8 . 6 2 E - - 0 2 3 3 9 E - 0 9 1 6 1 E - 0 6 3 7 0 E - 0 9 3 5 8 E - • 0 9 8 8 1 E - • 0 6 1 4 9 E - • 0 6 1 6 0 E - • 0 2 2 1 7 E - • 0 3 8 . 4 8 E - - 0 2 4 8 7 E - 0 9 1 1 0 E - 0 6 5 3 0 E - 0 9 3 1 8 E - - 0 9 1 2 6 E - • 0 5 7 6 1 E - • 0 7 1 1 7 E - • 0 2 2 2 5 E - - 0 3 5 . 5 2 E - - 0 2 2 3 0 E - 0 8 2 2 1 E - 0 7 2 5 5 E - 0 8 3 5 3 E - • 0 9 4 1 0 E - • 0 5 3 6 2 E - • 0 8 2 6 8 E - • 0 3 2 3 8 E - • 0 3 7 . 2 0 E - - 0 2 6 6 1 E - 0 8 7 6 4 E - 0 8 7 3 2 E - 0 8 2 8 1 E - - 0 9 1 5 5 E - • 0 4 4 5 0 E - • 0 9 9 5 6 E - • 0 4 2 4 2 E - - 0 3 6 . 5 9 E - • 0 2 4 2 7 E - 0 7 1 2 8 E - 0 8 4 2 4 E - 0 7 6 7 6 E - • 0 9 8 4 9 E - • 0 4 1 6 4 E - • 1 0 2 0 2 E - • 0 4 2 8 7 E - • 0 3 3 . 3 7 E - • 0 2 2 5 0 E - 0 6 1 7 8 E - 0 9 2 8 2 E - 0 6 1 9 6 E - - 0 8 3 1 2 E - • 0 3 4 1 0 E - • 1 2 3 3 6 E - • 0 5 2 9 4 E - - 0 3 5 . 9 0 E - • 0 2 2 0 5 E - 0 8 4 3 9 E - 0 7 2 9 9 E - 0 8 1 4 4 E - • 0 8 4 7 0 E - • 0 5 1 7 9 E - • 0 7 5 9 6 E - • 0 3 3 0 9 E - • 0 3 6 . 2 1 E - • 0 2 2 6 0 E - 0 8 2 7 2 E - 0 7 4 6 5 E - 0 8 1 2 5 E - - 0 8 7 9 9 E - • 0 5 6 7 4 E - • 0 8 3 5 0 E - • 0 3 2 7 1 E - - 0 3 5 . 9 1 E - • 0 2 1 2 7 E - 0 7 5 3 9 E - 0 8 2 3 2 E - 0 7 1 2 2 E - • 0 8 3 8 4 E - - 0 4 2 7 9 E - • 0 9 7 2 0 E - • 0 4 2 7 4 E - • 0 3 5 . 2 1 E - • 0 2 5 6 8 E - 0 7 1 1 6 E - 0 8 1 0 4 E - 0 6 2 5 1 E - - 0 8 1 5 7 E - • 0 3 1 5 3 E - • 1 0 1 7 7 E - • 0 4 2 9 2 E - - 0 3 5 . 5 3 E - • 0 2 8 4 9 E - 0 7 7 4 1 E - 0 9 1 6 0 E - 0 6 2 5 7 E - • 0 8 2 6 1 E - - 0 3 6 7 1 E - • 1 1 1 1 9 E - • 0 4 2 9 6 E - • 0 3 4 . 4 2 E - 0 2 4 8 5 E - 0 6 1 2 5 E - 0 9 9 3 3 E - 0 6 8 5 8 E - • 0 8 1 2 4 E - • 0 2 2 0 0 E - • 1 2 2 0 8 E - - 0 5 2 9 7 E - 0 3 5 . 9 5 E - 0 2 9 0 3 E - 0 9 8 7 7 E - 0 7 1 5 0 E - 0 8 1 3 1 E - • 0 8 2 3 8 E - - 0 5 6 2 5 E - • 0 7 1 0 4 E - - 0 2 2 7 1 E - • 0 3 6 . 3 8 E - - 0 2 1 7 8 E - 0 8 4 0 5 E - 0 7 3 1 7 E - 0 8 1 1 9 E - • 0 8 5 5 2 E - • 0 5 1 4 1 E - • 0 7 4 9 6 E - - 0 3 2 6 5 E - • 0 3 6 . 0 4 E - 0 2 9 6 9 E - 0 8 6 4 4 E - 0 8 1 9 1 E - 0 7 1 0 9 E - • 0 8 3 2 9 E - - 0 4 3 9 3 E - • 0 9 8 3 8 E - - 0 4 2 6 0 E - • 0 3 5 . 6 9 E - 0 2 7 9 9 E - 0 7 7 9 8 E - 0 9 1 5 0 E - 0 6 1 9 6 E - • 0 8 2 4 9 E - • 0 3 7 4 3 E - • 1 1 1 2 4 E - - 0 4 2 9 1 E - • 0 3 5 . 4 2 E - 0 2 1 3 6 E - 0 6 4 5 4 E - 0 9 2 5 7 E - 0 6 2 7 7 E - • 0 8 4 1 8 E - - 0 3 2 6 4 E - • 1 1 7 5 6 E - • 0 5 3 0 0 E - • 0 3 4 . 2 5 E - 0 2 4 9 0 E - 0 6 1 2 9 E - 0 9 9 1 8 E - 0 6 8 4 2 E - • 0 8 1 1 6 E - • 0 2 2 0 3 E - • 1 2 2 0 8 E - - 0 5 2 9 7 E - • 0 3 7 . 0 6 E - 0 2 3 2 9 E - 0 9 1 7 9 E - 0 6 7 3 6 E - 0 9 8 6 2 E - • 0 9 1 3 8 E - - 0 5 1 9 0 E - • 0 6 1 5 6 E - - 0 2 1 9 9 E - • 0 3 6 . 5 5 E - 0 2 7 0 6 E - 0 9 7 9 1 E - 0 7 1 6 3 E - 0 8 8 3 2 E - 0 9 2 9 0 E - - 0 5 4 0 9 E - • 0 7 7 4 1 E - 0 3 2 0 4 E - 0 3 6 . 2 4 E - 0 2 7 0 6 E - 0 8 8 7 1 E - 0 8 1 4 2 E - 0 7 9 H E - 0 9 2 5 1 E - 0 4 6 8 4 E - • 0 9 1 0 9 E - 0 3 2 5 2 E - 0 3 5 . 8 8 E - 0 2 7 8 1 E - 0 7 8 6 2 E - 0 9 1 4 1 E - 0 6 1 6 9 E - 0 8 2 3 9 E • 0 3 8 3 2 E - - 1 1 1 3 1 E - 0 4 2 9 3 E - 0 3 5 . H E - 0 2 2 1 7 E - 0 6 2 7 9 E - 0 9 4 1 6 E - 0 6 4 0 1 E - • 0 8 6 4 1 E - - 0 3 1 0 2 E - - 1 1 4 7 3 E - 0 5 3 0 1 E - 0 3 4 . 0 9 E - 0 2 4 7 9 E - 0 6 1 3 5 E - 0 9 8 7 8 E - 0 6 1 1 3 E - 0 7 1 0 6 E - - 0 2 2 2 5 E - - 1 2 2 2 0 E - 0 5 3 0 2 E - - 0 3 136 MgH 2P0 4 + MgHP04 MgP04" AMg AN A P pKsp mol/L mol/L mol/L mg/L mg/L mg/L @T°C 1.62E-05 4 57E-04 3 86E-08 -2.00E-08 -3.89E-13 -5.78E-07 13 46 5.43E-06 2 88E-04 4 49E-08 -1.61E-08 -7.78E-13 -4.91E-07 13 41 9.03E-07 1 71E-04 9 40E-08 -1.91E-08 3.89E-13 -5.87E-07 13 10 1.62E-08 2 49E-05 1 06E-07 -7.84E-10 0.00E+00 -1.37E-07 13 04 7.68E-09 1 80E-05 1 16E-07 1.46E-09 0.00E+00 3.28E-07 13 01 3.13E-10 4 85E-06 2 06E-07 -5.99E-07 -1.94E-13 -1.15E-07 12 86 6.17E-05 6 90E-04 2 33E-08 -2.07E-09 0.00E+00 -5.57E-08 13 67 4.32E-06 2 88E-04 5 67E-08 -2.42E-08 -3.89E-13 -5.98E-07 13 62 1.00E-07 5 03E-05 7 23E-08 -4.16E-09 0.00E+00 -3.48E-07 13 22 1.03E-08 2 13E-05 1 24E-07 -1.48E-07 -3.89E-13 -2.56E-08 13 00 1.19E-09 6 35E-06 9 42E-08 -3.85E-07 3.89E-13 -7.07E-08 13 14 5.40E-10 6 81E-06 2 35E-07 -8.23E-16 -3.76E-07 1.61E-13 12 83 4.49E-07 1 77E-04 2 22E-07 -1.53E-08 -3.89E-13 -3.44E-07 12 81 1.16E-05 4 00E-04 4 34E-08 6.48E-07 5.83E-13 7.83E-08 13 42 4.63E-08 4 67E-05 1 44E-07 -2.64E-15 1.20E-07 -5.37E-14 12 98 8.01E-05 9 37E-04 3 61E-08 -1.18E-08 5.83E-13 -2.11E-07 13 41 8.13E-09 1 96E-05 1 39E-07 -2.64E-15 -7.79E-07 -2.15E-13 13 02 8.23E-10 1 24E-05 5 36E-07 -6.49E-07 -1.94E-13 -1.31E-07 12 50 3.60E-06 4 02E-04 1 41E-07 -5.66E-08 0.00E+00 -8.99E-07 12 98 1.45E-05 3 84E-04 3 28E-08 -7.19E-01 3.15E-02 -2.45E+01 13 53 6.26E-08 5 24E-05 1 35E-07 -1.19E-14 -2.40E-07 -1.34E-13 13 00 1.10E-08 2 15E-05 1 25E-07 -1.28E-09 0.00E+00 -2.10E-07 13 04 7.31E-09 1 90E-05 1 44E-07 1.21E-09 1.94E-13 2.30E-07 12 97 7.22E-10 7 40E-06 2 25E-07 6.08E-10 -3.89E-13 3.06E-07 12 85 3.71E-06 5 95E-04 3 29E-07 -6.81E-07 1.94E-13 -3.78E-07 12 63 4.08E-05 1 03E-03 9 09E-08 -3.12E-08 0.00E+00 -5.09E-07 13 10 6.01E-08 7 41E-05 2 93E-07 5.27E-15 -1.49E-07 -1.34E-13 12 61 5.93E-04 3 17E-03 6 32E-08 -3.08E-08 -1.94E-13 -4.78E-07 13 20 6.72E-05 1 35E-03 9 44E-08 -2.12E-08 -3.89E-13 -3.39E-07 13 06 2.47E-08 6 16E-05 5 02E-07 7.00E-09 3.89E-13 6.98E-07 12 45 2.50E-07 2 54E-04 8 44E-07 -5.16E-07 -1.94E-13 -3.67E-07 12 22 3.42E-05 7 16E-04 5 26E-08 -2.29E-08 0.00E+00 -4.98E-07 13 35 6.26E-08 7 37E-05 2 78E-07 -1.21E-08 1.94E-13 -2.23E-07 12 64 6.72E-04 3 43E-03 6 53E-08 -1.52E-08 -3.89E-13 -2.21E-07 13 17 8.33E-05 1 37E-03 8 10E-08 -8.72E-09 1.94E-13. -1.29E-07 13 14 2.82E-09 2 17E-05 5 47E-07 -1.34E-08 1.94E-13 -6.94E-07 12 48 1.87E-05 4 87E-04 3 70E-08 -2.78E-09 1.94E-13 -7.46E-08 13 51 1.03E-05 3 63E-04 3 71E-08 -6.82E-09 -3.89E-13 -2.01E-07 13 51 3.64E-07 7 95E-05 4 99E-08 -3.66E-09 0.00E+00 -2.36E-07 13 39 2.14E-06 1 78E-04 4 25E-08 -2.54E-09 0.00E+00 -9.86E-08 13 46 1 . 7 3 E • 0 8 1 9 2 E - 0 5 5 9 5 E - 0 8 - 5 . 2 7 E - 0 7 5 . 8 3 E - 1 3 - 9 . 6 9 E - 0 8 1 3 3 2 6 . 6 1 E • 1 0 6 3 8 E - 0 6 1 6 5 E - 0 7 - 3 . 3 6 E - 0 7 - 1 . 9 4 E - 1 3 - 7 . 4 2 E - 0 8 1 2 9 5 4 . 6 1 E • 0 5 6 8 1 E - 0 4 3 0 3 E - 0 8 - 1 . 7 8 E - 0 8 0 . 0 0 E + 0 0 - 4 . 3 3 E - 0 7 1 3 5 8 5 . 9 6 E • 0 5 7 8 1 E - 0 4 3 H E - 0 8 - 2 . 3 9 E - 0 9 3 . 8 9 E - 1 3 - 5 . 4 9 E - 0 8 1 3 5 6 4 . 3 0 E - 0 6 2 5 7 E - 0 4 4 4 8 E - 0 8 - 1 . 0 4 E - 0 8 - 1 . 9 4 E - 1 3 - 3 . 2 4 E - 0 7 1 3 4 3 4 . 6 2 E • 0 7 8 7 6 E - 0 5 4 8 1 E - 0 8 - 6 . 8 4 E - 0 9 - 7 . 7 8 E - 1 3 - 3 . 8 2 E - 0 7 1 3 4 1 8 . 2 5 E - 0 9 1 7 5 E - 0 5 1 0 3 E - 0 7 - 5 . 9 8 E - 0 7 - 1 . 9 4 E - 1 3 - 1 . 1 1 E - 0 7 1 3 0 9 1 . 4 2 E • 0 9 2 0 2 E - 0 5 7 7 4 E - 0 7 - 1 . 5 1 E - 0 9 2 . 9 2 E - 1 3 - 3 . 1 5 E - 0 7 1 2 3 4 1 . 1 2 E - 0 4 1 1 5 E - 0 3 3 6 7 E - 0 8 - 1 . 8 5 E - 0 8 1 . 9 4 E - 1 3 - 3 . 9 9 E - 0 7 1 3 4 7 5 . 0 8 E - 0 5 7 6 1 E - 0 4 3 5 0 E - 0 8 - 6 . 2 8 E - 0 9 1 . 9 4 E - 1 3 - 1 . 6 2 E - 0 7 1 3 4 9 2 . 6 8 E - 0 6 2 0 1 E - 0 4 4 4 3 E - 0 8 - 1 . 3 2 E - 0 8 9 . 7 2 E - 1 4 - 4 . 9 0 E - 0 7 1 3 5 6 2 . 6 5 E - - 0 7 5 7 4 E - 0 5 3 6 4 E - 0 8 - 4 . 6 8 E - 0 7 - 1 . 9 4 E - 1 3 - 6 . 6 2 E - 0 8 1 3 5 3 2 . 3 3 E - - 0 8 3 0 2 E - 0 5 1 H E - 0 7 - 7 . 4 8 E - 0 7 1 . 9 4 E - 1 3 - 1 . 3 8 E - 0 7 1 3 0 7 1 . 6 9 E - • 0 9 . 1 5 7 E - 0 5 3 8 5 E - 0 7 - 4 . 0 4 E - 0 7 - 9 . 7 2 E - 1 4 - 1 . 0 0 E - 0 7 1 2 7 9 2 . 1 8 E - - 0 5 8 7 5 E - - 0 4 1 2 2 E - - 0 7 - 3 . 6 6 E - 0 8 9 . 7 2 E - 1 4 - 6 . 0 8 E - 0 7 1 3 1 9 7 . 1 4 E - • 0 6 4 6 3 E - - 0 4 1 0 0 E - - 0 7 - 4 . 0 8 E - 0 8 1 . 9 4 E - 1 3 - 8 . 7 1 E - 0 7 1 3 2 4 2 . 8 7 E - • 0 7 9 4 0 E - 0 5 1 0 1 E - 0 7 2 . 1 1 E - 1 4 9 . 1 1 E - 0 7 1 . 0 7 E - 1 3 1 3 2 5 3 . 2 4 E - • 0 8 4 9 3 E - 0 5 2 3 9 E - 0 7 - 1 . 3 2 E - 0 9 2 . 9 2 E - 1 3 - 1 . 3 1 E - 0 7 1 2 9 1 1 . 4 6 E - • 0 8 3 4 8 E - 0 5 2 5 9 E - • 0 7 - 3 . 6 9 E - 0 9 1 . 9 4 E - 1 3 - 5 . 3 3 E - 0 7 1 2 8 5 1 . 4 5 E - • 0 9 2 0 5 E - - 0 5 8 8 9 E - - 0 7 1 . 9 4 E - 0 9 - 9 . 7 2 E - 1 4 4 . 2 5 E - 0 7 1 2 4 0 6 . 9 4 E - - 0 5 1 4 0 E - - 0 3 9 7 5 E - - 0 8 - 3 . 9 6 E - 0 8 1 . 9 4 E - 1 3 - 5 . 8 4 E - 0 7 1 3 2 8 1 . 4 2 E - • 0 5 6 1 7 E - - 0 4 9 1 0 E - - 0 8 - 2 . 5 9 E - 0 8 - 1 . 9 4 E - 1 3 - 5 . 1 2 E - 0 7 1 3 2 7 3 . 6 1 E - • 0 7 9 8 9 E - • 0 5 8 8 1 E - - 0 8 - 5 . 2 7 E - 1 5 - 5 . 4 9 E - 0 7 - 2 . 2 8 E - 1 3 1 3 2 9 1 . 2 3 E - • 0 8 2 7 2 E - - 0 5 1 8 9 E - - 0 7 - 1 . 3 2 E - 1 5 - 1 . 3 5 E - 0 7 5 . 3 7 E - 1 4 1 2 9 7 6 . 1 7 E - • 0 9 2 4 0 E - - 0 5 2 8 7 E - • 0 7 - 4 . 8 3 E - 0 7 9 . 7 2 E - 1 4 - 1 . 2 5 E - 0 7 1 2 8 0 1 . 4 5 E - • 0 9 1 9 8 E - 0 5 8 4 8 E - - 0 7 - 9 . 7 2 E - 0 7 0 . 0 0 E + 0 0 - 2 . 4 7 E - 0 7 1 2 4 4 1 . 3 8 E - • 0 4 1 3 6 E - 0 3 4 6 7 E - - 0 8 - 2 . 9 8 E - 0 9 1 . 9 4 E - 1 3 - 5 . 3 6 E - 0 8 1 3 5 3 2 . 8 7 E - • 0 5 6 4 1 E - - 0 4 4 8 6 E - - 0 8 - 2 . 0 2 E - 0 8 1 . 9 4 E - 1 3 - 4 . 3 5 E - 0 7 1 3 5 3 5 . 2 7 E - • 0 7 1 0 7 E - - 0 4 7 0 7 E - - 0 8 - 2 . 6 5 E - 0 7 - 5 . 8 3 E - 1 3 - 4 . 7 8 E - 0 8 1 3 3 8 1 . 1 9 E - • 0 8 2 4 4 E - • 0 5 1 6 0 E - - 0 7 - 8 . 5 2 E - 0 7 - 2 . 9 2 E - 1 3 - 1 . 9 2 E - 0 7 1 3 0 4 3 . 4 5 E - • 0 9 2 1 8 E - • 0 5 4 2 3 E - - 0 7 1 . 9 5 E - 0 9 - 3 . 8 9 E - 1 3 4 . 1 7 E - 0 7 1 2 6 6 2 . 1 5 E - 0 9 2 8 0 E - • 0 5 1 1 5 E - • 0 6 - 1 . 3 1 E - 1 1 0 . 0 0 E + 0 0 - 2 . 2 0 E - 0 9 1 2 3 3 APPENDIX E OPERATING DATA FOR REACTOR A Synthetic Supernatant Date Influent Lab Results Effluent Lab Results PO4-P NH4 .N Mg PO4-P NH4.N Mg pH T© (mg/L) (mg/L) (mg/L) (mg/L) (mg/L) (mg/L) Start 20-Jun-02 165.5 736.4 994.3 37.3 598.5 27.3 7.2 20 21-Jun-02 165.5 736.4 994.3 1 30.6 560.0 49.2 7.2 19 22-Jun-02 165.5 736.4 994.3 19.4 529.6 185.4 7.2 20 23-Jun-02 161.5 759.5 1059.4 30.8 658.2 45.2 7.2 20 24-Jun-02 161.5 759.5 1059.4 28.5 618.0 46.1 7.2 20 25-Jun-02 163.0 734.0 996.7 23.5 548.8 83.9 7.2 20 26-Jun-02 Plug 27-Jun-02 160.9 769.0 1058.5 28.4 638.5 57.2 7.2 21 28-Jun-02 162.9 730.3 910.8 37.3 608.3 36.8 7.2 15 29-Jun-02 162,9 730.3 916.7 46.0 596.4 30.1 7.2 15 30-Jun-02 159.3 732.5 920.1 30.5 600.3 51.2 7.2 16 l-Jul-02 158.9 729.2 917.3 29.6 585.5 48.6 7.2 17 2-Jul-02 Plug 3-Jul-02 173.8 750.4 865.4 17.5 569.7 118.8 7.2 15 4-Jul-02 165.3 776.0 868.6 20.1 613.4 44.3 7.4 15 5-Jul-02 167.7 773.1 885.3 25.5 629.4 36.7 7.3 17 6-Jul-02 188.2 923.7 885.3 31.5 769.2 13.4 7.3 18 7-Jul-02 Plug 8-Jul-02 139.6 786.8 889.7 33.7 623.1 56.4 7.2 16 9-Jul-02 140.0 792.3 889.7 27.1 605.4 54.7 7.2 16 10-Jul-02 117.8 631.9 878.0 31.8 534.6 76.7 7.2 15 ll-Jul-02 118.4 701.4 866.8 23.4 586.3 81.2 7.3 15 12-Jul-02 117.0 707.8 866.8 19.4 564.3 73.0 7.4 15 13-Jul-02 121.1 710.7 803.6 17.2 599.4 62.7 7.4 18 14-Jul-02 119.6 707.5 803.6 25.6 558.3 30.1 7.4 17 15-Jul-02 Shut down and refill reactor Restart 16-Jul-02 135.7 700.5 1611.0 9.2 525.9 132.5 7.2 20 17-Jul-02 135.7 700.5 1611.0 7.9 531.2 207.4 7.2 19 18-Jul-02 Plug 19-Jul-02 139.2 679.0 1600.6 8.1 523.2 175.6 7.2 18 20-Jul-02 139.2 679.0 1600.6 9.0 509.5 180.3 7.2 0 21-Jul-02 135.5 718.2 1583.2 11.3 569.2 171.4 7.2 20 22-Jul-02 135.5 718.2 1583.2 10.6 526.9 213.7 7.2 20 23-Jul-02 130.2 715.5 1576.0 7.0 571.3 152.3 7.2 19 24-Jul-02 127.5 717.0 1561.1 6.1 521.5 275.9 7.2 19 25-Jul-02 108.9 590.5 1567.6 10.6 476.8 176.9 7.3 19 26-Jul-02 102.9 589.9 1598.4 10.6 469.8 205.6 7.2 19 27-Jul-02 Plug 28-Jul-02 140.8 658.7 1598.5 9.1 483.3 170.6 7.2 18 29-Jul-02 141.6 679.8 1600.3 10.7 552.3 153.3 7.2 18 30-Jul-02 144.9 723.5 1431.3 6.5 529.4 174.3 7.3 18 31-Jul-02 145.3 733.0 1323.3 l-Aug-02 145.3 733.0 1683.2 2-Aug-02 152.6 707.4 1670.5 3-Aug-02 Plug 4-Aug-02 Plug 5-Aug-02 151.4 710.7 1697.3 6-Aug-02 140.9 685.3 1620.3 7-Aug-02 138.0 675.9 1620.3 8-Aug-02 139.8 675.9 1620.3 9-Aug-02 136.2 661.0 1611.8 10-Aug-02 133.5 657.1 1609.5 ll-Aug-02 Plug 12-Aug-02 133.1 640.3 1450.1 13-Aug-02 132.0 637.9 1446.3 14-Aug-02 137.4 676.0 1456.3 15-Aug-02 133.5 681.4 1436.8 16-Aug-02 124.3 664.0 1430.5 17-Aug-02 Shut down 9.4 529.8 182.8 7.2 17 7.1 541.1 244.5 7.2 17 10.4 562.2 237.3 7.2 16 11.6 546.2 196.6 7.1 16 14.8 509.3 207.9 7.1 15 15.0 548.9 188.4 7.1 15 13.0 501.2 167.6 7.1 15 13.7 510.3 165.6 7.1 16 12.0 511.8 223.5 7.1 21 9.6 516.8 169.7 7.4 20 4.2 462.5 175.7 7.4 19 5.1 480.2 262.1 7.3 18 6.2 530.0 177.9 7.3 17 7.2 491.7 175.5 7.3 17 Removal Efficiency (%) Mg Total Supernatant Recycle PO4-P NH4.N Mg Influent Flow Influent Flow Flow Flow (mg/L) (mg/L) (mg/L) (mL/min) (mL/min) (mL/min) (mL/min) 74.5 7.9 76.6 50 78.4 11.3 65.4 50 84.4 4.1 25.4 50 78.5 2.5 61.6 50 79.4 5.3 69.1 55 82.8 11.0 47.4 56 79.6 4.0 60.0 54 73.4 3.3 70.9 52 67.6 6.4 74.3 48 77.7 4.4 61.1 50 78.2 6.3 62.9 50 87.2 2.9 37.1 60 85.8 7.5 64.8 58 82.5 5.9 69.3 50 80.7 3.7 88.8 50 72.4 9.5 49.3 50 77.5 11.5 55.2 48 68.5 1.3 38.8 50 76.7 1.2 39.1 50 80.7 7.0 41.1 50 83.0 (1.2) 53.2 50 75.5 9.7 70.3 48 91.9 10.4 49.4 65 92.9 8.5 24.9 60 93.0 8.0 32.5 65 92.3 10.3 31.2 63 90.1 6.6 28.7 63 90.6 12.4 16.9 65 93.6 5.4 37.9 70 94.0 8.8 12.9 71 89.0 8.2 6.0 63 87.8 5.9 16.5 77 92.2 12.0 36.0 75 91.1 4.4 36.4 73 94.6 12.4 26.1 70 425 375 4025 350 300 3850 200 150 4300 450 400 3550 390 335 3510 350 294 3300 400 346 3300 375 323 3425 375 327 3375 350 300 3550 350 300 3400 275 215 3295 400 342 3100 370 320 3200 370 320 3200 400 350 3600 350 302 3800 350 300 3850 325 275 3745 350 300 - 3650 300 250 3700 380 332 3580 400 335 3190 350 290 2850 400 335 3150 385 322 3315 415 352 3585 400 335 3800 450 380 3950 350 279 3800 525 462 3675 500 423 4000 450 375 4050 485 412 3965 425 355 3725 92.2 12.2 21.7 75 425 350 3375 94.0 9.1 22.5 75 400 325 4120 91.9 4.6 14.8 75 450 375 4250 90.8 7.8 30.5 75 450 375 4050 87.3 10.3 25.3 73 425 352 4125 87.2 4.2 23.6 73 480 407 3840 89.0 12.2 33.5 70 450 380 3830 88.2 9.1 31.8 70 465 395 3535 89.3 6.9 14.8 75 460 385 3690 91.6 5.8 18.1 75 525 450 3665 96.2 12.5 29.3 73 425 352 3625 95.3 9.8 15.2 69 325 256 3975 94.3 4.9 32.2 73 400 327 3750 93.0 11.1 26.4 75 450 375 3410 Total Recycle Conditions at the inlet Flow Ratio (mL/min) P04.P NH 4-N Mg Molar Removal Inlet to outlet PO4.P NH4 -N Mg Mg:P Removal Ratio 4450 9.5 146.0 649.8 117.0 3.5E-03 3.7E-03 3.7E-03 1.1 4200 11.0 141.9 631.2 142.0 3.6E-03 5.1E-03 3.8E-03 1.1 4500 21.5 124.1 552.3 248.6 3.4E-03 1.6E-03 2.6E-03 0.8 4000 7.9 143.6 675.2 117.7 3.6E-03 1.2E-03 3.0E-03 0.8 3900 9.0 138.7 652.4 149.4 3.6E-03 2.5E-03 4.3E-03 1.2 3650 9.4 136.9 616.6 159.5 3.7E-03 4.8E-03 3.1E-03 0.8 3700 8.3 139.2 665.2 142.9 3.6E-03 1.9E-03 3.5E-03 1.0 3800 9.1 140.3 629.1 126.3 3.3E-03 1.5E-03 3.7E-03 1.1 3750 9.0 142.0 636.9 117.3 3.1E-03 2.9E-03 3.6E-03 1.2 3900 10.1 136.6 627.9 131.4 3.4E-03 2.0E-03 3.3E-03 1.0 3750 9.7 136.2 625.0 131.0 3.4E-03 2.8E-03 3.4E-03 1.0 3570 12.0 135.9 586.6 188.8 3.8E-03 1.2E-03 2.9E-03 0.8 3500 7.8 141.3 663.4 125.9 3.9E-03 3.6E-03 3.4E-03 0.9 3570 8.6 145.1 668.7 119.6 3.9E-03 2.8E-03 3.4E-03 0.9 3570 8.6 162.8 798.8 119.6 4.2E-03 2.1E-03 4.4E-03 1.0 4000 9.0 122.1 688.4 111.2 2.9E-03 4.7E-03 2.3E-03 0.8 4150 10.9 120.8 683.7 122.0 3.0E-03 5.6E-03 2.8E-03 0.9 4200 11.0 101.0 541.7 125.4 2.2E-03 5.0E-04 2.0E-03 0.9 4070 11.5 100.2 593.5 133.3 2.5E-03 5.1E-04 2.1E-03 0.9 4000 10.4 100.3 606.7 123.8 2.6E-03 3.0E-03 2.1E-03 0.8 4000 12.3 100.9 592.2 133.9 2.7E-03 -5.1E-04 2.9E-03 1.1 3960 9.4 104.5 618.1 101.5 2.5E-03 4.3E-03 2.9E-03 1.2 3590 8.0 113.6 586.7 261.8 3.4E-03 4.3E-03 5.3E-03 1.6 3200 8.1 112.4 580.4 276.2 3.4E-03 3.5E-03 2.8E-03 0.8 3550 7.9 116.6 568.6 260.1 3.5E-03 3.2E-03 3.5E-03 1.0 3700 8.6 116.4 567.8 261.9 3.5E-03 4.2E-03 3.4E-03 1.0 4000 8.6 114.9 609.1 240.3 3.3E-03 2.9E-03 2.8E-03 0.8 4200 9.5 113.4 601.5 257.3 3.3E-03 5.3E-03 1.8E-03 0.5 4400 8.8 109.9 604.2 245.2 3.3E-03 2.4E-03 3.8E-03 1.1 4150 10.9 101.6 571.6 316.7 3.1E-03 3.6E-03 1.7E-03 0.5 4200 7.0 95.9 519.6 188.1 2.8E-03 3.1E-03 4.6E-04 0.2 4500 8.0 87.0 499.1 246.2 2.5E-03 2.1E-03 1.7E-03 0.7 4500 9.0 117.3 548.9 266.4 3.5E-03 4.7E-03 3.9E-03 1.1 4450 8.2 120.3 577.5 240.9 3.5E-03 1.8E-03 3.6E-03 1.0 4150 8.8 121.0 604.4 235.8 3.7E-03 5.4E-03 2.5E-03 0.7 3800 7.9 119.7 603.6 233.5 3 6E-03 5.3E-03 2.1E-03 0.6 4520 10.3 118.1 595.5 315.6 3 6E-03 3.9E-03 2.9E-03 0.8 4700 9.4 127.2 589.5 278.4 3 8E-03 1.9E-03 1.7E-03 0.4 4500 10.0 126.1 592.2 282.9 3 7E-03 3.3E-03 3.5E-03 1.0 4550 10.7 116.7 567.6 278.3 3 3E-03 4.2E-03 2.9E-03 0.9 4320 9.0 117.0 573.1 246.4 3 3E-03 1.7E-03 2.4E-03 0.7 4280 9.5 118.0 570.7 252.0 3 4E-03 5.0E-03 3.5E-03 1.0 4000 8.6 115.7 561.5 242.6 3 3E-03 3.7E-03 3.2E-03 1.0 4150 9.0 111.7 549.9 262.4 3 2E-03 2.7E-03 1.6E-03 0.5 4190 7.0 114.1 548.8 207.2 3 4E-03 2.3E-03 1.5E-03 0.5 4050 8.5 109.3 528.3 248.4 3 4E-03 4.7E-03 3.0E-03 0.9 4300 12.2 108.2 532.5 309.2 3 3E-03 3.7E-03 1.9E-03 0.6 4150 9.4 109.1 557.1 262.2 3 3E-03 1.9E-03 3.5E-03 1.0 3860 7.6 103.6 553.3 238.4 3 1E-03 4.4E-03 2.6E-03 0.8 N:P Mg:P N:P Product of S.S (ratio) P04-P Conditions Removal at inlet at inlet Ionic Constiunets at inlet inside the reactor Ratio (at inlet) Feed gives Recycle gives 1.0 1.0 9.9 1.1E-06 14.5 13.9 33.7 1.4 1.3 9.9 1.2E-06 16.6 11.8 28.1 0.5 2.6 9.9 1.6E-06 22.2 5.5 18.5 0.3 1.1 10.4 1.1E-06 14.9 16.2 27.3 0.7 1.4 10.4 1.3E-06 17.6 13.9 25.7 1.3 1.5 10.0 1.3E-06 17.6 13.1 21.2 0.5 1.3 10.6 1.3E-06 15.2 15.1 25.3 0.4 1.2 9.9 1.1E-06 12.8 13.8 33.6 0.9, 1.1 9.9 1.0E-06 12.2 14.2 41.4 0.6 1.2 10.2 1.1E-06 14.7 12.3 27.8 0.8 1.2 10.2 1.1E-06 14.6 12.7 26.9 0.3 1.8 9.6 1.4E-06 19.6 10.5 16.1 0.9 1.2 10.4 1.1E-06 22.3 16.2 17.8 0.7 1.1 10.2 1.1E-06 20.4 15.0 22.8 0.5 0.9 10.9 1.5E-06 27.4 16.9 28.2 1.6 1.2 12.5 8.9E-07 12.2 12.2 30.3 1.8 1.3 12.5 9.6E-07 13.2 10.2 24.9 0.2 1.6 11.9 6.5E-07 9.0 8.4 29.1 0.2 1.7 13.1 7.5E-07 13.3 8.0 21.5 1.2 1.6 13.4 7.1E-07 14.3 8.8 17.7 -0.2 1.7 13.0 . 7.6E-07 17.1 7.6 15.9 1.7 1.3 13,1 6.2E-07 12.4 10.0 23.2 1.3 3.0 11.4 1.7E-06 22.8 12.7 8.2 1.0 3.2 11.4 1.7E-06 23.5 12.3 7.1 0.9 2.9 10.8 1.6E-06 22.5 13.1 7.2 1.2 2.9 10.8 1.6E-06 22.6 12.1 8.0 0.9 2.7 11.7 1.6E-06 19.3 11.9 10.2 1.6 2.9 11.7 1.7E-06 20.1 10.8 9.6 0.7 2.9 12.2 1.5E-06 21.2 11.2 6.3 1.2 4.0 12.5 1.7E-06 24.0 8.6 5.6 1.1 2.5 12.0 8.9E-07 13.9 12.0 9.3 0.8 3.7 12.7 1.0E-06 14.0 9.7 9.4 1.3 2.9 10.4 1.6E-06 22.4 11.7 8.2 0.5 2.6 10.6 1.6E-06 21.8 13.1 9.5 1.4 2.5 11.1 1.6E-06 25.5 12.4 5.8 1.5 2.5 11.2 1.6E-06 22.0 13.4 8.3 1.1 3.5 11.2 2.1E-06 29.0 10.4 6.5 0.5 2.8 10.3 2.0E-06 23.9 12.2 9.4 0.9 2.9 10.4 2.0E-06 21.2 12.6 10.4 1.3 3.1 10.8 1.7E-06 16.2 10.9 13.4 0.5 2.7 10.8 1.6E-06 16.6 13.0 13.3 1.5 2.8 10.7 1.6E-06 17.1 12.4 11.7 1.1 2.7 10.7 1.5E-06 15.9 13.5 12.1 0.8 3.0 10.9 1.5E-06 14.2 12.4 10.7 0.7 2.3 10.6 1.2E-06 27.6 14.3 8.4 1.4 2.9 10.7 1.4E-06 27.1 11.5 3.7 1.1 3.7 10.9 1.7E-06 26.4 8.2 4.7 0.6 3.1 11.3 1.5E-06 26.7 10.5 5.6 1.4 3.0 11.8 1.3E-06 22.9 12.1 6.4 Dilution Factor Total for P NH 4-N conditions inside the reactor Feed gives Recycle gives Total Dilution Factor for N Feed gives 47.7 0.7 62.1 541.3 603.4 7.1E-02 11.2 39.9 0.7 52.6 513.3 565.9 1.0E-01 11.8 24.1 0.8 24.5 506.1 530.6 3.9E-02 11.0 43.5 0.7 76.0 584.2 660.1 2.2E-02 13.2 39.5 ' 0.7 65.2 556.2 • 621.4 : 4.8E-02 . 14.9 34.4 0.7 59.1 496.1 555.3 9.9E-02 15.3 40.4 0.7 71.9 569.5 641.4 3.6E-02 15.4 47.5 0.7 62.1 548.2 610.3 3.0E-02 12.5 55.6 0.6 63.7 536.7 600.4 5.7E-02 11.7 40.0 0.7 56.3 546.5 602.8 4.0E-02 11.8 39.6 0.7 58.3 530.9 589.2 5.7E-02 12.2 26.6 0.8 45.2 525.8 571.0 2.7E-02 14.5 33.9 0.8 75.8 543.3 619.1 6.7E-02 14.4 37.8 0.7 69.3 564.1 633.4 5.3E-02 12.4 45.1 0.7 82.8 689.5 772.3 3.3E-02 12.4 42.5 0.7 68.8 560.8 629.7 8.5E-02 11.1 35.0 0.7 57.7 554.3 612.0 1.0E-01 10.3 37.5 0.6 45.1 490.1 535.2 1.2E-02 10.5 29.5 0.7 47.4 539.5 586.9 1.1E-02 10.6 26.5 0.7 53.1 514.9 568.0 6.4E-02 10.8 23.5 0.8 44.4 554.4 598.9 -1.1E-02 10.0 33.2 0.7 59.3 504.7 564.0 8.8E-02 9.7 20.9 0.8 65.4 467.3 532.7 9.2E-02 29.2 19.4 0.8 63.5 473.1 536.6 7.6E-02 30.2 20.4 0.8 64.1 464.3 528.3 7.1E-02 29.3 20.2 0.8 59.1 456.5 515.6 9.2E-02 27.3 22.1 0.8 63.2 510.2 573.4 5.9E-02 24.9 20.4 0.8 57.3 476.7 534.0 1.1E-01 24.5 17.5 0.8 61.8 512.8 574.6 4.9E-02 25.1 14.1 0.9 48.2 477.5 525.7 8.0E-02 26.7 21.2 0.8 65.0 417.2 482.2 7.2E-02 23.5 19.1 0.8 55.5 417.6 473.0 5.2E-02 27.4 19.9 0.8 54.9 434.9 489.8 1.1E-01 26.6 22.6 0.8 62.9 492.1 555.1 3.9E-02 26.3 18.2 0.8 61.9 475.2 537.1 1.1E-01 24.1 21.7 0.8 67.5 470.5 538.1 1.1E-01 26.1 16.9 0.9 52.7 493.2 546.0 8.3E-02 27.9 21.5 0.8 56.4 508.4 564.8 4.2E-02 26.7 23.0 0.8 59.2 491.5 550.8 7.0E-02 28.3 24.3 0.8 53.0 461.8 514.8 9.3E-02 26.0 26.3 0.8 63.7 487.9 551.6 3.8E-02 27.4 24.1 0.8 60.0 448.5 508.5 1.1E-01 26.5 25.5 0.8 65.3 451.0 516.3- 8.0E-02 28.2 23.1 0.8 61.0 455.0 516.0 6.2E-02 29.1 22.7 0.8 68.8 452.0 520.8 5.1E-02 26.0 15.2 0.9 55.4 414.0 469.4 1.1E-01 26.1 12.8 0.9 40.2 443.9 484.1 9.1E-02 23.4 16.1 0.9 53.7 479.0 532.6 4.4E-02 25.3 18.4 0.8 64.5 434.4 498.9 9.8E-02 27.8 Mg Conditions Dilution inside the reactor Factor Recycle gives Total for Mg Concentration in Moles inside the reactor PO4-P NH4-N Mg Mg:P (molar ratio) (including recycle) 24.7 35.9 0.7 1.5E-03 4.3E-02 1.5E-03 1.0 45.1 56.9 0.6 1.3E-03 4.0E-02 2.3E-03 1.8 177.2 188.3 0.2 7.8E-04 3.8E-02 7.7E-03 10.0 40.1 53.4 0.5 1.4E-03 4.7E-02 2.2E-03 1.6 41.5 56.4 0.6 1.3E-03 4.4E-02 2.3E-03 1.8 75.8 91.1 0.4 1.1E-03 4.0E-02 3.7E-03 3.4 51.0 66.5 0.5 1.3E-03 4.6E-02 2.7E-03 2.1 33.2 45.6 0.6 1.5E-03 4.4E-02 1.9E-03 1.2 27.1 38.8 0.7 1.8E-03 4.3E-02 1.6E-03 0.9 46.6 58.4 0.6 1.3E-03 4.3E-02 2.4E-03 1.9 44.1 56.3 0.6 1.3E-03 4.2E-02 2.3E-03 1.8 109.6 124.2 0.3 8.6E-04 4.1E-02 5.1E-03 6.0 39.3 53.7 0.6 1.1E-03 4.4E-02 2.2E-03 2.0 32.9 45.3 0.6 1.2E-03 4.5E-02 1.9E-03 1.5 12.0 24.4 0.8 1.5E-03 5.5E-02 1.0E-03 0.7 50.7 61.9 0.4 1.4E-03 4.5E-02 2.5E-03 1.9 50.1 60.4 0.5 1.1E-03 4.4E-02 2.5E-03 2.2 70.3 80.8 0.4 1.2E-03 3.8E-02 3.3E-03 2.7 74.7 85.4 0.4 9.5E-04 4.2E-02 3.5E-03 3.7 66.6 77.4 0.4 8.5E-04 4.1E-02 3.2E-03 3.7 58.0 68.1 0.5 7.6Er04 4.3E-02 2.8E-03 3.7 27.2 37.0 0.6 1.1E-03 4.0E-02 1.5E-03 1.4 117.7 146.9 0.4 6.7E-04 3.8E-02 . 6.0E-03 9.0 184.8 215.0 0.2 * 6.2E-04 3.8E-02 8.8E-03 14.2 155.8 185.1 0.3 6.6E-04 3.8E-02 7.6E-03 11.6 161.5 188.7 0.3 6.5E-04 3.7E-02 7.8E-03 11.9 153.6 178.5 0.3 7.1E-04 4.1E-02 7.3E-03 10.3 193.3 217.8 0.2 6.6E-04 3.8E-02 9.0E-03 13.6 136.8 161.8 0.3 5.7E-04 4.1E-02 6.7E-03 11.8 252.6 279.4 0.1 4.6E-04 3.8E-02 1.1E-02 25.2 154.8 178.3 0.1 6.9E-04 3.4E-02 7.3E-03 10.7 182.8 210.1 0.1 6.2E-04 3.4E-02 8.6E-03 14.0 153.5 180.2 0.3 6.4E-04 3.5E-02 7.4E-03 11.5 136.6 162.8 0.3 7.3E-04 4.0E-02 6.7E-03 9.2 156.4 180.5 0.2 5.9E-04 3.8E-02 7.4E-03 12.6 162.4 188.5 0.2 7.0E-04 3.8E-02 7.8E-03 11.1 222.8 250.8 0.2 5.5E-04 3.9E-02 1.0E-02 18.9 214.6 241.3 0.1 7.0E-04 4.0E-02 9.9E-03 14.3 177.0 205.3 0.3 7.4E-04 3.9E-02 8.4E-03 11.4 188.4 214.4 0.2 7.9E-04 3.7E-02 8.8E-03 11.2 167.4 194.8 0.2 8.5E-04 3.9E-02 8.0E-03 9.4 150.0 176.5 0.3 7.8E-04 3.6E-02 7.3E-03 9.3 146.3 174.5 0.3 8.2E-04 3.7E-02 7.2E-03 8.7 198.8 227.9 0.1 7.4E-04 3.7E-02 9.4E-03 12.6 148.5 174.4 0.2 7.3E-04 3.7E-02 7.2E-03 9.8 157.3 183.4 0.3 4.9E-04 3.4E-02 7.5E-03 15.4 242.2 265.6 0.1 4.1E-04 3.5E-02 1.1E-02 26.3 160.8 186.0 0.3 5.2E-04 3.8E-02 7.7E-03 14.7 155.1 182.9 0.2 6.0E-04 3.6E-02 7.5E-03 12.6 N:P Product of Ps (eg) SS ratio Effluent Crystal Harvest (molar ratio) Ionic Constiunets in reactor in reactor SS Volume Volume (including recycle) (including recycle) (1) (1) 28.0 9.8E-08 7.3E-08 1.3 0.8 5.5 31.4 1.2E-07 7.3E-08 1.7 1.1 48.8 2.3E-07 7.3E-08 3.1 2.5 33.6 1.5E-07 7.3E-08 2.0 1.2 7.9 1.3 34.8 1.3E-07 7.3E-08 1.8 1.1 35.7 1.6E-07 7.3E-08 2.3 1.4 9.0 1.3 35.1 1.6E-07 8.3E-08 2.0 1.2 28.4 1.3E-07 8.3E-08 1.5 1.0 23.9 1.2E-07 8.3E-08 1.5 1.0 9.8 1.3 33.3 1.3E-07 7.3E-08 1.8 1.2 32.9 1.2E-07 7.3E-08 1.7 1.1 10.6 1.3 9.9 1.3 47.5 1.8E-07 7.3E-08 2.5 1.6 40.4 1.1E-07 5.0E-08 2.1 1.0 10.5 1.3 37.0 1.0E-07 5.4E-08 1.9 1.0 37.9 8.0E-08 5.4E-08 1.5 0.6 11.0 1.3 10.6 1.3 32.7 1.6E-07 7.3E-08 2.2 1.6 10.0 1.3 38.6 1.2E-07 7.3E-08 1.7 1.2 9.5 1.3 31.5 1.5E-07 7.3E-08 2.1 1.7 44.0 1.4E-07 5.7E-08 2.5 1.9 47.5 1.1E-07 5.0E-08 2.2 1.5 10.6 1.3 56.4 9.1E-08 4.5E-08 2.0 1.4 10.1 1.3 37.6 6.6E-08 5.0E-08 1.3 0.8 9.8 1.3 56.5 1.5E-07 7.3E-08 2.1 0.8 6.0 61.3 2.1E-07 7.3E-08 2.9 1.2 8.2 1.3 57.4 1.9E-07 7.3E-08 2.6 1.0 8.0 1.3 56.6 1.9E-07 7.3E-08 2.6 1.1 7.1 1.3 57.4 2.1E-07 8.3E-08 2.6 1.3 57.8 2.3E-07 8.3E-08 2.7 1.4 72.5 1.5E-07 7.3E-08 2.1 0.8 8.9 1.3 82.2 2.0E-07 7.3E-08 2.7 1.2 8.5 1.3 50.2 1.7E-07 6.4E-08 2.7 1.3 54.7 1.8E-07 7.3E-08 2.5 1.4 9.1 1.3 8.5 1.3 54.4 1.7E-07 7.3E-08 2.3 1.0 54.2 1.9E-07 7.3E-08 2.7 1.2 9.0 1.3 65.1 1.7E-07 6.4E-08 2.6 0.9 54.8 2.1E-07 7.3E-08 2.9 1.2 9.0 1.3 71.4 2.2E-07 7.3E-08 3.0 1.2 8.3 58.0 2.8E-07 8.3E-08 3.4 1.6 9.3 1.3 8.8 1.3 52.9 2.5E-07 9.4E-08 2.6 1.3 9.2 1.3 46.8 2.5E-07 1.1E-07 2.4 1.4 46.3 2.7E-07 9.4E-08 2.8 1.6 9.5 1.3 46.7 2.0E-07 9.4E-08 2.2 1.1 8.8 1.3 44.7 2.2E-07 9.4E-08 2.3 1.2 49.5 2.6E-07 1.1E-07 2.4 1.2 9.3 1.3 50.8 2.0E-07 4.5E-08 4.4 1.8 . 8.8 1.3 68.2 1.2E-07 5.0E-08 2.5 0.7 83.3 1.6E-07 6.4E-08' 2.4 1.0 72.9 1.5E-07 5.7E-08 2.7 1.0 10.5 1.3 59.8 1.6E-07 5.7E-08 2.8 1.1 10.7 1.3 CRT Harvest Harvested Mean Mass P Theoretical Average Mass Crystal Size Removed Mass MAP Grown (days) In reactor SS (g) (mm) (g) (g) 396.5 429.0 414.7 453.7 468.0 422.5 432.9 14.0 1.9 450.7 11.0 1.9 451.2 10.0 1.9 488.7 11.0 2.0 494.4 11.0 2.1 466.2 10.0 1.9 430.4 390.5 440.7 481.0 530.4 555.1 611.0 9.0 2.6 605.4 10.5 2.5 633.2 66.5 525.1 56.1 442.5 30.2 238.0 1.81 73.1 576.6 61.9 488.5 57.2 451.1 1.95 63.8 503.7 55.6 438.8 2.01 51.8 409.1 53.5 421.8 2.14 53.7 424.0 1.86 46.9 370.0 1.80 69.8 551.1 63.7 503.0 1.90 70.0 552.1 2.28 1.97 50.9 402.0 1.75 47.2 372.7 34.9 275.3 35.9 283.6 2.13 40.8 321.8 1.91 36.2 285.5 43,1 340.4 1.81 60.1 474.6 52.7 415.6 1.85 1.96 62.5 493.0 2.05 59.6 470.2 61.9 488.4 59.2 467.3 2.58 66.7 526.3 2.36 48.1 380.0 64.5 508.8 2.83 55.0 434.1 2.78 70.1 553.4 2.54 76.6 604.1 70.1 553.1 11.5 2.6 619.0 10.5 2.7 588.8 10.0 2.7 610.7 10.0 2.7 641.8 12.0 2.7 620.8 10.0 2.7 632.8 11.0 2.7 653.0 10.0 2.8 667.3 13.0 2.7 712.6 14.0 2.7 656.8 3.05 67.5 532.8 63.9 504.5 2.88 75.7 597.5 2.59 2.79 74.2 585.7 62.3 492.0 2.89 70.5 556.5 2.45 68.1 537.0 68.3 539.4 2.81 66.1 521.3 2.90 79.0 623.7 64.3 507.6 48.3 381.1 3.00 59.3 467.7 3.02 62.5 492.9 Annacis Supernatant Date Mg Feed Influent Lab Results Inlet Mg PO4-P NH4.N Mg N:P PO4-P (mg/1) (mg/L) (mg/L) (mg/L) ratio (mg/L) 3-Sep-02 1700.3 132.6 4-Sep-02 1698.5 135.6 5-Sep-02 1693.9 135.6 6-Sep-02 1693.9 136.2 7-Sep-02 1693.9 131.1 8-Sep-02 1706.0 131.1 9-Sep-02 1706.0 131.1 10-Sep-02 1743.0 134.6 ll-Sep-02 1769.1 133.6 12-Sep-02 1403.2 128.4 13-Sep-02 1403.2 131.9 14-Sep-02 1456.3 131.9 15-Sep-02 1423.6 131.9 16-Sep-02 1449.9 141.4 17-Sep-02 1453.2 131.2 18-Sep-02 1450.4 130.2 19-Sep-02 1198.5 130.5 20-Sep-02 1198.5 130.5 21-Sep-02 shut down 1035.3 6.6 17.3 4.4 1056.3 6.0 17.2 3.4 1056.3 6.0 17.2 3.1 1000.8 6.3 16.3 1.8 1037.8 5.9 17.5 3.5 1037.8 5.9 17.5 3.4 1037.8 6.2 17.5 3.8 1081.1 7.2 17.8 3.4 1079.5 6.7 17.9 5.2 1084.5 6.4 1.8.7 2.9 1081.9 5.9 - 18.1 3.6 1081.9 5.9 18.1 5.2 1081.9 5.9 18.1 6.8 1058.2 5.5 16.6 5.3 1024.9 5.8 17.3 6.6 1037.5 5.5 17.6 7.4 1015.1 5.5 17.2 7.2 1015.1 5.5 17.2 3.1 156 Effluent Lab Results pH NH4.N Mg (mg/L) (mg/L) T© Removal Efficiency (%) PO4-P NH4.N Mg (mg/L) (mg/L) (mg/L) Mg Influent Flow (mL/min) 815.7 238.3 8.0 17 96.0 4.2 22.6 80 841.7 213.3 8.0 15 97.0 4.2 26.8 75 820.2 256.3 8.0 16 97.2 5.2 17.9 78 781.4 220.0 8.0 14 98.4 5.7 25.7 73 816.9 218.7 8.0 15 96.8 4.8 26.7 78 843.2 198.2 8.0 15 97.0 3.7 26.9 78 863.4 172.0 8.0 17 96.7 3.1 30.4 78 888.2 199.1 8.0 16 97.0 2.9 27.5 77 831.7 205.5 7.8 16 95.4 8.5 28.1 76 789.6 209.4 7.9 16 '97.2 9.6 '24.9 78 816,3 172.1. 7.9 17 96.6 8.0 33.1 80 863.2 170.4 7.9 18 95.3 4.3 31.2 80 871.3 159.3 7.9 18 93.9 3.8 32.6 78 818.2 135.6 7.9 17 95.6 7.5 44.0 77 825.2 155.5 7.9 15 94.0 4.6 32.9 78 851.4 146.3 7.9 15 93.4 4.0 32.2 80 782.8 188.1 7.9 16 93.3 5.7 15.6 82 643.8 164.4 7.9 13 97.1 22.4 26.3 82 Total Supernatant Recycle Influent Flow Flow Flow (mL/min) (mL/min) (mL/min) Total Recycle Flow Ratio (mL/min) Conditions at the inlet PQ4_P NH4-N 450 370 2750 3200 6.1 109.0 851.2 445 370 2755 3200 6.2 112.8 878.3 430 352 2670 3100 6.2 111.0 864.7 425 352 2725 3150 6.4 112.8 828.9 450 372 2750 3200 6.1 108.4 857.9 500 422 3000 3500 6.0 110.6 875.9 550 472 3150 3700 5.7 112.5 890.6 500 423 3000 3500 6.0 113.8 914.6 480 404 4020 4500 8.4 112.5 908.5 400 322 3650 4050 9.1 103.4 873.0 445 365 4155 4600 9.3 108.2 887.4 480 400 4020 4500 8.4 109.9 901.6 480 402 4020 4500 8.4 110.4 906.1 470 393 4040 4510 8.6 118.2 884.9 500 • 422 4300 4800 8.6 110.7 865.0 550 470 3950 4500 7.2 111.2 886.6 450 368 3940 4390 8.8 106.8 830.1 450 368 3940 4390 8.8 106.8 830.1 158 Molar Removal Inlet to outlet Mg PO4.P NH 4-N Mg Mg:P N:P Mg:P N:P Removal Removal at inlet at inlet Ratio Ratio 307.7 3.4E-03 2.5E-03 2.9E-03 0.8 0.8 3.6 17.3 291.3 3.5E-03 2.6E-03 3.2E-03 0.9 0.7 3.3 17.2 312.2 3.5E-03 3.2E-03 2.3E-03 0.7 0.9 3.6 17.2 296.1 3.6E-03 3.4E-03 3.1E-03 0.9 0.9 3.4 16.3 298.5 3.4E-03 2.9E-03 3.3E-03 1.0 0.9 3.6 17.5 271.1 3.5E-03 2.3E-03 3.0E-03 0.9 0.7 3.2 17.5 247.2 3.5E-03 1.9E-03 3.1E-03 0.9 0.6 2.8 17.5 274.5 3.6E-03 1.9E-03 3.1E-03 0.9 0.5 3.1 17.8 285.7 3.5E-03 5.5E-03 3.3E-03 1.0 1.6 3.3 17.9 278.8 3.2E-03 6.0E-03 2.9E-03 0.9 1.8 3.5 18.7 257,1 3.4E-03 5.1E-03 3.5E-03 1.0 1.5 3.1 18.2 247.6 3.4E-03 2.7E-03 3.2E-03 0.9 0.8 2.9 18.2 236.3 3.3E-03 2.5E-03 3.2E-03 0.9 0.7 2.8 18.2 242.1 3.6E-03 4.8E-03 4.4E-03 1.2 1.3 2.6 16.6 231.6 3.4E-03 2.8E-03 3.1E-03 0.9 0.8 2.7 17.3 215.7 3.4E-03 2.5E-03 2.9E-03 0.9 0.8 2.5 17.6 222.9 3.2E-03 3.4E-03 1.4E-03 0.4 1.1 2.7 17.2 222.9 3.3E-03 1.3E-02 2.4E-03 0.7 4.0 2.7 17.2 Product of S.S (ratio) P04-P Conditions Dilution Factor Ionic Constiunets at inlet inside the reactor forP (at inlet) Feed gives Recycle gives Total 2.7E-06 51.3 15.3 3.7 19.1 0.8 2.8E-06 51.9 15.7 2.9 18.6 0.8 2.9E-06 53.9 15.4 2.7 18.1 0.8 2.7E-06 49.8 15.2 1.6 16.8 0.9 2.7E-06 49.9 15.2 3.0 18.3 0.8 2.5E-06 47.2 15.8 2.9 18.7 0.8 2.4E-06 44.5 16.7 3.2 19.9 0.8 2.7E-06 51.4 16.3 2.9 19.2 0.8 2.8E-06 33.6 12.0 4.7 16.7 0.9 2.4E-06 36.3 10.2 2.6 12.9 0.9 2.4E-06 35.6 10.5 3.3 13.7 0.9 2.4E-06 35.4 11.7 . 4.6 16.4 0.9 2.3E-06 34.1 11.8 6.1 17.8 0.8 2.4E-06 36.6 12.3 4.7 17.0 0.9 2.1E-06 33.5 11.5 5.9 17.4 0.8 2.0E-06 30.7 13.6 6.5 20.1 0.8 1.9E-06 29.8 10.9 6.4 17.4 0.8 1.9E-06 28.5 10.9 2.8 13.7 0.9 NH4-N Conditions Dilution Factor Mg Conditions inside the reactor for N inside the reactor Feed gives Recycle gives Total Feed gives Recycle gives Total 119.7 701.0 820.7 3.6E-02 43.3 204.8 248.0 122.1 724.6 846.8 3.6E-02 40.5 183.6 224.1 119.9 706.4 826.4 4.4E-02 43.3 220.8 264.1 111.8 675.9 787.8 5.0E-02 40.0 190.3 230.2 120.6 702.0 822.7 4.1E-02 42.0 188.0 229.9 125.1 722.8 847.9 3.2E-02 38.7 169.9 208.6 132.4 ' 735.0 867.4 2.6E-02 36.8 146.5 183.2 130.7 761.3 891.9 2.5E-02 39.2 170.6 209.8 96.9 742.9 839.9 7.6E-02 30.5 183.6 214.0 86.2 711.6 797.8 8.6E-02 27.5 188.7 216.2 85.8 737.3 823.2 7.2E-02 24.9 155.4 180.3 96.2 771.1 867.3 3.8E-02 26.4 152.2 178.6 96.6 778.3 875.0 3.4E-02 25.2 142.3 167.5 92.2 733.0 825.2 6.7E-02 25.2 121.5 146.7 90.1 739.2 829.3 4.1E-02 24.1 139.3 163.4 108.4 747.3 855.7 3.5E-02 26.4 128.4 154.8 85.1 702.5 787.6 5.1E-02 22.8 168.8 191.6 85.1 577.8 662.9 2.0E-01 22.8 147.5 170.4 Dilution Factor for Mg Concentration in Moles inside the reactor PO4-P NH4-N Mg Mg:P N:P (molar ratio) (molar ratio) (including recycle) (including recycle) 0.2 6.2E-04 5.9E-02 1.0E-02 16.8 95.3 0.2 6.0E-04 6.0E-02 9.3E-03 15.5 100.7 0.2 5.8E-04 5.9E-02 1.1E-02 18.9 101.3 0.2 5.4E-04 5.6E-02 9.6E-03 17.7 103.8 0.2 5.9E-04 5.9E-02 9.6E-03 16.3 99.8 0.2 6.0E-04 6.1E-02 8.7E-03 14.4 100.5 0.3 6.4E-04 6.2E-02 7.6E-03 11.9 96.5 0.2 6.2E-04 6.4E-02 8.7E-03 14.1 102.9 0.3 5.4E-04 6.0E-02 8.9E-03 16.6 111.6 0.2 4.1E-04 5.7E-02 9.0E-03 21.7 137.4 0.3 4.4E-04 5.9E-02 7.5E-03 16.9 132.6 0.3 5.3E-04 6.2E-02 7.4E-03 14.1 117.4 0.3 5.8E-04 6.2E-02 7.0E-03 12.1 108.6 0.4 5.5E-04 5.9E-02 6.1E-03 11.1 107.3 0.3 5.6E-04 5.9E-02 6.8E-03 12.1 105.2 0.3 6.5E-04 6.1E-02 6.4E-03 10.0 94.4 0.1 5.6E-04 5.6E-02 8.0E-03 14.2 100.3 0.2 4.4E-04 4.7E-02 7.1E-03 16.0 106.9 Product of Ps(eg) S.S (ratio) Effluent Crystal Harvest Ionic Constiunets in the reactor SS Volume Volume (including recycle) (1) (1) 3.7E-07 5.3E-08 7.0 1.5 7.0 1.3 3.4E-07 5.3E-08 6.4 1.1 3.8E-07 5.3E-08 7.1 1.2 2.9E-07 5.3E-08 5.5 0.6 8.4 1.3 3.3E-07 5.3E-08 6.2 1.1 3.2E-07 5.3E-08 5.9 1.0 3.0E-07 5.3E-08 5.7 1.0 9.8 1.3 3.4E-07 5.3E-08 6.5 1.1 2.9E-07 8.3E-08 3.4 1.0 9.2 1.3 2.1E-07 6.7E-08 3.2 0.7 2.0E-07 6.7E-08 2.9 0.7 9.0 1.3 2.4E-07 6.7E-08 3.7 1.1 2.5E-07 6.7E-08 3.8 1.4 9.5 1.3 2.0E-07 6.7E-08 3.0 0.8 2.3E-07 6.4E-08 3.6 1.3 9.5 1.3 2.6E-07 6.7E-08 3.8 1.3 8.9 1.3 2.5E-07 6.4E-08 4.0 1.6 1.5E-07 6.7E-08 2.2 0.5 9.9 1.3 CRT Harvest Harvested Mean Mass P Theoretical Average Mass Crystal Size Removed Mass MAP Grown (days) In reactor SS (g) (mm) (g) (g) 8.5 3.3 596.1 2.71 67.8 537.0 70.1 555.0 66.8 529.3 12.5 4.0 ' 689.9 2.75 67.9 538.0 67.9 538.1 77.2 611.7 15.5 4.4 763.8 2.82 86.1 682.0 79.5 629.7 14.0 4.9 736.5 2.76 74.1 587.1 57.9 458.2 13.0 5.0 779.8 3.08 67.0 530.5 72.4 573. i 15.0 4.9 748.2 . 3.05 71.6 567.4 76.5 605.5 16.0 4.8 756.8 3.25 ^ 75.0 ' 593.9 13.0 4.4 732.2 2.88 82.3 651.5 64.5 511.0 15.0 4.2 786.1 2.70 67.2 531.9 164 Lulu Supernatant Date Mg Feed Influent Lab Results Inlet Effluent Lab Results Mg PO4-P NH4 .N Mg N:P PO4-P NH4 .N Mg (mg/1) (mg/L) (mg/L) (mg/L) ratio (mg/L) (mg/L) (mg/L; Start 2-Oct-02 1900.5 91.9 1024.4 5.5 24.7 3.0 863.5 190.2 3-Oct-02 1883.3 91.9 1024.4 5.5 24.7 3.5 879.1 179.4 4-Oct-02 2356.6 91.9 1024.4 5.8 24.7 3.9 886.4 190.4 5-Oct-02 2296.7 92.9 987.3 5.6 23.5 3.1 855.1 201.1 6-Oct-02 2223.9 91.6 965.7 5.5 23.3 3.5 831.5 135.8 7-Oct-02 2223.9 92.3 994.4 5.2 23.8 4.0 876.9 125.6 8-Oct-02 1559.7 93.8 1003.9 4.8 23.7 5.5 861.0 119.2 9-Oct-02 1663.1 95.1 1037.0 5.6 24.1 5.2 882.5 124.5 10-Oct-02 1681.3 92.3 974.0 5.2 23.4 6.0 812.9 136.1 25-Oct-02 1713.7 93.6 1000.1 6.1 23.6 4.7 869.2 130.2 26-Oct-02 1709.5 93.9 969.5 6.3 22.8 5.0 82.5.7 145.6 27-Oct-02 1701.2 93.9 969.5 6.3 22.8 6.8 829.3 125.0 28-Oct-02 1701.2 93.9 966.1 5.5 22.8 3.4 794.9 146.4 29-Oct-02 1833.5 92.6 931.8 6.0 22.3 3.7 792.9 159.4 30-Oct-02 1633.9 87.5 960.4 6.1 24.3 3.5 777.8 186.8 31-Oct-02 1699.3 91.7 978.5 6.4 23.6 3.3 809.3 180.9 l-Nov-02 1699.3 91.7 978.5 6.4 23.6 3.6 815.7 154.2 8-Nov-02 1465.5 76.2 1090.4 4.6 31.7 5.4 917.3 120.6 9-Nov-02 1465.5 76.2 1090.4 4.6 31.7 5.3 936.5 125.7 lO-Nov-02 1258.4 76.1 1107.4 5.1 32.2 4.9 916.9 129.8 ll-Nov-02 1258.4 75.7 1104.5 4.8 32.3 4.1 939.2 106.7 12-Nov-02 1394.5 72.2 1021.4 4.8 31.3 5.6 861.3 133.6 13-Nov-02 1368.5 72.5 975.8 5.2 29.8 5.4 828.2 133.4 14-Nov-02 1367.1 74.3 981.4 4.9 29.2 6.4 841.1 126.9 15-Nov-02 1409.2 75.7 1024.4 5.1 29.9 5.0 831.5 135.8 16-Nov-02 1409.2 74.4 1010.0 5.2 30.0 6.3 857.9 150.2 17-Nov-02 1411.9 76.6 999.3 5.0 28.9 5.4 814.6 137.4 18-Nov-02 1423.7 76.1 1016.4 4.9 29.5 5.2 825.7 138.1 pH T© Removal Efficiency (%) Mg Total Supernatant PO4-P NH4.N Mg Influent Flow Influent Flow Flow (mg/L) (mg/L) (mg/L) (mL/min) (mL/min) (mL/min) 7.8 13 96.3 3.7 21.5 65 520 455 7.8 14 95.7 2.1 24.2 64 520 456 7.7 14 95.2 3.5 23.3 65 630 565 7.7 13 96.3 2.9 20.8 65 600 535 7.8 14 95.9 5.7 31.6 50 575 525 7.8 12 95.3 3.0 39.3 50 550 500 7.8 14 93.3 3.2 34.7 60 525 465 7.8 13 93.9 3.9 36.2 60 525 465 7.7 11 92.7 5.7 31.5 60 520 460 7.7 11 94.4 2.6 31.4 70 650 580 7.7 10 94.0 4.2 25.5 70 630 560 7.7 11 91.9 3.9 34.9 69 630 561 7.8 12 95.9 6.9 27.8 71 610 539 7.8 8 95.5 3.4 28.7 72 605 533 7.8 9 95.4 5.2 23.2 75 515 440 7.7 8 95.8 4.2 23.7 75 550 475 7.7 8 95.5 4.7 29.2 75 600 525 7.7 10 92.0 5.1 29.6 65 570 505 7.7 10 92.2 2.3 30.5 70 580 510 7.7 10 92.4 2.7 32.2 84 565 481 7.7 11 94.0 4.3 25.9 60 540 480 7.7 12 91.1 3.2 27.5 71 550 479 7.7 12 91.5 2.5 26.4 71 550 479 7.7 10 90.3 2.3 26.3 70 570 500 7.7 11 92.4 7.2 24.8 70 560 490 7.7 11 90.3 2.4 19.8 70 540 470 7.7 12 91.9 6.3 26.7 70 540 470 7.7 9 92.3 7.1 24.5 69 550 481 166 Recycle Flow (mL/min) Total Recycle Conditions at the Flow Ratio Inlet (mL/min) PQ4.P NH4-N Mg Molar Removal Inlet to outlet PQ4.P NH4-N Mg 2980 3500 5.7 80.4 896.3 242.4 2.5E-03 2.3E-03 2.1E-03 3030 3550 5.8 80.6 898.3 236.6 2.5E-03 1.4E-03 2.4E-03 3170 3800 5.0 82.4 918.7 248.3 2.5E-03 2.3E-03 2.4E-03 3150 3750 5.3 82.8 880.4 253.8 2.6E-03 1.8E-03 2.2E-03 2905 3480 5.1 83.6 881.7 198.4 2.6E-03 3.6E-03 2.6E-03 2950 3500 5.4 84.0 904.0 206.9 2.6E-03 1.9E-03 3.3E-03 2775 3300 5.3 83.1 889.2 182.5 2.5E-03 2.0E-03 2.6E-03 2905 3430 5.5 84.2 918.5 195.0 2.6E-03 2.6E-03 2.9E-03 2680 3200 5.2 81.6 861.6 198.6 2.4E-03 3.5E-03 2.6E-03 2850 3500 4.4 83.5 892.4 189.9 2.5E-03 1.7E-03 2.5E-03 2870 3500 4.6 83.5 861.7 195.6 2.5E-03 2.6E-03 2.1E-03 2700 3330 4.3 83.6 863.3 192.0 2.5E-03 2.4E-03 2.8E-03 2490 3100 4.1 82.9 853.7 202.9 2.6E-03 4.2E-03 2.3E-03 2445 3050 4.0 81.6 820.9 223.5 2.5E-03 2.0E-03 2.6E-03 2475 2990 4.8 74.8 820.5 243.2 2.3E-03 3.1E-03 2.3E-03 2450 3000 4.5 79.2 845.1 237.2 2.4E-03 2.6E-03 2.3E-03 2400 3000 4.0 80.2 856.2 218.0 2.5E-03 2.9E-03 2.6E-03 2430 3000 4.3 67.5 966.0 171.2 2.0E-03 3.5E-03 2.1E-03 2420 3000 4.2 67.0 958.8 181.0 2.0E-03 1.6E-03 2.3E-03 2585 3150 4.6 64.8 942.7 191.5 1.9E-03 1.8E-03 2.5E-03 2710 3250 5.0 67.3 981.8 144.1 2.0E-03 3.0E-03 1.5E-03 2750 3300 5.0 62.9 889.6 184.2 1.9E-03 2.0E-03 2.1E-03 2950 3500 5.4 63.2 849.8 181.2 1.9E-03 1.5E-03 2.0E-03 2680 3250 4.7 65.2- 860.9 172.2 1.9E-03 1.4E-03 1.9E-03 2740 3300 4.9 66.2 896.3 180.6 2.0E-03 4.6E-03 1.8E-03 2960 3500 5.5' 64.7 879.0 ' 187.2 1.9E-03 1.5E-03 1.5E-03 2960 3500 5.5 66.7 869.8 187.4 2.0E-03 3.9E-03 2.1E-03 2850 3400 5.2 66.6 888.8 182.9 2.0E-03 4.5E-03 1.8E-03 167 Mg:P N:P Mg:P N:P Removal Removal at inlet at inlet Ratio Ratio Product of S.S (ratio) Ionic Constiunets at inlet (at inlet) Feed gives 0.9 0.9 3.9 24.7 0.9 0.5 3.8 24.7 0.9 0.9 3.9 24.7 0.8 0.7 4.0 23.5 1.0 ' 1.4 3.1 23.4 1.3 0.7 3.2 23.8 1.0 0.8 2.8 23.7 1.1 1.0 3.0 24.2 1.1 1.4 3.1 23.4 1.0 0.7 2.9 23.7 0.8 1.0 3.0 22.9 1.1 1.0 3.0 22.9 0.9 1.6 3.2 22.8 1.0 0.8 3.5 22.3 1.0 1.3 4.2 24.3 0.9 1.0 3.9 23.6 1.1 1.2 3.5 23.6 1.0 1.7 3.3 31.7 1.1 0.8 3.5 31.7 1.3 1.0 3.8 32.2 0.8 1.5 2.8 32.3 1.1 1.1 3.8 31.3 1.1 0.8 3.7 29.8 1.0 0.7 3.4 29.2 0.9 2.3. 3.5 30.0 0.8 0.8 3.7 30.1 1.0 2.0 3.6 28.9 0.9 2.3 3.5 29.6 1.7E-06 40.7 11.9 1.6E-06 39.9 11.8 1.8E-06 35.7 13.7 1.8E-06 38.2 13.2 1.4E-06 30.8 13.8 1.5E-06 33.8 13.2 1.3E-06 28.4 13.2 1.4E-06 32.4 12.9 1.3E-06 26.5 13.3 1.4E-06 26.9 15.5 1.4E-06 27.3 15.0 1.3E-06 26.9 15.8 1.4E-06 30.3 16.3 1.4E-06 31.5 16.2 1.4E-06 31.4 12.9 1.5E-06 ••' 30.1 14.5 L4E-06 28.4 16.0 1.1E-06 21.6 12.8 1.1E-06 22.0 12.9 1.1E-06 23.6 11.6 9.1E-07 17.3 11.2 9.9E-07 20.4 10.5 9.3E-07 18.9 9.9 9.3E-07 18.3 11.4 1.0E-06 18.3 11.2 1.0E-06 19.4 10.0 1.0E-06 20.6 10.3 1.0E-06 20.5 10.8 P04-P Conditions Dilution NH4-N Conditions Dilution inside the reactor Factor inside the reactor Factor Recycle gives Total for P Feed gives Recycle gives Total for N Feed gives 2.5 14.5 0.8 133.2 735.2 868.3 3.1E-02 36.0 3.0 14.8 0.8 131.6 750.4 881.9 1.8E-02 34.7 3.3 16.9 0.8 152.3 739.4 891.7 2.9E-02 41.2 2.6 15.9 0.8 140.9 718.3 859.2 2.4E-02 40.6 2.9 16.7 0.8 145.7 694.1 839.8 4.8E-02 32.8 3.4 16.5 0.8 142.1 739.1 881.2 2.5E-02 32.5 4.7 17.9 0.8 141.5 724.1 865.5 2.7E-02 29.0 4.4 17.3 0.8 140.6 747.4 888.0 3.3E-02 29.9 5.0 18.3 0.8 140.0 680.8 820.8 4.7E-02 32.3 3.8 19.3 0.8 165.7 707.8 873.5 2.1E-02 35.3 4.1 19.1 0.8 155.1 677.1 832.2 3.4E-02 35.2 5.5 21.3 0.7 163.3 672.4 835.7 3.2E-02 36.3 2.7 19.1 0.8 168.0 638.5 806.5 5.5E-02 39.9 3.0 19.2 0.8 162.8 635.6 798.5 2.7E-02 44.3 2.9 15.7 0.8 141.3 643.8 785.2 4.3E-02 41.9 2.7 17.2 0.8 154.9 660.9 815.9 3.5E-02 43.5 2.9 18.9 0.8 171.2 652.5 823.8 3.8E-02 43.6 4.3 17.2 0.7 183.5 743.0 926.5 4.1E-02 32.5 4.2 17.2 0.7 185.4 755.5 940.8 1.9E-02 35.0 4.1 15.7 0.8 169.1 752.5 921.6 2.2E-02 34.3 3.4 14.6 0.8 163.1 783.1 946.2 3.6E-02 23.9 4.6 15.1 0.8 148.3 717.8 866.0 2.6E-02 30.7 4.5 14.5 0.8 133.5 698.1 831.6 2.1E-02 28.5 5.2 16.7 0.7 151.0 693.6 844.6 1.9E-02 30.2 4.2 15.4 0.8 152.1 690.4 842.5 6.0E-02 30.6 5.3 ' 15.3 0.8 135.6 725.5 861.2 2.0E-02 28.9 4.5 14.8 0.8 134.2 688.9 823.1 5.4E-02 28.9 4.3 15.1 0.8 143.8 692.1 835.9 6.0E-02 29.6 169 Mg Conditions inside the reactor Recycle gives Total Dilution Factor for Mg Concentration in Moles inside the reactor PO4-P NH4-N Mg Mg:P (molar ratio) (including recycle) 162.0 198.0 0.2 4.7E-04 6.2E-02 8.2E-03 17.7 153.1 187.7 0.2 4.8E-04 6.3E-02 7.8E-03 16.4 158.8 200.0 0.2 5.5E-04 6.4E-02 8.3E-03 15.2 168.9 209.6 0.2 5.1E-04 6.1E-02 8.7E-03 17.1 113.3 146.1 0.3 5.4E-04 6.0E-02 6.1E-03 11.3 105.9 138.4 0.3 5.3E-04 6.3E-02 5.8E-03 10.8 100.2 129.3 0.3 5.8E-04 6.2E-02 5.4E-03 9.3 105.4 135.3 0.3 5.6E-04 6.3E-02 5.6E-03 10.1 113.9 146.2 0.3 5.9E-04 5.9E-02 6.1E-03 10.3 106.0 141.3 0.3 6.2E-04 6.2E-02 5.9E-03 9.4 119.4 154.6 0.2 6.2E-04 5.9E-02 6.4E-03 10.4 101.4 137.7 0.3 6.9E-04 6.0E-02 5.7E-03 8.3 117.6 157.5 0.2 6.1E-04 5.8E-02 6.6E-03 10.7 127.7 172.1 0.2 6.2E-04 5.7E-02 7.2E-03 11.6 154.6 196.5 . 0.2 5.1E-04 5.6E-02 8.2E-03 16.1 147.8 191.3 0.2 5.6E-04 5.8E-02 8.0E-03 14.3 123.4 167.0 0.2 6.1E-04 5.9E-02 7.0E-03 11.4 97.7 130.2 0.2 5.5E-04 6.6E-02 5.4E-03 9.8 101.4 136.4 0.2 5.5E-04 6.7E-02 5.7E-03 10.3 106.5 140.9 0.3 5.1E-04 6.6E-02 5.9E-03 11.6 89.0 112.9 0.2 4.7E-04 6.8E-02 4.7E-03 10.0 111.3 142.0 0.2 4.9E-04 6.2E-02 5.9E-03 12.1 112.4 140.9 0.2 4.7E-04 5.9E-02 5.9E-03 12.6 104.6 134.8 0.2 5.4E-04 6.0E-02 5.6E-03 10.5 112.8 143.4 0.2 5.0E-04 6.0E-02 6.0E-03 12.0 127.0 155.9 0.2 4.9E-04 6.2E-02 6.5E-03 13.1 116.2 145.1 0.2 4.8E-04 5.9E-02 6.0E-03 12.6 115.8 145.3 0.2 4.9E-04 6.0E-02 6.1E-03 12.4 170 N:P Product of Ps (eg) S.S (ratio) Effluent Crystal Harvest (molar ratio) Ionic constiunets in reactor SS Volume Volume (including recycle) (including recycle) (1) (1) 132.8 2.4E-07 4.1E-08 5.8 1.1 8.6 132.2 2.3E-07 4.1E-08 5.7 1.3 116.5 2.9E-07 5.1E-08 5.7 1.3 10.2 1.3 120.0 2.7E-07 4.7E-08 5.9 1.1 111.4 2.0E-07 4.6E-08 4.3 0.8 10.5 1.3 117.9 1.9E-07 4.5E-08 4.3 0.9 107.2 1.9E-07 4.6E-08 4.2 1.2 11.0 1.3 113.8 2.0E-07 4.5E-08 4.5 1.2 10.2 1.3 99.5 2.1E-07 5.1E-08 4.2 1.3 9.5 1.3 100.1 2.3E-07 5.1E-08 4.5 1.0 8.2 96.3 2.4E-07 5.0E-08 4.8 1.2 86.7 2.4E-07 5.0E-08 4.8 1.4 93.7 2.3E-07 4.6E-08 5.1 0.8 10.1 1.3 92.3 2.5E-07 4.6E-08 5.5 1.0 110.5 2.3E-07 4.6E-08 5.1 1.1 10.8 1.3 104.9 2.6E-07 5.1E-08 5.1 0.9 96.3 2.5E-07 5.1E-08 4.9 0.9 11.0 1:3 119.5 2.0E-07 5.0E-08 4.0 1.2 10.0 121.3 2.1E-07 5.1E-08 4.2 1.2 130.2 2.0E-07 4.7E-08 4.1 1.2 11.1 1.3 143.8 1.5E-07 5.3E-08 2.8 0.7 126.8 1.8E-07 4.9E-08 3.7 1.3 127.3 1.6E-07 5.0E-08 3.3 1.2 11.5 1.3 112.2 1.8E-07 5.1E-08 3.6 1.3 121.0 1.8E-07 5.6E-08 3.2 1.0 11.7 1.3 124.5 2.0E-07 5.3E-08 3.7 1.5 122.9 1.7E-07 5.1E-08 3.4 1.1 122.7 1.8E-07 5.1E-08 3.5' 1.1 12.0 1.3 171 CRT Harvest Harvested Mean Mass P Theoretical Average Mass Crystal Size Removed Mass MAP Grown (days) In reactor SS (g) (mm) (g) (g) 15.0 4.2 779.5 15.0 4.1 823.3 17.0 4.1 737.4 14.0 4.3 722.6 13.0 4.5 706.8 16.0 4.6 797.8 19.0 4.4 810.0 18.0 .. 4.8 805.9 18.0 4.7 762.3 19.0 4.4 831.6 19.0 4.3 782.1 22.0 4.2 793.4 58.0 457.4 57.7 455.5 2.86 71.2 561.7 68.9 543.4 3.19 66.4 523.6 63.3 499.8 3.15 58.6 462.5 2.63 59.7 471.4 2.35 56.6 446.9 73.8 582.1 71.2 561.6 69.7 550.0 2.84 69.9 551.2 67.9 535.5 2.90 52.9 417.2 60.1 474.2 3.24 . 66.2 522.3 51.0 402.2 51.5 406.7 2.81 48.7 384.3 49.2 388.0 45.4 358.3 3.43 45.8 361.2 48.3 381.0 3.19 49.4 389.4 45.4 358.4 47.6 376.0 3.00 48.6 383.8 APPENDIX F OPERATING DATA FOR REACTOR B Synthetic Supernatant Date Influent Lab Results Effluent Lab Results pH T© PO4-P NH 4.N Mg PO4-P NH4 .N Mg (mg/L) (mg/L) (mg/L) (mg/L) (mg/L) (mg/L) Start 16-Jul-02 135.7 700.5 1611.0 16.3 601.4 55.2 7.4 20 17-Jul-02 135.7 700.5 1611.0 17.2 588.0 52.9 7.4 19 18-Jul-02 137.5 685.2 1604.7 16.0 589.7 57.3 7.4 18 19-Jul-02 139.2 679.0 1600.6 13.9 578.6 86.5 7.4 18 20-Jul-02 Plug 21-Jul-02 135.5 718.2 1583.2 22.1 631.3 35.8 7.4 20 22-Jul-02 135.5 718.2 1583.2 20.3 622.3 37.7 7.4 20 23-Jul-02 130.2 715.5 1576.0 16.3 604.6 62.7 7.5 19 24-Jul-02 127.5 717.0 1561.1 15.8 633.6 48.3 7.5 19 25-Jul-02 108.9 590.5 1567.6 20.2 534.7 36.4 7.5 19 26-Jul-02 102.9 589.9 1598.4 25.6 509.6 30.1 7.5 19 27-Jul-02 139.3 650.2 1609.6 25.4 574.1 28.2 7.5 20 28-Jul-02 140.8 658.7 1598.5 24.6 519.1 23.8 7.5 18 29-Jul-02 Plug 30-Jul-02 ' 144.9 723.5 1431.3 30.5 551.8 44.9 7.4 18 31-Jul-02 145.3 733.0 1323.3 19.2 635.9 36.9 7.5 17 l-Aug-02 145.3 733.0 1683.2 12.5 621.7 35.5 7.5 17 2-Aug-02 152.6 707.4 1670.5 16.3 583.6 36.3 7.5 16 3-Aug-02 152.6 707.4 1670.5 13.3 598.3 31.0 7.5 18 4-Aug-02 150.7 709.4 1683.2 18.8 615.1 37.6 7.5 17 5-Aug-02 151.4 710.7 1697.3 11.1 603.1 40.3 7.5 16 6-Aug-02 140.9 685.3 1620.3 19.2 587.5 35.9 7.5 15 7-Aug-02 138.0 675.9 1620.3 9.9 574.8 48.7 7.5 15 8-Aug-02 139.8 675.9 1620.3 10.8 578.1 51.4 7.6 15 9-Aug-02 136.2 661.0 1611.8 9.2 520.3 70.4 7.6 16 10-Aug-02 133.5 657.1 1609.5 8.7 575.2 49.3 7.6 21 ll-Aug-02 Plug 12-Aug-02 133.1 640.3 1450.1 15.3 549.2 50.2 7.5 20 13-Aug-02 132.0 637.9 1446.3 16.7 553.2 30.4 7.5 19 14-Aug-02 137.4 676.0 1456.3 10.2 570.8 35.0 7.5 18 15-Aug-02 133.5 681.4 1436.8 19.5 578.2 33.8 7.5 17 16-Aug-02 124.3 664.0 1430.5 15.7 569.1 27.7 7.5 17 17-Aug-02 shutdown 174 Removal Efficiency (%) Mg Total Supernatant Recycle PO4-P NH4 .N Mg Influent Flow Influent Flow Flow Flow (mg/L) (mg/L) (mg/L) (mL/min) (mL/min) (mL/min) (mL/min) 86.8 5.7 88.7 45 500 455 5700 86.1 8.3 87.4 45 530 485 5770 87.2 5.4 88.9 45 500 455 5950 89.0 5.8 90.9 43 450 407 6050 82.2 4.3 82.9 45 550 505 6250 83.7 5.7 84.2 43 530 487 6270 86.4 8.0 87.4 45 550 505 6050 86.4 2.9 88.8 45 500 455 6200 80.1 2.8 81.2 35 510 475 5990 73.7 9.0. 68.5 28 550 522 5700 80.3 4.5 79.1 40 530 490 5970 81.1 4.4 80.6 40 505 465 5995 77.0 16.7 62.8 • 38 450 412 6150 85.5 5.0 67.9 33 380 347 5770 90.7 7.7 74.1 35 430 395 4670 88.4 10.2 73.3 35 430 395 5070 90.3 6.0 81.5 40 400 360 5100 86.4 5.0 74.3 40 460 420 5190 92.1 7.7 70.5 35 435 400 4815 85.1 6.6 73.1 33 400 367 4100 92.2 7.8 61.3 33 425 392 5075 91.6 6.4 63.0 30 350 320 3650 92.6 13.3 52.7 30 325 295 3425 92.9 4.9 61.8 30 375 345 3625 87.4 6.2 59.6 30 ' 350 320 3850 86.2 5.4 74.8 25 300 275 3850 91.9 7.9 71.2 25 300 275 3100 84.3 8.7 66.8 23 325 302 3625 86.3 7.2 74.9 25 325 300 3755 Total Flow (influent+recycle) (mL/min) Recycle Conditions at the Inlet Ratio PO4.P NH4-N Mg Molar Removal Inlet to outlet PO4.P NH4-N Mg 6200 11.4 123.5 637.5 145.0 3.5E-03 2.6E-03 3.7E-03 6300 10.9 124.2 641.1 136.8 3.5E-03 3.8E-03 3.5E-03 6450 11.9 125.1 623.6 144.4 3.5E-03 2.4E-03 3.6E-03 6500 13.4 125.9 614.1 152.9 3.6E-03 2.5E-03 2.7E-03 6800 11.4 124.4 659.4 129.5 3.3E-03 2.0E-03 3.9E-03 6800 11.8 124.5 659.9 128.5 3.4E-03 2.7E-03 3.7E-03 6600 11.0 119.5 656.9 128.9 3.3E-03 3.7E-03 2.7E-03 6700 12.4 116.0 652.5 140.5 3.2E-03 1.3E-03 3.8E-03 6500 11.7 101.5 550.0 107.6 2.6E-03 1.1E-03 2.9E-03 6250 10.4 97.6 559.9 81.4 2.3E-03 3.6E-03 2.1E-03 6500 11.3 128.8 601.1 121.5 3.3E-03 1.9E-03 3.8E-03 6500 11.9 129.6 606.5 126.6 3.4E-03 1.9E-03 4.2E-03 6600 13.7 132.7 662.4 120.9 3.3E-03 7.9E-03 3.1E-03 6150 15.2 132.7 669.3 114.9 3.7E-03 2.4E-03 3.2E-03 5100 10.9 133.5 673.3 137.0 3.9E-03 3.7E-03 4.2E-03 5500 11.8 140.2 649.8 136.0 4.0E-03 4.7E-03 4.1E-03 5500 12.8 137.4 636.6 167.1 4.0E-03 2.7E-03 5.6E-03 5650 11.3 137.6 647.7 146.4 3.8E-03 2.3E-03 4.5E-03 5250 11.1 139.2 653.5 136.6 4.1E-03 3.6E-03 4.0E-03 4500 10.3 129.3 628.8 133.7 3.6E-03 3.0E-03 4.0E-03 5500 11.9 127.3 623.4 125.8 3.8E-03 3.5E-03 3.2E-03 4000 10.4 127.8 618.0 138.9 3.8E-03 2.8E-03 3.6E-03 3750 10.5 123.7 599.9 148.8 3.7E-03 5.7E-03 3.2E-03 4000 9.7 122.8 604.5 128.8 3.7E-03 2.1E-03 3.3E-03 4200 11.0 121.7 585.4 124.3 3.4E-03 2.6E-03 3.0E-03 4150 12.8 121.0 584.7 120.5 3.4E-03 2.3E-03 3.7E-03 3400 10.3 126.0 619.6 121.4 3.7E-03 3.5E-03 3.6E-03 3950 11.2 124.0 633.2 101.7 3.4E-03 3.9E-03 2.8E-03 4080 11.6 114.8 612.9 110.0 3.2E-03 3.1E-03 3.4E-03 176 Mg:P N:P Mg:P N:P Product of S.S (ratio) Removal Removal at inlet at inlet Ionic Constiunets at inlet Ratio Ratio (at inlet) 1.1 0.7 1.5 11.4 1.1E-06 24.3 1.0 1.1 1.4 11.4 1.0E-06 23.2 1.0 0.7 1.5 11.0 1.1E-06 24.0 0.8 0.7 1.6 10.8 1.1E-06 25.2 1.2 0.6 1.3 11.7 1.0E-06 22.6 1.1 0.8 1.3 11.7 1.0E-06 22.5 0.8 1.1 1.4 12.2 9.6E-07 24.2 1.2 0.4 1.6 12.5 1.0E-06 25.4 1.1 0.4 1.4 12.0 5.7E-07 16.1 0.9 1.5 1.1 12.7 4.2E-07 11.9 1.1 0.6 1.2 10.3 8.9E-07 25.2 1.2 0.6 1.3 10.4 9.4E-07 26.7 0.9 2.4 1.2 11.1 1.0E-06 22.6 0.9 0.7 1.1 11.2 9.7E-07 27.3 1.1 0.9 1.3 11.2 1.2E-06 33.0 1.0 1.2 1.3 10.3 1.2E-06 33.2 1.4 0.7 1.6 10.3 1.4E-06 39.1 1.2 0.6 1.4 10.4 1.2E-06 34.9 1.0 0.9 1.3 10.4 1.2E-06 33.3 1.1 0.8 1.3 10.8 1.0E-06 29.1 0.8 0.9 1.3 10.8 9.5E-07 26.7 1.0 0.8 1.4 10.7 1.0E-06 36.6 0.9 1.5 1.6 10.7 1.0E-06 36.8 0.9 0.6 1.4 10.9 9.1E-07 31.9 0.9 0.8 1.3 10.6 8.4E-07 23.7 1.1 0.7 1.3 10.7 8.1E-07 22.8 1.0 0.9 1.2 10.9 9.0E-07 25.4 0.8 1.2 1.1 11.3 7.6E-07 21.4 1.1 1.0 1.2 11.8 7.3E-07 20.7 P04-P Conditions Dilution Factor NH4-N Conditions inside the reactor for P inside the reactor Feed gives Recycle gives Total Feed gives Recycle gives Total 10.0 10.4 9.7 8.7 15.0 15.8 14.7 12.9 25.0 26.2 24.4 21.6 0.8 0.8 0.8 0.8 51.4 53.9 48.3 42.5 552.9 538.5 544.0 538.6 604.3 592.4 592.4 581.1 10.1 9.7 10.0 8.7 8.0 8.6 10.5 10.1 20.3 18.7. 15.0 14.6 18.6 23.4 23.3 22.7 30.4 28.4 24.9 23.3 26.6 32.0 33.8 32.7 0.8 0.8 0.8 0.8 0.7 0.7 0.7 0.7 53.3 51.4 54.7 48.7 43.2 49.3 49.0 47.1 580.2 573.8 554.2 586.3 492.8 464.8 527.3 534.6 633.5 625.3 608.9 635.0 535.9 514.0 576.3 581.8 9.0 8.2 11.3 11.0 10.0 11.2 11.5 11.5 9.8 11.2 10.7 11.5 28.5 18.0 11.4 15.0 12.3 17.2 10.1 17.5 9.2 9.8 8.4 7.9 37.5 26.2 22.7 26.0 22.3 28.4 21.7 29.0 19.0 21.0 19.1 19.4 0.7 0.8 0.8 0.8 0.8 0.8 0.8 0.8 0.9 0.8 0.8 0.8 45.2 41.4 56.8 50.8 46.3 52.7 54.1 55.9 48.2 54.1 52.0 56.7 514.2 596.6 569.3 538.0 554.8 565.1 553.1 535.2 530.4 527.5 475.2 521.2 559.3 638.0 626.1 588.8 601.1 617.8 607.3 591.1 578.6 581.6 527.2 577.9 10.1 8.7 11.1 10.2 9.1 14.1 15.5 9.3 17.9 14.4 24.2 24.2 20.4 28.1 23.6 0.8 0.8 0.8 0.8 0.8 48.8 42.3 54.7 52.1 48.8 503.5 513.2 520.4 530.7 523.8 552.3 555.4 575.1 582.8 572.6 178 Dilution Factor Mg Conditions Dilution Factor for N inside the reactor for Mg Feed gives Recycle gives Total PO4-P 5.2E-02 11.7 50.8 7.6E-02 11.5 48.5 5.0E-02 11.2 52.9 5.4E-02 10.6 80.5 3.9E-02 10.5 32.9 5.2E-02 10.0 34.7 7.3E-02 10.7 57.4 2.7E-02 10.5 44.7 2.5E-02 8.4 33.5 8.2E-02 7.2 27.4 4.1E-02 9.9 25.9 4.1E-02 9.8 21.9 1.6E-01 8.2 41.9 4.7E-02 7.1 34.6 7.0E-02 11.6 32.5 9.4E-02 10.6 33.4 5.6E-02 12.1 28.7 4.6E-02 11.9 34.5 7.1E-02 11.3 37.0 6.0E-02 11.9 32.7 7.2E-02 9.7 44.9 5.9E-02 12.2 46.9 1.2E-01 12.9 64.3 4.4E-02 12.1 44.6 5.7E-02 10.4 46.0 5.0E-02 8.7 28.2 7.2E-02 10.7 31.9 8.0E-02 8.4 31.0 6.6E-02 8.8 25.5 62.5 0.6 8.1E-04 60.0 0.6 8.5E-04 64.1 0.6 7.9E-04 91.1 0.4 7.0E-04 43.4 0.7 9.8E-04 44.7 0.7 9.2E-04 68.2 0.5 8.0E-04 55.2 0.6 7.5E-04 42.0 0.6 8.6E-04 34.6 0.6 1.0E-03 35.8 0.7 1.1E-03 31.7 0.7 1.1E-03 50.1 0.6 1.2E-03 41.7 0.6 8.5E-04 44.0 0.7 7.3E-04 44.1 0.7 8.4E-04 40.9 0.8 7.2E-04 46.4 0.7 9.2E-04 48.3 0.6 7.0E-04 44.6 0.7 9.4E-04 54.6 0.6 6.1E-04 59.0 0.6 6.8E-04 77.2 0.5 6.2E-04 56.7 0.6 6.3E-04 56.4 0.5 7.8E-04 36.9 0.7 7.8E-04 42.6 0.6 6.6E-04 39.3 0.6 9.1E-04 34.2 0.7 7.6E-04 Concentration in Moles Mg:P N:P Product of inside the reactor (molar ratio) (molar ratio) Ionic Constiunets NH4-N Mg (including recycle) (including recycle) 4.3E-02 2.6E-03 3.2 53.5 8.9E-08 4.2E-02 2.5E-03 2.9 50.0 8.8E-08 4.2E-02 2.6E-03 3.3 53.6 8.8E-08 4.1E-02 3.7E-03 5.4 59.4 1.1E-07 4.5E-02 1.8E-03 1.8 46.1 7.9E-08 4.5E-02 1.8E-03 2.0 48.7 7.5E-08 4.3E-02 2.8E-03 3.5 54.1 9.8E-08 4.5E-02 2.3E-03 3.0 60.4 7.7E-08 3.8E-02 1.7E-03 2.0 44.6 5.7E-08 3.7E-02 1.4E-03 1.4 35.5 5.4E-08 4.1E-02 1.5E-03 1.3 37.7 6.6E-08 4.2E-02 1.3E-03 1.2 39.3 5.7E-08 4.0E-02 2.1E-03 1.7 33.0 1.0E-07 4.6E-02 1.7E-03 2.0 53.8 6.6E-08 4.5E-02 1.8E-03 2.5 61.0 5.9E-08 4.2E-02 1.8E-03 2.2 50.1 6.4E-08 4.3E-02 1.7E-03 2.3 59.6 5.2E-08 4.4E-02 1.9E-03 2.1 48.0 7.7E-08 4.3E-02 2.0E-03 2.8 62.0 6.0E-08 4.2E-02 1.8E-03 2.0 45.1 7.3E-08 4.1E-02 2.2E-03 3.7 67.3 5.7E-08 4.2E-02 2.4E-03 3.6 61.2 6.8E-08 3.8E-02 3.2E-03 5.2 61.0 7.4E-08 4.1E-02 2.3E-03 3.7 65.9 6.0E-08 3.9E-02 2.3E-03 3.0 50.5 7.1E-08 4.0E-02 1.5E-03 1.9 50.7 4.7E-08 4.1E-02 1.8E-03 2.7 62.4 4.7E-08 4.2E-02 1.6E-03 1.8 45.9 6.1E-08 4.1E-02 1.4E-03 1.9 53.7 4.4E-08 Ps(eg) S.S (ratio) Effluent SS Crystal Harvest CRT Harvest in reactor Volume Volume Average (1) (1) (days) In reactor SS 4.5E-08 4.5E-08 4.5E-08 4.5E-08 4.5E-08 4.5E-08 4.0E-08 4.0E-08 3.5E-08 3.5E-08 3.5E-08 3.5E-08 4.5E-08 3.5E-08 3.5E-08 3.5E-08 3.5E-08 3.5E-08 3.5E-08 3.5E-08 3.5E-08 2.8E-08 2.8E-08 2.8E-08 3.5E-08 3.5E-08 3.5E-08 3.5E-08 3.5E-08 2.0 2.0 2.0 2.4 1.8 1.7 2.5 1.9 1.6 1.5 1.9 1.6 2.2 1.9 1.7 1.8 1.5 2.2 1.7 2.0 1.6 2.4 2.6 2.1 2.0 1.3 1.3 1.7 1.2 1.2 1.2 1.2 1.5 1.1 1.0 1.5 1.2 1.1 1.1 1.1 0.9 1.6 1.2 0.7 0.9 0.7 1.2 0.7 1.1 0.8 1.1-1.1 0.8 1.1 0.8 0.6 1.0 0.7 10.8 10.3 11.0 10.8 10.6 10.2 11.0 10.5 10.0 11.0 10.7 11.0 11.0 10.9 11.0 10.7 10.2. 9.9 9.5 10.2 9.7 9.3 9.5 10.1 1.3 1.3 1.3 1.3 1.3 1.3 1.3 1.3 1.3 1.3 1.3 1.3 1.3 1.3 1.3 1.3 1.3 1.3 1.3 1.3 1.3 1.3 1.3 1.3 9.5 9.0 11.0 10.0 11.5 12.0 12.0 11.0 10.0 9.0 9.0 8.0 8.5 8.0 8.0 8.0 10.0 1.9 1.9 1.9 1.9 1.8 1.8 1.8 1.8 1.8 1.8 1.9 2.0 2.0 2.1 2.0 1.9 1.8 181 Harvested Mean Mass Crystal Size (g) (mm) Mass P Removed (g) Theoretical Mass MAP Grown (g) 77.1 608.8 451.2 1.97 81.6 644.2 501.3 1.91 78.6 620.3 72.6 573.0 521.4 1.89 487.8 1.90 81.0 639.1 503.9 1.94 79.5 627.6 511.4 2.10 81.7 645.1 72.2 569.5 519.8 2.20 59.7 471.0 508.0 2.37 57.0 450.0 500.7 1.95 78.9 622.8 76.4 602.9 492.5 2.03 527.1 1.65 66.2 522.2 62.1 490.0 568.0 2.23 74.9 591.4 76.7 605.6 573.3 2.04 71.5 564.0 545.0 2.36 78.7 621.1 589.7 2.47 80.3 633.4 533.1 2.25 63.4 500.3 549.0 2.03 71.8 566.7 503.6 1.85 59.0 465.4 516.3 1.67 53.6 422.8 61.6 486.4 525.7 1.96 569.5 2.01 53.6 423.1 515.8 1.73 45.0 355.5 514.6 1.32 50.0 394.7 48.9 386.2 527.2 1.89 46.4 365.9 Annacis Supernatant Date Mg Feed Influent Lab Results Inlet Effluent Lab Results Mg PO4-P NH4.N Mg N:P PO4-P NH4.N (mg/1) (mg/L) (mg/L) (mg/L) ratio (mg/L) (mg/L 4-Sep-02 1698.5 135.6 1056.3 6.0 17.2 5.9 908.1 5-Sep-02 1693.9 135.6 1056.3 6.0 17.2 6.6 910.3 6-Sep-02 1693.9 136.2 1000.8 6.3 16.3 3.4 859.5 7-Sep-02 1693.9 131.1 1037.8 5.9 17.5 5.8 916.0 8-Sep-02 1706.0 131.1 1037.8 5.9 17.5 5.8 887.4 9-Sep-02 1706.0 131.1 1037.8 6.2 17.5 4.1 846.3 10-Sep-02 1743.0 134.6 1081.1 7.2 17.8 7.4 939.0 ll-Sep-02 1769.1 133.6 1079.5 6.7 17.9 7.9 851.7 12-Sep-02 1403.2 128.4 1084.5 6.4 18.7 13.5 956.3 13-Sep-02 1403.2 131.9 1081.9 5.9 18.1 7.3 887.9 14-Sep-02 1456.3 131.9 1081.9 5.9 18.1 10.2 951.2 15-Sep-02' 1423.6 131.9 1081.9 5.9 18.1 11.6 958.0 16-Sep-02 1449.9 141.4 1058.2 5.5 16.6 12.4 918.9 17-Sep-02 1453.2 131.2 1024.9 5.8 17.3 11.5 906.3 18-Sep-02 1450.4 130.2 1037.5 5.5 17.6 11.4 859.3 19-Sep-02 1198.5 130.5 1015.1 5.5 17.2 10.6 813.7 pH Mg (mg/L) T© Removal Efficiency (%) Mg Influent Flow PO4-P NH4 .N Mg (mg/L) (mg/L) (mg/L) (mL/min) 71.7 8.3 15 95.2 5.2 56.2 40 59.0 8.3 16 94.6 4.7 64.6 40 58.3 8.3 14 97.3 5.3 64.4 42 61.4 8.3 15 95.1 3.5 59.1 38 76.1 8.3 15 95.2 6.5 49.6 35 63.5 8.3 17 96.6 11.1 56.5 35 62.3 8.2 16 93.9 3.5 65.5 40 49.8 8.2 16 93.5 13.2 70.2 41 39.2 8.3 16 88.4 3.0 70.8 42 58.2 8.3 17 93.9 9.5 57.4 43 42.7 8.3 18 91.5 4.1 66.3 40 35.6 8.2 18 90.4 3.3 71.5 39 38.3 8.2 17 89.5 -4.2 69.4 40 34.7 8.3 15 90.5 4.1 70.7 35 38.8 8.3 15 90.5 9.8 68.5 35 15.3 8.3 16 89.6 -2.2 84.4 40 184 Total Influent Flow Supernatant Flow Recycle Flow Total Flow Recycle Ratio (influent+recycle) (mL/min) (mL/min) (mL/min) (mL/min) 430 390 3820 4250 8.9 420 380 3580 4000 8.5 450 408 3500 3950 7.8 445 407 3655 4100 8.2 410 375 3240 3650 7.9 425 390 3975 4400 9.4 400 360 4100 4500 10.3 450 409 3700 4150 8.2 460 418 3690 4150 8.0 460 417 3690 4150 8.0 480 440 3520 4000 7.3 465 426 3335 3800 7.2 480 400 3020 3500 6.3 450 415 3550 4000 7.9 430 395 3830 4260 8.9 510 400 3730 4240 7.3 Conditions at the Inlet PQ4,P NH4-N Mg Molar Removal Inlet to outlet PQ4,P NH4 -N Mg Mg:P N:P Removal Removal Ratio Ratio 123.0 958.1 163.5 3.8E-03 122.7 955.7 166.8 3.7E-03 123.5 907.4 163.8 3.9E-03 119.9 949.2 150.0 3.7E-03 119.9 949.2 151.0 3.7E-03 120.3 952.3 146.2 3.7E-03 121.1 973.0 180.8 3.7E-03 121.5 981.1 167.3 3.7E-03 116.7 985.5 134.0 3.3E-03 119.5 980.7 136.5 3.6E-03 120.9 991.7 126.8 3.6E-03 120.8 991.1 124.8 3.5E-03 117.8 881.9 125.4 3.4E-03 121.0 945.1 118.4 3.5E-03 119.6 953.0 123.1 3.5E-03 102.4 796.1 98.3 3.0E-03 3.6E-03 3.8E-03 1.0 0.9 3.2E-03 4.4E-03 1.2 0.9 3.4E-03 4.3E-03 1.1 0.9 2.4E-03 3.7E-03 1.0 0.6 4.4E-03 3.1E-03 0.8 1.2 7.6E-03 3.4E-03 0.9 2.0 2.4E-03 4.9E-03 1.3 0.7 9.2E-03 4.8E-03 1.3 2.5 2.1E-03 3.9E-03 1.2 0.6 6.6E-03 3.2E-03 0.9 1.8 2.9E-03 3.5E-03 1.0 0.8 2.4E-03 3.7E-03 1.0 0.7 -2.6E-03 3.6E-03 1.1 -0.8 2.8E-03 3.4E-03 1.0 0.8 6.7E-03 3.5E-03 1.0 1.9 -1.3E-03 3.4E-03 1.2 -0.4 Mg:P N:P Product of S.S (ratio) P04-P Conditions at inlet at inlet Ionic Constiunets at inlet inside the reactor (at inlet) Feed gives Recycle gives Total 1.7 17.2 1.8E-06 64.5 12.4 5.3 17.8 1.8 17.2 1.9E-06 65.4 12.9 5.9 18.8 1.7 16.3 1.8E-06 63.9 14.1 3.0 17.1 1.6 17.5 1.6E-06 57.1 13.0 5.2 18.2 1.6 17.5 1.7E-06 57.5 13.5 5.1 18.6 1.6 17.5 1.6E-06 58.3 11.6 3.7 15.4 1.9 17.8 2.0E-06 58.3 10.8 6.7 17.5 1.8 17.9 1.9E-06 54.6 13.2 7.0 20.2 1.5 18.7 1.5E-06 46.7 12.9 12.0 24.9 1.5 18.2 1.5E-06 48.5 13.3 6.5 19.7 1.4 18.2 1.5E-06 46.0 14.5 9.0 23.5 1.3 18.2 1.4E-06 40.9 14.8 10.2 25.0 1.4 16.6 1.3E-06 35.7 16.2 10.7 26.8 1.3 17.3 1.3E-06 41.0 13.6 10.2 23.8 1.3 17.6 1.3E-06 42.5 12.1 10.2 22.3 1.2 17.2 7.7E-07 24.3 12.3 9.3 21.7 187 Dilution Factor forP NH4-N Conditions inside the reactor Feed gives Recycle gives Total Dilution Factor ForN Mg Conditions inside the reactor Feed gives Recycle gives Total 0.9 96.9 816.2 913.1 4.7E-02 16.5 64.4 80.9 0.8 100.4 814.8 915.1 4.3E-02 17.5 52.8 70.3 0.9 103.4 761.6 865.0 4.7E-02 18.7 51.7 70.4 0.8 103.0 816.6 919.6 3.1E-02 16.3 54.7 71.0 0.8 106.6 787.7 894.4 5.8E-02 17.0 67.5 84.5 0.9 92.0 764.5 856.5 1.0E-01 14.1 57.4 71.5 0.9 86.5 855.5 942.0 3.2E-02 16.1 56.8 72.8 0.8 106.4 759.3 865.7 1.2E-01 18.1 44.4 62.6 0.8 109.2 850.3 959.5 2.6E-02 14.8 34.8 49.7 0.8 108.7 789.5 898.2 8.4E-02 15.1 51.7 66.9 0.8 119.0 837.1 956.1 3.6E-02 15.2 37.6 52.8 0.8 121.3 840.8 962.0 2.9E-02 15.3 31.3 46.5 0.8 120.9 792.9 913.9 -3.6E-02 17.2 33.1 50.3 0.8 106.3 804.4 910.7 3.6E-02 13.3 30.8 44.1 0.8 96.2 772.5 868.7 8.8E-02 12.4 34.9 47.3 0.8 95.8 715.8 811.6 -1.9E-02 11.8 13.5 25.3 188 Dilution Factor Concentration in Moles for Mg inside the reactor PCyP NH4-N Mg Mg:P N:P (molar ratio) (molar ratio) (including recycle) (including recycle) 0.5 5.7E-04 6.5E-02 3.4E-03 5.9 113.7 0.6 6.1E-04 6.5E-02 2.9E-03 4.8 107.8 0.6 5.5E-04 6.2E-02 2.9E-03 5.3 112.3 0.5 5.9E-04 6.6E-02 3.0E-03 5.0 111.9 0.4 6.0E-04 6.4E-02 3.5E-03 5.9 106.4 0.5 5.0E-04 6.1E-02 3.0E-03 6.0 123.5 0.6 5.6E-04 6.7E-02 3.0E-03 5.4 119.3 0.6 6.5E-04 6.2E-02 2.6E-03 4.0 95.0 0.6 8.0E-04 6.9E-02 2.1E-03 2.6 85.2 0.5 6.4E-04 6.4E-02 2.8E-03 4.4 100.7 0.6 . 7.6E-04 6.8E-02 2.2E-03 2.9 90.0 0.6 8.1E-04 6.9E-02 1.9E-03 2.4 85.2 0.6. 8.7E-04 6.5E-02 2.1E-03 2.4 75.4 0.6 7.7E-04 6.5E-02 1.8E-03 2.4 84.7 0.6 7.2E-04 6.2E-02 2.0E-03 2.7 86.4 0.7 7.0E-04 5.8E-02 1.1E-03 1.5 83.0 Product of Ps(eg) S.S (ratio) Effluent SS Crystal Harvest Ionic Constiunets in reactor Volume Volume (including recycle) (1) (1) 1.3E-07 2.9E-08 4.4 1.3 7.0 1.2E-07 2.9E-08 4.0 1.2 8.0 1.3 1.0E-07 2.8E-08 3.6 0.6 1.1E-07 2.9E-08 .4.0 1.1 8.5 1.3 1.3E-07 2.9E-08 4.7 1.3 9.0E-08 2.8E-08 3.3 0.8 9.3 1.3 1.2E-07 3.5E-08 3.3 1.2 1.0E-07 3.5E-08 3.0 0.9 1.1E-07 3.2E-08 3.6 1.5 10.6 1.3 1.1E-07 3.2E-08 3.6 1.1 10.3 1.3 1.1E-07 3.2E-08 3.6 1.3 1.1E-07 3.5E-08 3.1 1.1 11.0 1.3 1.2E-07 3.5E-08 3.4 1.2 10.7 1.3 9.2E-08 3.2E-08 2.9 1.1 10.5 1.3 8.8E-08 3.2E-08 2.8 1.1 4.3E-08 3.2E-08 1.3 0.4 11.0 1.3 CRT Harvest Harvested Mean Mass P Theoretical Average Mass Crystal Size Removed Mass MAP Grown (days) In reactor SS (g) (mm) (g) (g) 72.5 572.1 8.0 2.3 513.2 1.58 70.2 554.2 77.8 614.3 9.0 2.6 507.3 1.74 73.1 576.8 67.4 531.6 11.5 2.9 553.9 1.83 71.1 560.9 65.5 517.0 73.6 580.9 15.0 3.0 638.4 2.22 68.4 539.5 14.0 3.1 651.0 2.37 74.3 586.7 76.5 603.5 16.0 3.1 633.8. 2.10 73.1 576.9 14.5 3.5 559.5 1.79 72.9 575.2 13.0 3.5 643.0 1.67 71.0 560.1 67.0 528.9 15.0 3.3 618.3 1.85 67.4 531.8 191 Lulu Supernatant Date Mg Feed Influent Lab Results Inlet Effluent Lab Results Mg PO4-P NH4 .N Mg N:P PO4-P NH4.N Mg (mg/1) (mg/L) (mg/L) (mg/L) ratio (mg/L) (mg/L) (mg/L) 2-Oct-02 1900.5 91.9 1024.4 5.5 24.7 5.0 925.6 35.0 3-Oct-02 1883.3 91.9 1024.4 5.5 24.7 7.4 953.4 30.8 4-Oct-02 2356.6 91.9 1024.4 5.8 24.7 5.2 943.4 47.3 5-Oct-02 2296.7 92.9 987.3 5.6 23.5 3.7 917.3 48.1 6-Oct-02 2223.9 91.6 965.7 5.5 23.3 5.7 891.0 58.5 7-Oct-02 2223.9 92.3 994.4 5.2 23.8 5.6 911.6 51.2 8-Oct-02 1559.7 93.8 1003.9 4.8 23.7 8.9 922.4 33.1 9-Oct-02 1663.1 95.1 1037.0 5.6 24.1 8.6 965.1 22.6 10-Oct-02 1681.3 92.3 974.0 5.2 23.4 7.2 883.3 25.1 8-Nov-02 1465.5 76.2 1090.4 4.6 31.7 7.9 1021.3 25.0 9-Nov-02 1465.5 76.2 1090.4 4.6 31.7 7.7 1019.4 23.9 lO-Nov-02 1258.4 76.1 1107.4 5.1 32.2 7.4 1023.0 23.1 ll-Nov-02 1258.4 75.7 1104.5 4.8 32.3 7.5 995.7 20.0 12-Nov-02 1394.5 72.2 1021.4 4.8 31.3 6.6 937.1 27.3 13-Nov-02 1368.5 72.5 975.8 5.2 29.8 5.5 891.3 25.0 14-Nov-02 1367.1 74.3 981.4 4.9 29.2 6.0 907.3 24.1 15-Nov-02 1409.2 75.7 1024.4 5.1 29.9 7.8 959.0 31.1 16-Nov-02 1409.2 74.4 1010.0 5.2 30.0 8.0 919.7 27.1 17-Nov-02 1411.9 76.6 999.3 5.0 28.9 7.7 927.2 22.2 6-Dec-02 1398.6 80.1 905.7 4.2 25.0 9.0 830.1 26.7 7-Dec-02 1385.8 79.4 903.2 4.4 25.2 8.9 835.2 26.1 8-Dec-02 1356.0 82.9 897.3 5.3 24.0 8.3 827.1 23.1 9-Dec-02 1441.5 83.1 914.7 5.3 24.3 5.4 829.7 54.0 10-Dec-02 1453.3 82.7 925.8 5.1 24.8 5.1 835.0 55.5 ll-Dec-02 1439.2 81.4 922.4 4.6 25.1 4.9 840.2 48.1 12-Dec-02 1425.8 78.9 915.4 4.9 25.7 4.0 796.4 75.6 13-Dec-02 1487.3 79.0 884.0 5.1 24.7 4.1 799.9 89.5 14-Dec-02 1487.3 79.0 884.0 5.1 24.7 4.2 786.6 87.2 15-Dec-02 1484.1 81.5 879.0 5.1 23.9 4.3 719.3 110.3 16-Dec-02 1484.1 81.5 879.0 5.1 23.9 4.8 756.9 105.2 17-Dec-02 1495.7 83.3 905.6 5.5 24.1 4.9 803.3 97.3 18-Dec-02 1489.8 83.1 901.8 5.4 24.0 6.9 721.5 127.5 19-Dec-02 1501.1 82.4 911.5 5.3 24.5 6.9 747.6 136.9 20-Dec-02 1501.1 82.4 911.5 5.3 24.5 7.2 775.3 152.3 192 pH T© Removal Efficiency (%) Mg Total Supernatant P04-P NH4.N Mg Influent Flow Influent Flow Flow (mg/L) (mg/L) (mg/L) (mL/min) (mL/min) (mL/min) 8.2 13 94.3 4.9 65.1 25 500 475 8.2 14 91.5 2.5 65.8 23 510 487 8.2 14 94.0 3.6 57.2 25 560 535 8.2 13 95.8 2.4 58.4 24 500 476 8.2 14 93.4 2.8 50.7 24 470 446 8.2 12 93.6 3.4 56.8 23 450 427 8.2 14 90.0 2.3 66.2 24 400 376 8.2 13 90.5 2.2 73.8 25 515 490 8.2 11 91.8 4.6 71.2 25 510 485 8.4 11 89.2 1.7 66.3 30 630 600 8.4 8 89.3 1.5 69.5 26 515 489 8.4 10 89.7 2.2 69.0 35 633 598 8.4 11 89.6 4.7 72.5 35 645 610 8.4 12 90.4 3.5 62.7 32 650 618 8.4 12 92.0 3.9 66.0 32 640 608 8.4 10 91.5 2.4 68.9 33 620 587 8.4 • 10 89.2 1.1 60.9 34 640 606 8.4 9 88.6 3.8 66.5 35 650 615 8.4 8 89.4 2.1 71.8 34 650 616 8.4 8 88.1 3.4 65.0 31 600 569 8.4 7 88.1 2.5 65.6 32 620 588 8.4 8 89.4 2.4 71.4 33 590 557 8.3 9 93.1 2.6 48.5 45 650 605 8.3 7 93.4 2.9 48.9 45 630 585 8.3 7 93.5 1.8 55.4 45 625 580 8.2 7 94.4 4.2 44.0 55 600 ' 545 8.2 7 94.3 0.5 35.5 55 610 555 8.2 8 94.2 2.2 37.4 53 585 532 7.9 8 94.1 8.2 33.3 65 600 535 7.9 5 93.4 3.0 38.4 65 580 515 7.9 5 93.3 0.2 43.0 66 595 529 7.6 5 90.5 8.1 35.4 75 580 505 7.6 9 90.4 5.9 30.6 77 600 523 7.6 9 90.1 2.8 20.9 77 615 538 193 Recycle Total Recycle Conditions at the Molar Removal Flow Flow Ratio inlet Inlet to outlet aL/min) (mL/min) P04.P NH4-N Mg PO4.P NH4-N Mg 3500 4000 7.0 87.3 973.2 100.3 2.7E-03 3.4E-03 2.7E-03 3590 4100 7.0 87.7 978.2 90.2 2.6E-03 1.8E-03 2.4E-03 3520 4080 6.3 87.8 978.6 110.7 2.7E-03 2.5E-03 2.6E-03 3550 4050 7.1 88.4 939.9 115.6 2.7E-03 1.6E-03 2.8E-03 3530 4000 7.5 86.9 916.4 118.8 2.6E-03 1.8E-03 2.5E-03 3350 3800 7.4 87.6 943.5 118.6 2.6E-03 2.3E-03 2.8E-03 3400 3800 8.5 88.1 943.7 98.1 2.6E-03 1.5E-03 2.7E-03 3265 3780 6.3 90.4 986.6 86.1 2.6E-03 1.5E-03 2.6E-03 3140 3650 6.2 87.7 926.3 87.4 2.6E-03 3.1E-03 2.6E-03 2870 3500 4.6 72.5 1038.5 74.2 2.1E-03 1.2E-03 2.0E-03 2885 3400 5.6 72.3 1035.3 78.4 2.1E-03 1.1E-03 2.2E-03 3067 3700 4.8 71.9 1046.2 74.4 2.1E-03 1.7E-03 2.1E-03 2935 3580 4.6 71.6 1044.6 72.8 2.1E-03 3.5E-03 2.2E-03 3050 3700 4.7 68.7 971.2 73.2 2.0E-03 . 2.4E-03 1.9E-03 3360 4000 5.3 68.9 927.0 73.4 2.0E-03 2.5E-03 2.0E-03 3430 4050 5.5 70.3 929.2 77.4 2.1E-03 1.6E-03 2.2E-03 3160 3800 4.9 71.7 969.9 79.7 2.1E-03 7.8E-04 2.0E-03 3350 4000 5.2 70.4 955.6 80.8 2.0E-03 2.6E-03 2.2E-03 3550 4200 5.5 72.6 947.0 78.6 2.1E-03 1.4E-03 2.3E-03 3350 3950 5.6 76.0 858.9 76.3 2.2E-03 2.1E-03 2.0E-03 3430 4050 5.5 75.3 856.6 75.7 2.1E-03 1.5E-03 2.0E-03 3440 4030 5.8 78.2 847.1 80.9 2.3E-03 1.4E-03 2.4E-03 3450 4100 5.3 77.4 851.4 104.7 2.3E-03 1.6E-03 2.1E-03 3420 4050 5.4 76.8 859.7 108.5 2.3E-03 1.8E-03 2.2E-03 3425 4050 5.5 75.5 856.0 107.9 2.3E-03 1.1E-03 2.5E-03 3400 4000 5.7 71.6 831.5 135.2 2.2E-03 2.5E-03 2.5E-03 3470 4080 5.7 71.9 804.3 138.7 2.2E-03 3.1E-04 2.0E-03 3365 3950 5.8 71.9 803.9 139.4 2.2E-03 1.2E-03 2.1E-03 3420 4020 5.7 72.6 783.8 165.3 2.2E-03 4.6E-03 2.3E-03 3420 4000 5.9 72.3 780.5 170.9 2.2E-03 1.7E-03 2.7E-03 3505 4100 5.9 74.0 805.2 170.8 2.2E-03 1.4E-04 3.0E-03 3320 3900 5.7 72.4 785.1 197.3 2.1E-03 4.5E-03 2.9E-03 3650 4250 6.1 71.9 794.5 197.2 2.1E-03 3.3E-03 2.5E-03 3605 4220 5.9 72.1 797.3 192.6 2.1E-03 1.6E-03 1.7E-03 194 Mg:P N : P Mg:P N : P Product of S.S (ratio) P 0 4 -P Conditions removal Removal at inlet at inlet Ionic Constiunets at inlet inside the reactor Ratio Ratio (at inlet) Feed gives Recycle gives Total 1.0 1.3 1.5 24.7 8.2E-07 38.9 10.9 4.4 15.3 0.9 0.7 1.3 24.7 7.4E-07 35.9 10.9 6.5 17.4 1.0 0.9 1.6 24.7 9.1E-07 44.1 12.0 4.5 16.6 1.0 0.6 1.7 23.5 9.2E-07 43.3 10.9 3.2 14.1 0.9 0.7 1.8 23.4 9.1E-07 43.3 10.2 5.1 15.3 1.0 0.9 1.7 23.8 9.4E-07 45.5 10.4 4.9 15.3 1.0 0.6 1.4 23.7 7.8E-07 36.8 9.3 7.9 17.2 1.0 0.6 1.2 24.2 7.4E-07 34.1 12.3 7.4 19.7 1.0 1.2 1.3 23.4 6.8E-07 30.7 12.3 6.2 18.4 1.0 0.6 1.3 31.7 5.4E-07 32.9 13.1 6.4 19.5 1.1 0.5 1.4 31.7 5.6E-07 34.9 11.0 6.6 17.5 1.0 0.8 1.3 32.2 5.4E-07 33.6 12.3' 6.1 18.4 1.0 1.7 1.3 32.3 5.2E-07 32.7 12.9 6.1 19.0 0.9 1.2 1.4 . 31.3 4.7E-07 28.7 12.1 5.4 17.5 1.0 1.2 1.4 29.8 4.5E-07 27.3 11.0 4.6 15.7 1.1 0.8 1.4 29.2 4.9E-07 30.1 10.8 5.1 15.9 1.0 0.4 1.4 30.0 5.3E-07 32.6 12.1 6.4 18.5 1.1 1.3 1.5 30.1 5.2E-07 32.6 11.4 6.7 18.1 1.1 0.7 1.4 28.9 5.2E-07 32.5 11.2 6.5 17.7 0.9 1.0 1.3 25.0 4.8E-07 29.3 11.5 7.6 19.2 1.0 0.7 1.3 25.2 4.7E-07 28.7 11.5 7.6 19.1 1.1 0.6 1.3 24.0 5.1E-07 31.5 11.5 7.1 18.5 0.9 0.7 1.7 24.4 6.6E-07 36.0 12.3 4.5 16.8 0.9 0.8 1.8 24.8 6.9E-07 37.4 11.9 4.3 16.2 1.1 0.5 1.8 25.1 6.7E-07 36.4 11.7 4.2 15.8 1.1 1.1 2.4 25.7 7.7E-07 36.8 10.7 3.4 14.2 0.9 0.1 2.5 24.8 7.7E-07 36.7 10.7 3.5 14.3 1.0 0.6 2.5 24.8 7.7E-07 36.8 10.6 3.6 14.2 1.0 2.1 2.9 23.9 9.0E-07 - 26.5 10.8 3.6 14.5 1.2 0.8 3.1 23.9 9.3E-07 27.2 10.5 4.1 14.6 1.4 0.1 3.0 24.1 9.8E-07 28.7 10.7 4.2 15.0 1.4 2.1 . 3.5 24.0 1.1E-06 17.1 10.8 5.8 16.6 1.2 1.6 3.5 24.5 1.1E-06 17.2 10.1 5.9 16.1 0.8 0.7 3.4 24.5 1.1E-06 16.9 10.5 6.1 16.6 195 Dilution NH4-N Conditions Dilution Mg Conditions Factor inside the reactor Factor inside the reactor forP Feed gives Recycle gives Total forN Feed gives Recycle gives Total 0.8 121.6 809.9 931.6 0.04 12.5 30.6 43.1 0.8 121.7 834.8 956.5 0.02 11.2 27.0 38.2 0.8 134.3 813.9 948.3 0.03 15.2 40.8 56.0 0.8 116.0 804.1 920.1 0.02 14.3 42.2 56.5 0.8 107.7 786.3 894.0 0.02 14.0 51.7 65.6 0.8 111.7 803.6 915.3 0.03 14.0 45.2 59.2 0.8 99.3 825.3 924.6 0.02 10.3 29.6 40.0 0.8 134.4 833.6 968.0 0.02 11.7 19.5 31.2 0.8 129.4 759.9 889.3 0.04 12.2 21.6 33.8 0.7 186.9 837.5 1024.4 0.01 13.4 20.5 33.9 0.8 156.8 865.0 1021.8 0.01 11.9 20.3 32.2 0.7 179.0 847.9 1026.9 0.02 12.7 19.1 31.9 0.7 188.2 816.3 1004.5 0.04 13.1 16.4 29.6 0.7 170.6 772.5 943.1 0.03 12.9 22.5 35.4 0.8 148.3 748.7 897.0 0.03 11.7 21.0 32.7 0.8 142.2 768.4 910.6 0.02 11.9 20.4 32.2 0.7 163.4 797.5 960.8 0.01 13.4 25.9 39.3 0.7 155.3 770.2 925.5 0.03 13.1 22.7 35.8 0.8 146.6 783.7 930.3 0.02 12.2 18.7 30.9 0.7 130.5 704.0 834.5 0.03 11.6 22.7 34.3 0.7 131.1 707.4 838.5 0.02 11.6 22.1 33.6 0.8 124.0 706.0 830.1 0.02 11.8 19.7 31.6 0.8 135.0 698.1 833.1 0.02 16.6 45.4 62.0 0.8 133.7 705.1 838.8 0.02 16.9 46.8 63.7 0.8 132.1 710.6 842.6 0.02 16.6 40.7 57.3 0.8 124.7 676.9 801.6 0.04 20.3 64.3 84.6 0.8 120.2 680.3 800.5 0.00 20.7 76.1 96.8 0.8 119.1 670.1 789.2 0.02 20.6 74.3 94.9 0.8 117.0 611.9 728.9 0.07 24.7 93.8 118.5 0.8 113.2 647.2 760.3 0.03 24.8 90.0 114.7 0.8 116.8 686.7 803.5 0.00 24.8 83.1 107.9 0.8 116.8 614.2 731.0 0.07 29.3 108.6 137.9 0.8 112.2 642.1 754.2 0.05 27.8 117.6 145.4 0.8 116.2 662.3 778.5 0.02 28.1 130.1 158.1 196 Dilution Factor Concentration in Moles Mg:P N:P forMg inside the reactor (molar ratio) (molar ratio) P04-P NH4-N Mg (including recycle) (including recycle) 0.6 4.9E-04 6.7E-02 1.8E-03 3.6 135.1 0.6 5.6E-04 6.8E-02 1.6E-03 2.8 121.5 0.5 5.3E-04 6.8E-02 2.3E-03 4.4 126.8 0.5 4.6E-04 6.6E-02 2.4E-03 5.2 144.0 0.4 4.9E-04 6.4E-02 2.7E-03 5.6 129.7 0.5 4.9E-04 6.5E-02 2.5E-03 5.0 132.4 0.6 5.5E-04 6.6E-02 1.7E-03 3.0 119.1 0.6 6.4E-04 6.9E-02 1.3E-03 2.0 108.7 0.6 5.9E-04 6.4E-02 1.4E-03 2.4 106.9 0.5 6.3E-04 7.3E-02 1.4E-03 2.2 116.3 0.6 5.6E-04 7.3E-02 1.3E-03 2.4 129.2 0.6 5.9E-04 7.3E-02 1.3E-03 2.2 123.3 0.6 6.1E-04 7.2E-02 1.2E-03 2.0 116.9 0.5 5.6E-04 6.7E-02 1.5E-03 2.6 119.5 0.6 5.1E-04 6.4E-02 1.4E-03 2.7 126.7 0.6 5.1E-04 6.5E-02 1.3E-03 2.6 127.1 0.5 6.0E-04 6.9E-02 1.6E-03 2.7 114.9 0.6 5.9E-04 6.6E-02 1.5E-03 2.6 113.0 0.6 5.7E-04 6.6E-02 1.3E-03 2.3 116.2 0.6 6.2E-04 6.0E-02 1.4E-03 2.3 96.3 0.6 6.2E-04 6.0E-02 1.4E-03 2.3 97.2 0.6 6.0E-04 5.9E-02 1.3E-03 2.2 99.3 0.4 5.4E-04 6.0E-02 2.6E-03 4.8 109.9 0.4 5.2E-04 6.0E-02 2.7E-03 5.1 114.5 0.5 5.1E-04 6.0E-02 2.4E-03 4.7 118.0 0.4 4.6E-04 5.7E-02 3.5E-03 7.7 125.3 0.3 4.6E-04 5.7E-02 4.0E-03 8.8 124.3 0.3 4.6E-04 5.6E-02 4.0E-03 8.6 123.0 0.3 4.7E-04 5.2E-02 4.9E-03 10.6 111.7 0.3 4.7E-04 5.4E-02 4.8E-03 10.2 115.6 0.4 4.8E-04 5.7E-02 4.5E-03 9.3 118.9 0.3 5.4E-04 5.2E-02 5.7E-03 10.7 97.5 0.3 5.2E-04 5.4E-02 6.1E-03 11.7 103.9 0.2 5.4E-04 5.6E-02 6.6E-03 12.3 103.7 Product of Ps (eg) S.S (ratio) Effluent Crystal Harvest CRT Ionic Constiunets (In reactor) in reactor SS Volume Volume (including recycle) (1) (1) (days) 5.9E-08 2.1E-08 2.8 0.7 10.0 6.1E-08 2.1E-08 3.0 1.0 10.8 1.3 15.0 8.5E-08 2.1E-08 4.1 1.1 10.5 1.3 11.0 7.1E-08 2.1E-08 3.3 0.7 8.6E-08 2.1E-08 4.1 1.4 8.0E-08 2.1E-08 3.8 1.2 11.0 1.3 14.0 6.1E-08 2.1E-08 2.9 1.2 5.7E-08 2.2E-08 2.6 0.8 11.0 1.3 15.0 5.3E-08 2.2E-08 2.4 0.7 6.5E-08 1.6E-08 4.0 1.2 10.9 1.3 15.0 5.5E-08 1.6E-08 3.4 1.1 5.8E-08 1.6E-08 3.6 1.1 11.0 1.3 17.0 5.4E-08 1.6E-08 3.4 0.9 5.6E-08 1.6E-08 3.4 1.0 11.0 1.3 18.0 4.4E-08 1.7E-08 2.7 0.7 4.5E-08 1.6E-08 2.8 0.8 6.7E-08 1.6E-08 4.1 1.4 10.8 1.3 19.0 5.8E-08 1.6E-08 3.6 1.2 4.9E-08 1.6E-08 3.1 0.9 11.0 1.3 20.0 5.3E-08 1.6E-08 3.2 1.2 5.2E-08 1.6E-08 3.2 1.1 4.7E-08 1.6E-08 2.8 0.9 8.3E-08 1.8E-08 4.5 1.3 8.3E-08 1.8E-08 4.5 1.2 7.3E-08 1.8E-08 4.0 1.0 9.2E-08 2.1E-08 4.4 1.1 1.1E-07 2.1E-08 5.1 1.4 1.0E-07 2.1E-08 4.9 1.3 1.2E-07 3.4E-08 3.5 1.0 1.2E-07 3.4E-08 3.6 1.1 1.2E-07 3.4E-08 3.7 1.1 1.6E-07 6.3E-08 2.6 1.0 1.7E-07 6.3E-08 2.7 1.1 2.0E-07 6.3E-08 3.1 1.3 Harvest Harvested Mean Mass P Theoretical NaOH usage Average Mass Crystal Size Removed Mass MAP Grown In reactor SS (g) (mm) (g) (g) (g) 59.3 467.6 3.2 614.2 1.93 59.0 465.3 3.1 625.2 1.75 66.6 525.2 61.0 481.3 54.9 433.4 3.2 671.1 2.30 53.2 419.5 45.7 360.4 3.2 705.8 2.56 60.7 479.2 59.2 466.9 3.1 740.1 2.04 58.7 462.9 47.9 377.9 3.2 635.9 2.19 58.8 463.8 59.5 469.9 3.2 . 656.0 2.43 58.1 458.6 58.4 460.9 57.4 453.3 3.0 686.9 2.85 58.9 464.9 58.4 460.5 3.3 675.5 2.37 60.7 479.3 57.9 456.7 168.5 59.2 467.3 144.6 59.4 469.0 147.9 67.4 532.0 150.4 65.0 513.2 153.2 63.6 501.6 125.1 58.4 461.0 136.2 59.5 469.7 105.8 57.0 449.9 116.5 59.1 466.2 69.0 56.4 445.2 75.1 59.2 467.3 61.5 54.7 431.6 40.5 56.1 442.9 10.6 57.5 454.0 15.3 APPENDIX G APPENDIX G CHEMICAL ANALYSIS OF STRUVITE CRYSTAL 200 Supernatant Date Reactor Sample Solution Crystal Mass Volume mg L Mg mg/L 9-NOV-02 Reactor A,D>4.75mm 72.0 0.050 132.99 9-NOV-02 Reactor A,D>2.83mm 30.5 0.050 57.22 9-NOV-02 Reactor A,D>2mm 31.4 0.050 60.62 9-NOV-02 Reactor A,D>lmm 30.5 0.050 60.48 9-NOV-02 Reactor A,D>0.5mm 32.3 0.050 63.04 9-NOV-02 Reactor B,D>2.83mm 25.5 0.050 55.97 9-NOV-02 Reactor B,D>2mm 33.2 0.050 60.06 9-NOV-02 Reactor B,D>lmm 30.4 0.050 52.71 9-NOV-02 Reactor B,D>0.5mm 34.6 0.050 68.21 l-Nov-02 Reactor A,D>2.83mm 35.3 0.050 76.58 l-Nov-02 Reactor A,D>2mm 36.7 0.050 79.07 l-Nov-02 Reactor A,D>lmm 32.1 0.050 65.32 l-Nov-02 Reactor A,D>0.5mm 33.9 0.050 68.91 28-Oct-02 Reactor B,D>2.83mm 35.7 0.050 73.55 28-Oct-02 Reactor B,D>2mm 31.0 0.050 67.25 28-Oct-02 Reactor B,D>lmm 35.7 0.050 73.92 28-Oct-02 Reactor B,D>0.5mm 36.4 0.050 69.03 10-Oct-02 Reactor A,D>2.83mm 39.7 0.050 72.50 10-Oct-02 Reactor A,D>2mm 38.3 0.050 77.30 10-Oct-02 Reactor A,D>lmm 32.6 0.050 62.31 10-Oct-02 Reactor A,D>0.5mm 33.5 0.050 65.04 10-Oct-02 Reactor B,D>2.83mm 30.7 0.050 63.57 10-Oct-02 Reactor B,D>2mm 37.6 0.050 78.92 10-Oct-02 Reactor B,D>lmm 35.2 0.050 71.39 10-Oct-02 Reactor B,D>0.5mm 34.1 0.050 64.28 Theoretical Ca Al Fe K NH3-N P04-P C03-C Mg mg/L mg/L mg/L mg/L mg/L mg/L mg/L mg/L 14.66 0.43 0.357 Most K 78.42 174.98 30 142.59 12.31 0.05 0.089 analyses 34.29 71.17 12 60.40 11.54 0.05 0.105 were below 31.89 73.42 15 62.18 9.83 0.08 0.206 the detection 31.57 72.52 10 60.40 9.33 0.11 0.110 limit 35.25 82.92 8 63.97 7.74 0.04 0.095 27.18 56.25 10 50.50 7.47 0.05 0.535 37.26 77.32 10 65.75 9.40 0.03 0.135 31.36 72.29 15 60.20 5.50 0.09 0.078 36.14 83.36 18 68.52 6.69 0.04 0.064 36.51 84.20 9 69.91 9.12 0.25 0.396 35.33 88.21 o. 72.68 10.30 0.04 0.328 32.16 82.54 10 63.57 8.65 0.04 0.226 36.52 82.67 15 67.13 13.90 0.06 0.285 39.01 85.43 8 70.70 7.48 0.09 0.172 33.11 76.28 15 61.39 11.15 0.07 0.368 36.07 - 87.06 10 70.70 8.51 0.18 0.245 38,78 88.31 20 72.09 6.29 0.35 0.155 40.11 95.74 5 78.62 7.15 0.06 0.079 40.06 92.25 18 75.85 9.23 0.09 0.125 30.59 78.38 10 64.56 6.01 0.08 0.257 33.74 75.61 15 66.34 5.97 0.25 0.366 31.05 70.29 10 60.80 10.24 0.10 0.251 36.22 87.14 8 74.46 11.36 0.16 0.175 35.53 80.66 0 69.71 9.07 0.08 0.296 32.98 80.35 20 67.53 Theoretical Theoretical % %of %of NH3-N P04-P Struvite % of Theoretical Theoretical Theoretical Mg mg/L mg/L Mg NH3-N P04-P mMol/L 82.15 181.72 94.47 93.22 94.19 96.01 5.47 34.80 76.98 93.98 94.62 95.53 91.78 2.35 35.83 79.25 91.81 97.37 86.09 91.99 2.49 34.80 76.98 93.76 100.02 87.72 93.53 2.49 36.85 81.52 97.45 98.44 92.82 101.09 2.59 29.09 64.36 95.71 110.70 89.82 86.60 2.30 37.88 83.79 92.83 91.25 95.60 91.65 2.47 34.68 76.73 89.46 87.43 87.39 93.54 2.17 39.48 87.33 94.41 99.45 88.90 94.87 2.80 40.28 89.10 97.14 109.45 88.04 93.92 3.15 41.87 92.63 95.08 108.70 81.86 94.67 3.25 36.62 81.02 96.28 102.64 84.95 101.24 2.69 38.68 85.56 96.76 102.55 91.70 96.02 2.83 40.73 ; 90.10 97.13 103.94 93.21 94.24 3.02 35.37 78.24 98.97 109.44 90.64 96.83 2.76 40.73 90.10 95.49 104.46 85.97 96.05 3.04 41.53 91.87 94.03 95.67 90.85 95.56 2.84 45.30 100.20 91.13 92.13 86.23 95.03 2.98 43.70 96.67 95.34 101.83 89.29 94.90 3.18 37.19 82.28 90.16 96.41 79.43 94.63 2.56 38.22 84.55 90.76 97.94 85.54 88.81 2.67 35.03 77.48 93.39 104.45 85.66 90.05 2.61 42.90 94.90 93.06 105.90 81.99 91.28 3.24 40.16 88.84 92.80 102.32 85.86 90.21 2.94 38.91 86.07 89.97 95.09 82.08 92.76 2.64 Ca Al Fe NH3-N P04-P C03-C Mg:P N:P mMol/L mMol/L mMol/L mMol/L mMol/L mMol/L Mole Ratio Mole Ratio 0.37 0.015 0.31 0.001 0.29 0.001 0.25 0.002 0.23 0.003 0.19 0.000 0.19 0.001 0.24 0.000 0.14 0.002 0.17 0.000 0.23 0.008 0.26 o:ooo 0.22 0.000 0.35 0.001 0.19 0.002 0.28 0.001 0.21 0.006 0.16 0.012 0.18 0.001 0.23 0.002 0.15 0.002 0.15 0.008 0.26 0.003 0.28 . 0.005 0.23 0.002 0.007 5.53 0.002 2.37 0.002 , 2.20 0.004 2.18 0.002 2.44 0.002 1.87 0.010 2.59 0.003 2.17 0.002 2.51 0.002 2.53 0.007 2.45 0.006 2.22 0.004 2.53 0.005 2.71 0.003 2.29 0.007 2.50 0.005 2.69 0.003 2.79 0.002 2.79 0.003 2.11 0.005 2.34 0.007 2.14 0.005 2.51 0.004 2.46 0.006 2.28 5.63 1.75 2.28 0.25 2.35 0.50 2.32 0.08 2.66 -0.08 1.80 0.08 2.48 0.08 2.32 0.50 2.67 0.75 2.70 0.00 2.83 -0.75 2.65 0.08 2.65 0.50 2.74 -0.08 2.44 0.50 2.79 0.08 2.83 0.92 3.07 -0.33 2.96 0.75 2.51 0.08 2.42 0.50 2.25 0.08 2.79 -0.08 2.59 -0.75 2.58 0.92 0.97 0.98 1.03 1.04 1.06 0.94 1.07 0.94 0.97 0.92 1.28 1.04 1.00 1.04 0.94 0.94 1.05 0.94 1.17 0.94 1.15 0.87 1.01 0.84 1.07 0.96 1.10 0.99 1.13 0.94 1.09 0.90 1.00 0.95 0.97 0.91 1.07 0.94 1.02 0.84 1.10 0.96 1.16 0.95 1.16 0.90 1.14 0.95 1.03 0.89 204 Mg:N %Mg %N %P %Ca %C %A1 %Fe %C03 Mole Ratio 0.99 9.23 5.37 0.99 9.37 5.45 1.13 9.64 4.91 1.14 9.90 5.00 1.06 9.75 5.30 1.23 10.96 5.12 0.95 9.04 5.45 1.00 8.66 4.99 1.12 9.85 5.07 1.24 10.84 5.02 1.33 10.76 4.67 1.21 10.16 4.85 1.12 10.15 5.23 1.12 10.29 5.32 1.21 10.84 5.17 1.21 10.34 4.90 1.05 9.47 5.18 1.07 9.12 4.92 1.14 10.08 5.09 1.21 9.55 4.53 1.14 9.70 4.88 1.22 10.34 4.89 1.29 10.49 4.68 1.19 10.13 4.90 1.16 9.42 4.68 12.12 1.02 1.46 11.58 2.03 0.49 11.61 1.85 0.96 11.80 1.62 0.16 12.76 1.45 -0.15 10.93 1.53 0.20 11.57 1.13 0.15 11.81 1.55 0.99 11.97 0.80 1.30 11.85 0.96 0.00 11.95 1.25 -1.23 12.78 , 1.61 0.16 12.12 1.28 0.88 11.89 1.95 -0.14 12.22 1.21 0.97 12.12 1.57 0.14 12.06 1.18 1.51 11.99 0.80 -0.50 11.98 0.94 1.17 11.94 1.42 0.15 11.21 0.91 0.90 11.36 0.98 0.16 11.52 1.37 -0.13 11.38 1.62 -1.28 11.71 1.34 1.61 0.028 0.026 7.29 0.003 0.018 2.46 0.003 0.020 4.78 0.008 0.037 0.82 0.012 0.020 -0.77 0.002 0.023 0.98 0.003 0.084 0.75 0.000 0.026 4.93 0.009 0.014 6.50 0.001 0.012 0.00 0.030 0.057 -6.13 0.002 0.054 0.78 0.001 0.036 4.42 0.004 0.043 -0.70 0.010 0.031 4.84 0.006 0.054 0.70 0.021 0.037 7.55 0.040 0.022 -2.52 0.004 0.013 5.87 0.009 0.022 0.77 0.007 0.041 4.48 0.036 0.063 0.81 0.009 0.036 -0.66 0.018 0.028 -6.39 0.007 0.046 8.06 205 Solution Supernatant Date Reactor Crystal Mass Volume Mg Sample try* L mg/L Annacis 4-Oct-02 Reactor A,D>2.83mm 35.9 0.050 67.52 4-Oct-02 Reactor A,D>2mm 29.8 0.050 60.14 4-Oct-02 Reactor A,D>lmm 34.6 0.050 62.88 4-Oct-02 Reactor A,D>0.5mm 30.2 0.050 56.71 4-Oct-02 Reactor B,D>2.83mm 29.7 0.050 65.34 4-Oct-02 Reactor B,D>2mm 36.9 0.050 62.14 4-Oct-02 Reactor B,D>lmm 29.4 0.050 58.13 4-Oct-02 Reactor B,D>0.5mm 30.4 0.050 61.34 18-Sep-02 Reactor A,D>4.75mm 54.5 0.050 112.23 18-Sep-02 Reactor A,D>2.83mm 28.4 0.050 59.81 18-Sep-02 Reactor A,D>2mm 26.6 0.050 60.47 18-Sep-02 Reactor A,D>lmm 36.8 0.050 67.92 18-Sep-02 Reactor B,D>2.83mm 41.6 0.050 77.14 18-Sep-02 Reactor B,D>2mm 33.4 0.050 64.08 18-Sep-02 Reactor B,D> 1mm 36.1 0.050 69.31 18-Sep-02 Reactor B,D>0.5mm 59.0 0.050 107.99 13-Sep-02 Reactor A,D>2mm 30.2 0.050 54.38 13-Sep-02 Reactor A,D>lmm 34.1 0.050 60.21 13-Sep-02 Reactor B,D>2mm 40.3 0.050 83.46 13-Sep-02 Reactor B,D>lmm 29.5 0.050 51.38 Blank 0.0 0.050 0.07 Theoretic Ca Al Fe K NH3-N P04-P C03-C Mg mg/L mg/L mg/L mg/L mg/L mg/L mg/L mg/L 5.64 0.12 0.550 35.31 85.13 25 71.09 8.26 0.20 0.380 30.24 70.21 18 59.01 9.68 0.19 0.187 36.97 81.39 20 68.52 7.35 0.10 0.230 28.46 75.32 10 59.81 4.28 0.15 0.180 30.69 68.14 9 58.82 10.38 0.08 0.110 35.12 85.69 5 73.08 3.58 0.15 0.149 30.83 70.88 8 58.22 15.21 0.07 0.087 27.54 75.41 15 60.20 7.36 0.18 0.215 59.79 126.37 11 107.93 7.09 0.20 0.065 30.45 60.06 28 56.24 7.20 0.15 0.114 24.89 58.61 20 52.68 9.71 0.20 0.250 38.55 85.36 25 72.88 8.99 0.19 0.173 42.65 97.06 9 82.38 5.57 0.15 0.246 33.99 70.08 16 66.14 6.18 0.09 0.271 38.02 87.42 10 71.49 5.15 0.10 0.095 54.44 140.95 19 116.84 7.44 0.11 0.152 29.33 73.82 6 59.81 9.41 0.17 0.135 35.12 78.64 5 67.53 15.77 0.21 0.245 37.81 81.20 12 79.81 10.79 0.25 0.183 30.12 63.58 10 58.42 -0.06 0.03 -0.0210 1.05 0.52 9 Theoretical Theoretical % %of %of NH3-N P04-P Struvite % of Theoretical Theoretical Theoretical Mg mg/L mg/L Mg NH3-N P04-P mMol/L 40.96 90.61 90.64 94.88 83.65 93.38 2.78 34.00 75.21 93.44 101.79 85.86 92.66 2.47 39.48 87.33 91.76 91.67 91.00 92.61 2.58 34.46 76.22 90.80 94.71 79.56 98.14 2.33 33.89 74.96 96.22 110.98 87.48 90.21 2.69 42.10 93.13 85.78 84.94 80.93 91.45 2.55 33.54 74.20 94.44 99.72 88.78 94.83 2.39 34.68 76.73 91.92 101.78 76.38 97.61 2.52 62.18 137.55 96.63 103.92 94.47 91.50 4.62 32.40 71.68 93.35 106.23 90.74 83.07 2.46 30.35 67.14 93.25 114.66 78.56 86.53 2.49 41.99 92.88 91.26 93.11 89.33 91.35 2.79 47.46 105.00 91.06 93.56 87.66 91.95 3.17 38.11 84.30 88.59 96.78 86.46 82.52 2.63 41.19 91.11 94.00 96.85 89.76 95.38 2.85 67.32 148.91 88.67 92.37 79.32 94.31 4.44 34.46 76.22 89.69 90.81 82.08 96.17 2.23 38.91 86.07 89.14 89.06 87.58 90.77 2.48 45.98 101.71 87.92 104.49 79.96 79.32 3.43 33.66 74.46 86.30 87.83 86.38 84.70 2.11 208 Ca Al Fe NH3-N P04-P C03-C Mg:P N:P mMol/L mMol/L mMol/L mMol/L mMol/L mMol/L Mole Ratio Mole Ratio 0.14 0.003 0.21 0.006 0.24 0.006 0.18 0.003 0.11 0.004 0.26 0.002 0.09 0.004 0.38 0.001 0.18 0.006 0.18 0.006 0.18 0.004 0.24 0.006 0.23 0.006 0.14 0.004 0.16 0.002 0.13 0.003 0.19 0.003 0.24 0.005 0.39 0.007 0.27 0.008 0.010 2.45 0.007 2.09 0.004 2.57 0.004 1.96 0.004 2.12 0.002 2.43 0.003 2.13 0.002 1.89 0.004 4.20 0.002 2.10 0.002 1.70 0.005 2.68 0.003 2.97 0.005 2.35 0.005 2.64 0.002 3.81 0.003 2.02 0.003 2.43 0.005 2.63 0.004 2.08 2.73 1.33 2.25 0.75 2.61 0.92 2.41 0.08 2.18 0.00 2.75 -0.33 2.27 -0.08 2.42 0.50 4.06 0.17 1.92 1.58 1.87 0.92 2.74 1.33 3.11 0.00 2.24 0.58 2.80 0.08 4.53 0.83 2.36 -0.25 2.52 -0.33 2.60 0.25 2.03 0.08 1.02 0.90 1.10 0.93 0.99 0.98 0.97 0.81 1.23 0.97 0.93 0.89 1.05 0.94 1.04 0.78 1.14 1.03 1.28 1.09 1.33 0.91 1.02 0.98 1.02 0.95 1.17 1.05 1.02 0.94 0.98 0.84 0.95 0.85 0.98 0.97 1.32 1.01 1.04 1.02 209 Mg:N %Mg %N %P %Ca %C ' %A1 %Fe %C03 Mole Ratio 13 9.39 4.77 11.78 0.79 2.23 0.013 0.080 11.14 19 10.08 4.90 11.69 1.40 1.51 0.029 0.067 7.55 01 9.08 5.19 11.69 1.41 1.59 0.023 0.030 7.95 19 9.38 4.54 12.38 1.23 0.17 0.012 0.042 0.83 27 10.99 4.99 11.38 0.73 0.00 0.020 0.034 0.00 05 8.41 4.62 11.54 1.41 -0.54 0.007 0.018 -2.71 12 9.87 5.06 11.97 0.62 -0.17 0.020 0.029 -0.85 33 10.08 4.36 12.32 2.51 0.99 0.007 0.018 4.93 10 10.29 5.39 11.55 0.68 0.18 0.014 0.022 0.92 17 10.52 5.18 10.48 1.26 3.35 0.030 0.015 16.73 46 11.35 4.48 10.92 1.36 2.07 0.023 0.025 10.34 04 9.22 5.10 11.53 1.33 2.17 0.023 0.037 10.87 07 9.26 5.00 11.60 1.09 0.00 0.019 0.023 0.00 12 9.58 4.93 10.41 0.84 1.05 0.018 0.040 5.24 08 9.59 5.12 12.04 0.86 0.14 0.008 0.040 0.69 16 9.15 4.53 11.90 0.44 0.85 0.006 0.010 4.24 11 8.99 4.68 12.14 1.24 -0.50 0.013 0.029 -2.48 02 8.82 5.00 11.46 1.39 -0.59 0.021 0.023 -2.93 31 10.35 4.56 10.01 1.96 0.37 0.022 0.033 1.86 02 8.70 4.93 10.69 1.84 0.17 0.037 0.035 0.85 210 APPENDIX H APPENDIX H M O D E L RESULTS 211 Synthetic Supernatant Influent Actual Effluent Predicted Effluent Date Mg NH4 P04 pH Mg NH4 P04 Mg NH4 mg/L mg/L mg/L mg/L mg/L mg/L mg/L mg/L Reactor B 16-Jul-02 145.0 637.5 123.5 7.4 55.2 601.4 16.3 58.8 587.8 17-Jul-02 136.8 641.1 124.2 7.4 52.9 588.0 17.2 51.4 591.9 18-Jul-02 144.4 623.6 125.1 7.4 57.3 589.7 16.0 57.4 573.4 19-Jul-02 152.9 614.1 125.9 7.4 86.5 578.6 13.9 64.3 563.0 21-Jul-02 129.5 659.4 124.4 7.4 35.8 631.3 22.1 45.3 610.8 22-Jul-02 128.5 659.9 124.5 7.4 37.7 622.3 20.3 44.4 611.4 23-Jul-02 128.9 656.9 119.5 7.5 62.7 604.6 16.3 46.7 609.5 24-Jul-02 140.5 652.5 116.0 7.5 48.3 633.6 15.8 58.7 605.4 25-Jul-02 107.6 550.0 101.5 7.5 36.4 534.7 20.2 41.7 512.0 26-Jul-02 81.4 559.9 97.6 7.5 30.1 509.6 25.6 26.1 528.0 27-Jul-02 121.5 601.1 128.8 7.5 28.2 574.1 25.4 35.4 551.5 28-Jul-02 126.6 606.5 129.6 7.5 23.8 579.7 24.6 38.6 555.8 30-Iul-02 120.9 662.4 132.7 7.4 44.9 551.8 30.5 34.3 612.6 31-Jul-02 114.9 669.3 132.7 7.5 36.9 635.9 19.2 27.8 619.1 l-Aug-02 137.0 673.3 133.5 7.5 35.5 621.7 12.5 43.2 619.3 2-Aug-02 136.0 649.8 140.2 7.5 36.3 583.6 16.3 38.7 593.7 3-Aug-02 167.1 636.6 137.4 7.5 31.0 598.3 13.3 66.8 578.9 4-Aug-02 146.4 647.7 137.6 7.5 37.6 615.1 18.8 48.6 591.4 5-Aug-02 136.6 653.5 139.2 7.5 40.3 603.1 11.1 39.7 597.7 6-Aug-02 133.7 628.8 129.3 7.5 35.9 587.5 19.2 43.8 577.0 7-Aug-02 125.8 623.4 127.3 7.5 48.7 574.8 9.9 39.0 573.4 8-Aug-02 138.9 618.0 127.8 7.6 51.4 578.1 10.8 47.4 565.2 9-Aug-02 148.8 599.9 123.7 7.6 70.4 520.3 9.2 59.0 548.2 10-Aug-02 128.8 604.5 122.8 7.6 49.3 575.2 8.7 42.4 554.7 12-Aug-02 124.3 585.4 121.7 7.5 50.2 549.2 15.3 41.8 537.8 13-Aug-02 120.5 584.7 121.0 7.5 30.4 553.2 16.7 39.4 538.0 14-Aug-02 121.4 619.6 126.0 7.5 35.0 570.8 10.2 36.6 570.8 15-Aug-02 101.7 633.2 124.0 7.5 33.8 578.2 19.5 24.6 588.8 16-Aug-02 110.0 612.9 114.8 7.5 27.7 569.1 15.7 34.8 569.5 ictor A 20-Jun-02 117.0 649.8 146.0 7.2 27.3 598.5 37.3 32.8 601.3 21-Jun-02 142.0 631.2 141.9 7.2 49.2 560.0 30.6 51.1 578.8 22-Jun-02 248.6 552.3 124.1 7.2 185.4 529.6 19.4 158.7 500.6 23-Jun-02 117.7 675.2 143.6 7.2 45.2 658.2 30.8 33.6 626.7 24-Jun-02 149.4 652.4 138.7 7.2 46.1 618.0 28.5 57.9 599.7 25-Iun-02 159.5 616.6 136.9 7.2 83.9 548.8 23.5 67.8 563.7 27-Jun-02 142.9 665.2 139.2 7.2 57.2 638.5 28.4 . 54.2 614.1 28-Jun-02 126.3 629.1 140.3 7.2 36.8 608.3 ' 37.3 43.4 581.3 29-Jun-02 117.3 636.9 142.0 7.2. 30.1 596.4 46.0 37.1 590.6 30-Jun-02 131.4 627.9 136.6 7.2 51.2 600.3 30.5 46.6 579.0 l-Jul-02 131.0 625.0 136.2 7.2 48.6 585.5 29.6 46.6 576.3 3-Jul-02 188.8 586.6 135.9 .7.2 118.8 569.7 17.5 94.2 532.1 4-Jul-02 125.9 663.4 141.3 7.4 44.3 613.4 20.1 34.7 610.8 212 5-Jul-02 119.6 668.7 145.1 7.3 6-Jul-02 119.6 798.8 162.8 7.3 8-Jul-02 111.2 688.4 122.1 7.2 9-Jul-02 122.0 683.7 120.8 7.2 10-Jul-02 125.4 541.7 101.0 7.2 ll-Jul-02 133.3 593.5 100.2 7.3 12-Jul-02 123.8 606.7 100.3 7.4 13-Jul-02 133.9 606.7 100.9 7.4 14-Jul-02 101.5 618.1 104.5 7.4 16-Jul-02 261.8 586.7 113.6 7.2 17-Jul-02 276.2 580.4 112.4 7.2 19-Jul-02 260.1 568.6 116.6 7.2 20-Jul-02 261.9 567.8 116.4 7.2 21-Jul-02 240.3 609.1 114.9 7.2 22-Jul-02 257.3 601.5 113.4 7.2 23-Jul-02 245.2 604.2 109.9 7.2 24-Jul-02 316.7 571.6 101.6 7.2 25-Jul-02 188.1 519.6 95.9 7.3 26-Jul-02 246.2 499.1 87.0 7.2 28-Jul-02 266.4 548.9 117.3 7.2 29-Jul-02 240.9 577.5 120.3 7.2 30-Jul-02 235.8 604.4 121.0 7.3 31-Jul-02 233.5 603.6 119.7 7.2 l-Aug-02 315.6 595.5 118.1 7.2 2-Aug-02 278.4 589.5 127.2 7.2 5-Aug-02 282.9 592.2 126.1 7.1 6-Aug-02 278.3 567.6 116.7 7.1 7-Aug-02 246.4 573.1 117.0 7.1 8-Aug-02 252.0 570.7 118.0 7.1 9-Aug-02 242.6 561.5 115.7 7.1 10-Aug-02 262.4 549.9 111.7 7.1 12-Aug-02 207.2 548.8 114.1 7.4 13-Aug-02 248.4 528.3 109.3 7.4 14-Aug-02 309.2 532.5 108.2 7.3 15-Aug-02 262.2 557.1 109.1 7.3 16-Aug-02 238.4 553.3 103.6 7.3 36.7 629.4 25.5 29.9 617.0 13.4 769.2 31.5 20.8 741.9 56.4 623.1 33.7 39.1 646.9 54.7 605.4 27.1 47.1 640.5 76.7 534.6 31.8 64.6 506.6 81.2 586.3 23.4 67.3 555.4 73.0 564.3 19.4 57.8 568.6 62.7 599.4 17.2 64.8 566.8 30.1 558.3 25.6 38.2 581.7 132.5 525.9 9.2 178.9 538.9 207.4 531.2 7.9 193.8 533.0 175.6 523.2 8.1 175.2 519.7 180.3 509.5 9.0 177.1 519.0 171.4 569.2 11.3 157.9 561.6 213.7 526.9 10.6 175.3 554.2 152.3 571.3 7.0 165.4 558.2 275.9 521.5 6.1 241.6 528.3 176.9 476.8 10.6 121.9 481.5 205.6 469.8 10.6 184.9 463.8 170.6 483.3 9.1 181.0 499.7 153.3 552.3 10.7 153.9 527.3 174.3 529.4 6.5 147.3 553.4 182.8 529.8 9:4 147.0 553.8 244.5 541.1 7.1 227.8 544.9 237.3 562.2 10.4 185.5 535.9 196.6 546.2 11.6 191.5 539.6 207.9 509.3 14.8 195.5 519.9 188.4 548.9 15.0 163.7 525.4 167.6 501.2 13.0 168.3 522.5 165.6 510.3 13.7 161.2 514.5 223.5 511.8 12.0 184.3 504.9 169.7 516.8 9.6 123.6 500.6 175.7 462.5 4.2 167.8 481.8 262.1 480.2 5.1 229.0 486.3 177.9 530.0 6.2 181.6 510.6 175.5 491.7 7.2 162.8 509.7 213 Influent P04 Mg mg/L mol/L Influent NH4 P04 mol/L mol/L Predicted Effluent IPin IPeq Mg NH4 P04 mol/L mol/L mol/L 13.6 6.0E-03 4.6E-02 15.4 5.6E-03 4.6E-02 14.3 5.9E-03 4.5E-02 13.0 6.3E-03 4.4E-02 17.0 . 5.3E-03 4.7E-02 17.3 5.3E-03 4.7E-02 14.7 5.3E-03 4.7E-02 11.8 5.8E-03 4.7E-02 17.5 4.4E-03 3.9E-02 27.1 3.3E-03 4.0E-02 19.1 5.0E-03 4.3E-02 17.4 5.2E-03 4.3E-02 22.3 5.0E-03 4.7E-02 21.7 4.7E-03 4.8E-02 14.0 5.6E-03 4.8E-02 16.2 5.6E-03 4.6E-02 9.6 6.9E-03 4.5E-02 13.0 6.0E-03 4.6E-02 15.7 5.6E-03 4.7E-02 14.8 5.5E-03 4.5E-02 16.7 5.2E-03 4.5E-02 11.2 5.7E-03 4.4E-02 9.3 6.1E-03 4.3E-02 12.8 5.3E-03 4.3E-02 16.6 5.1E-03 4.2E-02 17.6 5.0E-03 4.2E-02 17.9 5.0E-03 4.4E-02 25.8 4.2E-03 4.5E-02 18.8 4.5E-03 4.4E-02 38.8 4.8E-03 4.6E-02 25.9 5.8E-03 4.5E-02 9.6 1.0E-02 3.9E-02 36.4 4.8E-03 4.8E-02 22.1 6.1E-03 4.7E-02 20.1 6.6E-03 4.4E-02 26.2 5.9E-03 4.7E-02 34.6 5.2E-03 4.5E-02 39.8 4.8E-03 4.5E-02 28.4 5.4E-03 4.5E-02 28.6 5.4E-03 4.5E-02 15.3 7.8E-03 4.2E-02 25.0 5.2E-03 4.7E-02 4.0E-03 2.4E-03 4.2E-02 4.0E-03 2.1E-03 4.2E-02 4.0E-03 2.4E-03 4.1E-02 4.1E-03 2.6E-03 4.0E-02 4.0E-03 1.9E-03 4.4E-02 4.0E-03 1.8E-03 4.4E-02 3.9E-03 1.9E-03 4.4E-02 3.7E-03 2.4E-03 4.3E-02 3.3E-03 1.7E-03 3.7E-02 3.2E-03 1.1E-03 3.8E-02 4.2E-03 1.5E-03 3.9E-02 4.2E-03 1.6E-03 4.0E-02 4.3E-03 1.4E-03 4.4E-02 4.3E-03 1.1E-03 4.4E-02 4.3E-03 1.8E-03 4.4E-02 4.5E-03 1.6E-03 4.2E-02 4.4E-03 2.7E-03 4.1E-02 4.4E-03 2.0E-03 4.2E-02 4.5E-03 1.6E-03 4.3E-02 4.2E-03 1.8E-03 4.1E-02 4.1E-03 1.6E-03 4.1E-02 4.1E-03 1.9E-03 4.0E-02 4.0E-03 2.4E-03 3.9E-02 4.0E-03 1.7E-03 4.0E-02 3.9E-03 1.7E-03 3.8E-02 3.9E-03 1.6E-03 3.8E-02 4.1E-03 1.5E-03 4.1E-02 4.0E-03 1.0E-03 4.2E-02 3.7E-03 1.4E-03 4.1E-02 4.7E-03 1.4E-03 4.3E-02 4.6E-03 2.1E-03 4.1E-02 4.0E-03 6.5E-03 3.6E-02 4.6E-03 1.4E-03 4.5E-02 4.5E-03 2.4E-03 4.3E-02 4.4E-03 2.8E-03 4.0E-02 4.5E-03 2.2E-03 4.4E-02 4.5E-03 1.8E-03 4.1E-02 4.6E-03 1.5E-03 4.2E-02 4.4E-03 1.9E-03 4.1E-02 4.4E-03 1.9E-03 4.1E-02 4.4E-03 3.9E-03 3.8E-02 4.6E-03 1.4E-03 4.4E-02 4.4E-04 1.1E-06 4.5E-08 5.0E-04 1.0E-06 4.5E-08 4.6E-04 1.1E-06 4.5E-08 4.2E-04 1.1E-06 4.5E-08 5.5E-04 1.0E-06 4.5E-08 5.6E-04 1.0E-06 4.5E-08 4.7E-04 9.6E-07 4.0E-08 3.8E-04 1.0E-06 4.0E-08 5.6E-04 5.7E-07 3.5E-08 8.8E-04 4.2E-07 3.5E-08 6.2E-04 8.9E-07 3.5E-08 5.6E-04 9.4E-07 3.5E-08 7.2E-04 1.0E-06 4.5E-08 7.0E-04 9.7E-07 3.5E-08 4.5E-04 1.2E-06 3.5E-08 5.2E-04 1.2E-06 3.5E-08 3.1E-04 1.4E-06 3.5E-08 4.2E-04 1.2E-06 3.5E-08 5.1E-04 1.2E-06 3.5E-08 4.8E-04 1.0E-06 3.5E-08 5.4E-04 9.5E-07 3.5E-08 3.6E-04 1.0E-06 2.8E-08 3.0E-04 1.0E-06 2.8E-08 4.1E-04 9.1E-07 2.8E-08 5.4E-04 8.4E-07 3.5E-08 5.7E-04 8.1E-07 3.5E-08 5.8E-04 9.0E-07 3.5E-08 8.3E-04 7.6E-07 3.5E-08 6.1E-04 7.3E-07 3.5E-08 1.3E-03 1.1E-06 7.3E-08 8.4E-04 1.2E-06 7.3E-08 3.1E-04 1.6E-06 7.3E-08 1.2E-03 1.1E-06 7.3E-08 7.1E-04 1.3E-06 7.3E-08 6.5E-04 1.3E-06 7.3E-08 8.5E-04 1.3E-06 8.3E-08 1.1E-03 1.1E-06 8.3E-08 1.3E-03 1.0E-06 8.3E-08 9.2E-04 1.1E-06 7.3E-08 9.2E-04 1.1E-06 7.3E-08 4.9E-04 1.4E-06 7.3E-08 8.1E-04 1.1E-06 5.0E-08 214 30.8 4.9E-03 4.8E-02 36.8 4.9E-03 5.7E-02 30.3 4.6E-03 4.9E-02 25.4 5.0E-03 4.9E-02 23.4 5.2E-03 3.9E-02 16.0 5.5E-03 4.2E-02 16.1 5.1E-03 4.3E-02 12.8 5.5E-03 4.3E-02 23.8 4.2E-03 4.4E-02 8.0 1.1E-02 4.2E-02 7.4 1.1E-02 4.1E-02 8.4 1.1E-02 4.1E-02 8.3 1.1E-02 4.1E-02 9.8 9.9E-03 4.3E-02 9.0 1.1E-02 4.3E-02 8.3 1.0E-02 4.3E-02 6.0 1.3E-02 4.1E-02 11.5 7.7E-03 3.7E-02 8.9 1.0E-02 3.6E-02 8.5 1.1E-02 3.9E-02 9.4 9.9E-03 4.1E-02 8.3 9.7E-03 4.3E-02 9.4 9.6E-03 4.3E-02 6.2 1.3E-02 4.3E-02 8.8 1.1E-02 4.2E-02 9.6 1.2E-02 4.2E-02 11.2 1.1E-02 4.1E-02 11.6 1.0E-02 4.1E-02 11.3 1.0E-02 4.1E-02 12.0 1.0E-02 4.0E-02 12.2 1.1E-02 3.9E-02 7.6 8.5E-03 3.9E-02 6.5 1.0E-02 3.8E-02 6.1 1.3E-02 3.8E-02 6.4 1.1E-02 4.0E-02 7.2 9.8E-03 4.0E-02 4.7E-03 1.2E-03 4.4E-02 5.3E-03 8.6E-04 5.3E-02 3.9E-03 1.6E-03 4.6E-02 3.9E-03 1.9E-03 4.6E-02 3.3E-03 2.7E-03 3.6E-02 3.2E-03 2.8E-03 4.0E-02 3.2E-03 2.4E-03 4.1E-02 3.3E-03 2.7E-03 4.0E-02 3.4E-03 1.6E-03 4.2E-02 3.7E-03 7.4E-03 3.8E-02 3.6E-03 8.0E-03 3.8E-02 3.8E-03 7.2E-03 3.7E-02 3.8E-03 7.3E-03 3.7E-02 3.7E-03 6.5E-03 4.0E-02 3.7E-03 7.2E-03 4.0E-02 3.5E-03 6.8E-03 4.0E-02 3.3E-03 9.9E-03 3.8E-02 3.1E-03 5.0E-03 3.4E-02 2.8E-03 7.6E-03 3.3E-02 3.8E-03 7.4E-03 3.6E-02 3.9E-03 6.3E-03 3.8E-02 3.9E-03 6.1E-03 4.0E-02 3.9E-03 6.0E-03 4.0E-02 3.8E-03 9.4E-03 3.9E-02 4.1E-03 7.6E-03 3.8E-02 4.1E-03 7.9E-03 3.9E-02 3.8E-03 8.0E-03 3.7E-02 3.8E-03 6.7E-03 3.8E-02 3.8E-03 6.9E-03 3.7E-02 3.7E-03 6.6E-03 3.7E-02 3.6E-03 7.6E-03 3.6E-02 3.7E-03 5.1E-03 3.6E-02 3.5E-03 6.9E-03 3.4E-02 3.5E-03 9.4E-03 3.5E-02 3.5E-03 7.5E-03 3.6E-02 3.3E-03 6.7E-03 3.6E-02 9.9E-04 1.1E-06 5.4E-08 1.2E-03 1.5E-06 5.4E-08 9.8E-04 8.9E-07 7.3E-08 8.2E-04 9.6E-07 7.3E-08 7.6E-04 6.5E-07 7.3E-08 5.2E-04 7.5E-07 5.7E-08 5.2E-04 7.1E-07 5.0E-08 4.1E-04 7.8E-07 4.5E-08 7.7E-04 6.2E-07 5.0E-08 2.6E-04 1.7E-06 7.3E-08 2.4E-04 1.7E-06 7.3E-08 2.7E-04 1.6E-06 7.3E-08 2.7E-04 1.6E-06 7.3E-08 3.2E-04 1.6E-06 8.3E-08 2.9E-04 1.7E-06 8.3E-08 2.7E-04 1.5E-06 7.3E-08 1.9E-04 1.7E-06 7.3E-08 3.7E-04 8.9E-07 6.4E-08 2.9E-04 1.0E-06 7.3E-08 2.7E-04 1.6E-06 7.3E-08 3.0E-04 1.6E-06 7.3E-08 2.7E-04 1.6E-06 6.4E-08 3.0E-04 1.6E-06 7.3E-08 2.0E-04 2.1E-06 7.3E-08 2.8E-04 2.0E-06 8.3E-08 3.1E-04 2.0E-06 9.4E-08 3.6E-04 1.7E-06 1.1E-07 3.7E-04 1.6E-06 9.4E-08 3.7E-04 1.6E-06 9.4E-08 3.9E-04 1.5E-06 9.4E-08 3.9E-04 1.5E-06 1.1E-07 2.5E-04 1.2E-06 4.5E-08 2.1E-04 1.4E-06 5.0E-08 2.0E-04 1.7E-06 6.4E-08 2.1E-04 1.5E-06 5.7E-08 2.3E-04 1.3E-06 5.7E-08 215 IPout Error Mol Reduction Absolute Concentration error % Relative Absc Mg NH4 P04 Mg NH4 mg/L mg/L mg/L 4.5E-08 2.1E-08 3.5E-03 3.6 13.6 2.7 6.4 2.3 4.5E-08 5.7E-08 3.5E-03 1.5 3.9 1.8 2.8 0.7 4.5E-08 3.7E-08 3.6E-03 0.1 16.3 1.7 0.2 2.8 4.5E-08 2.1E-08 3.6E-03 22.2 15.6 0.9 25.6 2.7 4.5E-08 1.2E-07 3.5E-03 9.5 20.4 5.1 26.5 3.2 4.5E-08 1.3E-07 3.5E-03 6.7 10.9 3.0 17.8 1.8 4.0E-08 5.0E-08 3.4E-03 16.0 5.0 1.6 25.5 0.8 4.0E-08 6.7E-04 3.4E-03 10.4 28.2 4.0 21.6 4.5 3.5E-08 1.9E-06 2.7E-03 5.3 22.8 2.7 14.5 4.3 3.5E-08 8.7E-08 2.3E-03 4.0 18.4 1.5 13.3 3.6 3.5E-08 3.0E-06 3.5E-03 7.2 22.6 6.3 25.6 3.9 3.5E-08 4.2E-06 3.6E-03 14.8 23.9 7.1 62.4 4.1 4.5E-08 2.4E-06 3.6E-03 10.6 60.8 8.2 23.7 11.0 3.5E-08 2.4E-05 3.6E-03 9.1 16.8 2.5 24.6 2.6 3.5E-08 2.2E-05 3.9E-03 7.7 2.5 1.5 21.8 0.4 3.5E-08 1.3E-04 4.0E-03 2.4 10.1 0.0 6.7 1.7 3.5E-08 2.1E-06 4.1E-03 35.9 19.5 3.6 115.8 3.3 3.5E-08 2.7E-05 4.0E-03 11.0 23.8 5.8 29.4 3.9 3.5E-08 1.0E-04 4.0E-03 28.6 5.4 4.7 259.2 0.9 3.5E-08 3.7E-06 3.7E-03 24.6 10.4 4.5 127.9 1.8 3.5E-08 2.5E-06 3.6E-03 29.1 1.4 6.7 292.7 0.2 2.8E-08 5.9E-06 3.8E-03 36.6 12.9 0.4 339.6 2.2 2.8E-08 2.5E-07 3.7E-03 49.9 28.0 0.1 543.5 5.4 2.8E-08 2.0E-06 3.6E-03 33.7 20.5 4.1 388.3 3.6 3.5E-08 1.5E-07 3.4E-03 26.5 11.4 1.3 172.6 2.1 3.5E-08 1.2E-07 3.3E-03 22.7 15.2 0.9 136.3 2.7 3.5E-08 1.6E-06 3.5E-03 26.4 0.0 7.7 259.8 0.0 3.5E-08 1.8E-07 3.2E-03 5.1 10.5 6.3 26.2 1.8 3.5E-08 1.1E-08 3.1E-03 19.1 0.5 3.2 121.9 0.1 7.3E-08 1.6E-06 3.5E-03 5.5 2.8 1.5 20.2 0.5 7.3E-08 3.0E-06 3.7E-03 1.9 18.8 4.7 3.9 3.4 7.3E-08 1.3E-05 3.7E-03 26.7 29.1 9.8 14.4 5.5 7.3E-08 2.0E-06 3.5E-03 11.6 31.6 5.6 25.7 4.8 7.3E-08 1.7E-06 3.8E-03 11.8 18.3 6.4 25.5 3.0 7.3E-08 3:7E-07 3.8E-03 16.1 14.9 3.4 19.2 2.7 8.3E-08 6.5E-07 3.6E-03 3.0 24.5 2.2 5.3 3.8 8.3E-08 1.8E-07 3.4E-03 6.6 27.0 2.7 17.9 4.4 8.3E-08 9.3E-08 3.3E-03 7.0 5.7 6.2 23.3 1.0 7.3E-08 5.8E-07 3.5E-03 ' 4.6 21.4 2.1 8.9 3.6 7.3E-08 4.9E-07 3.5E-03 2.0 9.2 1.1 4.2 1.6 7.3E-08 2.5E-08 3.9E-03 24.6 37.6 2.2 20.7 6.6 5.0E-08 1.5E-04 3.8E-03 9.7 2.6 4.9 21.8 0.4 5.4E-08 9.7E-05 3.7E-03 6.8 12.4 5.3 18.5 2.0 5.4E-08 4.2E-08 4.1E-03 7.4 27.3 5.4 55.5 3.5 7.3E-08 6.3E-09 3.0E-03 17.2 23.8 3.4 30.6 3.8 7.3E-08 9.9E-09 3.1E-03 7.6 35.1 1.7 13.8 5.8 7.3E-08 2.6E-07 2.5E-03 12.2 28.0 8.3 15.9 5.2 5.7E-08 7.3E-06 2.7E-03 13.9 30.9 7.4 17.1 5.3 5.0E-08 3.0E-05 2.7E-03 15.2 4.4 3.3 20.8 0.8 4.5E-08 6.1E-05 2.8E-03 2.0 32.5 4.4 3.3 5.4 5.0E-08 7.9E-05 2.6E-03 8.1 23.4 1.8 26.9 4.2 7.3E-08 4.2E-07 3.4E-03 46.4 13.0 1.3 35.0 2.5 7.3E-08 1.5E-07 3.4E-03 13.7 1.8 0.5 6.6 0.3 7.3E-08 1.0E-06 3.5E-03 0.4 3.5 0.3 0.2 0.7 7.3E-08 9.2E-07 3.5E-03 3.2 9.5 0.6 1.8 1.9 8.3E-08 1.2E-06 3.4E-03 13.5 7.6 1.5 7.9 1.3 8.3E-08 3.4E-07 3.4E-03 38.4 27.3 1.7 18.0 5.2 7.3E-08 3.0E-07 3.3E-03 13.1 13.1 1.3 8.6 2.3 7.3E-08 6.9E-04 3.1E-03 34.3 6.9 0.1 12.4 1.3 6.4E-08 2.5E-08 2.7E-03 55.0 4.6 0.9 31.1 1.0 7.3E-08 4.1E-05 2.5E-03 20.7 6.0 1.7 10.1 1.3 7.3E-08 9.3E-07 3.5E-03 10.4 16.4 0.6 6.1 3.4 7.3E-08 7.2E-06 3.6E-03 0.6 25.0 1.2 0.4 4.5 6.4E-08 1.7E-05 3.6E-03 27.0 24.0 1.8 15.5 4.5 7.3E-08 9.4E-06 3.6E-03 35.9 24.0 0.1 19.6 4.5 7.3E-08 1.5E-07 3.6E-03 16.7 3.8 0.9 6.8 0.7 8.3E-08 5.5E-06 3.8E-03 51.8 26.3 1.6 21.8 4.7 9.4E-08 2.5E-06 3.8E-03 5.2 6.6 2.0 2.6 1.2 1.1E-07 1.4E-07 3.4E-03 12.3 10.6 3.6 5.9 2.1 9.4E-08 8.7E-07 3.4E-03 24.7 23.5 3.4 13.1 4.3 9.4E-08 9.2E-07 3.4E-03 0.7 21.3 1.7 0.4 4.2 9.4E-08 6.5E-07 3.3E-03 4.3 4.2 1.7 2.6 0.8 1.1E-07 4.7E-08 3.2E-03 39.2 6.9 0.2 17.5 1.3 4.5E-08 3.0E-05 3.4E-03 46.1 16.2 2.0 27.2 3.1 5.0E-08 5.2E-07 3.3E-03 7.9 19.3 2.4 4.5 4.2 6.4E-08 1.4E-08 3.3E-03 33.0 6.1 1.0 12.6 1.3 5.7E-08 1.9E-07 3.3E-03 3.7 19.4 0.2 2.1 3.7 5.7E-08 9.5E-08 3.1E-03 12.8 18.0 0.0 7.3 3.7 )lute Error Actual Error % Actual Error P04 Mg NH4 P04 Mg NH4 P04 mg/L mg/L mg/L 16.8 3.6 -13.6 -2.7 6.4 -2.3 -16.8 10.4 -1.5 3.9 -1.8 -2.8 0.7 -10.4 10.7 0.1 -16.3 -1.7 0.2 -2.8 -10.7 6.5 -22.2 -15.6 -0.9 -25.6 -2.7 -6.5 23.2 9.5 -20.4 -5.1 26.5 -3.2 -23.2 14.6 6.7 -10.9 -3.0 17.8 -1.8 -14.6 9.9 -16.0 5.0 -1.6 -25.5 0.8 -9.9 25.4 10.4 -28.2 -4.0 21.6 -4.5 -25.4 13.4 5.3 -22.8 -2.7 14.5 -4.3 -13.4 5.8 -4.0 18.4 1.5 -13.3 3.6 5.8 24.7 7.2 -22.6 -6.3 25.6 -3.9 -24.7 29.1 14.8 -23.9 -7.1 62.4 -4.1 -29.1 26.8 -10.6 60.8 -8.2 -23.7 11.0 -26.8 12.8 -9.1 -16.8 2.5 -24.6 -2.6 12.8 11.8 7.7 -2.5 1.5 21.8 -0.4 11.8 0.2 2.4 10.1 0.0 6.7 1.7 -0.2 27.4 35.9 -19.5 -3.6 115.8 -3.3 -27.4 30.8 11.0 -23.8 -5.8 29.4 -3.9 -30.8 42.4 28.6 -5.4 4.7 71.0 -0.9 42.4 23.2 24.6 -10.4 -4.5 68.5 -1.8 -23.2 67.9 29.1 -1.4 6.7 59.8 -0.2 67.9 3.9 36.6 -12.9 0.4 71.3 -2.2 3.9 1.0 49.9 28.0 0.1 70.8 5.4 1.0 46.9 33.7 -20.5 4.1 68.5 -3.6 46.9 8.2 26.5 -11.4 1.3 52.7 -2.1 8.2 5.5 22.7 -15.2 0.9 74.8 -2.7 5.5 76.0 26.4 0.0 7.7 75.4 0.0 76.0 32.4 5.1 10.5 6.3 15.1 1.8 32.4 20.2 19.1 0.5 3.2 69.1 0.1 20.2 4.0 5.5 2.8 1.5 20.2 0.5 4.0 15.3 1.9 18.8 -4.7 3.9 3.4 -15.3 50.3 -26.7 -29.1 -9.8 -14.4 -5.5 -50.3 18.1 -11.6 -31.6 5.6 -25.7 -4.8 18.1 22.5 11.8 -18.3 -6.4 25.5 -3.0 -22.5 14.6 -16.1 14.9 -3.4 -19.2 2.7 -14.6 7.7 -3.0 -24.5 -2.2 -5.3 -3.8 -7.7 7.3 6.6 -27.0 -2.7 17.9 -4.4 -7.3 13.6 7.0 -5.7 -6.2 23.3 -1.0 -13.6 6.9 -4.6 -21.4 -2.1 -8.9 -3.6 -6.9 3.6 -2.0 -9.2 -1.1 -4.2 -1.6 -3.6 12.4 -24.6 -37.6 -2.2 -20.7 -6.6 -12.4 24.4 -9.7 -2.6 4.9 -21.8 -0.4 24.4 218 20.9 -6.8 -12.4 5.3 -18.5 -2.0 20.9 17.1 7.4 -27.3 5.4 '55.5 -3.5 17.1 10.1 -17.2 23.8 -3.4 -30.6 3.8 -10.1 6.4 -7.6 35.1 -1.7 -13.8 5.8 -6.4 26.3 -12.2 . -28.0 -8.3 -15.9 -5.2 -26.3 31.7 -13.9 -30.9 -7.4 -17.1 -5.3 -31.7 16.9 -15.2 4.4 -3.3 -20.8 0.8 -16.9 25.6 2.0 -32.5 -4.4 3.3 -5.4 -25.6 7.2 8.1 23.4 -1.8 26.9 4.2 -7.2 13.9 46.4 13.0 -1.3 35.0 2.5 -13.9 6.4 -13.7 1.8 -0.5 -6.6 0.3 -6.4 3.3 -0.4 -3.5 0.3 -0.2 -0.7 3.3 7.0 -3.2 9.5 -0.6 -1.8 1.9 -7.0 13.3 -13.5 -7.6 -1.5 -7.9 -1.3 -13.3 15.7 -38.4 27.3 -1.7 -18.0 5.2 -15.7 18.6 13.1 -13.1 1.3 8.6 -2.3 18.6 1.3 -34.3 6.9 -0.1 -12.4 1.3 -1.3 8.8 -55.0 4.6 0.9 -31.1 1.0 8.8 15.9 -20.7 -6.0 -1.7 -10.1 -1.3 -15.9 6.9 10.4 16.4 -0.6 6.1 3.4 -6.9 11.7 0.6 -25.0 -1.2 0.4 -4.5 -11.7 27.3 -27.0 24.0 1.8 -15.5 4.5 27.3 0.6 -35.9 24.0 0.1 -19.6 4.5 0.6 12.9 -16.7 3.8 -0.9 -6.8 0.7 -12.9 15.3 -51.8 -26.3 -1.6 -21.8 -4.7 -15.3 16.9 -5.2 -6.6 -2.0 -2.6 -1.2 -16.9 24.5 -12.3 10.6 -3.6 -5.9 2.1 -24.5 22.8 -24.7 -23.5 -3.4 -13.1 -4.3 -22.8 13.1 0.7 21.3 -1.7 0.4 4.2 -13.1 12.2 -4.3 4.2 -1.7 -2.6 0.8 -12.2 1.8 -39.2 -6.9 0.2 -17.5 -1.3 1.8 20.6 -46.1 -16.2 -2.0 -27.2 -3.1 -20.6 56.1 -7.9 19.3 2.4 -4.5 4.2 56.1 20.1 -33.0 6.1 1.0 -12.6 1.3 20.1 3.3 3.7 -19.4 0.2 2.1 -3.7 3.3 0.3 -12.8 18.0 0.0 -7.3 3.7 -0.3 Annacis Supernatant Influent Actual Effluent Predicted Effluent Date Mg NH4 P04 pH Mg NH4 P04 Mg NH4 P04 mg/L mg/L mg/L mg/L mg/L mg/L mg/L mg/L mg/L Reactor A 3-Sep-02 307.7 851.2 109.0 8.0 238.3 815.7 4.4 224.6 803.3 3.1 4-Sep-02 291.3 878.3 112.8 8.0 213.3 841.7 3.4 205.4 828.8 3.3 5-Sep-02 312.2 864.7 111.0 8.0 256.3 820.2 3.1 227.4 815.9 3.0 6-Sep-02 296.1 828.9 112.8 8.0 220.0 781.4 1.8 210.3 779.4 3.4 7-Sep-02 298.5 857.9 108.4 8.0 218.7 816.9 3.5 216.0 810.4 3.2 8-Sep-02 271.1 875.9 110.6 8.0 198.2 843.2 3.4 187.2 827.5 3.6 9-Sep-02 247.2 890.6 112.5 8.0 172.0 863.4 3.8 162.2 841.6 4.1 10-Sep-02 274.5 914.6 113.8 8.0 199.1 888.2 3.4 187.9 864.7 3.5 ll-Sep-02 285.7 908.5 112.5 7.8 205.5 831.7 5.2 201.5 860.0 5.1 12-Sep-02 278.8 873.0 103.4 7.9 209.4 789.6 2.9 201.0 828.2 4.2 13-Sep-02 257.1 887.4 108.2 7.9 172.1 816.3 3.6 175.9 840.6 4.7 14-Sep-02 247.6 901.6 109.9 7.9 170.4 863.2 5.2 165.3 854.1 5.0 15-Sep-02 236.3 906.1 110.4 7.9 159.3 871.3 6.8 153.8 858.5 5.3 16-Sep-02 242.1 884.9 118.2 7.9 135.6 818.2 5.3 153.7 833.9 5.5 17-Sep-02 231.6 865.0 110.7 7.9 155.5 825.2 6.6 149.0 817.4 5.5 18-Sep-02 215.7 886.6 111.2 7.9 155.5 825.2 6.6 133.3 839.1 6.3 19-Sep-02 222.9 830.1 106.8 7.9 188.1 782.8 7.2 143.8 784.5 5.9 20-Sep-02 222.9 830.1 106.8 7.9 188.1 643.8 3.1 144.0 784.6 6.2 Reactor B 4-Sep-02 163.5 958.1 123.0 8.3 71.7 908.1 5.9 70.6 904.6 4.7 5-Sep-02 166.8 955.7 122.7 8.3 59.0 910.3 6.6 74.0 902.3 4.5 6-Sep-02 163.8 907.4 123.5 8.3 58.3 859.5 3.4 70.6 853.7 4.8 7-Sep-02 150.0 949.2 119.9 8.3 61.4 916.0 5.8 60.4 897.5 5.6 8-Sep-02 151.0 949.2 119.9 8.3 76.1 887.4 5.8 61.3 897.5 5.5 9-Sep-02 146.2 952.3 120.3 8.3 63.5 846.3 4.1 56.3 900.5 5.7 10-Sep-02 180.8 973.0 121.1 8.2 62.3 939.0 7.4 89.3 920.2 4.5 ll-Sep-02 167.3 981.1 121.5 8.2 49.8 851.7 7.9 76.1 928.6 5.2 12-Sep-02 134.0 985.5 116.7 8.3 39.2 956.3 13.5 48.2 936.1 7.4 13-Sep-02 136.5 980.7 119.5 8.3 58.2 887.9 7.3 48.5 930.0 7.4 14-Sep-02 126.8 991.7 120.9 8.3 42.7 951.2 10.2 39.1 941.2 9.1 15-Sep-02 124.8 991.1 120.8 8.2 35.6 958.0 11.6 38.1 941.2 10.3 16-Sep-02 125.4 881.9 117.8 8.2 38.3 918.9 12.4 41.4 833.4 10.7 17-Sep-02 118.4 945.1 121.0 8.3 34.7 906.3 11.5 32.5 895.6 11.5 18-Sep-02 123.1 953.0 119.6 8.3 38,8 859.3 11.4 37.1 903.5 10.0 19-Sep-02 98.3 796.1 "102.4 8.3 15.3 813.7 10.6 29.7 756.6 14.9 20-Sep-02 220 Influent Influent Predicted Effluent IPin IPeq IPout Mg NH4 P04 Mg NH4 P04 mol/L mol/L mol/L mol/L mol/L mol/L 1.3E-02 1.2E-02 1.3E-02 1.2E-02 1.2E-02 1.1E-02 1.0E-02 1.1E-02 1.2E-02 1.1E-02 1.1E-02 1.0E-02 9.7E-03 1.0E-02 9.5E-03 8.9E-03 9.2E-03 9.2E-03 6.7E-03 6.9E-03 6.7E-03 6.2E-03 6.2E-03 6.0E-03 7.4E-03 6.9E-03 5.5E-03 5.6E-03 5.2E-03 5.1E-03 5.2E-03 4.9E-03 5.1E-03 4.0E-03 6.1E-02 3 5E-03 6.3E-02 3 6E-03 6.2E-02 3 6E-03 5.9E-02 3 6E-03 6.1E-02 3 5E-03 6.3E-02 3 6E-03 6.4E-02 3 6E-03 6.5E-02 3 7E-03 6.5E-02 3 6E-03 6.2E-02 3 3E-03 6.3E-02 3 5E-03 6.4E-02 3 5E-03 6.5E-02 3 6E-03 6.3E-02 3 8E-03 6.2E-02 3 6E-03 6.3E-02 3 6E-03 5.9E-02 3 4E-03 5.9E-02 3 4E-03 6.8E-02 4.0E-03 6.8E-02 4.0E-03 6.5E-02 4 OE-03 6.8E-02 3 9E-03 6.8E-02 3 9E-03 6.8E-02 3 9E-03 6.9E-02 3 9E-03 7.0E-02 3 9E-03 7.0E-02 3 8E-03 7.0E-02 3 9E-03 7.1E-02 3 9E-03 7.1E-02 3 9E-03 6.3E-02 3 8E-03 6.7E-02 3 9E-03 6.8E-02 3 9E-03 5.7E-02 3 3E-03 9.2E-03 5.7E-02 8.4E-03 5.9E-02 9.4E-03 5.8E-02 8.7E-03 5.6E-02 8.9E-03 5.8E-02 7.7E-03 5.9E-02 6.7E-03 6.0E-02 7.7E-03 6.2E-02 8.3E-03 6.1E-02 8.3E-03 5.9E-02 7.2E-03 6.0E-02 6.8E-03 6.1E-02 6.3E-03 6.1E-02 6.3E-03 6.0E-02 6.1E-03 5.8E-02 5.5E-03 6.0E-02 5.9E-03 5.6E-02 5.9E-03 5.6E-02 2.9E-03 6.5E-02 3.OE-03 6.4E-02 2.9E-03 6.1E-02 2.5E-03 6.4E-02 2.5E-03 6.4E-02 2.3E-03 6.4E-02 3.7E-03 6.6E-02 3.1E-03 6.6E-02 2.0E-03 6.7E-02 2.0E-03 6.6E-02 1.6E-03 6.7E-02 1.6E-03 6.7E-02 1.7E-03 6.0E-02 1.3E-03 6.4E-02 1.5E-03 6.5E-02 1.2E-03 5.4E-02 1.0E-04 2.7E-06 1.1E-04 2.7E-06 9.8E-05 2.8E-06 1.1E-04 2.6E-06 1.0E-04 2.6E-06 1.2E-04 2.5E-06 1.3E-04 2.3E-06 1.1E-04 2.7E-06 1.6E-04 2.8E-06 1.4E-04 2.4E-06 1.5E-04 2.3E-06 1.6E-04 2.3E-06 1.7E-04 2.2E-06 1.8E-04 2.4E-06 1.8E-04 2.1E-06 2.0E-04 2.0E-06 1.9E-04 1.9E-06 2.0E-04 1.9E-06 1.5E-04 1.8E-06 1.5E-04 1.9E-06 1.6E-04 1.7E-06 1.8E-04 1.6E-06 1.8E-04 1.6E-06 1.9E-04 1.6E-06 1.5E-04 2.0E-06 1.7E-04 1.9E-06 2.4E-04 1.5E-06 2.4E-04 1.5E-06 2.9E-04 1.4E-06 3.3E-04 1.4E-06 3.5E-04 1.2E-06 3.7E-04 1.3E-06 3.2E-04 1.3E-06 4.8E-04 7.6E-07 5.3E-08 5.3E-•08 5.3E-08 5.3E-•08 5.3E-08 5.3E-•08 5.3E-08 5.3E-•08 5.3E-08 5.3E-•08 5.3E-08 5.3E-•08 5.3E-08 5.3E-•08 5.3E-08 5.3E--08 8.3E-08 8.3E-•08 6.7E-08 6.7E--08 6.7E-08 6.7E-•08 6.7E-08 6.7E--08 6.7E-08 6.7E -08 6.7E-08 6.7E -08 6.4E-08 6.4E -08 6.7E-08 6.7E -08 6.4E-08 6.4E -08 6.7E-08 6.7E •08 2.9E-08 2.9E -08 2.9E-08 2.9E -08 2.8E-08 2.8E -08 2.9E-08 2.9E -08 2.9E-08 2.9E -08 2.8E-08 2.8E -08 3.5E-08 3.5E -08 3.5E-08 3.5E -08 3.2E-08 3.2E -08 3.2E-08 3.2E -08 3.2E-08 3.2E -08 3.5E-08 3.5E -08 3.5E-08 3.5E -08 3.2E-08 3.2E -08 3.2E-08 3.2E -08 3.2E-08 3.2E -08 Error Mol Reduction Absolute Concentration error % Relative Absolute Error Actual Error Mg NH4 P04 Mg NH4 P04 Mg NH4 mg/L mg/L mg/L mg/L mg/L 6.0E-06 3.4E-03 13.6 12.4 1.2 5.7 1.5 28.4 -13.6 -12.4 4.1E-05 3.5E-03 7.9 12.9 0.1 3.7 1.5 3.0 -7.9 -12.9 1.2E-05 3.5E-03 28.9 4.3 0.1 11.3 0.5 2.1 -28.9 -4.3 3.4E-05 3.5E-03 9.7 1.9 1.6 4.4 0.2 87.7 -9.7 -1.9 6.1E-06 3.4E-03 2.7 6.6 0.3 1.2 0.8 8.4 -2.7 -6.6 3.6E-05 3.5E-03 11.1 15.7 0.3 5.6 1.9 8.2 -11.1 -15.7 1.7E-04 3.5E-03 9.8 21.7 0.4 5.7 2.5 10.0 -9.8 -21.7 1.1E-04 3.6E-03 11.2 23.5 0.0 5.6 2.6 1.3 -11.2 -23.5 2.2E-05 3.5E-03 4.0 28.3 0.1 2.0 3.4 2.7 -4.0 28.3 7.3E-07 3.2E-03 8.4 38.6 1.3 4.0 4.9 43.3 -8.4 38.6 1.4E-05 3.3E-03 3.9 24.3 1.1 2.3 3.0 30.6 3.9 24.3 4.1E-05 3.4E-03 5.1 9.0 0.2 3.0 1.0 4.3 -5.1 -9.0 4.7E-08 3.4E-03 5.5 12.7 1.5 3.5 1.5 21.6 -5.5 -12.7 5.1E-07 3;6E-03 18.1 15.6 0.2 13.3 1.9 4.1 18.1 15.6 7.3E-08 3.4E-03 6.5 7.8 1.1 4.2 0.9 16.6 -6.5 -7.8 2.4E-07 3.4E-03 22.2 14.0 0.3 14.3 1.7 5.0 -22.2 14.0 2.4E-08 3.3E-03 44.3 1.8 1.2 23.5 0.2 17.2 -44.3 1.8 2.0E-08 3.2E-03 44.1 140.9 3.1 23.4 21.9 100.3 -44.1 140.9 1.1E-07 3.8E-03 1.0 3.5 1.2 1.4 0.4 20.3 -1.0 -3.5 5.2E-08 3.8E-03 15.1 8.1 2.1 25.5 0.9 31.5 15.1 -8.1 1.2E-07 3.8E-03 12.3 5.8 1.4 21.1 0.7 42.9 12.3 -5.8 2.9E-07 3.7E-03 1.0 18.5 0.2 1.6 2.0 4.0 -1.0 -18.5 2.4E-07 3.7E-03 14.8 10.0 0.3 19.4 1.1 5.0 -14.8 10.0 8.5E-07 3.7E-03 7.3 54.3 1.6 11.4 6.4 38.6 -7.3 54.3 6.0E-04 3.8E-03 27.0 18.7 2.9 43.3 2.0 39.0 27.0 -18.7 1.5E-08 3.8E-03 26.2 76.9 2.6 52.6 9.0 33.4 26.2 76.9 9.1E-07 3.5E-03 9.0 20.2 6.1 23.1 2.1 45.1 9.0 -20.2 2.2E-06 3.6E-03 9.7 42.1 0.1 16.6 4.7 1.4 -9.7 42.1 2.2E-05 3.6E-03 3.6 . 10.1 1.1 8.5 1.1 11.2 -3.6 -10.1 1.4E-05 3.6E-03 2.5 16.8 1.3 6.9 1.8 11.4 2.5 -16.8 1.4E-06 3.5E-03 3.0 85.5 1.7 7.9 9.3 13.4 3.0 -85.5 4.7E-05 3.5E-03 2.2 10.7 0.0 6.4 1.2 0.0 -2.2 -10.7 1.6E-05 3.5E-03 1.7 44.2 1.4 4.4 5.1 12.1 -1.7 44.2 3.3E-04 2.8E-03 14.4 57.1 4.3 94.0 7.0 40.2 14.4 -57.1 222 % Actual Error P04 Mg NH4 P04 mg/L -1.2 -0.1 -0.1 1.6 -0.3 0.3 0.4 0.0 -0.1 1.3 1.1 -0.2 -1.5 0.2 -1.1 -0.3 -1.2 3.1 -1.2 -2.1 1.4 -0.2 -0.3 1.6 -2.9 -2.6 -6.1 0.1 -1.1 -1.3 -1.7 0.0 -1.4 4.3 -5.7 -3.7 -11.3 -4.4 -1.2 -5.6 -5.7 -5.6 -2.0 -4.0 2.3 -3.0 -3.5 13.3 -4.2 -14.3 -23.5 -23.4 -1.4 25.5 21.1 -1.6 -19.4 -11.4 43.3 52.6 23.1 -16.6 -8.5 6.9 7.9 -6.4 -4.4 94.0 -1.5 -1.5 -0.5 -0.2 -0.8 -1.9 -2.5 -2.6 3.4 4.9 3.0 -1.0 -1.5 1.9 -0.9 1.7 0.2 21.9 -0.4 -0.9 -0.7 -2.0 1.1 6.4 -2.0 9.0 -2.1 4.7 -1.1 -1.8 -9.3 -1.2 5.1 -7.0 -28.4 -3.0 -2.1 87.7 -8.4 8.2 10.0 1.3 -2.7 43.3 30.6 -4.3 -21.6 4.1 -16.6 -5.0 -17.2 100.3 -20.3 -31.5 42.9 -4.0 -5.0 38.6 -39.0 -33.4 -45.1 ' 1.4 -11.2 -11.4 -13.4 0.0 -12.1 40.2 223 Lulu Supernatant Influent Actual Effluent Predicted Effluent Date Mg NH4 P04 pH Mg NH4 P04 Mg NH4 P04 mg/L mg/L mg/L mg/L mg/L mg/L mg/L mg/L mg/L Reactor A 2-Oct-02 242.4 896.3 80.4 7.8 190.2 863.5 3.0 181.5 861.2 2.8 3-Oct-02 236.6 898.3 80.6 7.8 179.4 879.1 3.5 175.6 863.2 2.9 4-Oct-02 248.3 918.7 82.4 7.7 190.4 886.4 3.9 186.2 882.9 3.2 5-Oct-02 253.8 880.4 82.8 7.7 201.1 855.1 3.1 191.2 844.3 3.0 6-Oct-02 198.4 881.7 83.6 7.8 135.8 831.5 3.5 136.1 845.8 4.2 7-Oct-02 206.9 904.0 84.0 7.8 125.6 876.9 4.0 144.0 867.7 3.8 8-Oct-02 182.5 889.2 83.1 7.8 119.2 861.0 5.5 121.0 853.7 4.7 9-Oct-02 195.0 918.5 84.2 7.8 124.5 882.5 5.2 132.1 882.2 4.0 10-Oct-02 198.6 861.6 81.6 7.7 136.1 812.9 6.0 138.2 826.8 4.7 25-Oct-02 189.9 892.4 83.5 7.7 130.2 869.2 4.7 128.2 856.9 4.9 26-Oct-02 195.6 861.7 83.5 7.7 145.6 825.7 5.0 133.8 826.1 4.7 27-Oct-02 192.0 863.3 83.6 7.7 125.0 829.3 6.8 130.1 827.7 4.8 28-Oct-02 202.9 853.7 82.9 7.8 146.4 794.9 3.4 141.1 818.0 4.2 29-Oct-02 223.5 820.9 81.6 7.8 159.4 792.9 3.7 162.4 785.7 3.8 30-Oct-02 243.2 820.5 74.8 7.8 186.8 777.8 3.5 187.1 788.2 3.3 31-Oct-02 237.2 845.1 79.2 7.7 180.9 809.3 3.3 178.0 811.0 3.7 l-Nov-02 218.0 856.2 80.2 7.7 154.2 815.7 3.6 158.3 821.8 4.1 8-Nov-02 171.2 966.0 67.5 7.7 120.6 917.3 5.4 121.9 937.6 4.6 9-Nov-02 181.0 958.8 67.0 7.7 125.7 936.5 5.3 131.8 930.5 4.3 lO-Nov-02 191.5 942.7 64.8 7.7 129.8 916.9 4.9 143.6 915.2 3.8 1 l-Nov-02 144.1 981.8 67.3 7.7 106.7 939.2 4.1 96.1 954.1 6.1 12-Nov-02 184.2 889.6 62.9 7.7 133.6 861.3 5.6 138.2 863.1 4.3 13-Nov-02 181.2 849.8 63.2 7.7 133.4 828.2 5.4 135.3 823.4 4.7 14-Nov-02 172.2 860.9 65.2 7.7 126.9 841.1 6.4 125.1 833.7 5.1 15-Nov-02 180.6 896.3 66.2 7.7 135.8 831.5 5.0 132.1 868.4 4.5 16-Nov-02 187.2 879.0 64.7 7.7 150.2 857.9 6.3 139.8 851.7 4.3 17-Nov-02 187.4 869.8 66.7 7.7 137.4 814.6 5.4 138.7 841.7 4.6 18-Nov-02 182.9 888.8 66.6 7.7 138.1 825.7 5.2 134.3 860.8 4.6 eactor B 2-Oct-02 100.3 973.2 87.3 8.2 35.0 925.6 5.0 36.8 936.6 6.4 3-Oct-02 90.2 978.2 87.7 8.2 30.8 953.4 7.4 27.9 942.3 8.3 4-Oct-02 110.7 978.6 87.8 8.2 47.3 943.4 5.2 45.8 941.2 5.1 5-Oct-02 115.6 939.9 88.4 8.2 48.1 917.3 3.7 50.1 902.2 5.0 6-Oct-02 118.8 916.4 86.9 8.2 58.5 891.0 5.7 54.2 879.2 4.6 7-Oct-02 118.6 943.5 87.6 8.2 51.2 911.6 5.6 53.4 906.0 4.5 8-Oct-02 98.1 943.7 88.1 8.2 33.1 922.4 8.9 34.5 907.1 7.2 9-Oct-02 86.1 986.6 90.4 8.2 22.6 965.1 8.6 23.2 950.4 10.3 10-Oct-02 87.4 926.3 87.7 8.2 25.1 883.3 7.2 26.3 891.1 10.0 8-Nov-02 78.4 1035.3 72.3 8.4 23.9 1019.4 7.7 27.3 1005.9 7.2 9-Nov-02 74.4 1046.2 71.9 8.4 23.1 1023.0 7.4 22.7 1016.3 5.9 224 10-Nov-02 72.8 1044.6 71.6 8.4 20.0 995.7 7.5 21.9 1015.2 6.7 1 l-Nov-02 73.2 971.2 68.7 8.4 27.3 937.1 6.6 22.9 942.1 4.5 12-Nov-02 73.4 927.0 68.9 8.4 25.0 891.3 5.5 25.2 899.3 7.5 13-Nov-02 77.4 929.2 70.3 8.4 24.1 907.3 6.0 29.4 901.5 9.1 14-Nov-02 79.7 969.9 71.7 8.4 31.1 959.0 7.8 29.9 941.2 8.2 15-Nov-02 80.8 955.6 70.4 8.4 27.1 919.7 8.0 29.6 926.1 5.1 16-Nov-02 78.6 947.0 72.6 8.4 22.2 927.2 7.7 28.1 917.9 8.2 6-Dec-02 76.3 858.9 76.0 8.4 26.7 830.1 9.0 23.6 828.5 8.8 7-Dec-02 75.7 856.6 75.3 8.4 26.1 835.2 8.9 23.5 826.6 8.9 8-Dec-02 80.9 847.1 78.2 8.4 23.1 827.1 8.3 25.9 815.4 8.2 9-Dec-02 104.7 851.4 77.4 8.3 54.0 829.7 5.4 47.9 818.6 4.9 10-Dec-02 108.5 859.7 76.8 8.3 55.5 835.0 5.1 51.8 827.0 4.5 ll-Dec-02 107.9 856.0 75.5 8.3 48.1 840.2 4.9 52.1 823.8 4.5 12-Dec-02 135.2 831.5 71.6 8.2 75.6 796.4 4.0 81.6 800.6 3.4 13-Dec-02 138.7 804.3 71.9 8.2 89.5 799.9 4.1 84.9 773.3 3.4 14-Dec-02 139.4 803.9 71.9 8.2 87.2 786.6 4.2 85.6 772.9 3.3 15-Dec-02 165.3 783.8 72.6 7.9 110.3 719.3 4.3 111.7 752.9 4.3 16-Dec-02 170.9 780.5 72.3 7.9 105.2 756.9 4.8 117.3 749.6 4.1 17-Dec-02 170.8 805.2 74.0 7.9 97.3 803.3 4.9 115.8 773.5 4.0 18-Dec-02 197.3 785.1 72.4 7.6 127.5 721.5 6.9 145.3 755.2 6.1 19-Dec-02 197.2 794.5 71.9 7.6 136.9 747.6 6.9 145.5 764.7 6.0 20-Dec-02 192.6 797.3 72.1 7.6 152.3 775.3 7.2 140.8 767.5 6.1 225 Influent Influent Predicted Effluent IPin IPeq IPout Error Mg NH4 P04 Mg NH4 P04 mol/L mol/L mol/L mol/L mol/L mol/L 1.0E-02 6.4E-02 2.6E-03 7.5E-03 6.1E-02 9.0E-05 1.7E-06 4.1E-08 4.1E-08 2.8E-04 9.7E-03 6.4E-02 2.6E-03 7.2E-03 6.2E-02 9.3E-05 1.6E-06 4.1E-08 4.1E-08 3.7E-04 1.0E-02 6.6E-02 2.7E-03 7.7E-03 6.3E-02 1.0E-04 1.8E-06 5.1E-08 5.1E-08 3.4E-04 1.0E-02 6.3E-02 2.7E-03 7.9E-03 6.0E-02 9.8E-05 1.8E-06 4.7E-08 4.7E-08 3.3E-04 8.2E-03 6.3E-02 2.7E-03 5.6E-03 6.0E-02 1.3E-04 1.4E-06 4.6E-08 4.6E-08 1.6E-08 8.5E-03 6.5E-02 2.7E-03 5.9E-03 6.2E-02 1.2E-04 1.5E-06 4.5E-08 4.5E-08 1.0E-08 7.5E-03 6.3E-02 2.7E-03 5.0E-03 6.1E-02 1.5E-04 1.3E-06 4.6E-08 4.6E-08 4.5E-08 8.0E-03 6.6E-02 2.7E-03 5.4E-03 6.3E-02 1.3E-04 1.4E-06 4.5E-08 4.5E-08 3.0E-08 8.2E-03 6.2E-02 2.6E-03 5.7E-03 5.9E-02 1.5E-04 1.3E-06 5.1E-08 5.1E-08 4.5E-09 7.8E-03 6.4E-02 2.7E-03 5.3E-03 6.1E-02 1.6E-04 1.3E-06 5.1E-08 5.1E-08 2.3E-08 8.0E-03 6.2E-02 2.7E-03 5.5E-03 5.9E-02 1.5E-04 1.3E-06 5.0E-08 5.0E-08 1.4E-08 7.9E-03 6.2E-02 2.7E-03 5.4E-03 5.9E-02 1.6E-04 1.3E-06 5.0E-08 5.0E-08 2.1E-08 8.3E-03 6.1E-02 2.7E-03 5.8E-03 5.8E-02 1.3E-04 1.4E-06 4.6E-08 4.6E-08 7.9E-09 9.2E-03 5.9E-02 2.6E-03 6.7E-03 5.6E-02 1.2E-04 1.4E-06 4.6E-08 4.6E-08 6.8E-04 1.0E-02 5.9E-02 2.4E-03 7.7E-03 5.6E-02 1.1E-04 1.4E-06 4.6E-08 4.6E-08 3.6E-05 9.8E-03 6.0E-02 2.6E-03 7.3E-03 5.8E-02 1.2E-04 1.5E-06 5.1E-08 5.1E-08 1.8E-04 9.0E-03 6.1E-02 2.6E-03 6.5E-03 5.9E-02 1.3E-04 1.4E-06 5.1E-08 5.1E-08 5.1E-04 7.0E-03 6.9E-02 2.2E-03 5.0E-03 6.7E-02 1.5E-04 1.1E-06 5.0E-08 5.0E-08 2.6E-09 7.4E-03 6.8E-02 2.2E-03 5.4E-03 6.6E-02 1.4E-04 1.1E-06 5.1E-08 5.1E-08 6.0E-04 7.9E-03 6.7E-02 2.1E-03 5.9E-03 6.5E-02 1.2E-04 1.1E-06 4.7E-08 4.7E-08 1.9E-04 5.9E-03 7.0E-02 2.2E-03 4.0E-03 6.8E-02 2.0E-04 9.0E-07 5.3E-08 5.3E-08 2.2E-08 7.6E-03 6.4E-02 2.0E-03 5.7E-03 6.2E-02 1.4E-04 9.8E-07 4.9E-08 4.9E-08 1.1E-04 7.5E-03 6.1E-02 2.0E-03 5.6E-03 5.9E-02 1.5E-04 9.2E-07 5.0E-08 5.0E-08 1.2E-04 7.1E-03 6.1E-02 2.1E-03 5.1E-03 6.0E-02 1.7E-04 9.2E-07 5.1E-08 5.1E-08 3.8E-04 7.4E-03 6.4E-02 2.1E-03 5.4E-03 6.2E-02 1.4E-04 1.0E-06 5.6E-08 4.9E-08 -7.8E+03 7.7E-03 6.3E-02 2.1E-03 5.8E-03 6.1E-02 1.4E-04 1.0E-06 5.3E-08 4.9E-08 -4.3E+03 7.7E-03 6.2E-02 2.2E-03 5.7E-03 6.0E-02 1.5E-04 1.0E-06 5.1E-08 5.1E-08 3.4E-04 7.5E-03 6.3E-02 2.1E-03 5.5E-03 6.1E-02 1.5E-04 1.0E-06 5.1E-08 5.1E-08 4.2E-04 4.1E-03 6.9E-02 2.8E-03 1.5E-03 6.7E-02 2.1E-04 8.1E-07 2.1E-08 2.1E-08 3.2E-05 3.7E-03 7.0E-02 2.8E-03 1.1E-03 6.7E-02 2.7E-04 7.3E-07 2.1E-08 2.1E-08 2.9E-04 4.6E-03 7.0E-02 2.8E-03 1.9E-03 6.7E-02 1.6E-04 9.0E-07 2.1E-08 2.1E-08 4.7E-06 4.8E-03 6.7E-02 2.9E-03 2.1E-03 6.4E-02 1.6E-04 9.1E-07 2.1E-08 2.1E-08 2.2E-06 4.9E-03 6.5E-02 2.8E-03 2.2E-03 6.3E-02 1.5E-04 9.0E-07 2.1E-08 2.1E-08 4.5E-07 4.9E-03 6.7E-02 2.8E-03 2.2E-03 6.5E-02 1.5E-04 9.3E-07 2.1E-08 2.1E-08 9.7E-07 4.0E-03 6.7E-02 2.8E-03 1.4E-03 6.5E-02 2.3E-04 7.7E-07 2.1E-08 2.1E-08 5.9E-05 3.5E-03 7.0E-02 2.9E-03 9.5E-04 6.8E-02 3.3E-04 7.3E-07 2.2E-08 2.2E-08 1.3E-08 3.6E-03 6.6E-02 2.8E-03 1.1E-03 6.4E-02 3.2E-04 6.7E-07 2.2E-08 2.2E-08 1.8E-04 3.2E-03 7.4E-02 2.3E-03 1.1E-03 7.2E-02 2.3E-04 5.6E-07 1.6E-08 1.9E-08 2.5E+03 3.1E-03 7.5E-02 2.3E-03 9.3E-04 7.3E-02 1.9E-04 5.3E-07 1.6E-08 1.3E-08 -3.0E+03 226 3.0E-03 7.5E-02 2.3E-03 9.0E-04 7.2E-02 2.2E-04 5.2E--07 1 6E-08 1.4E-•08 -1.7E+03 3.0E-03 6.9E-02 2.2E-03 9.4E-04 6.7E-02 1.4E-04 4.6E--07 1 6E-08 9.1E-•09 -7.2E+03 3.0E-03 6.6E-02 2.2E-•03 1.OE-03 6.4E-02 2.4E--04 4.4E-•07 1 7E-08 1.6E-•08 -3.0E+02 3.2E-•03 6.6E-02 2.3E--03 1.2E-03 6.4E-02 2.9E--04 4.8E--07 1 6E-08 2.3E-•08 6.6E+03 3.3E-03 6.9E-02 2.3E-•03 1.2E-03 6.7E-02 2.6E-04 5.3E-•07 1 6E-08 2.2E-•08 5.5E+03 3.3E-03 6.8E-02 2.3E-03 1.2E-03 6.6E-02 1.7E-04 5.2E--07 1 6E-08 1.3E-•08 -2.7E+03 3.2E-03 6.8E-02 2.3E-03 1.2E-03 6.6E-02 2.7E-04 5.1E--07 1 6E-08 2.0E-•08 4.1E+03 3.1E--03 6.1E-02 2.5E-•03 9.7E-04 5.9E-02 2.8E-•04 4.7E-•07 1 6E-08 1.6E-•08 1.6E-04 3.1E-•03 6.1E-02 2.4E-•03 9.7E-04 5.9E-02 2.9E-•04 4.6E--07 1 6E-08 1.6E-•08 1.2E-04 3.3E-•03 6.0E-02 2.5E-•03 1.1E-03 5.8E-02 2.6E-•04 5.IE -07 1 6E-08 1.6E--08 2.9E-04 4.3E-•03 6.1E-02 2.5E--03 2.0E-03 5.8E-02 1.6E-•04 6.5E -07 1 8E-08 1.8E •08 6.0E-06 4.5E-•03 6.1E-02 2.5E-•03 2.1E-03 5.9E-02 1.5E-•04 6.8E -07 1 8E-08 1.8E -08 2.4E-06 4.4E--03 6.1E-02 2.4E--03 2.1E-03 5.9E-02 1.5E-•04 6.6E -07 1 8E-08 1.8E •08 1.1E-06 5.6E--03 5.9E-02 2.3E--03 3.4E-03 5.7E-02 1.1E-•04 7.6E -07 2 1E-08 2.1E -08 3.8E-04 5.7E--03 5.7E-02 2.3E--03 3.5E-03 5.5E-02 LIE-•04 7.6E -07 2 1E-08 2.1E -08 3.1E-04 5.7E -03 5.7E-02 2.3E -03 3.5E-03 5.5E-02 LIE-•04 7.6E -07 2 1E-08 2.1E -08 3.0E-04 6.8E -03 5.6E-02 2.3E -03 4.6E-03 5.4E-02 1.4E -04 8.9E -07 3 4E-08 3.4E -08 3.3E-05 7.0E -03 5.6E-02 2.3E -03 4.8E-03 5.4E-02 1.3E -04 9.1E -07 3 4E-08 3.4E -08 2.1E-05 7.0E -03 5.7E-02 2.4E -03 4.8E-03 5.5E-02 1.3E -04 9.7E -07 3 4E-08 3.4E -08 5.6E-05 8.IE -03 5.6E-02 2.3E -03 6.0E-03 5.4E-02 2.0E -04 LIE -06 6 3E-08 6.3E -08 1.2E-06 8.IE -03 5.7E-02 2.3E -03 6.0E-03 5.5E-02 1.9E -04 LIE -06 6.3E-08 6.3E -08 9.5E-07 7.9E -03 5.7E-02 2.3E -03 5.8E-03 5.5E-02 2.0E -04 1.0E -06 6.3E-08 6.3E -08 1.3E-06 227 Mol Reduction Absolute Concentration error % Relative Absolute Error Actual Error Mg NH4 P04 Mg NH4 P04 Mg NH4 P04 mg/L mg/L mg/L mg/L mg/L mg/L 2.5E-03 8.8 2.2 0.2 4.6 0.3 6.7 -8.8 -2.2 -0.2 2.5E-03 3.7 16.0 0.6 2.1 1.8 17.5 -3.7 -16.0 -0.6 2.6E-03 4.1 3.5 0.7 2.2 0.4 17.6 -4.1 -3.5 -0.7 2.6E-03 9.9 10.8 0.1 4.9 1.3 2.0 -9.9 -10.8 -0.1 2.6E-03 0.3 14.4 0.7 0.2 1.7 21.0 0.3 14.4 0.7 2.6E-03 18.4 9.2 0.2 14.6 1.0 5.3 18.4 -9.2 -0.2 2.5E-03 1.8 7.3 0.9 1.5 0.8 16.0 1.8 -7.3 -0.9 2.6E-03 7.6 0.3 1.1 6.1 0.0 21.9 7.6 -0.3 -1.1 2.5E-03 2.2 14.0 1.3 1.6 1.7 21.9 2.2 14.0 -1.3 2.5E-03 2.0 12.4 0.2 1.5 1.4 3.5 -2.0 -12.4 0.2 2.5E-03 11.8 0.4 0.3 8.1 0.1 5.9 -11.8 0.4 -0.3 2.5E-03 5.1 1.7 2.0 4.1 0.2 28.7 • 5.1 -1.7 -2.0 2.5E-03 5.3 23.1 0.8 3.6 2.9 22.0 -5.3 23.1 0.8 2.5E-03 3.0 7.2 0.1 1.9 0.9 1.8 3.0 -7.2 0.1 2.3E-03 0.3 10.4 0.2 0.2 1.3 5.8 0.3 10.4 -0.2 2.4E-03 3.0 1.6 0.4 1.6 0.2 11.3 -3.0 1.6 0.4 2.5E-03 4.0 6.1 0.5 2.6 0.8 13.0 4.0 6.1 0.5 2.0E-03 116.5 20.4 0.8 2169.8 2.2 14.9 116.5 20.4 -0.8 2.0E-03 126.6 6.1 0.9 2411.1 0.6 17.2 126.6 -6.1 -0.9 2.0E-03 138.7 1.7 1.1 2809.8 0.2 22.8 138.7 -1.7 -1.1 2.0E-03 92.0 14.9 2.0 2266.2 1.6 49.6 92.0 14.9 2.0 1.9E-03 132.7 1.8 1.3 2383.4 0.2 23.0 132.7 1.8 -1.3 1.9E-03 129.9 4.8 0.7 2412.5 0.6 13.0 129.9 -4.8 -0.7 1.9E-03 118.7 7.4 1.2 1869.7 0.9 19.4 118.7 -7.4 -1.2 2.0E-03 127.1 36.9 0.6 2527.1 4.4 11.4 127.1 36.9 -0.6 2.0E-03 133.5 6.2 2.0 2115.8 0.7 31.9 133.5 -6.2 -2.0 2.0E-03 133.3 27.1 0.8 2477.5 3.3 15.1 133.3 27.1 -0.8 2.0E-03 129.1 35.1 0.5 2507.3 4.3 10.4 129.1 35.1 -0.5 2.6E-03 1.8 11.0 1.4 5.2 1.2 28.9 1.8 11.0 1.4 2.6E-03 2.9 11.2 0.9 9.5 1.2 11.7 2.7E-03 1.5 2.2 0.2 3.2 0.2 3.3 2.7E-03 2.0 15.1 1.3 4.1 1.6 34.5 2.0 -15.1 1.3 2.7E-03 4.3 11.8 1.1 7.3 1.3 19.0 -4.3 -11.8 -1.1 2.7E-03 2.2 5.6 1.1 4.2 0.6 19.3 2.2 -5.6 -1.1 2.6E-03 1.4 15.3 1.7 4.3 1.7 19.1 1.4 -15.3 -1.7 2.6E-03 0.6 14.7 1.8 2.7 1.5 20.7 0.6 -14.7 1.8 2.5E-03 1.2 7.8 2.8 4.9 0.9 39.4 1.2 7.8 2.8 2.1E-03 3.3 13.6 0.6 14.0 1.3 7.2 3.3 -13.6 -0.6 2.1E-03 0.4 6.6 1.5 1.7 0.6 19.8 -0.4 -6.6 -1.5 228 2.1E-03 1.9 19.5 0.7 9.5 2.0 9.9 1.9 19.5 -0.7 2.1E-03 4.5 5.0 2.1 16.3 0.5 32.2 -4.5 5.0 -2.1 2.0E-03 0.3 7.9 2.0 1.0 0.9 36.1 0.3 7.9 2.0 2.0E-03 5.3 5.8 3.1 22.0 0.6 51.1 5.3 -5.8 3.1 2.0E-03 1.3 17.7 0.4 4.0 1.8 5.5 -1.3 -17.7 0.4 2.1E-03 2.5 6.4 2.9 9.3 0.7 36.2 2.5 6.4 -2.9 2.1E-03 , 5.9 9.3 0.5 26.8 1.0 6.8 5.9 -9.3 0.5 2.2E-03 3.2 1.6 0.2 11.9 0.2 2.1 -3.2 -1.6 -0.2 2.1E-03 2.5 8.6 0.1 9.6 1.0 1.0 -2.5 -8.6 -0.1 2.3E-03 2.8 11.7 0.1 12.1 1.4 1.3 2.8 -11.7 -0.1 2.3E-03 6.1 11.0 0.4 11.3 1.3 7.7 -6.1 -11.0 -0.4 2.3E-03 3.6 8.0 0.5 6.5 1.0 10.8 -3.6 -8.0 -0.5 2.3E-03 4.0 16.4 0.4 8.3 1.9 8.1 4.0 -16.4 -0.4 2.2E-03 6.0 4.2 0.6 7.9 0.5 15.8 6.0 4.2 -0.6 2.2E-03 4.5 26.6 0.8 5.1 3.3 18.4 -4.5 -26.6 -0.8 2.2E-03 1.6 13.7 0.8 1.9 1.7 20.1 -1.6 -13.7 -0.8 2.2E-03 1.4 33.6 0.0 1.3 4.7 0.5 1.4 33.6 0.0 2.2E-03 12.1 7.3 0.7 11.5 1.0 14.4 12.1 -7.3 -0.7 2.3E-03 18.5 29.8 0.9 19.1 3.7 18.6 18.5 -29.8 -0.9 2.1E-03 17.8 33.6 0.8 13.9 4.7 11.9 17.8 33.6 -0.8 2.1E-03 8.6 17.1 0.9 6.3 2.3 13.5 8.6 17.1 -0.9 2.1E-03 11.5 7.8 1.0 7.5 1.0 14.0 -11.5 -7.8 -1.0 % Actual Error Mg NH4 P04 -4.6 -0.3 -6.7 -2.1 -1.8 -17.5 -2.2 -0.4 -17.6 -4.9 -1.3 -2.0 0.2 1.7 21.0 14.6 -1.0 -5.3 1.5 -0.8 -16.0 6.1 0.0 -21.9 1.6 1.7 -21.9 -1.5 -1.4 3.5 -8.1 0.1 -5.9 4.1 -0.2 -28.7 -3.6 2.9 22.0 1.9 -0.9 1.8 0.2 1.3 -5.8 -1.6 0.2 11.3 2.6 0.8 13.0 2169.8 2.2 -14.9 2411.1 -0.6 -17.2 2809.8 -0.2 -22.8 2266.2 1.6 49.6 2383.4 0.2 -23.0 2412.5 -0.6 -13.0 1869.7 -0.9 -19.4 2527.1 4.4 -11.4 2115.8 -0.7 -31.9 2477.5 3.3 -15.1 2507.3 4.3 -10.4 5.2 1.2 28.9 4.1 -1.6 34.5 -7.3 -1.3 -19.0 4.2 -0.6 -19.3 4.3 -1.7 -19.1 2.7 -1.5 20.7 4.9 0.9 39.4 14.0 -1.3 -7.2 -1.7 -0.6 -19.8 9.5 2.0 -9.9 -16.3 0.5 -32.2 1.0 0.9 36.1 22.0 -0.6 51.1 -4.0 -1.8 5.5 9.3 0.7 -36.2 26.8 -1.0 6.8 -11.9 -0.2 -2.1 -9.6 -1.0 -1.0 12.1 -1.4 -1.3 -11.3 -1.3 -7.7 -6.5 -1.0 -10.8 8.3 -1.9 -8.1 7.9 0.5 -15.8 -5.1 -3.3 -18.4 -1.9 -1.7 -20.1 1.3 4.7 0.5 11.5 -1.0 -14.4 19.1 -3.7 -18.6 13.9 4.7 -11.9 6.3 2.3 -13.5 -7.5 -1.0 -14.0 

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