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Jurg Keller - One of the best experts on this subject based on the ideXlab platform.
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biological Phosphorus Removal from abattoir wastewater at very short sludge ages mediated by novel pao clade comamonadaceae
Water Research, 2015Co-Authors: Damien J Batstone, Jurg KellerAbstract:Recent increases in global Phosphorus costs, together with the need to remove Phosphorus from wastewater to comply with water discharge regulations, make Phosphorus recovery from wastewater economically and environmentally attractive. Biological Phosphorus (Bio-P) Removal process can effectively capture the Phosphorus from wastewater and concentrate it in a form that is easily amendable for recovery in contrast to traditional (chemical) Phosphorus Removal processes. However, Bio-P Removal processes have historically been operated at medium to long solids retention times (SRTs, 10-20 days typically), which inherently increases the energy consumption while reducing the recoverable carbon fraction and hence makes it incompatible with the drive towards energy self-sufficient wastewater treatment plants. In this study, a novel high-rate Bio-P Removal process has been developed as an energy efficient alternative for Phosphorus Removal from wastewater through operation at an SRT of less than 4 days. The process was most effective at an SRT of 2-2.5 days, achieving >90% phosphate Removal. Further reducing the SRT to 1.7 days resulted in a loss of Bio-P activity. 16S pyrotag sequencing showed the community changed considerably with changes in the SRT, but that Comamonadaceae was consistently abundant when the Bio-P activity was evident. FISH analysis combined with DAPI staining confirmed that bacterial cells of Comamonadaceae arranged in tetrads contained polyphosphate, identifying them as the key polyphosphate accumulating organisms at these low SRT conditions. Overall, this paper demonstrates a novel, high-rate Phosphorus Removal process that can be effectively integrated with short SRT, energy-efficient carbon Removal and recovery processes.
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simultaneous nitrification denitrification and Phosphorus Removal from nutrient rich industrial wastewater using granular sludge
Biotechnology and Bioengineering, 2008Co-Authors: Gulsum Yilmaz, Romain Lemaire, Jurg Keller, Zhiguo YuanAbstract:The biological Removal of nitrogen and Phosphorus from nutrient-rich abattoir wastewater using granular sludge has been investigated. A lab-scale sequencing batch reactor, seeded with granular sludge developed using synthetic wastewater, was operated for 13 months under alternating anaerobic and aerobic conditions. It is demonstrated that the granules could be sustained and indeed further developed with the use of abattoir wastewater. The organic, nitrogen, and Phosphorus loading rates applied were 2.7 gCOD L-1 day-1, 0.43 gN L-1 day-1, and 0.06 gP L-1 day-1, respectively. The Removal efficiency of soluble COD, soluble nitrogen and soluble Phosphorus were 85%, 93%, and 89%, respectively. However, the high suspended solids in the effluent limited the overall Removal efficiency to 68%, 86%, and 74% for total COD, TN, and TP, respectively. This good nutrient Removal was achieved through the process known as simultaneous nitrification, denitrification, and Phosphorus Removal, likely facilitated by the presence of large anoxic zones in the center of the granules. The Removal of nitrogen was likely via nitrite optimizing the use of the limited COD available in the wastewater. Accumulibacter spp. were found to be responsible for most of the denitrification, further reducing the COD requirement for nitrogen and Phosphorus Removal. Mineral precipitation was evaluated and was not found to significantly contribute to the overall nutrient Removal. It is also shown that the minimum HRT in a granular sludge system is not governed by the sludge settleability, as is the case with floccular sludge systems, but likely by the limitations associated with the transfer of substrates in granules. Biotechnol. Bioeng. 2008;100: 529-541. © 2007 Wiley Periodicals, Inc.
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competition between polyphosphate and glycogen accumulating organisms in enhanced biological Phosphorus Removal systems with acetate and propionate as carbon sources
Journal of Biotechnology, 2006Co-Authors: Adrian Oehmen, Aaron Marc Saunders, Zhiguo Yuan, Teresa M Vives, Jurg KellerAbstract:Enhanced biological Phosphorus Removal (EBPR) is a widely used process for achieving Phosphorus Removal from wastewater. A potential reason for EBPR failure is the undesirable growth of glycogen accumulating organisms (GAOs), which can compete for carbon sources with the bacterial group responsible for Phosphorus Removal from wastewater: the polyphosphate accumulating organisms (PAOs). This study investigates the impact of carbon source on EBPR performance and the competition between PAOs and GAOs. Two sequencing batch reactors (SBRs) were operated during a 4-6 month period and fed with a media containing acetate or propionate, respectively, as the sole carbon source. It was found that the acetate fed SBR rarely achieved a high level of Phosphorus Removal, and that a large portion of the microbial community was comprised of Candidatus Competibacter phosphatis, a known GAO. The propionate fed SBR, however, achieved stable Phosphorus Removal throughout the study, apart from one brief disturbance. The bacterial community of the propionate fed SBR was dominated by Candidatus Accumulibacter phosphatis, a known PAO, and did not contain Competibacter In a separate experiment, another SBR was seeded with a mixture of PAOs and a group of alphaproteobacterial GAOs, both enriched with propionate as the sole carbon source. Stable EBPR was achieved and the PAO population increased while the GAOs appeared to be out-competed. The results of this paper suggest that propionate may provide PAOs with a selective advantage over GAOs in the PAO-GAO competition, particularly through the minimisation of Competibacter Propionate may be a more suitable substrate than acetate for enhancing Phosphorus Removal in EBPR systems. (c) 2005 Elsevier B.V. All rights reserved.
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simultaneous nitrification denitrification and Phosphorus Removal in a lab scale sequencing batch reactor
Biotechnology and Bioengineering, 2003Co-Authors: Raymond J Zeng, Romain Lemaire, Zhiguo Yuan, Jurg KellerAbstract:Simultaneous nitrification and denitrification (SND) via the nitrite pathway and anaerobic-anoxic-enhanced biological Phosphorus Removal (EBPR) are two processes that can significantly reduce the energy and COD demand for nitrogen and Phosphorus Removal. The combination of these two processes has the potential of achieving simultaneous nitrogen and Phosphorus Removal with a minimal requirement for COD. A lab-scale sequencing batch reactor (SBR) was operated in alternating anaerobic-aerobic mode with a low dissolved oxygen (DO) concentration (0.5 mg/L) during the aerobic period, and was demonstrated to accomplish nitrification, denitrification, and Phosphorus Removal. Under anaerobic conditions, COD was taken up and converted to polyhydroxyalkanoates (PHAs), accompanied by Phosphorus release. In the subsequent aerobic stage, PHA was oxidized and Phosphorus was taken up to <0.5 mg/L by the end of the cycle. Ammonia was also oxidized during the aerobic period, but without accumulation of nitrite or nitrate in the system, indicating the occurrence of simultaneous nitrification and denitrification. However, off-gas analysis showed that the final denitrification product was mainly nitrous oxide (N(2)O), not N(2). Further experimental results demonstrated that nitrogen Removal was via nitrite, not nitrate. These experiments also showed that denitrifying glycogen-accumulating organisms (DGAOs), rather than denitrifying polyphosphate-accumulating organisms (DPAOs), were responsible for the denitrification activity.
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simultaneous nitrification denitrification and Phosphorus Removal in a lab scale sequencing batch reactor
Biotechnology and Bioengineering, 2003Co-Authors: Raymond J Zeng, Romain Lemaire, Zhiguo Yuan, Jurg KellerAbstract:Simultaneous nitrification and denitrification (SND) via the nitrite pathway and anaerobic-anoxic-enhanced biological Phosphorus Removal (EBPR) are two processes that can significantly reduce the energy and COD demand for nitrogen and Phosphorus Removal. The combination of these two processes has the potential of achieving simultaneous nitrogen and Phosphorus Removal with a minimal requirement for COD. A lab-scale sequencing batch reactor (SBR) was operated in alternating anaerobic-aerobic mode with a low dissolved oxygen (DO) concentration (0.5 mg/L) during the aerobic period, and was demonstrated to accomplish nitrification, denitrification, and Phosphorus Removal. Under anaerobic conditions, COD was taken up and converted to poly-hydroxyalkanoates (PHAs), accompanied by Phosphorus release. In the subsequent aerobic stage, PHA was oxidized and Phosphorus was taken up to <0.5 mg/L by the end of the cycle. Ammonia was also oxidized during the aerobic period, but without accumulation of nitrite or nitrate in the system, indicating the occurrence of simultaneous nitrification and denitrification. However, off-gas analysis showed that the final denitrification product was mainly nitrous oxide (N2O), not N-2. Further experimental results demonstrated that nitrogen Removal was via nitrite, not nitrate. These experiments also showed that denitrifying glycogen-accumulating organisms (DGAOs), rather than denitrifying polyphosphate-accumulating organisms (DPAOs), were responsible for the denitrification activity. (C) 2003 Wiley Periodicals, Inc.
Yongzhen Peng - One of the best experts on this subject based on the ideXlab platform.
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enhanced nitrogen and Phosphorus Removal from municipal wastewater in an anaerobic aerobic anoxic sequencing batch reactor with sludge fermentation products as carbon source
Bioresource Technology, 2017Co-Authors: Yue Yuan, Baikun Li, Lei Wu, Xiyao Li, Qiong Zhang, Yongzhen PengAbstract:Abstract An anaerobic-aerobic-anoxic sequencing batch reactor (AOA-SBR) using sludge fermentation products as carbon source was developed to enhance nitrogen and Phosphorus Removal in municipal wastewater with low C/N ratio (
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advanced nitrogen and Phosphorus Removal in the pre denitrification anaerobic anoxic aerobic nitrification sequence batch reactor pre a2nsbr treating low carbon nitrogen c n wastewater
Chemical Engineering Journal, 2016Co-Authors: Weihua Zhao, Yong Zhang, Meixiang Wang, Yongzhen PengAbstract:Abstract In order to treat domestic wastewater with high ammonia but low carbon source (low C/N ratio), a novel two sludge pre-A2NSBR system (anaerobic/anoxic/aerobic nitrification) was firstly developed by exchanging the sequence of aerobic nitrification and anoxic phase of the conventional A2NSBR process (anaerobic/aerobic nitrification/anoxic). The system was operated for 186 days to treat real domestic wastewater with low carbon/nitrogen (C/N = 4.03). Anoxic duration was adjusted and post-aeration phase was added to enhance nitrogen and Phosphorus Removal. Results indicate that adding post-aeration phase is indispensable to achieve enhanced Phosphorus Removal, the pre-A2NSBR system achieved a high denitrifying Phosphorus Removal efficiency of 96.86% with efficient utilization of limited carbon source. Specifically, the ammonia effluent was 0.46 mg/L, which solved the bottleneck problem of high ammonia residues in conventional A2NSBR process. The fluorescence in situ hybridization (FISH) results showed that PAOs was enriched and GAOs was inhibited in the A2SBR, nitrifiers also became dominant in the N-SBR. Moreover, the profiles variation of real-time online indicator such as pH, ORP and DO were demonstrated closely related with the nutrient Removal performance, and based on this, it is possible or expected to establish the real time control strategy in the future.
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optimizing aeration rate in an external nitrification denitrifying Phosphorus Removal endpr system for domestic wastewater treatment
Chemical Engineering Journal, 2014Co-Authors: Weitang Zhang, Yongzhen Peng, Feng Hou, Qingsong Liu, Shuying WangAbstract:Abstract A ENDPR system, combining anaerobic–anoxic–oxic reactor with an external nitrification biological aerated filter (AAO-BAF), was developed to treat real domestic wastewater. The effluent was discharged after full nitrification in BAF, while nitrogen and Phosphorus Removal by denitrifying Phosphorus accumulating organisms (DPAOs) in the AAO reactor was achieved. To optimize aeration rate in the denitrifying Phosphorus Removal (DPR) reactor, oxidation–reduction potential (ORP) and DO was examined. When the aeration rate dropped to 20 L h−1, the Phosphorus Removal deteriorated greatly. During this phase, the polyphosphate (poly-P) amount in the sludge was reduced by 43% due to incomplete Phosphorus uptake and the secondary Phosphorus release. After increasing the aeration rate to 30 L h−1, the abilities of anaerobic Phosphorus release and anoxic Phosphorus uptake were both improved. Results demonstrated that AAO-BAF could be operated stably with high Removal efficiencies of NH 4 + (99%), TN (80%), and PO 4 3 - (94%) with low carbon requirement (COD/N ratio = 4.0) and low aeration rate (DO = 0.5 mg L−1, in AAO reactor).
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denitrifying Phosphorus Removal and impact of nitrite accumulation on Phosphorus Removal in a continuous anaerobic anoxic aerobic a2o process treating domestic wastewater
Enzyme and Microbial Technology, 2011Co-Authors: Wei Zeng, Yingying Yang, Xiangdong Wang, Yongzhen PengAbstract:Abstract A lab-scale anaerobic–anoxic–aerobic (A2O) process was operated to investigate denitrifying Phosphorus Removal and nitritation–denitritation from domestic wastewater, especially regarding the impact of nitrite accumulation caused by nitritation on Phosphorus Removal. The results showed that mean total nitrogen (TN) Removal was only about 47% and Phosphorus Removal was almost zero without the pre-anoxic zone and additional carbon source. Contrastively, with configuration of pre-anoxic zone, TN and Phosphorus Removal was increased to 75% and 98%, respectively, as well as denitrifying Phosphorus Removal of 66–91% occurred in the anoxic zone. Nitritation–denitritation was achieved through a combination of short aerobic actual hydraulic retention time and low dissolved oxygen levels (0.3–0.5 mg/L); however, Phosphorus Removal deteriorated with increase of nitrite accumulation rates. The free nitrous acid (FNA) concentration of 0.002–0.003 mg HNO2–N/L in the aerobic zone inhibited Phosphorus uptake, which was major cause of Phosphorus Removal deterioration. Through supplying the carbon sources to enhance denitrification and anaerobic Phosphorus release, nitrite and FNA concentrations in the aerobic zone were reduced, and Phosphorus Removal was improved. Compared with nitrification–denitrification, nitritation–denitritation reduced the carbon requirement by 30% and performed biological nutrients Removal well with mean TN and Phosphorus Removal of 85% and 96%, respectively.
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enrichment and culture of major organism groups in enhanced biological Phosphorus Removal systems
High technology letters, 2009Co-Authors: Y You, Zhiguo Yuan, Yongzhen PengAbstract:This research focused on the enrichment of Phosphorus accumulating organisms (PAO) and glycogen accumulating organisms (GAO) in enhanced biological Phosphorus Removal (EBPR) systems-SBR reactors fed with activated sludge. P/C and the carbon sources were considered as two main factors to control the enrichment conditions. So high P/C and alternate acetate and propionate were supplied to PAO, low P/C and acetate were supplied to g-GAO, and low P/C and propionate were supplied to α-GAO. Under the suitable pH, temperature, DO of the aerobic phase and load of the influent, the enrichment of these three kinds of groups was achieved with the results below: Accwnulibacter reached 80% of the total bacteria, and the efficiency of P Removal was over than 98%. Competibacter could reach 90%of the total bacteria, and also, α-GAO was a absolutely predominant group in its reactor. Furthennore, details just like the autoclaved feed and the completely dissolved feed can affect the results of the enrichment work.
Zhiguo Yuan - One of the best experts on this subject based on the ideXlab platform.
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enrichment and culture of major organism groups in enhanced biological Phosphorus Removal systems
High technology letters, 2009Co-Authors: Y You, Zhiguo Yuan, Yongzhen PengAbstract:This research focused on the enrichment of Phosphorus accumulating organisms (PAO) and glycogen accumulating organisms (GAO) in enhanced biological Phosphorus Removal (EBPR) systems-SBR reactors fed with activated sludge. P/C and the carbon sources were considered as two main factors to control the enrichment conditions. So high P/C and alternate acetate and propionate were supplied to PAO, low P/C and acetate were supplied to g-GAO, and low P/C and propionate were supplied to α-GAO. Under the suitable pH, temperature, DO of the aerobic phase and load of the influent, the enrichment of these three kinds of groups was achieved with the results below: Accwnulibacter reached 80% of the total bacteria, and the efficiency of P Removal was over than 98%. Competibacter could reach 90%of the total bacteria, and also, α-GAO was a absolutely predominant group in its reactor. Furthennore, details just like the autoclaved feed and the completely dissolved feed can affect the results of the enrichment work.
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simultaneous nitrification denitrification and Phosphorus Removal from nutrient rich industrial wastewater using granular sludge
Biotechnology and Bioengineering, 2008Co-Authors: Gulsum Yilmaz, Romain Lemaire, Jurg Keller, Zhiguo YuanAbstract:The biological Removal of nitrogen and Phosphorus from nutrient-rich abattoir wastewater using granular sludge has been investigated. A lab-scale sequencing batch reactor, seeded with granular sludge developed using synthetic wastewater, was operated for 13 months under alternating anaerobic and aerobic conditions. It is demonstrated that the granules could be sustained and indeed further developed with the use of abattoir wastewater. The organic, nitrogen, and Phosphorus loading rates applied were 2.7 gCOD L-1 day-1, 0.43 gN L-1 day-1, and 0.06 gP L-1 day-1, respectively. The Removal efficiency of soluble COD, soluble nitrogen and soluble Phosphorus were 85%, 93%, and 89%, respectively. However, the high suspended solids in the effluent limited the overall Removal efficiency to 68%, 86%, and 74% for total COD, TN, and TP, respectively. This good nutrient Removal was achieved through the process known as simultaneous nitrification, denitrification, and Phosphorus Removal, likely facilitated by the presence of large anoxic zones in the center of the granules. The Removal of nitrogen was likely via nitrite optimizing the use of the limited COD available in the wastewater. Accumulibacter spp. were found to be responsible for most of the denitrification, further reducing the COD requirement for nitrogen and Phosphorus Removal. Mineral precipitation was evaluated and was not found to significantly contribute to the overall nutrient Removal. It is also shown that the minimum HRT in a granular sludge system is not governed by the sludge settleability, as is the case with floccular sludge systems, but likely by the limitations associated with the transfer of substrates in granules. Biotechnol. Bioeng. 2008;100: 529-541. © 2007 Wiley Periodicals, Inc.
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competition between polyphosphate and glycogen accumulating organisms in enhanced biological Phosphorus Removal systems with acetate and propionate as carbon sources
Journal of Biotechnology, 2006Co-Authors: Adrian Oehmen, Aaron Marc Saunders, Zhiguo Yuan, Teresa M Vives, Jurg KellerAbstract:Enhanced biological Phosphorus Removal (EBPR) is a widely used process for achieving Phosphorus Removal from wastewater. A potential reason for EBPR failure is the undesirable growth of glycogen accumulating organisms (GAOs), which can compete for carbon sources with the bacterial group responsible for Phosphorus Removal from wastewater: the polyphosphate accumulating organisms (PAOs). This study investigates the impact of carbon source on EBPR performance and the competition between PAOs and GAOs. Two sequencing batch reactors (SBRs) were operated during a 4-6 month period and fed with a media containing acetate or propionate, respectively, as the sole carbon source. It was found that the acetate fed SBR rarely achieved a high level of Phosphorus Removal, and that a large portion of the microbial community was comprised of Candidatus Competibacter phosphatis, a known GAO. The propionate fed SBR, however, achieved stable Phosphorus Removal throughout the study, apart from one brief disturbance. The bacterial community of the propionate fed SBR was dominated by Candidatus Accumulibacter phosphatis, a known PAO, and did not contain Competibacter In a separate experiment, another SBR was seeded with a mixture of PAOs and a group of alphaproteobacterial GAOs, both enriched with propionate as the sole carbon source. Stable EBPR was achieved and the PAO population increased while the GAOs appeared to be out-competed. The results of this paper suggest that propionate may provide PAOs with a selective advantage over GAOs in the PAO-GAO competition, particularly through the minimisation of Competibacter Propionate may be a more suitable substrate than acetate for enhancing Phosphorus Removal in EBPR systems. (c) 2005 Elsevier B.V. All rights reserved.
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simultaneous nitrification denitrification and Phosphorus Removal in a lab scale sequencing batch reactor
Biotechnology and Bioengineering, 2003Co-Authors: Raymond J Zeng, Romain Lemaire, Zhiguo Yuan, Jurg KellerAbstract:Simultaneous nitrification and denitrification (SND) via the nitrite pathway and anaerobic-anoxic-enhanced biological Phosphorus Removal (EBPR) are two processes that can significantly reduce the energy and COD demand for nitrogen and Phosphorus Removal. The combination of these two processes has the potential of achieving simultaneous nitrogen and Phosphorus Removal with a minimal requirement for COD. A lab-scale sequencing batch reactor (SBR) was operated in alternating anaerobic-aerobic mode with a low dissolved oxygen (DO) concentration (0.5 mg/L) during the aerobic period, and was demonstrated to accomplish nitrification, denitrification, and Phosphorus Removal. Under anaerobic conditions, COD was taken up and converted to polyhydroxyalkanoates (PHAs), accompanied by Phosphorus release. In the subsequent aerobic stage, PHA was oxidized and Phosphorus was taken up to <0.5 mg/L by the end of the cycle. Ammonia was also oxidized during the aerobic period, but without accumulation of nitrite or nitrate in the system, indicating the occurrence of simultaneous nitrification and denitrification. However, off-gas analysis showed that the final denitrification product was mainly nitrous oxide (N(2)O), not N(2). Further experimental results demonstrated that nitrogen Removal was via nitrite, not nitrate. These experiments also showed that denitrifying glycogen-accumulating organisms (DGAOs), rather than denitrifying polyphosphate-accumulating organisms (DPAOs), were responsible for the denitrification activity.
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simultaneous nitrification denitrification and Phosphorus Removal in a lab scale sequencing batch reactor
Biotechnology and Bioengineering, 2003Co-Authors: Raymond J Zeng, Romain Lemaire, Zhiguo Yuan, Jurg KellerAbstract:Simultaneous nitrification and denitrification (SND) via the nitrite pathway and anaerobic-anoxic-enhanced biological Phosphorus Removal (EBPR) are two processes that can significantly reduce the energy and COD demand for nitrogen and Phosphorus Removal. The combination of these two processes has the potential of achieving simultaneous nitrogen and Phosphorus Removal with a minimal requirement for COD. A lab-scale sequencing batch reactor (SBR) was operated in alternating anaerobic-aerobic mode with a low dissolved oxygen (DO) concentration (0.5 mg/L) during the aerobic period, and was demonstrated to accomplish nitrification, denitrification, and Phosphorus Removal. Under anaerobic conditions, COD was taken up and converted to poly-hydroxyalkanoates (PHAs), accompanied by Phosphorus release. In the subsequent aerobic stage, PHA was oxidized and Phosphorus was taken up to <0.5 mg/L by the end of the cycle. Ammonia was also oxidized during the aerobic period, but without accumulation of nitrite or nitrate in the system, indicating the occurrence of simultaneous nitrification and denitrification. However, off-gas analysis showed that the final denitrification product was mainly nitrous oxide (N2O), not N-2. Further experimental results demonstrated that nitrogen Removal was via nitrite, not nitrate. These experiments also showed that denitrifying glycogen-accumulating organisms (DGAOs), rather than denitrifying polyphosphate-accumulating organisms (DPAOs), were responsible for the denitrification activity. (C) 2003 Wiley Periodicals, Inc.
Raymond J Zeng - One of the best experts on this subject based on the ideXlab platform.
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Phosphorus Removal in an enhanced biological Phosphorus Removal process roles of extracellular polymeric substances
Environmental Science & Technology, 2013Co-Authors: Hailing Zhang, Wei Fang, Yongpeng Wang, Guoping Sheng, Raymond J ZengAbstract:Phosphorus-accumulating organisms are considered to be the key microorganisms in the enhanced biological Phosphorus Removal (EBPR) process. A large amount of Phosphorus is found in the extracellular polymeric substances (EPS) matrix of these microorganisms. However, the roles of EPS in Phosphorus Removal have not been fully understood. In this study, the Phosphorus in the EBPR sludge was fractionated and further analyzed using quantitative (31)P nuclear magnetic resonance spectroscopy. The amounts and forms of Phosphorus in EPS as well as their changes in an anaerobic-aerobic process were also investigated. EPS could act as a reservoir for Phosphorus in the anaerobic-aerobic process. About 5-9% of Phosphorus in sludge was reserved in the EPS at the end of the aerobic phase and might further contribute to the Phosphorus Removal. The chain length of the intracellular long-chain polyphosphate (polyP) decreased in the anaerobic phase and then recovered under aerobic conditions. However, the polyP in the EPS had a much shorter chain length than the intracellular polyP in the whole cycle. The migration and transformation of various forms of Phosphorus among microbial cells, EPS, and bulk liquid were also explored. On the basis of these results, a model with a consideration of the roles of EPS was proposed, which is beneficial to elucidate the mechanism of Phosphorus Removal in the EBPR system.
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simultaneous nitrification denitrification and Phosphorus Removal in a lab scale sequencing batch reactor
Biotechnology and Bioengineering, 2003Co-Authors: Raymond J Zeng, Romain Lemaire, Zhiguo Yuan, Jurg KellerAbstract:Simultaneous nitrification and denitrification (SND) via the nitrite pathway and anaerobic-anoxic-enhanced biological Phosphorus Removal (EBPR) are two processes that can significantly reduce the energy and COD demand for nitrogen and Phosphorus Removal. The combination of these two processes has the potential of achieving simultaneous nitrogen and Phosphorus Removal with a minimal requirement for COD. A lab-scale sequencing batch reactor (SBR) was operated in alternating anaerobic-aerobic mode with a low dissolved oxygen (DO) concentration (0.5 mg/L) during the aerobic period, and was demonstrated to accomplish nitrification, denitrification, and Phosphorus Removal. Under anaerobic conditions, COD was taken up and converted to polyhydroxyalkanoates (PHAs), accompanied by Phosphorus release. In the subsequent aerobic stage, PHA was oxidized and Phosphorus was taken up to <0.5 mg/L by the end of the cycle. Ammonia was also oxidized during the aerobic period, but without accumulation of nitrite or nitrate in the system, indicating the occurrence of simultaneous nitrification and denitrification. However, off-gas analysis showed that the final denitrification product was mainly nitrous oxide (N(2)O), not N(2). Further experimental results demonstrated that nitrogen Removal was via nitrite, not nitrate. These experiments also showed that denitrifying glycogen-accumulating organisms (DGAOs), rather than denitrifying polyphosphate-accumulating organisms (DPAOs), were responsible for the denitrification activity.
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simultaneous nitrification denitrification and Phosphorus Removal in a lab scale sequencing batch reactor
Biotechnology and Bioengineering, 2003Co-Authors: Raymond J Zeng, Romain Lemaire, Zhiguo Yuan, Jurg KellerAbstract:Simultaneous nitrification and denitrification (SND) via the nitrite pathway and anaerobic-anoxic-enhanced biological Phosphorus Removal (EBPR) are two processes that can significantly reduce the energy and COD demand for nitrogen and Phosphorus Removal. The combination of these two processes has the potential of achieving simultaneous nitrogen and Phosphorus Removal with a minimal requirement for COD. A lab-scale sequencing batch reactor (SBR) was operated in alternating anaerobic-aerobic mode with a low dissolved oxygen (DO) concentration (0.5 mg/L) during the aerobic period, and was demonstrated to accomplish nitrification, denitrification, and Phosphorus Removal. Under anaerobic conditions, COD was taken up and converted to poly-hydroxyalkanoates (PHAs), accompanied by Phosphorus release. In the subsequent aerobic stage, PHA was oxidized and Phosphorus was taken up to <0.5 mg/L by the end of the cycle. Ammonia was also oxidized during the aerobic period, but without accumulation of nitrite or nitrate in the system, indicating the occurrence of simultaneous nitrification and denitrification. However, off-gas analysis showed that the final denitrification product was mainly nitrous oxide (N2O), not N-2. Further experimental results demonstrated that nitrogen Removal was via nitrite, not nitrate. These experiments also showed that denitrifying glycogen-accumulating organisms (DGAOs), rather than denitrifying polyphosphate-accumulating organisms (DPAOs), were responsible for the denitrification activity. (C) 2003 Wiley Periodicals, Inc.
Yves Comeau - One of the best experts on this subject based on the ideXlab platform.
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Phosphorus Removal and carbon dioxide capture in a pilot conventional septic system upgraded with a sidestream steel slag filter
Water, 2020Co-Authors: Dominique Claveau-mallet, Hatim Seltani, Yves ComeauAbstract:The objective of this work was to demonstrate the Removal of the Phosphorus and carbon dioxide capture potential of a conventional septic system upgraded with a sidestream steel slag filter used in recirculation mode. A pilot scale sidestream experiment was conducted with two septic tank and drainfield systems, one with and one without a sidestream slag filter. The experimental system was fed with real domestic wastewater. Recirculation ratios of 25%, 50% and 75% were tested. Limestone soils and non-calcareous soils were used as drainfield media. The tested system achieved a satisfactory compromise between Phosphorus Removal and pH at the effluent of the septic tank, thus eliminating the need for a neutralization step. The Phosphorus Removal efficiency observed in the second compartment of the septic tank was 30% in the slag filter upgraded system, compared to −3% in the control system. The slag filter reached a Phosphorus retention of 105 mg/kg. The drainfield of non-calcareous soils achieved very high Phosphorus Removal in both control and upgraded systems. In the drainfield of limestone soil, the slag filtration reduced the groundwater Phosphorus contamination load by up to 75%. The Removal of chemical oxygen demand of the drainfields was not affected by the pH rise induced by the slag filter. Phosphorus Removal in the septic tank with a slag filter was attributed to either sorption on newly precipitated calcium carbonate, or the precipitation of phosphate minerals, or both. Recirculation ratio design criteria were proposed based on simulations. Simulations showed that the steel slag filter partly inhibited the biological production of carbon dioxide in the septic tank. The influent alkalinity strongly influenced the recirculation ratio needed to raise the pH in the septic tank. The recirculation mode allowed clogging mitigation compared to a mainstream configuration, because an important part of chemical precipitation occurred in the septic tank. The control septic tank produced carbon dioxide, whereas the slag filter-upgraded septic tank was a carbon dioxide sink.
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Phosphorus Removal by steel slag filters modeling dissolution and precipitation kinetics to predict longevity
Environmental Science & Technology, 2014Co-Authors: Dominique Claveaumallet, Benoit Courcelles, Yves ComeauAbstract:This article presents an original numerical model suitable for longevity prediction of alkaline steel slag filters used for Phosphorus Removal. The model includes kinetic rates for slag dissolution, hydroxyapatite and monetite precipitation and for the transformation of monetite into hydroxyapatite. The model includes equations for slag exhaustion. Short-term batch tests using slag and continuous pH monitoring were conducted. The model parameters were calibrated on these batch tests and experimental results were correctly reproduced. The model was then transposed to long-term continuous flow simulations using the software PHREEQC. Column simulations were run to test the effect of influent P concentration, influent inorganic C concentration and void hydraulic retention time on filter longevity and P retention capacity. High influent concentration of P and inorganic C, and low hydraulic retention time of voids reduced the filter longevity. The model provided realistic P breakthrough at the column outlet. Re...