Author: Robert SimmPublisher: National Library of Canada
ISBN:
Category : Sewage
Languages : en
Pages : 119
Book Description
Enhanced Biological Phosphorus Removal Using a Sequencing Batch RBC
Author: Robert SimmPublisher: National Library of Canada
ISBN:
Category : Sewage
Languages : en
Pages : 119
Book Description
Enhanced Biological Phosphorus Removal in Sequencing Batch Reactor Systems
Author: Shuh-Ren JingPublisher:
ISBN:
Category : Sewage
Languages : en
Pages : 182
Book Description
Optimization of Enhanced Biological Phosphorus Removal in Sequencing Batch Reactors at the Dauphin Borough Wastewater Treatment Plant
Author: James A. FrazierImplementing Enhanced Biological Phosphorous Removal in High Strength Wastewater
Author: Chang Hoon AhnEnhanced Biological Phosphorus Removal at High Temperature Using Different Carbon Sources - Key Microorganisms and Processes
Author: Rogelio Ernesto Zuniga MontanezPublisher:
ISBN:
Category :
Languages : en
Pages :
Book Description
Municipal wastewater contains a number of constituents that can have detrimental effects if discharged to receiving water bodies. Phosphorus (P) is of specific interest as a limiting nutrient in aquatic ecosystems that can cause eutrophication. In enhanced biological phosphorus removal (EBPR), polyphosphate accumulating organisms (PAOs) store excess P intracellularly. To achieve this accumulation, the organisms are exposed consecutively to anaerobic and either aerobic or anoxic conditions. During the anaerobic phase, PAOs consume and store organic carbon with P release, followed by the aerobic/anoxic phase during which the stored carbon is oxidized and P is taken up and stored as polyphosphate. PAOs are not the only bacteria that can thrive under these cyclic conditions and they face competition from glycogen accumulating organisms (GAOs). The latter have a similar metabolism but do not accumulate P. Most research to date has focused on the use of certain volatile fatty acids (VFAs) as carbon sources and on process conditions at temperatures common in temperate climates. Much remains unknown about the potential of EBPR in tropical regions and the suitability of other carbon substrates to drive the accumulation of phosphate. The purpose of this dissertation is to contribute to the understanding of EBPR at high temperatures and with unconventional carbon sources. Three different studies were designed and conducted with the following aims: (a) to evaluate the long-term EBPR stability and key microbial community in a wastewater treatment plant (WWTP) designed to achieve P removal in Singapore, (b) to study the process efficiency, biochemical transformations and organisms involved in a laboratory-scale EBPR reactor fed by alternating the substrates acetate and glutamate, and (c) to assess the potential of using unconventional carbon sources for EBPR by testing glutamate and glucose as alternating substrates at the laboratory-scale. The research included experiments at the full- and laboratory-scale, all at a mean temperature of 30 °C. Sustained observations in all three studies served to uncover the biochemical and microbial community dynamics. In the full-scale study, I conducted a yearlong evaluation of the EBPR activity at a WWTP that had been retrofitted to facilitate EBPR in Singapore. A mean P removal efficiency of 90 % was observed throughout the sampling period, similar to temperate climate installations and contrary to earlier reports that EBPR was not feasible at high temperatures. The main PAOs present in the reactor were Tetrasphaera, Candidatus Accumulibacter (Accumulibacter) and Dechloromonas, with mean relative abundances of 1.53, 0.43 and 0.69 %, respectively. The PAO community underwent changes during the surveyed period, with a marked transition from a Tetrasphaera-dominated community to a more even one. The link between PAOs and the P released in the anaerobic compartment was supported by a statistically significant correlation between the relative abundance of these organisms and the measured P concentrations. GAOs and PAOs coexisted without compromising the EBPR activity. In one of the laboratory-scale studies, glutamate and acetate were alternated as the carbon source for a reactor operated at 30 °C. Complete and stable P removal was achieved with a predominantly glutamate-containing feed, after modifying operating parameters commonly used in VFA-fed systems to a COD/P ratio of 40:1 mg COD/mg P and a cycle duration of 8 h. Long-term EBPR with a feed dominated by glutamate in a laboratory-scale reactor has not been previously reported. The P and carbon cycling patterns were different for glutamate and acetate. Reduced P release and polyhydroxyalkanoate (PHA) accumulation happened when glutamate was fed, but not with acetate, where glutamate appeared to be stored as an unidentified non-PHA compound or as different compounds. The PAO Accumulibacter and the GAO Candidatus Competibacter (Competibacter) remained the only known EBPR bacteria during the period of good EBPR performance, at similar relative abundances. A canonical correlation analysis revealed that the relative abundance of some non-PAO organisms correlated more strongly with variables that denoted good EBPR activity than did the abundance of any of the known PAOs. In the last study, a laboratory-scale sequencing batch reactor was used to test the EBPR potential of glutamate and glucose as alternating carbon sources in a high temperature process. The recommended influent COD/P ratio and batch duration for VFA-fed systems were unsuccessful. After modifications, COD/P ratios of 20:1 and 40:1 mg COD/ mg P resulted in complete P removal, but only in the short term. The EBPR stoichiometry with these two carbon substrates differed from that of VFA-fed systems. For both, lower P and PHA cycling was observed, and intracellular carbon storage compounds that were not PHA appeared to contribute to P cycling, as shown from carbon balances. A very diverse EBPR community was present in the reactor, including Accumulibacter, Tetrasphaera and Dechloromonas PAOs, and Competibacter, Defluviicoccus, Micropruina and Kineosphaera GAOs. Most of these organisms have not been reported before in laboratory-scale EBPR reactors operated at high temperatures. The work presented in this dissertation expands the understanding of EBPR by showing that the process is possible and stable in full-scale treatment plants at high temperature, with removal efficiencies similar to those observed in temperate climates. In addition, it was shown that unconventional carbon sources, specifically, glutamate and glucose, do participate in EBPR and that complete and stable phosphorus removal can be achieved with glutamate as dominant substrate at high temperature. A core PAO and GAO community was present in the three systems, where the interactions among members were more complex than previously considered, including competition, coexistence and succession events. The results obtained from this work enhance our fundamental knowledge of EBPR as an industrial process, as well as the metabolic diversity, niches and dynamics of PAOs and GAOs. The study outcomes can inform design and operational strategies at full-scale treatment plants. Lastly, the consideration of both high temperatures and unconventional carbon sources for EBPR is expected to aid in the development of more efficient treatment processes.
Simultaneous Enhanced Biological High-strength Phosphorus Removal and Nitrite Accumulation in a Lab-scale Sequencing Batch Reactor
Author: Zhihang YuanPublisher:
ISBN:
Category :
Languages : en
Pages : 0
Book Description
The enhanced biological phosphorus removal (EBPR) has been widely applied in treating domestic wastewater, while the performance on high-strength P wastewater is less investigated and the feasibility of coupling with short-cut nitrogen removal process remains unknown. This study first achieved the simultaneous high-efficient P removal and stable nitrite accumulation in one sequencing batch reactor for treating the synthetic digested manure wastewater. The average effluent P could be down to 0.8 ± 1.0 mg P/L and the P removal efficiency was 99.5 ± 0.8%. Candidatus Accumulibacter was the dominant polyphosphate accumulating organism with the relative abundance of 14.2-33.1%, while the presence of glycogen accumulating organisms (Defluviicoccus and Candidatus Competibacter) with relatively higher abundance (15.6-40.3%) did not deteriorate the EBPR performance. Moreover, nitrite accumulation happened in the system with the effluent nitrite up to 20.4 ± 6.4 mg N/L and the nitrite accumulation ratio was nearly 100% for 140 days (420 cycles). Nitrosomonas was the dominant ammonia-oxidizing bacteria with relative abundance of 0.3-2.4% while nitrite-oxidizing bacteria were almost undetected (
Studies on Biological Phosphorus Removal in a Sequencing Batch Reactor
Author: Edwin F. BarthSimultaneous Enhanced Biological Phosphorus Removal and Polyhydroxyalkanoates Recovery
Author: Rafael Perez-FeitoStudy of the Effect of Low Levels of Oxygen During the Anaerobic Stage in Biological Phosphorus Removal, Using a Lab-scale Sequencing Batch Reactor
Author: Elizabeth Patricia Sanhueza-TorresPublisher:
ISBN:
Category :
Languages : en
Pages : 84
Book Description
Effect of Sulphide on Enhanced Biological Phosphorus Removal
Author: Francisco Javier Rubio RinconPublisher: CRC Press
ISBN: 135164808X
Category : Technology & Engineering
Languages : en
Pages : 293
Book Description
The enhanced biological removal of phosphorus (EBPR) is a popular process due to high removal efficiency, low operational costs, and the possibility of phosphorus recovery. Nevertheless, the stability of the EBPR depends on different factors such as: temperature, pH, and the presence of toxic compounds. While extensive studies have researched the effects of temperature and pH on EBPR systems, little is known about the effects of different toxic compounds on EBPR. For example, sulphide has shown to inhibit different microbial activities in the WWTP, but the knowledge about its effects on EBPR is limited. Whereas the sulphide generated in the sewage can cause a shock effect on EBPR, the continuously exposure to sulphide potentially generated in WWTP can cause the acclimatization and adaptation of the biomass. This research suggests that sulphate reducing bacteria can proliferate in WWTP, as they are reversibly inhibited by the recirculation of sludge through anaerobic-anoxic-oxic conditions. The research enhances the understanding of the effect of sulphide on the anaerobic-oxic metabolism of PAO. It suggests that the filamentous bacteria Thiothrix caldifontis could play an important role in the biological removal of phosphorus. It questions the ability of PAO to generate energy from nitrate respiration and its use for the anoxic phosphorus uptake. Thus, the results obtained in this research can be used to understand the stability of the EBPR process under anaerobic-anoxic-oxic conditions, especially when exposed to the presence of sulphide.