title: Influence of nitrite accumulation on "Candidatus Accumulibacter" population structure and enhanced biological phosphorus removal from municipal wastewater.
abstract: A modified University of Cape Town (MUCT) process was used to treat real municipal wastewater with low carbon to nitrogen ratio (C/N). To our knowledge, this is the first study where the influence of nitrite accumulation on "Candidatus Accumulibacter" clade-level population structure was investigated during nitritation establishment and destruction. Real time quantitative PCR assays were conducted using the polyphosphate kinase 1 gene (ppk1) as a genetic marker. Abundances of total "Candidatus Accumulibacter", the relative distributions and population structure of the five "Candidatus Accumulibacter" clades were characterized. Under complete nitrification, clade I using nitrate as electron acceptor was below 5% of total "Candidatus Accumulibacter". When the reactor was transformed into nitritation, clade I gradually disappeared. Clade IID using nitrite as electron acceptor for denitrifying phosphorus (P) removal was always the dominant "Candidatus Accumulibacter" throughout the operational period. This clade was above 90% on average in total "Candidatus Accumulibacter", even up to nearly 100%, which was associated with good performance of denitrifying P removal via nitrite pathway. The nitrite concentrations affected the abundance of clade IID. The P removal was mainly completed by anoxic P uptake of about 88%. The P removal efficiency clearly had a positive correlation with the nitrite accumulation ratio. Under nitritation, the P removal efficiency was 30% higher than that under complete nitrification, suggesting that nitrite was appropriate as electron acceptor for denitrifying P removal when treating carbon-limited wastewater.
authors.affiliation: Key Laboratory of Beijing for Water Environment Recovery, Department of Environmental Engineering, Beijing University of Technology, Beijing 100124, China. Electronic address: zengwei_1@263.net.
authors.forename: Wei
authors.initials: W
authors.lastname: Zeng
authors.affiliation: Key Laboratory of Beijing for Water Environment Recovery, Department of Environmental Engineering, Beijing University of Technology, Beijing 100124, China.
authors.forename: Boxiao
authors.initials: B
authors.lastname: Li
authors.affiliation: Key Laboratory of Beijing for Water Environment Recovery, Department of Environmental Engineering, Beijing University of Technology, Beijing 100124, China.
authors.forename: Xiangdong
authors.initials: X
authors.lastname: Wang
authors.affiliation: Key Laboratory of Beijing for Water Environment Recovery, Department of Environmental Engineering, Beijing University of Technology, Beijing 100124, China.
authors.forename: Xinlong
authors.initials: X
authors.lastname: Bai
authors.affiliation: Key Laboratory of Beijing for Water Environment Recovery, Department of Environmental Engineering, Beijing University of Technology, Beijing 100124, China.
authors.forename: Yongzhen
authors.initials: Y
authors.lastname: Peng
mesh_terms: D020562:Betaproteobacteria / Q000201:enzymology / Q000235:genetics / Q000378:metabolism*; D019149:Bioreactors / Q000382:microbiology; D002947:Cities; D058440:Denitrification; D009566:Nitrates / Q000378:metabolism; D058465:Nitrification; D009573:Nitrites / Q000378:metabolism*; D010758:Phosphorus / Q000302:isolation & purification* / Q000378:metabolism; D017856:Phosphotransferases (Phosphate Group Acceptor) / Q000235:genetics; D062065:Wastewater / Q000737:chemistry*; D014874:Water Pollutants, Chemical / Q000302:isolation & purification* / Q000378:metabolism
chemical_list: D009566:Nitrates; D009573:Nitrites; D010758:Phosphorus; D017856:Phosphotransferases (Phosphate Group Acceptor); D062065:Wastewater; D014874:Water Pollutants, Chemical; C022424:polyphosphate kinase
keywords: Candidatus Accumulibacter; Denitrifying phosphorus removal; Municipal wastewater; Nitritaton; Polyphosphate kinase 1 gene (ppk1)