title: Nitrogen removal and nitrous oxide emission from a step-feeding multiple anoxic and aerobic process.
abstract: The multiple anoxic and aerobic (AO) process is an advanced biological nitrogen-removal process, and nitrous oxide (N2O) emission might affect its sustainable application. Nitrogen removal and N2O emission in a step-feeding multiple AO sequencing batch reactor (SBRS) was examined, in comparison with a one-feeding sequencing batch reactor (SBRO). Nitrogen removal was enhanced by 12.6% in SBRScompared to the removal percentage of 75.8% in SBRO. Activated sludge in SBRs possessed a higher N2O emission factor during nitrification, denitrification and simultaneous nitrification and denitrification (SND) than in SBRO. A high N2O emission factor was observed during SND in both reactors, with the emission factor of 4.38% in SBRSand 4.66% in SBRO. More N2O emission occurred in the presence of nitrite. Bacteroidetes and Proteobacteria dominated in both SBRSand SBRO. A similar abundance of Thauera, Dechloromonas and Zoogloea possible for denitrification was observed in SBRSand SBRO. Moreover, nosZ from Proteobacteria dominated in both SBRSand SBRO, with dominating genus of Acidovorax, Ralstonia, Thauera and Marinobacter.
authors.affiliation: a Key Laboratory of Microorganism Application and Risk Control (MARC) of Shenzhen, Graduate School at Shenzhen , Tsinghua University , Shenzhen , People's Republic of China.
authors.forename: Yuepeng
authors.initials: Y
authors.lastname: Sun
authors.affiliation: a Key Laboratory of Microorganism Application and Risk Control (MARC) of Shenzhen, Graduate School at Shenzhen , Tsinghua University , Shenzhen , People's Republic of China.
authors.forename: Huoqing
authors.initials: H
authors.lastname: Wang
authors.affiliation: a Key Laboratory of Microorganism Application and Risk Control (MARC) of Shenzhen, Graduate School at Shenzhen , Tsinghua University , Shenzhen , People's Republic of China.
authors.forename: Guangxue
authors.identifier: http://orcid.org/0000-0003-1982-2998
authors.initials: G
authors.lastname: Wu
authors.affiliation: a Key Laboratory of Microorganism Application and Risk Control (MARC) of Shenzhen, Graduate School at Shenzhen , Tsinghua University , Shenzhen , People's Republic of China.
authors.forename: Yuntao
authors.initials: Y
authors.lastname: Guan
mesh_terms: D019149:Bioreactors; D058440:Denitrification; D058465:Nitrification; D009584:Nitrogen / Q000737:chemistry*; D009609:Nitrous Oxide; D012722:Sewage
chemical_list: D012722:Sewage; D009609:Nitrous Oxide; D009584:Nitrogen
keywords: Biological nitrogen removal; microbial community; multiple anoxic and aerobic process; nitrous oxide; step-feeding