title: Start-up of single-stage partial nitrification-anammox process treating low-strength swage and its restoration from nitrate accumulation.
abstract: A single-stage partial nitrification-anammox (PN/A) reactor treating low-strength swage was operated for 288days to investigate the recovery of nitrogen removal from nitrate accumulation. The reactor was quickly started up by inoculating anammox sludge. However, nitrite oxidizing bacteria (NOB) abundance gradually increased on day 25, leading to high effluent nitrate concentration. Two strategies were executed to control the effluent nitrate. In strategy I, dissolved oxygen (DO) concentration was kept low (0.17±0.08mg/L), but nitrate production increased from 4.71 to 38.18mg-N/L. In strategy II, intermittent aeration operation mode (aeration 7min/anoxic 21min) was adopted, which significantly lowered the nitrate concentration to 1.3mg-N/L, indicating the NOB was inhibited. The high nitrogen removal rate of 73mg-N/(L·d) was achieved. The evolution of bacterial activity and abundance verified the changes of the nitrogen removal performance and proved the intermittent aeration strategy could successfully solve the problem of nitrate build-up in the PN/A process.
authors.affiliation: Key Laboratory of Beijing for Water Quality Science and Water Environment Recovery Engineering, Engineering Research Center of Beijing, Beijing University of Technology, Beijing 100124, PR China.
authors.forename: Yuanyuan
authors.initials: Y
authors.lastname: Miao
authors.affiliation: Key Laboratory of Beijing for Water Quality Science and Water Environment Recovery Engineering, Engineering Research Center of Beijing, Beijing University of Technology, Beijing 100124, PR China.
authors.forename: Liang
authors.initials: L
authors.lastname: Zhang
authors.affiliation: State Key Laboratory of Urban Water Resource and Environment, Harbin Institute of Technology, Harbin 150090, PR China.
authors.forename: Yandong
authors.initials: Y
authors.lastname: Yang
authors.affiliation: Key Laboratory of Beijing for Water Quality Science and Water Environment Recovery Engineering, Engineering Research Center of Beijing, Beijing University of Technology, Beijing 100124, PR China. Electronic address: pyz@bjut.edu.cn.
authors.forename: Yongzhen
authors.initials: Y
authors.lastname: Peng
authors.affiliation: Key Laboratory of Beijing for Water Quality Science and Water Environment Recovery Engineering, Engineering Research Center of Beijing, Beijing University of Technology, Beijing 100124, PR China; Department of Civil and Environmental Engineering, University of Connecticut, Storrs, CT 06269, USA.
authors.forename: Baikun
authors.initials: B
authors.lastname: Li
authors.affiliation: Key Laboratory of Beijing for Water Quality Science and Water Environment Recovery Engineering, Engineering Research Center of Beijing, Beijing University of Technology, Beijing 100124, PR China.
authors.forename: Shuying
authors.initials: S
authors.lastname: Wang
authors.affiliation: Key Laboratory of Beijing for Water Quality Science and Water Environment Recovery Engineering, Engineering Research Center of Beijing, Beijing University of Technology, Beijing 100124, PR China.
authors.forename: Qian
authors.initials: Q
authors.lastname: Zhang
mesh_terms: D064751:Ammonium Compounds / Q000737:chemistry; D001419:Bacteria / Q000378:metabolism*; D019149:Bioreactors / Q000382:microbiology; D058440:Denitrification; D009566:Nitrates / Q000737:chemistry / Q000378:metabolism*; D058465:Nitrification / Q000502:physiology*; D009584:Nitrogen / Q000378:metabolism*; D009589:Nitrogen Oxides / Q000378:metabolism; D012722:Sewage / Q000737:chemistry* / Q000382:microbiology; D014865:Waste Disposal, Fluid / Q000379:methods
chemical_list: D064751:Ammonium Compounds; D009566:Nitrates; D009589:Nitrogen Oxides; D012722:Sewage; D009584:Nitrogen
keywords: Intermittent aeration; Low-strength swage; Nitrate accumulation; Nitrite oxidization bacteria; Single-stage partial nitrification-anammox