title: The nitritation performance of biofilm reactor for treating domestic wastewater under high dissolved oxygen.
abstract: The objective of this study was to investigate the nitritation performance in a biofilm reactor for treating domestic wastewater. The reactor was operated in continuous feed mode from phases 1 to 3. The dissolved oxygen (DO) was controlled at 3.5-7 mg/L throughout the experiment. The biofilm reactor showed excellent nitritation performance after the inoculation of nitrifying sludge, with the hydraulic retention time being reduced from 24 to 7 hr. Above 90% nitrite accumulation ratio (NAR) was maintained in phase 1. Afterwards, nitratation occurred with the low NH4(+)-N concentration in the reactor. The improvement of NH4(+)-N concentration to 20-35 mg/L had a limited effect on the recovery of nitritation. However, nitritation recovered rapidly when sequencing batch feed mode was adopted in phase 4, with the effluent NH4(+)-N concentration above 7 mg/L. The improvement of ammonia oxidizing bacteria (AOB) activity and the combined inhibition effect of free ammonia (FA) and free nitrous acid (FNA) on the nitrite oxidizing bacteria (NOB) were two key factors for the rapid recovery of nitritation. Sludge activity was obtained in batch tests. The results of batch tests had a good relationship with the long term operation performance of the biofilm reactor.
authors.affiliation: Key Laboratory of Beijing for Water Quality Science and Water Environment Recovery Engineering, Beijing University of Technology, Beijing 100124, China. Electronic address: zhengzhaomingb@sina.com.
authors.forename: Zhaoming
authors.initials: Z
authors.lastname: Zheng
authors.affiliation: School of Water Resources and Environmental Engineering, East China Institute of Technology, Nanchang 330013, China.
authors.forename: Zebing
authors.initials: Z
authors.lastname: Li
authors.affiliation: Key Laboratory of Beijing for Water Quality Science and Water Environment Recovery Engineering, Beijing University of Technology, Beijing 100124, China.
authors.forename: Jing
authors.initials: J
authors.lastname: Ma
authors.affiliation: Key Laboratory of Beijing for Water Quality Science and Water Environment Recovery Engineering, Beijing University of Technology, Beijing 100124, China.
authors.forename: Jia
authors.initials: J
authors.lastname: Du
authors.affiliation: Key Laboratory of Beijing for Water Quality Science and Water Environment Recovery Engineering, Beijing University of Technology, Beijing 100124, China. Electronic address: ghui0066@163.com.
authors.forename: Guanghui
authors.initials: G
authors.lastname: Chen
authors.affiliation: Key Laboratory of Beijing for Water Quality Science and Water Environment Recovery Engineering, Beijing University of Technology, Beijing 100124, China.
authors.forename: Wei
authors.initials: W
authors.lastname: Bian
authors.affiliation: Key Laboratory of Beijing for Water Quality Science and Water Environment Recovery Engineering, Beijing University of Technology, Beijing 100124, China.
authors.forename: Jun
authors.initials: J
authors.lastname: Li
authors.affiliation: Key Laboratory of Beijing for Water Quality Science and Water Environment Recovery Engineering, Beijing University of Technology, Beijing 100124, China.
authors.forename: Baihang
authors.initials: B
authors.lastname: Zhao
mesh_terms: D001419:Bacteria; D018441:Biofilms; D019149:Bioreactors / Q000382:microbiology*; D058465:Nitrification; D010100:Oxygen; D014865:Waste Disposal, Fluid / Q000379:methods*; D062065:Wastewater / Q000737:chemistry / Q000382:microbiology*
chemical_list: D010100:Oxygen; D062065:Wastewater
keywords: Biofilm reactor; Control measures; Domestic wastewater; High dissolved oxygen; Nitritation