title: Reactor performance and microbial characteristics of CANON process with step-wise increasing of C/N ratio.
abstract: In this study, the nitrogen removal performance and microbial characteristics of completely autotrophic nitrogen removal over nitrite (CANON) process was investigated with a step-wise increasing of C/N ratio (0.5, 1, 2 and 4) in a membrane bioreactor. The microbial distribution of aerobic ammonia-oxidizing bacteria (AOB) and anaerobic AOB (AAOB) was analysed by fluorescence in situ hybridization (FISH). Results showed that the denitrification ratio rose up correspondingly with the increase of influent C/N, and nitrogen removal rate (NRR) reached the maximum when C/N was 1 due to the harmonious work of denitrification and CANON. However, NRR decreased when influent C/N was more than 2. The threshold C/N ratio of CANON process was 2.2; so the sewage with a high C/N ratio should be pretreated by combining with pre-oxidation of organics or anaerobic-energy-producing process. FISH results showed decreasing numbers of both AOB and AAOB with the addition of organics.
authors.affiliation: a Henan Collaborative Innovation Center of Environmental Pollution Control and Ecological Restoration , School of Material and Chemical Engineering, Zhengzhou University of Light Industry , Zhengzhou 450001 , People's Republic of China.
authors.forename: Xiaojing
authors.initials: X
authors.lastname: Zhang
authors.affiliation: b Key Laboratory of Beijing for Water Quality Science and Water Environment Recovery Engineering , Beijing University of Technology , Beijing 100124 , People's Republic of China.
authors.forename: Dong
authors.initials: D
authors.lastname: Li
authors.affiliation: b Key Laboratory of Beijing for Water Quality Science and Water Environment Recovery Engineering , Beijing University of Technology , Beijing 100124 , People's Republic of China.
authors.forename: Yuhai
authors.initials: Y
authors.lastname: Liang
authors.affiliation: b Key Laboratory of Beijing for Water Quality Science and Water Environment Recovery Engineering , Beijing University of Technology , Beijing 100124 , People's Republic of China.|c State Key Laboratory of Urban Water Resource and Environment , Harbin Institute of Technology , Harbin 150090 , People's Republic of China.
authors.forename: Jie
authors.initials: J
authors.lastname: Zhang
mesh_terms: D019149:Bioreactors / Q000382:microbiology*; D002244:Carbon / Q000032:analysis* / Q000378:metabolism; D058440:Denitrification; D017404:In Situ Hybridization, Fluorescence; D009573:Nitrites / Q000032:analysis* / Q000378:metabolism; D009584:Nitrogen / Q000032:analysis* / Q000378:metabolism
chemical_list: D009573:Nitrites; D002244:Carbon; D009584:Nitrogen
keywords: C/N; CANON; FISH; denitrification; nitrogen removal