title: Effect of COD/N ratio on nitrogen removal and microbial communities of CANON process in membrane bioreactors.
abstract: In this study, the effect of COD/N ratio on completely autotrophic nitrogen removal over nitrite (CANON) process was investigated in five identical membrane bioreactors. The five reactors were simultaneously seeded for 1L CANON sludge and be operated for more than two months under same conditions, with influent COD/N ratio of 0, 0.5, 1, 2 and 4, respectively. DGGE was used to analyze the microbial communities of aerobic ammonia-oxidizing bacteria (AOB) and anaerobic ammonia-oxidizing bacteria (AAOB) in five reactors. Results revealed the harmonious work of CANON and denitrification with low COD concentration, whereas too high COD concentration suppressed both AOB and AAOB. AOB and AAOB biodiversity both decreased with COD increasing, which then led to worse nitrogen removal. The suppressing threshold of COD/N ratio for CANON was 1.7. CANON was feasible for treating low COD/N sewage, while the high sewage should be converted by anaerobic biogas producing process in advance.
authors.affiliation: Henan Collaborative Innovation Center of Environmental Pollution Control and Ecological Restoration, School of Material and Chemical Engineering, Zhengzhou University of Light Industry, Zhengzhou 450001, China. Electronic address: zhangxiaojing@zzuli.edu.cn.
authors.forename: Xiaojing
authors.initials: X
authors.lastname: Zhang
authors.affiliation: Henan Collaborative Innovation Center of Environmental Pollution Control and Ecological Restoration, School of Material and Chemical Engineering, Zhengzhou University of Light Industry, Zhengzhou 450001, China.
authors.forename: Hongzhong
authors.initials: H
authors.lastname: Zhang
authors.affiliation: Henan Collaborative Innovation Center of Environmental Pollution Control and Ecological Restoration, School of Material and Chemical Engineering, Zhengzhou University of Light Industry, Zhengzhou 450001, China.
authors.forename: Changming
authors.initials: C
authors.lastname: Ye
authors.affiliation: Henan Collaborative Innovation Center of Environmental Pollution Control and Ecological Restoration, School of Material and Chemical Engineering, Zhengzhou University of Light Industry, Zhengzhou 450001, China.
authors.forename: Mingbao
authors.initials: M
authors.lastname: Wei
authors.affiliation: Henan Collaborative Innovation Center of Environmental Pollution Control and Ecological Restoration, School of Material and Chemical Engineering, Zhengzhou University of Light Industry, Zhengzhou 450001, China.
authors.forename: Jingjing
authors.initials: J
authors.lastname: Du
mesh_terms: D000693:Anaerobiosis / Q000187:drug effects; D052818:Autotrophic Processes; D001419:Bacteria / Q000187:drug effects / Q000378:metabolism*; D001673:Biodegradation, Environmental / Q000187:drug effects; D057919:Biological Oxygen Demand Analysis; D019149:Bioreactors / Q000382:microbiology*; D001709:Biotechnology / Q000295:instrumentation* / Q000379:methods*; D002244:Carbon / Q000494:pharmacology; D058645:Denaturing Gradient Gel Electrophoresis; D058440:Denitrification / Q000187:drug effects; D009573:Nitrites / Q000378:metabolism; D009584:Nitrogen / Q000302:isolation & purification*; D010084:Oxidation-Reduction; D014865:Waste Disposal, Fluid; D062065:Wastewater / Q000382:microbiology; D018508:Water Purification
chemical_list: D002244:Carbon; D009573:Nitrites; D009584:Nitrogen; D062065:Wastewater
keywords: CANON; COD/N; Denitrification; Membrane bioreactor (MBR); Microbial community