title: Minimization of nitrous oxide emission in a pilot-scale oxidation ditch: generation, spatial variation and microbial interpretation.
abstract: Nitrous oxide (N2O) emission from wastewater treatment plants (WWTPs) has received increasing attention. This paper presented how N2O emission was significantly reduced in a pilot-scale Carrousel oxidation ditch under reasonable nitrification and denitrification. N2O emission from the reactor was found as low as 0.027% of influent nitrogen, which was much less than that from other processes. Further measurements on spatial variation of N2O emission in the alternative aerobic/anoxic zones with help of a series of batch experiments demonstrated that about 90% of the emission was contributed by nitrifier denitrification (ND). Moreover, the taxonomic analysis based on high through-put 16S rRNA gene sequencing revealed that the high abundance of denitrifying bacteria and nitrite-oxidizing bacteria (NOB) was responsible for low nitrite accumulations and consequent low N2O emissions. However, N2O generation would be greatly increased upon the normal operation being shocked by either ammonia overload or aeration failure of the oxidation ditch system.
authors.affiliation: Department of Environmental Engineering, Peking University, Key Laboratory of Water and Sediment Sciences, Ministry of Education, Beijing 100871, China.
authors.forename: Maosheng
authors.initials: M
authors.lastname: Zheng
authors.affiliation: Department of Environmental Engineering, Peking University, Key Laboratory of Water and Sediment Sciences, Ministry of Education, Beijing 100871, China.
authors.forename: Yuhao
authors.initials: Y
authors.lastname: Tian
authors.affiliation: Department of Environmental Engineering, Peking University, Key Laboratory of Water and Sediment Sciences, Ministry of Education, Beijing 100871, China.
authors.forename: Tang
authors.initials: T
authors.lastname: Liu
authors.affiliation: Department of Environmental Engineering, Peking University, Key Laboratory of Water and Sediment Sciences, Ministry of Education, Beijing 100871, China.
authors.forename: Tao
authors.initials: T
authors.lastname: Ma
authors.affiliation: Department of Environmental Engineering, Peking University, Key Laboratory of Water and Sediment Sciences, Ministry of Education, Beijing 100871, China.
authors.forename: Li
authors.initials: L
authors.lastname: Li
authors.affiliation: Department of Environmental Engineering, Peking University, Key Laboratory of Water and Sediment Sciences, Ministry of Education, Beijing 100871, China.
authors.forename: Can
authors.initials: C
authors.lastname: Li
authors.affiliation: Department of Environmental Engineering, Peking University, Key Laboratory of Water and Sediment Sciences, Ministry of Education, Beijing 100871, China.
authors.forename: Muhammad
authors.initials: M
authors.lastname: Ahmad
authors.affiliation: Department of Environmental Engineering, Peking University, Key Laboratory of Water and Sediment Sciences, Ministry of Education, Beijing 100871, China.
authors.forename: Qian
authors.initials: Q
authors.lastname: Chen
authors.affiliation: Department of Environmental Engineering, Peking University, Key Laboratory of Water and Sediment Sciences, Ministry of Education, Beijing 100871, China. Electronic address: nijinren@iee.pku.edu.cn.
authors.forename: Jinren
authors.initials: J
authors.lastname: Ni
mesh_terms: D000641:Ammonia / Q000032:analysis; D001419:Bacteria / Q000235:genetics / Q000378:metabolism*; D061249:Batch Cell Culture Techniques; D001673:Biodegradation, Environmental; D019149:Bioreactors / Q000382:microbiology; D009566:Nitrates / Q000032:analysis; D009573:Nitrites / Q000032:analysis; D009609:Nitrous Oxide / Q000032:analysis*; D010084:Oxidation-Reduction; D010100:Oxygen / Q000032:analysis; D010865:Pilot Projects; D012336:RNA, Ribosomal, 16S / Q000235:genetics; D017423:Sequence Analysis, RNA; D014874:Water Pollutants, Chemical / Q000032:analysis
chemical_list: D009566:Nitrates; D009573:Nitrites; D012336:RNA, Ribosomal, 16S; D014874:Water Pollutants, Chemical; D000641:Ammonia; D009609:Nitrous Oxide; D010100:Oxygen
keywords: Microbial community; Nitrifier denitrification; Nitrous oxide; Oxidation ditch; Spatial variation