title: Quantifying N2O emissions and production pathways from fresh waste during the initial stage of disposal to a landfill.
abstract: Intensive nitrous oxide (N2O) emissions usually occur at the working face of landfills. However, the specific amounts and contributions of the multiple pathways to N2O emissions are poorly understood. N2O emissions and the mutual conversions of N-species in both open and sealed simulated landfill reactors filled with fresh refuse were examined during a 100-h incubation period, and N2O sources were calculated using15N isotope labelling. N2O peak fluxes were above 70μgNkg-1waste h-1for both treatments. The sealed incubation reactors became a N2O sink when N2O in the ambient environment was sufficient. The total amount of N2O emissions under sealed conditions was 2.15±0.56mgNkg-1waste, which was higher than that under open conditions (1.91±0.34mgNkg-1waste). The NO2-peak appeared prior to the peak in N2O flux. The degree and duration of total nitrogen reduction in open incubations were larger and longer than those of sealed incubations and could possibly be due to oxygen supplementation. Denitrification (DF) was a major source of N2O generation during these incubations. The contribution of the DF pathway decreased from 89.2% to 61.3% during the open incubations. The effects of nitrification (NF) and nitrification-coupled denitrification (NCD) increased during the increasing phase and the decreasing phase of N2O flux, contributing 24.1-37.4% and 31.7-34.4% of total N2O emissions, respectively. In sealed treatments, the DF pathway accounted for more than 90% of the total N2O emission during the entire incubation.
authors: CAS Key Laboratory of Urban Pollutant Conversion, Institute of Urban Environment, Chinese Academy of Sciences, Xiamen 361021, China. Electronic address: xjwang@iue.ac.cn.
authors: Xiaojun
authors: X
authors: Wang
authors: CAS Key Laboratory of Urban Pollutant Conversion, Institute of Urban Environment, Chinese Academy of Sciences, Xiamen 361021, China. Electronic address: jiasheng360@126.com.
authors: Mingsheng
authors: M
authors: Jia
authors: CAS Key Laboratory of Urban Pollutant Conversion, Institute of Urban Environment, Chinese Academy of Sciences, Xiamen 361021, China. Electronic address: hanzhang@iue.ac.cn.
authors: Han
authors: H
authors: Zhang
authors: CAS Key Laboratory of Urban Pollutant Conversion, Institute of Urban Environment, Chinese Academy of Sciences, Xiamen 361021, China. Electronic address: sqpan@iue.ac.cn.
authors: Songqing
authors: S
authors: Pan
authors: Institute of Environmental Engineering, National Sun Yat-Sen University, Kaohsiung 80424, Taiwan. Electronic address: jkao@mail.nsysu.edu.tw.
authors: Chih Ming
authors: CM
authors: Kao
authors: CAS Key Laboratory of Urban Pollutant Conversion, Institute of Urban Environment, Chinese Academy of Sciences, Xiamen 361021, China. Electronic address: shchen@iue.ac.cn.
authors: Shaohua
authors: S
authors: Chen
mesh_terms: D000393:Air Pollutants / Q000032:analysis*; D058440:Denitrification; D058465:Nitrification; D009585:Nitrogen Dioxide / Q000032:analysis*; D012037:Refuse Disposal / Q000379:methods*; D064091:Waste Disposal Facilities; D014866:Waste Products / Q000032:analysis*
chemical_list: D000393:Air Pollutants; D014866:Waste Products; D009585:Nitrogen Dioxide
keywords: (15)N isotope labelling; Denitrification; Fresh refuse; N(2)O emissions; N(2)O sources