title: Short tests to couple N₂O emission mitigation and nitrogen removal strategies for landfill leachate recirculation.
abstract: Landfills implemented with onsite leachate recirculation can efficiently remove pollutants, but currently they are reckoned as N2O emission hot spots. In this project, we evaluated the relationship between N2O emission and nitrogen (N) removal efficiency with different types of leachate recirculated. Nitrate supplemented leachate showed low N2O emission rates with the highest N removal efficiency (~70%), which was equivalent to ~1% nitrogen emitted as N2O. Although in nitrite containing leachates' N removal efficiencies also reached to ~60%, their emitted N2O comprised ~40% of total removed nitrogen. Increasing nitrogen load promoted N2O emission and N removal efficiency, except in ammonia type leachate. When the ratio of BOD to total nitrogen increased from 0.2 to 0.4, the N2O emission flux from nitrate supplemented leachate decreased from ~25 to <0.5 μg N/kg-soil·h. We argue prior to leachate in situ recirculation, sufficient pre-aeration is critical to mitigate N2O surges and simultaneously enhance nitrogen removal efficiency.
authors.affiliation: Shanghai Key Lab for Urban Ecological Processes and Eco-Restoration, School of Ecological and Environmental Science, East China Normal University, 500 Dong Chuan Road, Shanghai 200062, PR China. Electronic address: 15083030465@163.com.
authors.forename: Dong
authors.initials: D
authors.lastname: Wu
authors.affiliation: Shanghai Key Lab for Urban Ecological Processes and Eco-Restoration, School of Ecological and Environmental Science, East China Normal University, 500 Dong Chuan Road, Shanghai 200062, PR China. Electronic address: wangchao0705@126.com.
authors.forename: Chao
authors.initials: C
authors.lastname: Wang
authors.affiliation: School of Civil Engineering and Geosciences, Newcastle University, Newcastle upon Tyne NE1 7RU, UK. Electronic address: jandolfing@ncl.ac.uk.
authors.forename: Jan
authors.initials: J
authors.lastname: Dolfing
authors.affiliation: Shanghai Key Lab for Urban Ecological Processes and Eco-Restoration, School of Ecological and Environmental Science, East China Normal University, 500 Dong Chuan Road, Shanghai 200062, PR China. Electronic address: bxie@des.ecnu.edu.cn.
authors.forename: Bing
authors.initials: B
authors.lastname: Xie
mesh_terms: D019149:Bioreactors; D058440:Denitrification; D009584:Nitrogen / Q000032:analysis; D009609:Nitrous Oxide / Q000032:analysis*; D012037:Refuse Disposal / Q000379:methods*; D014874:Water Pollutants, Chemical / Q000032:analysis*; D014877:Water Pollution, Chemical / Q000517:prevention & control* / Q000706:statistics & numerical data
chemical_list: D014874:Water Pollutants, Chemical; D009609:Nitrous Oxide; D009584:Nitrogen
keywords: BOD(5)/TN ratio; Leachate treatment; N(2)O emission flux; Nitrogen form; Nitrogen load; Nitrogen removal