title: Kinetics of nitrous oxide production by denitrification in municipal solid waste.
abstract: As one of the Nitrous Oxide (N2O) production pathways, denitrification plays an important role in regulating the emission of N2O into the atmosphere. In this study, the influences of different substrate concentrations and transient conditions on the denitrification rate and N2O-reducing activities were investigated. Results revealed that N2O production rates (i.e. denitrification rates) were stimulated by increased total organic carbon (TOC) concentration, while it was restrained under high oxygen concentrations. Moreover, the impact of nitrate concentrations on N2O production rates depended on the TOC/NO3--N ratios. All the N2O production rate data fitted well to a multiplicative Monod equation, with terms describing the influence of TOC and nitrate concentrations, and an Arrhenius-type equation. Furthermore, results demonstrated that high temperatures minimized the N2O-reducing activities in aged municipal solid waste, resulting in an accumulation of N2O. On the other hand, a transient condition caused by changing O2 concentrations may strongly influence the N2O production rates and N2O-reducing activities in solid waste. Finally, based on the results, we believe that a landfill aeration strategy properly designed to prevent rising temperatures and to cycle air injection is the key to reducing emissions of N2O during remediation of old landfills by means of in situ aeration.
authors.affiliation: Department of Environmental Engineering, School of Civil and Environmental Engineering, University of Science and Technology Beijing, 30 Xueyuan Road, Haidian District, Beijing 100083, China; Graduate School of Engineering, Kyushu University, Japan. Electronic address: wucf@ustb.edu.cn.
authors.forename: Chuanfu
authors.initials: C
authors.lastname: Wu
authors.affiliation: Department of Urban and Environmental Engineering, Faculty of Engineering, Kyushu University, 744 Motooka, Nishi-ku, Fukuoka 819-0395, Japan.
authors.forename: Takayuki
authors.initials: T
authors.lastname: Shimaoka
authors.affiliation: Department of Urban and Environmental Engineering, Faculty of Engineering, Kyushu University, 744 Motooka, Nishi-ku, Fukuoka 819-0395, Japan.
authors.forename: Hirofumi
authors.initials: H
authors.lastname: Nakayama
authors.affiliation: Department of Urban and Environmental Engineering, Faculty of Engineering, Kyushu University, 744 Motooka, Nishi-ku, Fukuoka 819-0395, Japan.
authors.forename: Teppei
authors.initials: T
authors.lastname: Komiya
mesh_terms: D001272:Atmosphere; D058440:Denitrification / Q000502:physiology*; D009566:Nitrates / Q000032:analysis; D009609:Nitrous Oxide / Q000737:chemistry*; D062611:Solid Waste / Q000032:analysis*
chemical_list: D009566:Nitrates; D062611:Solid Waste; D009609:Nitrous Oxide
keywords: Denitrification; Different substrate concentrations; Municipal solid waste; N(2)O production; Transient condition