title: Mathematical modeling of nitrous oxide production in an anaerobic/oxic/anoxic process.
abstract: This study incorporates three currently known nitrous oxide (N2O) production pathways: ammonium-oxidizing bacteria (AOB) denitrification, incomplete hydroxylamine (NH2OH) oxidation, and heterotrophic denitrification on intracellular polymers, into a mathematical model to describe N2O production in an anaerobic/oxic/anoxic (AOA) process for the first time. The developed model was calibrated and validated by four experimental cases, then evaluated by two independent anaerobic/aerobic (AO) studies from literature. The modeling results displayed good agreement with the measured data. N2O was primarily generated in the aerobic stage by AOB denitrification (67.84-81.64%) in the AOA system. Smaller amounts of N2O were produced via incomplete NH2OH oxidation (15.61-32.17%) and heterotrophic denitrification on intracellular polymers (0-12.47%). The high nitrite inhibition on N2O reductase led to the increased N2O accumulation in heterotrophic denitrification on intracellular polymers. The new model was capable of modeling nitrification-denitrification dynamics and heterotrophic denitrification on intracellular polymers in the AOA system.
authors.affiliation: School of Environmental Science and Engineering, Chang'an University, Xi'an 710064, Shaanxi, China.
authors.forename: Xiaoqian
authors.initials: X
authors.lastname: Ding
authors.affiliation: School of Environmental Science and Engineering, Chang'an University, Xi'an 710064, Shaanxi, China; Key Laboratory of Subsurface Hydrology and Ecological Effect in Arid Region of Ministry of Education, Xi'an 710064, Shaanxi, China. Electronic address: 626710287@qq.com.
authors.forename: Jianqiang
authors.initials: J
authors.lastname: Zhao
authors.affiliation: School of Civil Engineering, Chang'an University, Xi'an 710064, Shaanxi, China.
authors.forename: Bo
authors.initials: B
authors.lastname: Hu
authors.affiliation: School of Environmental Science and Engineering, Chang'an University, Xi'an 710064, Shaanxi, China; Key Laboratory of Subsurface Hydrology and Ecological Effect in Arid Region of Ministry of Education, Xi'an 710064, Shaanxi, China.
authors.forename: Ying
authors.initials: Y
authors.lastname: Chen
authors.affiliation: School of Environmental Science and Engineering, Chang'an University, Xi'an 710064, Shaanxi, China.
authors.forename: Guanghuan
authors.initials: G
authors.lastname: Ge
authors.affiliation: School of Civil Engineering, Chang'an University, Xi'an 710064, Shaanxi, China.
authors.forename: Xiaoling
authors.initials: X
authors.lastname: Li
authors.affiliation: School of Environmental Science and Engineering, Chang'an University, Xi'an 710064, Shaanxi, China.
authors.forename: Sha
authors.initials: S
authors.lastname: Wang
authors.affiliation: School of Environmental Science and Engineering, Chang'an University, Xi'an 710064, Shaanxi, China.
authors.forename: Kun
authors.initials: K
authors.lastname: Gao
authors.affiliation: School of Environmental Science and Engineering, Chang'an University, Xi'an 710064, Shaanxi, China.
authors.forename: Xiaolei
authors.initials: X
authors.lastname: Tian
mesh_terms: D000332:Aerobiosis; D000693:Anaerobiosis; D001419:Bacteria / Q000378:metabolism*; D002138:Calibration; D003198:Computer Simulation; D058440:Denitrification; D052836:Heterotrophic Processes; D008962:Models, Theoretical; D009609:Nitrous Oxide / Q000378:metabolism*; D015203:Reproducibility of Results
chemical_list: D009609:Nitrous Oxide
keywords: AOA process; AOB denitrification; Heterotrophic denitrification on intracellular polymers; N(2)O modeling; N(2)O production pathway