title: Evaluation of Nitrous Oxide Emission from Sulfide- and Sulfur-Based Autotrophic Denitrification Processes.
abstract: Recent studies have shown that sulfide- and sulfur-based autotrophic denitrification (AD) processes play an important role in contributing to nitrous oxide (N2O) production and emissions. However, N2O production is not recognized in the current AD models, limiting their ability to predict N2O accumulation during AD. In this work, a mathematical model is developed to describe N2O dynamics during sulfide- and sulfur-based AD processes for the first time. The model is successfully calibrated and validated using N2O data from two independent experimental systems with sulfide or sulfur as electron donors for AD. The model satisfactorily describes nitrogen reductions, sulfide/sulfur oxidation, and N2O accumulation in both systems. Modeling results revealed substantial N2O accumulation due to the relatively low N2O reduction rate during both sulfide- and sulfur-based AD processes. Application of the model to simulate long-term operations of activated sludge systems performing sulfide- and sulfur-based AD processes indicates longer sludge retention time reduced N2O emission. For sulfide-based AD process, higher initial S/N ratio also decreased N2O emission but with a higher operational cost. This model can be a useful tool to support process operation optimization for N2O mitigation during AD with sulfide or sulfur as electron donor.
authors: Centre for Technology in Water and Wastewater, School of Civil and Environmental Engineering, University of Technology Sydney , Sydney, New South Wales 2007, Australia.
authors: Yiwen
authors: Y
authors: Liu
authors: State Key Laboratory of Pollution Control and Resources Reuse, College of Environmental Science and Engineering, Tongji University , Shanghai 200092, China.|Laboratory of Microbial Ecology and Technology (LabMET), Ghent University , Coupure Links 653, 9000 Ghent, Belgium.
authors: Lai
authors: L
authors: Peng
authors: Centre for Technology in Water and Wastewater, School of Civil and Environmental Engineering, University of Technology Sydney , Sydney, New South Wales 2007, Australia.
authors: Huu Hao
authors: HH
authors: Ngo
authors: Centre for Technology in Water and Wastewater, School of Civil and Environmental Engineering, University of Technology Sydney , Sydney, New South Wales 2007, Australia.
authors: Wenshan
authors: W
authors: Guo
authors: College of Environmental Science and Engineering and Key Laboratory of Environmental Biology and Pollution Control, Ministry of Education, Hunan University , Changsha 410082, China.
authors: Dongbo
authors: D
authors: Wang
authors: Department of Environmental Science and Engineering, School of Architecture and Environment, Sichuan University , Chengdu, Sichuan 610065, China.
authors: Yuting
authors: Y
authors: Pan
authors: State Key Laboratory of Pollution Control and Resources Reuse, College of Environmental Science and Engineering, Tongji University , Shanghai 200092, China.
authors: Jing
authors: J
authors: Sun
authors: State Key Laboratory of Pollution Control and Resources Reuse, College of Environmental Science and Engineering, Tongji University , Shanghai 200092, China.
authors: Bing-Jie
authors: BJ
authors: Ni
mesh_terms: D052818:Autotrophic Processes; D019149:Bioreactors; D058440:Denitrification; D009609:Nitrous Oxide; D013440:Sulfides; D013455:Sulfur
chemical_list: D013440:Sulfides; D013455:Sulfur; D009609:Nitrous Oxide