title: Effective carbon and nitrogen removal with reduced sulfur oxidation in an anaerobic baffled reactor for fresh leachate treatment.
abstract: The application of an anaerobic baffled reactor (ABR) with four compartments was investigated for the simultaneous removal of carbon and nitrogen from leachate. The nitrified effluent was recycled to compartment 3 of the ABR, thereby avoiding the adverse influence of nitrogen oxides on anaerobic methanogenesis in compartment 1. Nitrified effluent recirculation not only enhanced chemical oxygen demand removal (>95.6%) but also improved the total nitrogen removal efficiency from 12.7% to 67.4% with increasing recirculation ratio from 0.25 to 2. The challenge of insufficient carbon sources for heterotrophic denitrification in compartment 3 with a high recirculation ratio could be overcome by step feeding of leachate. Moreover, various reduced sulfurs (e.g., sulfide, elemental sulfur, and organic sulfur) were involved in nitrate reduction via sulfur-based autotrophic denitrification. The addition of sulfide to compartment 3 further confirmed nitrate reduction using reduced sulfur as an electron donor. The interaction of organic carbon, reduced sulfur, and nitrate in leachate treatment needs further study.
authors: Institute of Biofilm Technology, Key Laboratory of Yangtze River Water Environment, College of Environmental Science and Engineering, Tongji University, 1239 Siping Road, Shanghai 200092, PR China.
authors: Zhixuan
authors: Z
authors: Yin
authors: Institute of Biofilm Technology, Key Laboratory of Yangtze River Water Environment, College of Environmental Science and Engineering, Tongji University, 1239 Siping Road, Shanghai 200092, PR China. Electronic address: sally.xieli@tongji.edu.cn.
authors: Li
authors: L
authors: Xie
authors: Institute of Biofilm Technology, Key Laboratory of Yangtze River Water Environment, College of Environmental Science and Engineering, Tongji University, 1239 Siping Road, Shanghai 200092, PR China.
authors: Xinwei
authors: X
authors: Cui
authors: Institute of Biofilm Technology, Key Laboratory of Yangtze River Water Environment, College of Environmental Science and Engineering, Tongji University, 1239 Siping Road, Shanghai 200092, PR China.
authors: Qi
authors: Q
authors: Zhou
mesh_terms: D000693:Anaerobiosis; D052818:Autotrophic Processes; D019149:Bioreactors; D002244:Carbon / Q000302:isolation & purification* / Q000378:metabolism; D058440:Denitrification; D052836:Heterotrophic Processes; D009566:Nitrates / Q000378:metabolism; D009584:Nitrogen / Q000302:isolation & purification* / Q000378:metabolism; D009589:Nitrogen Oxides / Q000378:metabolism; D010084:Oxidation-Reduction; D013440:Sulfides / Q000378:metabolism; D013455:Sulfur / Q000378:metabolism*; D018505:Waste Management / Q000379:methods*
chemical_list: D009566:Nitrates; D009589:Nitrogen Oxides; D013440:Sulfides; D013455:Sulfur; D002244:Carbon; D009584:Nitrogen
keywords: Anaerobic–aerobic system; Leachate; Recirculation ratio; Simultaneous denitrification and methanogenesis; Sulfur-based autotrophic denitrification