title: COD removal characteristics in air-cathode microbial fuel cells.
abstract: Exoelectrogenic microorganisms in microbial fuel cells (MFCs) compete with other microorganisms for substrate. In order to understand how this affects removal rates, current generation, and coulombic efficiencies (CEs), substrate removal rates were compared in MFCs fed a single, readily biodegradable compound (acetate) or domestic wastewater (WW). Removal rates based on initial test conditions fit first-order kinetics, but rate constants varied with circuit resistance. With filtered WW (100Ω), the rate constant was 0.18h(-)(1), which was higher than acetate or filtered WW with an open circuit (0.10h(-)(1)), but CEs were much lower (15-24%) than acetate. With raw WW (100Ω), COD removal proceeded in two stages: a fast removal stage with high current production, followed by a slower removal with little current. While using MFCs increased COD removal rate due to current generation, secondary processes will be needed to reduce COD to levels suitable for discharge.
authors.affiliation: State Key Joint Laboratory of Environment Simulation and Pollution Control, School of Environment, Tsinghua University, Beijing 100084, PR China; Department of Civil & Environmental Engineering, Penn State University, 231Q Sackett Building, University Park, PA 16802, USA. Electronic address: zhangxiaoyuan@tsinghua.edu.cn.
authors.forename: Xiaoyuan
authors.initials: X
authors.lastname: Zhang
authors.affiliation: State Key Laboratory of Urban Water Resource and Environment, Harbin Institute of Technology, No. 73 Huanghe Road, Nangang District, Harbin 150090, PR China.
authors.forename: Weihua
authors.initials: W
authors.lastname: He
authors.affiliation: Department of Civil & Environmental Engineering, Penn State University, 231Q Sackett Building, University Park, PA 16802, USA.
authors.forename: Lijiao
authors.initials: L
authors.lastname: Ren
authors.affiliation: Department of Civil & Environmental Engineering, Penn State University, 231Q Sackett Building, University Park, PA 16802, USA.
authors.forename: Jennifer
authors.initials: J
authors.lastname: Stager
authors.affiliation: CDM Smith, 14432 S.E. Eastgate Way, Suite 100, Bellevue, WA 98007, USA.
authors.forename: Patrick J
authors.initials: PJ
authors.lastname: Evans
authors.affiliation: Department of Civil & Environmental Engineering, Penn State University, 231Q Sackett Building, University Park, PA 16802, USA. Electronic address: blogan@psu.edu.
authors.forename: Bruce E
authors.initials: BE
authors.lastname: Logan
mesh_terms: D000085:Acetates / Q000032:analysis*; D000388:Air / Q000032:analysis; D001674:Bioelectric Energy Sources; D057919:Biological Oxygen Demand Analysis / Q000379:methods*; D004566:Electrodes / Q000382:microbiology*; D007700:Kinetics; D062065:Wastewater / Q000737:chemistry*; D014874:Water Pollutants, Chemical / Q000032:analysis*; D018508:Water Purification / Q000379:methods*
chemical_list: D000085:Acetates; D062065:Wastewater; D014874:Water Pollutants, Chemical
keywords: COD removal rate; Coulombic efficiency; Domestic wastewater; First-order reaction; Microbial fuel cell