title: Enhancing syntrophic metabolism in up-flow anaerobic sludge blanket reactors with conductive carbon materials.
abstract: Syntrophic metabolism of alcohols and fatty acids is a critical step in anaerobic digestion, which if enhanced can better stabilize the process and enable shorter retention times. Direct interspecies electron transfer (DIET) has recently been recognized as an alternative route to hydrogen interspecies transfer as a mechanism for interspecies syntrophic electron exchange. Therefore, the possibility of accelerating syntrophic metabolism of ethanol in up-flow anaerobic sludge blanket (UASB) reactors by incorporating conductive materials in reactor design was investigated. Graphite, biochar, and carbon cloth all immediately enhanced methane production and COD removal. As the hydraulic retention time was decreased the increased effectiveness of treatment in reactors with conductive materials increased versus the control reactor. When these conductive materials were removed from the reactors rates of syntrophic metabolism declined to rates comparable to the control reactor. These results suggest that incorporating conductive materials in the design of UASB reactors may enhance digester effectiveness.
authors.affiliation: Department of Microbiology, University of Massachusetts, Amherst, MA 01003-9298, USA; Key Laboratory of Industrial Ecology and Environmental Engineering (Dalian University of Technology), Ministry of Education, School of Environmental Science and Technology, Dalian University of Technology, Dalian 116024, China.
authors.forename: Zhiqiang
authors.initials: Z
authors.lastname: Zhao
authors.affiliation: Department of Microbiology, University of Massachusetts, Amherst, MA 01003-9298, USA; Key Laboratory of Industrial Ecology and Environmental Engineering (Dalian University of Technology), Ministry of Education, School of Environmental Science and Technology, Dalian University of Technology, Dalian 116024, China. Electronic address: zhangyb@dlut.edu.cn.
authors.forename: Yaobin
authors.initials: Y
authors.lastname: Zhang
authors.affiliation: Department of Microbiology, University of Massachusetts, Amherst, MA 01003-9298, USA.
authors.forename: T L
authors.initials: TL
authors.lastname: Woodard
authors.affiliation: Department of Microbiology, University of Massachusetts, Amherst, MA 01003-9298, USA.
authors.forename: K P
authors.initials: KP
authors.lastname: Nevin
authors.affiliation: Department of Microbiology, University of Massachusetts, Amherst, MA 01003-9298, USA.
authors.forename: D R
authors.initials: DR
authors.lastname: Lovley
mesh_terms: D000693:Anaerobiosis / Q000502:physiology*; D019149:Bioreactors; D002244:Carbon / Q000378:metabolism*; D002606:Charcoal / Q000378:metabolism; D004579:Electron Transport / Q000502:physiology; D006108:Graphite / Q000378:metabolism; D006859:Hydrogen / Q000378:metabolism; D008697:Methane / Q000378:metabolism; D012722:Sewage / Q000382:microbiology*; D014865:Waste Disposal, Fluid / Q000379:methods
chemical_list: D012722:Sewage; C540010:biochar; D002606:Charcoal; D002244:Carbon; D006108:Graphite; D006859:Hydrogen; D008697:Methane
keywords: Conductive carbon materials; Direct interspecies electron transfer; Syntrophic metabolism; Up-flow anaerobic sludge blanket