title: Syntrophic interactions between H2-scavenging and anode-respiring bacteria can improve current density in microbial electrochemical cells.
abstract: High current density of 10.0-14.6A/m(2) and COD removal up to 96% were obtained in a microbial electrochemical cell (MEC) fed with digestate at hydraulic retention time (HRT) of 4d and 8d. Volatile fatty acids became undetectable in MEC effluent (HRT 8d), except for trivial acetate (4.16±1.86mgCOD/L). Accumulated methane only accounted for 3.42% of ΔCOD. Pyrosequencing analyses showed abundant fermenters (Kosmotoga spp.) and homoacetogens (Treponema spp.) in anolytes. In anode biofilm, propionate fermenters (Kosmotoga, and Syntrophobacter spp.), homoacetogens (Treponema spp.), and anode-respiring bacteria (ARB) (Geobacter spp. and Dysgonomonas spp.) were dominant. These results imply that syntrophic interactions among fermenters, homoacetogens and ARB would allow MECs to maintain high current density and coulombic efficiency.
authors.affiliation: Department of Civil & Environmental Engineering, University of Waterloo, 200 University Ave. West, ON N2L 3G1, Canada. Electronic address: yaohuanlab@gmail.com.
authors.forename: Yaohuan
authors.initials: Y
authors.lastname: Gao
authors.affiliation: National Risk Management Research Laboratory, U.S. Environmental Protection Agency, 26 W. Martin Luther King Drive, Cincinnati, OH 45268, USA. Electronic address: ryu.hodon@epa.gov.
authors.forename: Hodon
authors.initials: H
authors.lastname: Ryu
authors.affiliation: National Risk Management Research Laboratory, U.S. Environmental Protection Agency, 26 W. Martin Luther King Drive, Cincinnati, OH 45268, USA. Electronic address: santodomingo.jorge@epa.gov.
authors.forename: Jorge W
authors.initials: JW
authors.lastname: Santo Domingo
authors.affiliation: Department of Civil & Environmental Engineering, University of Waterloo, 200 University Ave. West, ON N2L 3G1, Canada. Electronic address: hyungsool@uwaterloo.ca.
authors.forename: Hyung-Sool
authors.initials: HS
authors.lastname: Lee
mesh_terms: D000085:Acetates / Q000494:pharmacology; D000332:Aerobiosis / Q000187:drug effects; D001419:Bacteria / Q000187:drug effects / Q000235:genetics / Q000378:metabolism*; D001674:Bioelectric Energy Sources / Q000382:microbiology*; D018441:Biofilms / Q000187:drug effects; D057919:Biological Oxygen Demand Analysis; D004560:Electricity; D004566:Electrodes; D005232:Fatty Acids, Volatile / Q000032:analysis; D005798:Genes, Bacterial / Q000235:genetics; D006859:Hydrogen / Q000378:metabolism*; D007700:Kinetics; D008697:Methane / Q000378:metabolism; D056265:Microbial Interactions / Q000187:drug effects; D012336:RNA, Ribosomal, 16S / Q000235:genetics; D014835:Volatilization / Q000187:drug effects; D014865:Waste Disposal, Fluid
chemical_list: D000085:Acetates; D005232:Fatty Acids, Volatile; D012336:RNA, Ribosomal, 16S; D006859:Hydrogen; D008697:Methane
keywords: Anaerobic digester (AD); Anode-respiring bacteria (ARB); Homoacetogens; Methanogens; Microbial electrochemical cells (MECs)