title: Influence of ionic conductivity in bioelectricity production from saline domestic sewage sludge in microbial fuel cells.
abstract: This study aimed at manipulating ionic conductivity (EC) to harvest the maximum electrical energy from seawater-based domestic wastewater sewage sludge (SWS), unique to only a few cities, through microbial fuel cell (MFC). SWS has never been investigated as a MFC substrate before, and thus the influence of high in-situ EC on the energy recovery was unknown. In this study, the EC of the SWS was reduced through mixing it with fresh water-based domestic wastewater sewage sludge (FWS) or diluted 50% using deionized water while FWS and SWS were individually served as reference treatments. SWS:FWS mix (1:1) exhibited a maximum Coulombic efficiency of 28.6±0.5% at a COD removal of 59±3% while the peak power density was 20-fold higher than FWS. The improved performance was due to the lower ohmic internal resistance (36.8±4.2Ω) and optimal conductivity (12.8±0.2mScm(-1)). Therefore, dilution with FWS could enhance energy recovery from SWS.
authors.affiliation: Sino-Forest Applied Research Centre for Pearl River Delta Environment, and Department of Biology, Hong Kong Baptist University, Hong Kong Special Administrative Region.
authors.forename: Rengasamy
authors.initials: R
authors.lastname: Karthikeyan
authors.affiliation: Sino-Forest Applied Research Centre for Pearl River Delta Environment, and Department of Biology, Hong Kong Baptist University, Hong Kong Special Administrative Region.
authors.forename: Ammayaippan
authors.initials: A
authors.lastname: Selvam
authors.affiliation: CSIRO Land and Water, Commonwealth Scientific and Industrial Research Organisation (CSIRO), Underwood Avenue, Floreat, WA 6014, Australia.
authors.forename: Ka Yu
authors.initials: KY
authors.lastname: Cheng
authors.affiliation: Sino-Forest Applied Research Centre for Pearl River Delta Environment, and Department of Biology, Hong Kong Baptist University, Hong Kong Special Administrative Region. Electronic address: jwcwong@hkbu.edu.hk.
authors.forename: Jonathan Woon-Chung
authors.initials: JW
authors.lastname: Wong
mesh_terms: D001674:Bioelectric Energy Sources; D057919:Biological Oxygen Demand Analysis; D004553:Electric Conductivity; D004573:Electrolytes / Q000737:chemistry; D006863:Hydrogen-Ion Concentration; D007477:Ions; D054712:Salinity; D012722:Sewage / Q000382:microbiology*; D062065:Wastewater / Q000737:chemistry
chemical_list: D004573:Electrolytes; D007477:Ions; D012722:Sewage; D062065:Wastewater
keywords: Bioelectricity; Ionic conductivity; Microbial fuel cell; Power density; Saline sewage sludge