title: Effect of set potential on hexavalent chromium reduction and electricity generation from biocathode microbial fuel cells.
abstract: Setting a biocathode potential at -300 mV improved the subsequent performance of an MFC for Cr(VI) reduction compared to a control (no set potential). With this set potential, the startup time was reduced to 19 days, the reduction of Cr(VI) was improved to 19.7 mg/L d, and the maximum power density was increased to 6.4 W/m(3) compared to the control (26 days, 14.0 mg/L d and 4.1 W/m(3)). Set potentials of -150 mV and -300 mV also improved system performance and led to similarly higher utilization of metabolic energy gained (PMEG) than set potentials of +200 mV and -450 mV. We observed putative pili at -150 and -300 mV potentials, and aggregated precipitates on bacterial surfaces in both poised and nonpoised controls. These tests show that there are optimal potentials that can be set for developing a Cr(VI) biocathode.
authors.affiliation: Key Laboratory of Industrial Ecology and Environmental Engineering, Ministry of Education (MOE), School of Environmental Science and Technology, Dalian University of Technology, Dalian 116024, China. lphuang2008@gmail.com
authors.forename: Liping
authors.initials: L
authors.lastname: Huang
authors.forename: Xiaolei
authors.initials: X
authors.lastname: Chai
authors.forename: Guohua
authors.initials: G
authors.lastname: Chen
authors.forename: Bruce E
authors.initials: BE
authors.lastname: Logan
mesh_terms: D000693:Anaerobiosis; D001419:Bacteria / Q000648:ultrastructure; D001674:Bioelectric Energy Sources; D018533:Biomass; D002857:Chromium / Q000737:chemistry*; D004566:Electrodes / Q000382:microbiology; D010084:Oxidation-Reduction; D014874:Water Pollutants, Chemical / Q000737:chemistry*
chemical_list: D014874:Water Pollutants, Chemical; D002857:Chromium; C074702:chromium hexavalent ion