Electricity production in microbial fuel cell subjected to different operational modes

Abstract

The effects of inoculum species, substrate concentration, temperature, and cathodic electron acceptors on electricity production of microbial fuel cells (MFCs) were investigated in terms of start-up time and power output. When inoculated with aeration tank sludge, this MFC outperformed the cell that was inoculated with anaerobic sludge in terms of start-up time and power output. After running for a certain time period, the dominant populations of the two MFCs varied significantly. Within the tested range of substrate concentration (200-1800 mg L-1), the voltage output increased and the time span of the electricity generation lengthened with increasing substrate concentration. As the temperature declined from 35 to 10 °C, the maximum power density reduced from 2.229 to 1.620 W m-3, and anodic polarization resistance correspondingly dropped from 118 to 98 X. The voltage output of MFC-Cu2+ was 0.447 V, which is slightly lower than that achieved with MFC-[Fe(CN)6]3- (0.492 V), thereby indicating that MFCs could be used to treat wastewater containing Cu2+ pollutant in the cathode chamber with removal of organics in anode chamber and simultaneous electricity generation.