Efficacy of single-chamber microbial fuel cells for removal of cadmium and zinc with simultaneous electricity production

Simultaneous high power generation (3.6 W/m(2)) and high Cd (90%) and Zn (97%) removal efficiencies were demonstrated in a single chamber air-cathode microbial fuel cell (MFC). The maximum tolerable concentrations (MTCs) were estimated as 200 mu M for Cd and 400 mu M for Zn. Increasing the concentrations of Cd to 300 mu M and Zn to 500 mu M resulted in voltage drops by 71 and 74%, respectively. Feeding the MFCs with incrementally increased Cd and Zn concentrations resulted in much slower reduction in voltage output. Biosorption and sulfides precipitation are the major mechanisms for the heavy metal removal in the MFCs. (C) 2013 Elsevier Ltd. All rights reserved.