Simultaneous heavy metal reduction and voltage generation with synergy membrane-less microbial fuel cell

Abstract

Metal contaminated wastewater effluent from industries has caused several environmental problems and public health due to its toxicity. Conventional heavy metal reduction processes are neither economical nor environmentally friendly. A synergy economical single chamber up-flow membrane-less microbial fuel cell (UFML-MFC) was fabricated to study the feasibility of heavy metal reduction and voltage generation. Cu (II) was used as electron acceptor to explore the mechanism of metal treatment in UFML-MFC. The performances of the UFML-MFC were investigated with 0 mg/L, 5 mg/L and 10 mg/L concentration of Cu (II) in terms of voltage output, chemical oxygen demand (COD) reduction and Cu (II) reduction efficiency and electrode spacing distance. UFML-MFC used carbon felt as anode and cathode material where anode region was filled with 0.2 cm of gravels at anode region. Overall performance deteriorated with increased initial concentration of Cu (II). Voltage generation decreased from 71 mV to 11.1 mV. COD reduction decreased from 56% to 36%. Moreover, the Cu (II) reduction efficiency was reduced from 87.56% to 36.98%. These results showed that the increased concentration of the Cu (II) could potentially reduce the microbial activities. However, UFML-MFC showed that the shorter distance of electrode spacing (anode and cathode) could enhanced the voltage output. These results showed the great ability of integrating UFML-MFC for heavy metal reduction.