Removal of copper from aqueous solution by electrodeposition in cathode chamber of microbial fuel cell

Abstract: Based on energetic analysis, a novel approach for copper electrodeposition via cathodic reduction in microbial fuel cells (MFCs) was proposed for the removal of copper and recovery of copper solids as metal copper and/or Cu2O in a cathode with simultaneous electricity generation with organic matter. This was examined by using dual-chamber MFCs (chamber volume, 1L) with different concentrations of CuSO4 solution (50.3±5.8, 183.3±0.4, 482.4±9.6, 1007.9±52.0 and 6412.5±26.7mg Cu2+/L) as catholyte at pH 4.7, and different resistors (0, 15, 390 and 1000Ω) as external load. With glucose as a substrate and anaerobic sludge as an inoculum, the maximum power density generated was 339mW/m3 at an initial 6412.5±26.7mg Cu2+/L concentration. High Cu2+ removal efficiency (>99%) and final Cu2+ concentration below the USA EPA maximum contaminant level (MCL) for drinking water (1.3mg/L) was observed at an initial 196.2±0.4mg Cu2+/L concentration with an external resistor of 15Ω, or without an external resistor. X-ray diffraction analysis confirmed that Cu2+ was reduced to cuprous oxide (Cu2O) and metal copper (Cu) on the cathodes. Non-reduced brochantite precipitates were observed as major copper precipitates in the MFC with a high initial Cu2+ concentration (0.1M) but not in the others. The sustainability of high Cu2+ removal (>96%) by MFC was further examined by fed-batch mode for eight cycles. [Copyright &y& Elsevier]