A membrane-free baffled microbial fuel cell for cathodic reduction of Cu(II) with electricity generation

A membrane-free baffled microbial fuel cell (MFC) was developed to treat synthetic Cu(II) sulfate containing wastewater in cathode chamber and synthetic glucose-containing wastewater fed to anode chamber. Maximum power density of 314 mW/m3 with columbic efficiency of 5.3% was obtained using initial Cu2+ concentration of 6400 mg/L. Higher current density favored the cathodic reduction of Cu2+, and removal of Cu2+ by 70% was observed within 144 h using initial concentration of 500 mg/L. Powder X-ray diffraction (XRD) analysis indicated that the Cu2+ was reduced to Cu2O or Cu2O plus Cu which deposited on the cathode, and the deficient cathodic reducibility resulted in the formation of Cu4(OH)6SO4 at high initial Cu2+ concentration (500–6400 mg/L). This study suggested a novel low-cost approach to remove and recover Cu(II) from Cu2+-containing wastewater using MFC-type reactor.