Electricity production during the treatment of real electroplating wastewater containing Cr6+ using microbial fuel cell

Abstract

Microbial fuel cell (MFC) was employed to dispose Cr⁶⁺ in real electroplating wastewater and generate electricity simultaneously. The experiments were carried out in a dual-chamber MFC. Under the condition of pH 2 and using graphite paper as the cathode electrode chromium removal and power density were highest. Moreover, increasing initial concentration of Cr⁶⁺ could enhance the power density. The results indicated that when treating a real electroplating wastewater containing Cr⁶⁺ with the initial concentration of 204 ppm in the MFC, the maximum power density of 1600 mW/m² was generated at a columbic efficiency of 12%. In addition, 99.5% Cr⁶⁺ and 66.2% total Cr were removed through reduction of Cr₂O₇²⁻ to Cr₂O₃ precipitating on the surface of cathode electrode. MFC was proved to be a promising technology for removing Cr⁶⁺ from electroplating wastewater.