Electricity Generation From Wastewater Treatment Using A Microbial Fuel Cell

Microbial fuel cell(MFC)is a device directly converting organic substance into electricity with the microbial metabolism.At present,it is still in experimental stage,and the most of research concentrate on the study of factors affecting the performance of MFC,in order to provide a significant guidance for MFC practical application in wastewater treatment.In this study,MFC is typically designed as a two-chamber system with the bacteria in the anode chamber separated from the cathode chamber by a Proton Exchange Membrane(PEM).The bacteria in the anode are obtained from anaerobic activated sludge.This study selects the optimal condition of the MFC which is feed with municipal wastewater and industrial wastewater respectively.At the same time,the electrical performance and COD removal rate of the MFC were studied,while air and aerobic active sludge were supposed to be electron acceptors respectively in similar condition.The results indicate,in the treatment of municipal wastewater,the maximum current density was approximately 4.5mA/m~2,attained under the conditions of the initial COD of 1000mg/L,hydraulic retention time(HRT)is 12 hours,and electrode material of graphite.Temporality,the COD removal rate of the MFC is about 70%.In the process of dealing with industrial wastewater,the best operation conditions of the MFC:influent COD is 1000mg/L,HRT of 16 hours,the influent salinity control in about 8-10 g/L. Under these conditions,battery system output current density is 13 mA/m~2, and the wastewater system in the removal of COD is about 40%.In the continuous treatment of municipal wastewater,when the air for the electron acceptor,the MFC of output current density of about 8.1 mA/m~2,in the COD removal rate of 70%,while the aerobic sludge as an electronic receptor,the current density is 26 mA/m~2,COD removal efficiency of more than 90%.Analogously,in the treatment of industrial wastewater,when the air as electron acceptor,the maximum current density is about 13 mA/m~2,and the COD removal efficiency of about 50%,while the aerobic sludge as electron acceptor,the current density of about 17 mA/m~2,COD removal efficiency of about 80%.