Effects of Anode Materials on Electricity Generation and Organic Wastewater Treatment of 6 L Microbial Fuel Cells

Abstract

Anode material is one of the most important factors on the application of microbial fuel cells for wastewater treatment due to its key role in forming exoelectrogenic biofilm and transferring electrons along with the high investment cost. In this study, carbon brush (CB), carbon cloth (CC) and graphite felt (GF) were investigated as alternative anode materials for 6 L single-chamber dual air-cathode microbial fuel cells (MFCs) in terms of starting-up rate and electricity production with artificial wastewater and slaughter wastewater. The cost effectiveness of anode materials was also evaluated. The results showed that anode materials had no obvious effect on the start-up of MFC. All MFCs finished their started-up on day 24. Using artificial wastewater[acetate 1 g·L-1 in 50 mmol·L-1 phosphate buffer (PBS)] as substrate, the maximum power densities for the CB, CC and GF-MFCs were (56.3±1.8) W·m-3, (46.0±1.7) W·m-3, and (40.8±1.5) W·m-3, while with slaughter wastewater MFCs could produce (19.5±0.8) W·m-3, (16.9±0.6) W·m-3, and (11.9±0.5) W·m-3, respectively. COD removals of all the MFCs were approximately 90% with both artificial wastewater and slaughter wastewater. The CB-MFCs had a cost of (3.44±0.08) mW·yuan-1 with the artificial wastewater and (0.97±0.05) mW·yuan-1 with slaughter wastewater, which were 18.6%, 12.8% higher than that of CC-MFCs and 38.7%, 80% higher than that of GF-MFCs, respectively. These results demonstrate that carbon brush is the most suitable material used in large-scale MFC.