Effect of temperature and cathode material on power production in an earthenware microbial fuel cell

Abstract

This study investigates the performance of microbial fuel cells (MFCs) fed with municipal sewage water considering parameters such as temperature and cathode materials. Single chamber ceramic MFCs with the cathode exposed to water were used in this study. These MFCs were made from M+ fine clay which were fired to create a ceramic pot. All four of the ceramics were placed in water, one at 19oC and the other three at 37oC. Three ceramics, with different cathode materials, were exposed to water at 37oC. The cathode materials investigated were clean ceramic, activated carbon and carbon black Vulcan XC-72 (Cabot Corporation). The activated carbon and carbon black Vulcan XC-72 were fixed to the outside of the ceramic using polyvinyl alcohol (PVA) binder. The anode material was made of woven graphite fiber, the surface area of the anode was 136 cm2 . Voltage readings were taken over a 1000 Ω external resistance every 24 hours. Results indicate that 37oC is beneficial for power production. Investigation of cathode materials showed that the carbon black MFC produced the most power, 19.95 mW/m2 , followed by the activated carbon MFC with, 12.55 mW/m2 . The clean ceramic MFC produced 8.85 mW/m2 of power. The activated carbon MFC performed best in terms of wastewater treating ability. The COD in the former MFC decreased with 37.57%, followed by the carbon black MFC with, 34.46%. The carbon black MFC had a CE of 44 %. The use of MFC made of locally available clay material will allow to consider the possibility of sewage wastewater treatment with simultaneous generation of electricity