Selection of cheap electrodes for two-compartment microbial fuel cells

This work compares the performance of four microbial fuel cells (MFCs) equipped with different cheap electrodic materials during two-month long tests, in which they were operated under the same operating conditions. Despite using sp2 carbon materials (carbon felt, foam and cloth) as anode in the four MFCs, results demonstrates that there are important differences in the performance, pointing out the relevance of the surface area and other physical characteristics on the efficiency of MFCs. Differences were found not only in the production of electricity but also in the consumption of fuel (acetate) and even in the cathodic consumption of oxygen. Carbon felt was found to be the most efficient anode material whereas the worst results were obtained with carbon cloth. Performance seems to be in direct relationship with the specific area of the anode materials. In comparing the performance of the MFC equipped with carbon felt and stainless steel as cathodes, the later shows the worst performance, which clearly indicates how the cathodic process may become the bottleneck of the MFC performance.