Effects of cathodic platinum loadings and organic substrate concentrations on the performance of single chamber microbial fuel cells treating wastewater

Single electrode kinetics was investigated in a membrane-less single chamber air cathode microbial fuel cell (SCMFC) fed with raw wastewater. Anode kinetics was studied to better understand mass transport diffusion limitations without the addition of readily degradable organic substrates. Cathode electrode kinetics was investigated with varying platinum (Pt) loading. Even though higher Pt loading resulted in better cathode performance, a reduction of Pt loadings by two orders of magnitude did not significantly lower performance. The cathode performance decreased substantially over time especially for low currents due to the depletion of oxygen on the cathode surface. This study showed that the anode kinetics rather than cathode kinetics limited the overall performance of SCMFCs at low organics concentrations.