The Influence of Mediator Concentration on the Performance of Microbial Fuel Cell

Abstract

Electrochemical impedance spectroscopy (EIS), cyclic voltammetry (CV), power density and anode potential are used to characterize the mediator microbial fuel cell at different methylene blue (MB) concentrations. At lower MB concentration between 9.98×10-3 mmol/L and 1.66×10-1 mmol/L, the increased power density is enabled by using high mediator concentrations. Higher peak power density of 159.6 mw/m2 is observed compared with the peak power density of 36.0 mw/m2. But MB at too high concentration is disadvantageous to the perform of MFC. At the MB concentration of 2.50×10-1 mmol/L, the peak power output is just 128.4 mw/m2, which is lower than 159.6 mw/m2 at MB concentration of 1.66×10-1 mmol/L.