Effect of Anodic Biofilm Growth on the Performance of the Microbial Fuel Cell (MFC)

Electrochemical impedance spectroscopy (EIS) and Cyclic Voltammetry (CV) were used to explore the mechanism of the effect of anodic biofilm growth on power output of the microbial fuel cell (MFC) at different operational conditions. These operational conditions included MFC systems with and without the bacterial catalyst and at different periods of biofilm growth. Power density increased with the development of biofilm on the anodic surface. Higher power density of 594 mW/m² was observed on day 30 (a maturate bioflim) compared with the power density of 33.4 mW/m² on day 5 (an immature biofilm). The MFC without biofilm catalyst generated unnoticeable power density of 8.6 mW/m². These results showed that biofilm growth greatly reduced the anode polarization impedance and facilitated the kinetics of the electrochemical reactions so as to enhance extracellular electron transfer from bacteria to anode electrode and increase the power generation.