Microbial fuel cells for wastewater treatment

In the recent years the power densities of Microbial Fuel Cells (MFCs) have increased by orders of magnitude upon decreasing the internal ohmic resistance of the system. With the ohmic resistance of the MFC systems no longer a dominant issue, identification of other intrinsic resistances is the need of the hour. Electrochemical impedance spectroscopy (ElS) was used to study the impedance behavior of a microbial fuel cell (MFC) during initial biofilm growth in an acetate-fed, two-chamber MFC system with ferricyanide in the cathode using mixed culture of bacteria obtained from activated sludge as the bio-catalyst. Results showed that the kinetics of anode bio-electrochemical reactions were sluggish, thereby contributing to the majority of the polarization loss, Also the anode charge transfer resistance was found to vary during the initial biofilm growth indicating a direct correlation between the microbial processes and the system performance.