Microbial Fuel Cell: Study of Bioresource Potential of Dairy Effluent and Associated Process Limitations

Abstract Microbial fuel cells (MFCs) are devices that exploit the electrochemically active microorganisms for the oxidative conversion of organic compounds into electricity. MFC technology is therefore expected to be a viable solution for domestic and industrial wastewater treatment as an alternative to the currently applied activated-sludge process. Despite its potential, the technology is facing application challenges because of high cost, low stability, and limited understanding of cell design and operation. In this experimental study, a double-chambered MFC with graphite electrodes and a proton-conducting membrane is used in a batch mode to study the potential of resource recovery from dairy effluent and identify the process limitations. Results showed a promising cell performance as the chemical oxygen demand of the wastewater reduced from 4520 mg/l to 850 mg/l in 10 days including the time required for biofilm development. The highest open-circuit voltage of 396 mV was recorded on the third day along with the highest power density of 36.39 mW/m 2 corresponding to a current density of 0.30 A/m 2 . Further, the electrochemical impedance spectroscopy revealed that the activation polarization of aerated cathode is the main contributor to cell internal resistance followed by the ohmic resistance.