Electricity from food and bioindustry wastewaters using microbial fuel cells

Conversion of waste and renewable resources to energy using microbial fuel cells (MFCs) is an upcoming technology for a cleaner and sustainable environment. The potential for commercialization of this technology lies in the ability to extract the energy economically at high power outputs. This paper reports on removal of organic carbon present in a dairy wastewater with simultaneous production of electricity. The MFC anode biocatalyst was developed using an inoculum from a previous MFC enriched on model sugar and organic acid substrates. The tests were conducted using an air-cathode with Pt/C as the catalyst. The MFC was operated for several weeks to show long-term stability. Power densities greater than 600 mW/m² were obtained. Internal resistance of the MFC was assessed using electrochemical impedance spectroscopy showing limitations of the design and potential areas for improvement. Preliminary economics of this new green technology will be discussed identifying future research needs. This work demonstrates how the microbial fuel cell technology can be used to make maximum use of our resources.