Farm-based microbial fuel cell system for continuous treatment of swine wastewater

摘要

Microbial fuel cells (MFCs) have long held the promise of being a cost-effective technology for the energy-neutral treatment of wastewater. However, successful pilot-scale demonstrations for this promising technology are still limited to very few. Here we present a large-scale MFC system with a total volume of 110 L successfully treating swine wastewater at a small educational farm. The system was operated for over 200 days in continuous mode with a hydraulic residence time of 4 hours (flow rate of 380 mL/min, 0.1 gal/min). The results indicate a very stable waste treatment performance with up to 65% of chemical oxygen demand (COD) removed and a maximum treatment rate of 5.0 kg-COD/m3.day. The electrochemical performance of the system shows that the power recovered from the microbial transformation of waste organics into electricity is not only competitive with conventional cogeneration processes, but in-fact sufficient to sustain the operational energy requirements of system.