Electrical and degradation characteristics of microbial fuel cell using biogas slurry as substrate

In order to improve the efficiency of biomass energy utilization and reduce the cost for wastewater treatment, an air-cathode membrane-free microbial fuel cell (MFC) was constructed by using carbon cloth as electrode and cattle biogas slurry as anode fed. MFC could use biogas slurry to produce electricity, and the highest output voltage was 330 mV, the internal resistance was 10 kΩ and maximum power density was 10.98 mW·m^-2. Insoluble substance in MFC was the main reason for low output voltage and power density. After running for 24 h, the degradation rate of COD, total nitrogen and total phosphorus reached 20.73%, 67.82% and 72.56%, respectively. Therefore, MFC as a new way to generate electricity is quite promising in energy conservation and emissions reduction.