Power Generation by and Microbial Community Structure in Microbial Fuel Cell Treating Animal Wastewater

Two identical air-cathode single-chamber microbial fuel cells (MFCs) were operated with two different types of animal wastewater. The result showed that the MFC with swine wastewater showed 831 mW·m-2 of power density, while that with dairy wastewater showed 59 mW·m-2. It was shown that the microbial community structures on anode of both reactors were different. The most dominant bacteria on the anode of the MFC with swine wastewater were relative to members of phylum Acidobacteria and that on the anode of the MFC with dairy wastewater were relative to members of phylum Proteobacteria. The dominant species on the anode were different from those of influent wastewater and from cathode microbes. In the MFC with swine wastewater, a large amount of precipitation was observed on the surface of the cathode. The main components of the precipitation were phosphorous and magnesium, and calcium was also contained.