Synergy of Electricity Generation and Waste Disposal in Solid-State Microbial Fuel Cell (MFC) of Cow Manure Composting

摘要

A small-scale, composting, microbial fuel cell (MFC) system was constructed that used cow manure asthe reduced carbon energy source. The system was a single-chamber, air-cathode MFC with a reactor,resistance box and data processing unit. Factors such as moisture content, concentration of phosphatebuffer solution (PBS), catalyst addition and electrode area were investigated. Moisture contents of-2 80%, 70% and 60% resulted in maximum power densities of 34939, 369 and 122 mW m ,respectively. A moisture content of greater than 80% is suitable for generation of current in the-2 composting MFC. Addition of 0.1 mg Pt cm catalyst resulted in 10-fold greater maximum powerdensity with an output voltage twice as great as that generated in the absence of the catalyst. Aconcentration of 100 mM PBS resulted in maximum power density and output voltage. The power perunit area of electrode was inversely proportional to surface area of the electrode. Quantification ofcarbon, hydrogen and nitrogen (CHN) content indicated enhanced degradation or organic compoundsin addition to production of the electric current. The diversity of the microbial community, asdetermined by denaturing gradient gel electrophoresis (DGGE) was directly proportional to content ofwater, but inversely proportional to concentration of PBS. The results of this study demonstrated thatthe composting MFC can be used to treat wastes while generating electric current.