Electrical analysis of compost solid phase microbial fuel cell

Solid phase microbial fuel cells (SPMFCs) utilize the mechanism of soil compost fermentation to generate electricity from waste recycle. However, the issue of a long composting process time appeared should be noted. In this study agricultural waste would be utilized as the substrates of SPMFCs to find the optimal ratio of the organic substances (C/N) contained within the compost for a better power performance. Experimental results show that, when the ratio of bean residue: ground coffee waste: rice hull is 1:1:1, the optimal C/N ratio of 31:1 has the most appropriate nutrients required by the microbial and its power performance is also more stable. In addition, the power density achieved is approximately 8.5 times that of SPMFCs without the addition of bio-enzymes. On top of that, a better power density of 264 mW/m2, limit current density of 1535 mA/m2 and shorting the period of compost process could be achieved.