Earthen pot fuel cells
doi:10.1038/nindia.2010.116 Published online 19 August 2010
Researchers have devised a new microbial fuel cell (MFC) using an earthen pot that treats rice mill wastewaters while simultaneously generating electricity. Their earthen-pot-based MFC is a low-cost option that performs better than expensive polymer-based MFCs.
The earthen pot functioned as a proton exchange membrane for the MFC, with its efficacy being comparable to two equivalent nafion-based MFCs.
Apart from the efficient removal of organic matter, the earthen pot MFC showed higher removal levels of lignin and phenol (two other principal constituents of rice mill wastewaters) than MFCs with a nafion-based proton exchange membrane.
The earthen pot MFC also generated more power than nafion-based MFCs; the surface of the earthen pot MFC provides a larger area for proton transfer, which contributes towards its higher power generation. The total production cost of a single earthen pot MFC used in this study was less than fifty rupees.
"The earthen pot MFC can be used for simultaneously treating wastewater while recovering energy directly in the form of electricity for powering on-site, low-power devices," says lead researcher M. M. Ghangrekar. On a commercial level, individual homeowners, group housing schemes and industries generating organic wastewater will be those most likely to benefit from this technology, he adds.