Earthen Pot-Plant Microbial Fuel Cell Powered by Vetiver for Bioelectricity Production and Wastewater Treatment

Novel earthen pot-plant microbial fuel cells (PMFCs) are constructed as a wastewater filtering and microelectrical power system. Its performance is investigated at different influent chemical oxygen demand (COD) strengths of 50 mgL(-1) (P-COD50), 250 mg L-1 (P-COD250), and 500 mg L-1 (P-COD500). Two reference reactors, one unplanted with 250 mg L-1 (UP-COD250) and another planted with tap water devoid of external supply of organic (P-COD0), are constructed to show the effects of plants in treatment ability and electricity generation. Maximum average current density is achieved in P-COD250, that is, 242 +/- 10.5 mA m(-2) followed by UP-COD250, P-COD50, P-COD500, and P-COD0. Polarization curves also depict a similar order for power density. Variations of power output in low and high concentrated units are accompanied with lower substrates for bacteria in the former while the latter is due to osmotic shock of plants at higher COD concentration. At the same influent concentration, planted reactors enhances current density by 12.5%. Organic removal ability is promising in all the reactors, reaching almost 99%. However, plants enhanced, on average, 3% in COD removal. High COD removal is achieved with higher retention time. Planted reactors shows more significant increments in current during daytime after feeding than unplanted reactors, suggesting the role of root exudates via photo-synthates in current generation. These results can help in further optimizing of PMFCs in terms of configuration and substrates.