Anodic inoculum pre-treatment by extracts of Azadirachta indica leaves and Allium sativum peels for improved bioelectricity recovery from microbial fuel cell

Abstract The electrogenic bacterial consortia enrichment in the anodic chamber play a crucial role in determining the efficiency of microbial fuel cell (MFC). In order to use mix anaerobic culture enriched with active electrogenic species as inoculum, suppression of methanogens is important. This investigation focuses on potential of extracts of Azadirachta indica (Neem) leaves and Allium sativum (Garlic) peels in inhibiting activity of methanogenic microorganisms in the mixed anaerobic sludge. Specific methane yields of sludge treated with neem leaves extract, garlic peel extract and untreated sludge were found to be 0.068 ± 0.08 L CH4/g VSS.d, 0.073 ± 0.08 L CH4/g VSS.d, and 0.193 ± 0.08 L CH4/g VSS.d, respectively. However, the MFC operated with these pre-treated inoculums gave respective power densities of 5.6 W/m3, 5.0 W/m3, and 2.65 W/m3, respectively. Hence, it can be inferred that pre-treatment of mixed anaerobic sludge using neem leaves and garlic peels extract can be effective in enhancing power produced from MFCs.