Power generation from unconditioned industrial wastewaters using commercial membranes-based microbial fuel cells

The use of commercially available cation and anion exchange membranes to generate power from industrial wastewater obtained from three different industries (food, alcohol and dairy factories) without the addition of external microorganisms or chemicals by using microbial fuel cells (MFCs) was investigated. The results indicate that the original mixed culture of microorganisms presented in wastewater can act as an effective bio-anode. Overall, the tested wastewaters show a good tendency for power generation in both cation- and anion- based MFCs. However, when compared to anion membranes, cation membranes exhibit a distinctly higher performance for all tested wastewaters. Cation membrane-based MFCs generate 1007 mWm^-3 of power from food, 627 mWm^-3 from alcohol, and 507 mWm^-3 from dairy wastewaters while anion membranes generate 190.5, 164, and 38 mWm^-3, respectively. COD analyses and Coulombic efficiency measurements indicate that more organic pollutants are removed and higher efficiency is achieved by using cation membrane-MFCs rather than anion ones. SEM images of the anodes confirmed the formation of active bio-anodes with attached microorganisms, and FT-IR analyses reveal that the anion membranes are slightly affected by the wastewaters, especially by dairy wastewaters while the cation membranes exhibit a comparatively higher stability.