Electricity generation from retting wastewater consisting of recalcitrant compounds using continuous upflow microbial fuel cell

Recalcitrant compounds like phenol found in coconut husk retting effluent cause the deterioration of water quality when discharged from retting ponds into other water sources. Continuous upflow microbial fuel cell (MFC) was evaluated for treating retting wastewater at different loading rates to determine power generation, chemical oxygen demand (COD) consumption rate and phenol removal for a period of 270 days. A maximum power density of 254 mW/m² was achieved during the treatment of retting wastewater (external resistance — 350Ω). COD removal of 70% was accomplished at a loading rate of 0.45 g COD/L reactor/day and phenol removal of 95% was obtained at a loading rate of 0.28 g phenol/L reactor/day. The power density exhibited an increasing pattern as the loading rate of MFC was increased from 0.45 to 2.69 g COD/L reactor/day. This study describes the treatment of retting wastewater employing continuous upflow MFC with 95% phenol removal. Therefore, MFC can be considered as an alternative for the efficient removal of phenol and current generation in retting wastewater.