Performance of Microbial fuel cell as a post treatment unit of UASB reactor for distillery spent wash

Abstract

Post treatment of Up-flow anaerobic sludge blanket reactor (UASBR) effluents by a duel chambered Microbial fuel cell (MFC) was evaluated for high strength distillery spent wash. Bench scale UASBR (5 L capacity) and MFC (1 L capacity) with carbon electrodes having proton exchange membrane were used to elucidate the energy generation potential and substrate (COD) removal efficiency. Step by step, the influent COD concentration of UASB-MFC unit was increased. The MFC shows increasing trend of open circuit voltage, COD removal and substrate degradation rate with increase in influent COD concentration. The maximum COD removal (73.79%) and open circuit voltage (1.1 V) were achieved at 20600 mg/L of COD. At maximum COD concentration, MFC showed power density (maximum), substrate degradation rate and power yield as 61.61mW/m2, 1.086 kg COD/m3day and 0.041 W/kg CODR respectively. UASB-MFC combined unit gave maximum COD removal of 90%. The experimental data revealed the potential of MFC as feasible, economic (cost saving) and sustainable option.