Electricity and methane production from soybean edible oil refinery wastewater using microbial electrochemical systems

Abstract

High strength soybean edible oil refinery (SEOR) wastewater has been produced largely with the increase of global production of soybean edible oil over the last decade. This study describes that bioelectricity and biomethane production from SEOR wastewater using microbial fuel cells (MFCs) and microbial electrolysis cells (MECs). Different organic loading of SEOR wastewater influenced obviously power output and removal of chemical oxygen demand (COD) of MFCs. The maximum power density of ∼746 mW/m2 (∼24.1 W/m3) was obtained in MFCs with middle high organic loading of 2900 ± 100 mg/L COD. The maximum removals of COD were ∼96.4% and ∼95.8% for MFCs and MECs, respectively. The methane yield of 45.4 ± 1.1 L/kg-COD and production rate of 0.133 ± 0.005 m3/(m3 d) of MECs were higher than that obtained by conventional anaerobic digestion, indicating that microbial electrochemical system (MES) is a highly efficient technology for treating SEOR wastewater in a waste-to-energy form.