In situ production of hydrogen peroxide in a microbial fuel cell for recalcitrant wastewater treatment

BACKGROUND Microbial fuel cells (MFCs) offer a sustainable and energy efficient solution for in situ hydrogen peroxide (H2O2) production with simultaneous power generation. In MFCs, H2O2 is produced as a result of two-electron oxygen reduction at graphite cathode surface. However, due to poor catalytic properties of graphite cathode high yields of H2O2 are not attained. Therefore, this study investigates the feasibility of in situ H2O2 production in MFC for recalcitrant wastewater treatment. METHODOLOGY AND RESULTS In this study, a dual chamber MFC was used. A heat-treated graphite electrode was used as cathode and Nafion-117 as membrane. Cyclic voltammetric analysis was also performed to study the potential of heat-treated graphite cathode for H2O2 production. Experimentally, a maximum of 140 mg L−1 of H2O2 was produced with simultaneous power generation of 33.52 W m−3. Consequently, in situ Fenton oxidation experiments were performed and compared with conventional Fenton oxidation using a recalcitrant pollutant i.e. Acid Blue 113 dye. On average, 24% difference between the performance of the Fenton and in situ Fenton oxidation was observed while 42% reduction in the cost of process was obtained in the case of the in situ Fenton oxidation process. CONCLUSION The current study proved that MFC is a sustainable solution for in situ Fenton oxidation (followed by H2O2 production) with less requirement of H2O2. © 2017 Society of Chemical Industry