Long term operation of dual chamber microbial fuel cells for energy production and monitoring physicochemical changes of landfill leachate treatment

Abstract The present study investigates the efficiency of dual-chamber microbial fuel cells (DC-MFCs) in treating municipal landfill leachate at different concentrations (100%, 75%, 50% and 25%) during a 60-day batch operation. A DC-MFC with an anode volume of 1300 ml and a cathode of 650 ml, carbon cloth electrodes (8.5 cm diameter), and Nafion 117 membrane was analyzed with respect to physicochemical changes, energy recovery, and coulombic efficiency (CE). To accelerate the formation of the biofilm layer, the same initial leachate sample was grown in BHI culture medium and added to each MFC at a rate of 10% by volume. Key parameters, including pH, electrical conductivity (EC), alkalinity, chloride concentration, and chemical oxygen demand (COD), were monitored along with energy production through polarization curves. Blank samples were used as controls to confirm treatment efficacy. Results showed that the maximum COD removal efficiency was observed in reactors with concentrations of 100%, 75%, 50%, and 25%, achieving efficiencies of 99.32%, 99.28%, 98.75%, and 98.38%, respectively. The trends of EC, alkalinity, and chloride ion changes were similar and decreasing, while pH increased at all concentrations. The highest power density was achieved at 100% leachate concentration during days 33 to 46, when the voltage was constant (409.3 ± 3.5 V), and the power density was 16.75 ± 0.29 (128.85 ± 2.13) mW/m 2 (mW/m 3 ). The highest energy produced and CE were obtained for the reactor with 50% leachate, at rates of 3.26 ± 0.19 kWh/m 3 and 55.93%, respectively. DC-MFCs efficiently removed pollutants and produced energy from landfill leachate at different concentrations.