Bioelectricity production from food waste leachate using microbial fuel cells: Effect of NaCl and pH

Microbial fuel cells are a promising technology for simultaneous treatment and energy recovery from food waste leachate. This study evaluates the effects of NaCl (0–150 mM) and pH on the treatment of food waste leachate using microbial fuel cells. The food waste leachate amended with 100 mM NaCl enabled the highest maximum power density (1000 mW/m3) and lowest internal resistance (371 Ω). Increasing the anodic pH gradually from acidic to alkaline conditions (pH 4–9) resulted in a gradual increase in maximum power density to 9956 mW/m3 and decrease in internal cell resistance to 35.3 Ω. The coulombic efficiency obtained under acidic conditions was only 17.8%, but increased significantly to 60.0% and 63.4% in the neutral and alkaline pH’s MFCs, respectively. Maintaining a narrow pH window (6.3–7.6) was essential for efficient bioelectricity production and COD removal using microbial fuel cells for the treatment of food waste leachate.