Treatment of Aged Landfill Leachate by a Self-Sustained Microbial Fuel Cell-Microbial Electrolysis Cell System

Microbial fuel cells (MFCs) can supply power and drive reactions for microbial electrolysis cells (MECs) when they are connected in series. This study designed three different air-cathode single-chamber MfFC-MEC systems constructed with aged landfill leachate as the substrate to enhance energy recovery and pollutant removal efficiency. These systems were designated MFC (S-1), MFC-MEC (S-2) and MFC-MEC-MFC (S-3). Maximum voltage outputs of 146, 421, and 253 mV were obtained from the S-1, S-2 and S-3 systems, respectively. The removal efficiency of COD in the S-2 and S-3 systems was significantly enhanced compared to that of the Si system, and the removal rate of ammonia could reach more than 90%. In addition, the degradation of ammonia nitrogen in the S-1 and S-2 systems was consistent with fractal reaction kinetics, providing a theoretical basis for pollutant removal in the future. Therefore, it was demonstrated that the associated system could enhance the performance of electricity generation and thus could be applied to enrich wastewater treatment efficiency as a new and promising approach.