Removal of ammonia nitrogen from wastewater using an aerobic cathode microbial fuel cell

A new system for removing ammonia nitrogen was developed, which integrated a microbial fuel cell (MFC) with an aerobic bioreactor. A three-chamber reactor consisted of an anode chamber, a middle chamber and a cathode chamber. The chambers were separated by an anion exchange membrane and a cation exchange membrane (CEM), respectively. Driven by the power generated by the MFC, NH4+ in the middle chamber could migrate through CEM into the cathode chamber. The migrated NH4+ further removed via biological denitrification in the cathode chamber. Up to 90.2% of total NH4+-N could be removed with an initial concentration of 100 mg/L in 98 h. Affecting factors were investigated on the removal efficiency including cathode surface area, electrode spacing, chemical oxygen demand concentration, dissolved oxygen concentration, and NH4+-N concentration. The system was characterized by simple configuration and high efficiency, and was successfully applied to the treatment of brewery wastewater.