A microbial fuel cell system with manganese dioxide/titanium dioxide/graphitic carbon nitride coated granular activated carbon cathode successfully treated organic acids industrial wastewater with residual nitric acid

To meet the urgent demands for sustainable and efficient, environmental-friendly wastewater treatment, a Microbial fuel cell reactor system with MnO2/TiO2/g-C3N4 (manganese dioxide/ titanium dioxide/graphitic carbon nitride) @GAC (granular activated carbon) electrode was developed. It was both efficient and energy-saving in treating organic acid wastewater generated in Nylon production, with high-concentration COD and residual nitric acid. The MnO2/TiO2/g-C3N4 catalyst was deposited on GAC via in-situ growth and sol-gel method. The COD, NH4+-N and NO3-N was efficiently removed (respectively 98%, 99% and 99%). The COD removal capacity (17.77 kg COD m(-3)d(-1)) and the maximum power density (1176.47 mW m(-3)) was respectively 36.83% and 65.29% higher than the GAC cathode system. The anodic and cathodic microbial consortiums in MFC were analyzed and compared. The MnO2/TiO2/g-C3N4@GAC MFC system is technically feasible and cost-effective in treating industrial wastewater.