Cathodes of membrane and packed manganese dioxide/titanium dioxide/graphitic carbon nitride/granular activated carbon promoted treatment of coking wastewater in microbial fuel cell.

Abstract A more practical microbial fuel cell system with both catalytic cathode membrane and packed cathode of modified granular activated carbon with manganese dioxide/titanium dioxide/graphitic carbon nitride/(MnO2/TiO2/g-C3N4/GAC) was tested in treating high COD coking wastewater (> 3000 or > 6000 mg L-1). The decreased system internal resistance promoted treatment efficiency and electricity generation. With microbes acclimated, the system achieved both high removals of COD and NH4±-N (> 96%), decreased UV254 from 23.80-34.50 cm-1 in influent to 1.11-1.42 cm-1 in effluent. The capacity in COD removal reached 3.07 kg COD m-3d-1 and the maximum power density was 1680 mW m-3 much higher than those without the packed cathode. This system is feasible for sustainable treatment of coking wastewater.