Application of microbial fuel cell in wastewater treatment system by using algae as the oxygen supplier in cathodic chamber

A microbial fuel cell inoculated with activated sludge of a wastewater treatment plant was constructed. Oxygen was provided by algal photosynthesis in the cathodic chamber and the electricity generation characteristics of the fuel cell were then investigated. Results showed that binary quadratic equations can express the relationships between COD degradation rate and COD loading and between COD removal rate and COD loading in the cell. The relationships between power output and COD removal rate and between power output and COD loading rate can also be expressed as binary quadratic equations. The optimum COD loading rate for the fuel cell to obtain higher power density and higher Coulombic efficiency is about 2.0 kg/m
³
/day (with a external resistance of 1000 Ω).