Slaughterhouse wastewater biotreatment associated with bioelectricity generation and nitrogen recovery in hybrid system of microbial fuel cell with aerobic and anoxic bioreactors

A novel integrated system consisted of microbial fuel cell, aerobic bioreactor, and anoxic bioreactor (MFC-AB-ANB) was designed and constructed to investigate its potential for the treatment of slaughterhouses wastewater associated with power generation and nitrogen recovery. A biocathodic tubular type MFC was used in this study and was inoculated with freshly collected activated sludge. The MFC-AB-ANB system was continuously operated for 163 days. The results revealed that maximum efficiencies of COD removal, ammonium oxidation, nitrate reduction, nitrogen recovery, Columbic efficiency, and power generation were 99%, 99.3%, 100%, 100%, 13.37% and 162.55 mW/m2, respectively. A mathematical model was developed based on Nernst–Monod model coupled with nitrification-denitrification model to predicate and describe the removal of COD, ammonium, and nitrate during continuous operation of the system. Significant agreement between the predicted and experimental results was observed for the removal of COD, ammonium, nitrate, and power generation with determination coefficients of 0.9750, 0.95675, 0.95499, and 0.89897, respectively.