Optimization of operating conditions for maximizing power generation and organic matter removal in microbial fuel cell

Abstract

The effect of influent chemical oxygen demand (COD), hydraulic retention time (HRT), and influent pH on COD removal efficiency and power generation was studied in a dual-chambered microbial fuel cell (MFC) having stainless-steel mesh electrodes and treating synthetic wastewater. Statistical models were formulated based on these three variables to predict the responses, namely COD removal efficiency and power generation, in MFC using a two-level full factorial design. It was observed from statistical analyses that all the three variables affected the COD removal efficiency, whereas proper combination of the operating variables was of utmost importance in enhancing power generation. Average influent COD concentration of 2200-2400 mg/L and HRT of 22-25 h was found to be optimum for achieving optimal COD removal efficiency and power. Validation of the model's predictions for treatment of synthetic wastewater revealed the efficacy of these models. Under optimal conditions when these MFCs were operated with a graphite plate cathode and using aerated distilled water and persulfate as cathodic electrolyte, respective volumetric power densities of 979 and 7,408 mW/m3 were observed. � 2016 American Society of Civil Engineers.