Performance of microbial fuel cell operating with clay-manihot starch composite proton exchange membrane using RSM

Abstract

This study optimized the performance of a microbial fuel cell (MFC) operating with raw clay sample (RCS)–manihot starch composite functioning as proton exchange membrane for electric power generation and bio-treatment of wastewater using central composite design (CCD) technique of the response surface methodology (RSM). The clay sample was heated at different temperatures ranging from 100 ​°C to 900 ​°C. The responses, power density and biochemical oxygen demand (BOD) removal efficiency were functions of four critical quantitative variables: pH, proton exchange membrane (PEM) preparation temperature (PPT), anolyte concentration and relative mass of clay in the PEM manihot-clay composite. A 24 CCD was employed to model and predict the process parameters. Sanitary wastewater of maximum cell density 4.25 ​× ​104/100 ​mL sustained the cell. Optimal responses of 82.4 ​mW/m2 power density and 72.3% BOD removal efficiency were recorded at clay PPT (RCS – 300 ​°C), 80 v/v wastewater to 10% glucose solution anolyte concentration, pH of 6.5 and clay component of PEM of mass 70 ​g optimum conditions. The study therefore suggests that RSM is an effective tool for evaluating and optimizing the Rsc-manihot composite PEM-MFC device for clean energy recovery and wastewater treatment, thereby providing the necessary leeway to overcoming the challenge of MFC scalability and greater performance.