Application of a five level central composite design to optimize operating conditions for electricity generation in a microbial fuel cell

In this work, a five level central composite design (Box-Wilson design) was employed to optimize the operating conditions for the generation of electricity in a microbial fuel cell. The following three variables were studied: temperature, initial anodic compartment pH and salt bridge component concentrations (agar and KCl). The optimal voltage yield was 17.34% greater than that observed under basal conditions and was achieved with a temperature of 32 degrees C, constant pH of 7.0 and salt bridge component concentrations of agar: 8.0 g/100 ml and KCL: 2.9 g/100 ml. The maximum recorded voltage at an external resistance of 30 Omega was 861.27 mV. The current density was 2.16 mA/m(2), the power density was 1887.49 mW/m(2), and the columbic efficiency was 24.12%. (C) 2015 The Authors. Production and hosting by Elsevier B.V. on behalf of Taibah University.