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 °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 Ω was 861.27 mV. The current density was 2.16 mA/m2, the power density was 1887.49 mW/m2, and the columbic efficiency was 24.12%.