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: 8.0g/100ml and KCL: 2.9g/100ml. The maximum recorded voltage at an external resistance of 30Ω was 861.27mV. The current density was 2.16mA/m2, the power density was 1887.49mW/m2, and the columbic efficiency was 24.12%.