Bioelectricity generation in a microbial fuel cell: Study of two proton exchange membrane diameter

Dual chamber Microbial Fuel Cell (MFC) with saline catholyte was used in this laboratory scale study on the effect of Proton exchange membrane (PEM) diameter on energy output. Two different agar-agar salt-bridges PEM of diameters 1/2inch and 1inch were used in a plastic Microbial fuel cell unit with electrodes manufactured to the same dimensions (area of 1.33×10 -2 m 2 ). Brewery waste water was used as the substrate, with its microorganism as the biocatalyst. The cells were operated at room temperature and pH of 7.0±0.3. The cells were operated for 21days while the performance was monitored every three days. The set-up of 1/2inch PEM produced the maximum voltage of 47mV between the 13 th and the 15 th day while the MFC units with a 1inch PEM produce maximum voltage of 57mV between the 19 th and the 21day. The over potential in the MFC with 1inch was reduced with large proton transfer space giving the unit a better performance.