EVALUATION OF THE ELECTRICAL PERFORMANCE OF A SOIL-TYPE MICROBIAL FUEL CELL TREATED WITH A SUBSTRATE AT DIFFERENT ELECTRODE SPACINGS

Abstract

The effect of electrode spacing on the performance of a microbial fuel cell (MFC) under batch treatment with a substrate was investigated with three single-chamber MFCs built with biologically active soil. The electrodes consisted of a stainless-steel mesh with layers of activated carbon catalyst. The MFCs were fed with artificial urine after reaching a stationary phase. After the initial treatment, the cell with the smallest electrode gap produced the maximum peak power under polarization. At 2 cm, 5 cm and 8 cm electrode spacing, the maximum power was 726.2 µW, 547 µW and 520.3, respectively; while the average power of the MFCs from the first point of treatment with the substrate to the last point was 297 + 259.2, 505.43+ 42.5 and 433.81+ 64, respectively. A significant decrease in the internal resistance of the MFCs was observed during batch treatment. The impedance analysis of the MFCs showed that the reduction in internal resistance was largely due to a significant decrease in ohmic resistance compared to the charge transfer resistance.