PERFORMANCE OF A SINGLE CHAMBER SOIL MICROBIAL FUEL CELL ACROSS VARIED EXTERNAL LOADS FOR POWER GENERATION.

Abstract

The soil is beginning to receive attention as suitable inoculturns for Microbial Fuel Cells (MFC) designed for remediation and for electricity generation because of its high microbial load. However, not much has been done in wis aspect beyond laboratory based experiment. This study is aimed at generating electricity from agricultural soil . utilizing the microorganisms already present and the soil mutrients as the sole substrates and to investigate the performance of the soil Microbial Fuel Cell (MFC) across varied external loads. The study used the mud warr MFC Vi inoculared with mud prepared from topsoil, collected from a garden where crops have been cultivated over the pears . The electrodes (anode and cathode 7cm diameter each), made of carbon felr material with conducting wires wade of graphite, were housed in the same chamber and placed 4 cm apart. Voltage drop across seven external resistances 4670 , 2/90, 1000, 4700, 2200, 100 and 470, were measured every 24 hours, with a digital witi-meter, for 40 days. The maximum open circuit voltage from this study was 737 m whereas the maximum power density was 65.40 mW/m ar a current density of 190.7 mm. The optimum performance of the MFC was achieved with the 470 Q which is an indication that the internal resistance of the soil MFC of his present study is close to 470 A. This study revealed thar MFC, constructed from agricultural ropsoil are capable of producing electrical power continuously, across different external loads, without addition of any substrate.