Journal de la technologie microbienne et biochimique

Abstrait

Kinetic Studies and Simulation of Microbial Fuel Cells Voltage from Clostridium Spp. and Proteus

Mbugua JK, Mbui DN, Waswa AG, Mwaniki JM

Microbial Fuel Cells (MFC) can be employed in bio-remediation of organic pollutants. In In this study, MFC voltage generated from various fruit market wastes using Clostridium spp., Proteus spp. and rumen fluid microbes was fitted into linear, logistic and Gompertz growth models. The dual chamber MFC was constructed using 1.0 liters plastic containers. NaCl in 3% agarose based salt bridge was used to connect the two chambers while graphite rods and copper wires were used as electrodes. The study was done by inoculating microbes present in about 250 mL cow dung mixed with 250 mL water and 500 g of homogenized fruit wastes and market wastes respectively, then current/ voltage generated measured for 24 days. The control experiment had 250 mL cow dung spiked with water to 1000 mL. From this study, microscopic and biochemical studies of the cultures confirmed that Proteus and Clostridium spp. were found in the anodic compartment of MFC. The rumen fluid inoculate registered the highest current (0.074 mA) explained by a higher microbe’s population resulting in a higher substrate breakdown rate. Low voltage was recorded in a mixed culture of Clostridium spp. and Proteus ssp. compared to pure cultures. The Gompertz equation growth model was applicable, with regression values of 0.967 compared to 0.922 obtained in linear data fitting. The same was well reflected by the simulating growth model of Clostridium spp. In both cases, the voltage generated from the pure cultures could not be explained linearly due to low R² of 0.911 and 0.962 for Clostridium spp and Proteus respectively compared to 0.96 and 0.98 for the Gompertz equation fitting.