New design of benthic microbial fuel cell for bioelectricity generation: Comparative study

Benthic microbial fuel cells (BMFCs) are the potential sources for energy generation in which the chemical energy stored in the bonds between organic and non-organic materials are turned into electricity using microorganisms as the catalysts. In this study, new anodic chamber is fabricated for BMFC. The environmental conditions similar to those of Caspian Sea water have been applied to an experimental setup. The output power density in the BMFC has been measured and evaluated using various electrodes including graphite plate (GP), carbon cloth (CC) and granular activated carbon (GAC) at various distances 10, 20 and 50 cm, in different current and time steps. Based on the obtained results, too close or too far distance between the electrodes leads to an increase in the internal resistance and reduces the performance of the cell. In this regard, the optimized distance for the electrodes has been found to be 20 cm. The maximum power density of the GAC electrode before using the anodic chamber was 92.85 mW/m² in current density of 324.67 mA/m². This value has reached 170.02 mW/m² and 422.02 mA/m² after deployment in the anodic chamber under the same environmental conditions, which indicates that the maximum power density experienced an approximately double increase compared to the previous state.