Effects of Different Biological Carriers in Microbial Fuel Cells

In this study, to investigate their effects on battery power generation performance and wastewater treatment capacity, coal semicoke granular-activated carbon, granular graphite, and walnut shell-activated carbon were added to the anode compartment of a microbial fuel cell. As revealed from the experimental results, adding activated carbon and graphite can significantly decrease the startup time of microbial fuel cells as well as provide the shortest startup time of coal semicoke-activated carbon fluidized bed microbial fuel cells (MGAC-MFCs). The activated carbon particle diameter did not increase from 0.275 to 0.55 mm, and the voltage changed the chemical oxygen demand (COD) degradation efficiency. However, the 0.275 mm activated carbon exhibited a maximum open-circuit voltage of 935 mV as well as a COD degradation efficiency of 95%, and the operation cycle was shortened. After running a cycle, the COD removals of different systems were 85, 93, and 89%, and the maximum value was obtained by the MGAC-MFC system. After the activated carbon and graphite particles were added, the electrical performance and production capacity of the sewage treatment microbial fuel cells were significantly enhanced.