2022 年 13 巻 1 号 p. 118-123
Microbial fuel cell technology (MFCT) provides many benefits to rural regions, such as organic waste disposal and renewable energy recovery. However, its performance is low and must be improved for practical uses. Mixing steelmaking slag (SS) and lactic acid bacteria (LAB) with sediment can enhance the MFCT performance owing to LAB and iron ions dissolved from SS attaching to the electrode surface. This study proposes a simple method for attaching LAB and iron ions on carbon fiber electrode and subsequently evaluating its performance. A carbon fiber electrode was placed in a bottle containing tap water, SS, LAB, and bamboo powder (as nutrients for bacteria) for 7 days to allow LAB and iron ions to adhere to its surface. The electrode was then used as the cathode of MFCT. Results showed a decrease in the electrode potential and a consequent reduction in MFCT performance owing to the attached LAB and iron ions. The performance improved after the electrode was oxidized, suggesting that aeration is required during attachment to prevent the decrease in electrode potential. After 1 month of electricity generation, the electrode with the attachment produced high electrical current and exhibited low decrease in MFCT performance owing to electricity generation. Therefore, attaching LAB and iron ions on the electrode surface can improve the electrode performance and prevent performance degradation owing to electricity generation.
