2020 年 11 巻 2 号 p. 1-6
Sediment microbial fuel cells (SMFCs) have received considerable attention for remediating sediment and wastewater while providing electricity. This technology offers many benefits for rural regions, particularly for those in developing counties. SMFCs can treat agricultural wastewater, household sewage, and organic waste while providing electricity to households. However, the performance of SMFCs remains low and must be improved. It has reported that mixing steelmaking slag (SS) with littoral sediment improves SMFC performance. The present study examines the use of SS to potentially improve the performance of a SMFC that uses paddy soil as its fuel (PS-SMFC). Moreover, we examine changes in the performance of a SS-SMFC (the PS-SMFC that the anode chamber is filled with SS) that uses lactic acid bacteria (LAB) and BN strain of Bacillus subtilis (BNB) solution-mixed paddy soil as its fuel. In laboratory experiments, paddy soil was poured into the SS layer (the anode chamber) of a SS-SMFC. LAB or BNB were added to the SS-SMFC anode by mixing a bacteria solution with the paddy soil. The SMFC performance was evaluated by measuring the polarization (current–voltage relation) and power density. The power density of the SS-SMFC was observed to be 152 mW.m−2, which is approximately twice than that observed without using SS (80 mW.m−2, as reported in previous studies). This shows that the performance of a paddy soil-used SMFC increases after mixing SS with the paddy soil. Furthermore, the SS-SMFC power density increased from 66 to 191 mW.m−2 after adding BNB and to 247 mW.m−2 after adding LAB. Thus, adding LAB or BNB to paddy soil is shown to improve SMFC performance. In comparison with BNB, LAB has greater potential for increasing SMFC performance.
