Development of overlying water aeration system powered by sediment-microbial-fuel-cell for nutrient suppression

Sediment microbial fuel cells (SMFCs) represent a burgeoning technology that allows the remediation of sediments, such as nutrient suppression, while concurrently generating electricity. However, there is a limitation in that the nutrient suppression effect is restricted to a narrow range near the electrode. To address this issue, we developed an SMFC-aeration system, which intermittently aerates the overlying water with the power of SMFCs, thereby enhancing the nutrient suppression effect of SMFCs. The SMFC-aeration system achieved stable charge/discharge cycles through a capacitor-based circuit and aerated the overlying water. The dissolved NH₄⁺ and NO₂^- concentrations in the overlying water decreased. Suppression in the dissolved NH₄⁺ concentration near the anodes was also noticed compared to a consortium that employed only SMFCs. These findings were brought about by the synergistic effect of the SMFC-aeration system, which enabled the remediation of sediments and overlying water. To our knowledge, this is the first report on the intermittent operation of pumps by SMFCs, the increase of DO, and nutrient suppression. The SMFC-aeration system holds great potential as an environmental remediation method in closed-water areas in the future.