Remediation of Sediment Deposited near Sewage Outlet with Solar Cell-Combined Sediment Microbial Fuel Cells

It has been reported that solar cell-combined sediment microbial fuel cell (SC-SMFC) can be an alternative option for remediating sediment. Near a sewage outlet, huge amount of sediment accumulation causes many environmental problems, such as malodor and the restriction of benthos inhabitation. This study aims to employ SC-SMFC for remediating sediment deposited near a sewage outlet. Particularly, we aim to determine the remediation range of sediment from the anode of SC-SMFC. SC-SMFC was applied into the sediment deposited on the riverbank of a tidal river, and the distribution of sediment quality from the anode was examined at 14 weeks after the employment of SC-SMFC. Decreases in hydrogen sulfide, phosphate, manganese, and ammonium ion concentrations were found, indicating the sediment remediation owing the SC-SMFC application. A larger decrease in each ion concentration was found near the anode. From the ion distributions, the sediment located between 0 and 1 m from the anode was strongly influenced by the SC-SMFC application, which was approximately 6.7-fold longer than that obtained from the laboratory experiment. At in-situ, water current that can transport substances to the anode and the biodiversity of microorganisms that can produce much of electrons may partly contribute to the increasing SC-SMFC performance, leading to the long range of sediment remediation. Furthermore, it is newly found out that ammonium and manganese ions are efficiently removed from sediment via the anode oxidation during the SC-SMFC application. KeywordsSolar Cell; Sediment Microbial Fuel Cell; Sediment Quality; Remediation Range; Hydrogen Sulfide, Ammonium