Reduction Test of Hydrogen Sulfide in Silty Sediment of Fukuyama Inner Harbor Using Steelmaking Slag

摘要

Fukuyama inner harbor is an inlet located in the city area of Fukuyama, Hiroshima, Japan, where the offensive odor of the hydrogen sulfide released from organically enriched, anoxic sediments has become a social issue. Since hydrogen sulfide is also highly toxic and reactive with oxygen, its presence may cause further oxygen depletion in the bottom waters and ultimately, the total decay of local aquatic ecosystems. To evaluate its effects on dissolved sulfide formed in the sediments, steelmaking slag was applied in two different experimental treatments, capping the sediments and mixing with the sediments. The results revealed that both uses of the steelmaking slag significantly suppressed hydrogen sulfide gas by reducing the dissolved sulfide in the sediment interstitial water. This was clearly much more effective than the results obtained by capping with natural stones that was conducted as a control method. The examination with a SEM-EDX suggested that iron sulfide may form on the slag surface after immersing in the sulfide-containing Fukuyama harbor sediments. It was concluded that applying steelmaking slag would be an effective method to suppress the annoying odor of hydrogen sulfide gas generated from the sediments of coastal areas due to its chemical reaction with sulfide ions.