Study on volume reduction of cesium contaminated soil by magnetic separation; Treatment of organic matter

Nishimoto, Yuki*; Horie, Hiroki*; Akiyama, Yoko*; Nishijima, Shigehiro*; Mitsui, Seiichiro  ; Umezawa, Katsuhiro ; Kato, Mitsugu; Okada, Takashi ; Sekiyama, Tomio*

By the accident of Fukushima Daiichi Nuclear Power Plant, a large amount of soil was contaminated by radioactive cesium. We developed a new physical treatment method using magnetic separation that can separate high-dose 2:1 type clay minerals from contaminated soil selectively. However, there is an issue that it is difficult to capture 2:1 type clay minerals efficiently, because clay minerals form aggregations with soil organic matter. Our previous study indicated that aggregates can be dispersed effectively by treatment of organic matter with KCO solution. The purpose of this study is to assess the effect of the organic matter treatment on efficiency improvement of magnetic separation for 2:1 type clay minerals. The result showed that the possibility of effective treatment method for the soil rich in organic matter like agricultural soil by combination of the pretreatment with KCO solution and magnetic separation.