Development of Radioactive Cs removal method from polluted soils by leaching with exchangeable cations contained organic acid solutions

Research Project

Project/Area Number	25660050
Research Category	Grant-in-Aid for Challenging Exploratory Research
Allocation Type	Multi-year Fund
Research Field	Plant nutrition/Soil science
Research Institution	Meiji University
Principal Investigator	HIROSHI Takesako 明治大学, 農学部, 教授 (20206965)
Co-Investigator(Kenkyū-buntansha)	OZAWA Kiyoshi 明治大学, 農学部, 教授 (40360391) FUJIWARA Shunrokuro 明治大学, 農学部, 教授 (80575473)
Project Period (FY)	2013-04-01 – 2015-03-31
Project Status	Completed (Fiscal Year 2014)
Budget Amount *help	¥3,900,000 (Direct Cost: ¥3,000,000、Indirect Cost: ¥900,000) Fiscal Year 2014: ¥1,430,000 (Direct Cost: ¥1,100,000、Indirect Cost: ¥330,000) Fiscal Year 2013: ¥2,470,000 (Direct Cost: ¥1,900,000、Indirect Cost: ¥570,000)
Keywords	土壌中放射性セシウム除去 / 含陽イオン有機酸 / 洗浄法 / 陽イオン含有有機酸 / 土壌有機物 / 放射性セシウム除去 / 粒度別137Cs分布
Outline of Final Research Achievements	Polluted soils with radioactive elements are widely distributed by the explosion of Fukushima No.1 NPS caused by the Tsunami attack at March 2011. 137Cs is a main marker of the radioactivity and it accumulated in surface; 5cm depth of the polluted soils. So, the official removal is cut off 5cm of the surface soils both of agriculture and around houses. The high contaminated cut off soils are packed in big plastic bags and pile up at near the removal places. We investigated effective removal method by dropping or saturated leaching with exchangeable cation contained organic acids under normal temperature by reason of low cost removal. Results (1)137Cs is strongly adsorbed on clay fraction and the adsorbed on clay is most difficult to remove. (2) Dropping leaching method is not effective to remove, and the best result of saturated leaching is about 15% removal. (3) The best result is about 35% removal by saturated (1:10) stirring and filtered after 3 times under normal temperature.