Feasible decontamination of field soil - Decontaminate radioactive cesium with stable isotope cesium -

2021 Fiscal Year Final Research Report

• Project/Area Number: 17K00917
• Research Category: Grant-in-Aid for Scientific Research (C)
• Allocation Type: Multi-year Fund
• Section: 一般
• Research Field: Eating habits
• Research Institution: Shizuoka University
• Principal Investigator: YANAGA Makoto 静岡大学, 理学部, 准教授 (10246449)
• Project Period (FY): 2017-04-01 – 2022-03-31
• Keywords: 土壌除染 / 放射性セシウム / 原発事故 / 稲作 / カイワレダイコン

Outline of Final Research Achievements

Examination that the effect of addition of stable cesium on the transfer of radioactive cesium from paddy soil to rice using the soil of rice paddies of two areas in Fukushima city was performed. It was confirmed that the transfer factors of radioactive cesium for the brown rice cultivated with water including stable cesium ions were much larger than those for cultivated with water in which nothing had been added. This implies that the cesium ions added were replaced with radioactive cesium ions in soil.
The effect seemed to be strongly influenced by the difference of the soil ingredient. Another decontamination experiments were conducted on two types of soil contaminated with radioactive cesium, andosols and vermiculite, using an aqueous solution of potassium, rubidium or cesium. Rubidium ions contributed significantly to the removal of radioactive cesium from andosols, and did not cause plant growth disorders.

Free Research Field

核・放射化学

Academic Significance and Societal Importance of the Research Achievements

放射性セシウムにより汚染された土壌の除染が困難であることの大きな理由は、土壌中に含まれる粘土鉱物、バーミキュライトに取り込まれたセシウムを取り除くことが困難なことにある。本研究は、セシウム同士であるならばイオン半径が同じであることから同位体交換をする可能性を考えたものであることが大きな特徴である。また、黒ボク土からは、ルビジウムを用いることにより放射性セシウムを取り除くことができたことから、現実的な除染に近づくことができ、風評被害の低減化や除染廃棄物の減容化が期待される。