2025-07-11 日本原子力研究開発機構
＜関連情報＞
- https://www.jaea.go.jp/02/press2025/p25071103/
- https://www.sciencedirect.com/science/article/abs/pii/S0301479725020365
真空中での迅速なイオン交換による効率的な土壌汚染除去 Efficient soil decontamination via rapid ion exchange in vacuum
Iwao Shimoyama, Yuji Baba
Journal of Environmental Management Available online: 19 June 2025
DOI:https://doi.org/10.1016/j.jenvman.2025.126060
Highlights
- Heat treatment in vacuum was applied to radio-Cs contaminated soil from Fukushima.
- Decontamination ratio exceeded 90 % at approximately 1100 K.
- Heat treatment with NaCl in vacuum facilitated rapid ion exchange in clay minerals.
Abstract
Soil from Fukushima contaminated with radioactive Cs was effectively decontaminated through heat treatment with NaCl under vacuum. Although the decontamination ratio was about 10% after heat treatment at 1073 K in atmospheric conditions, the decontamination ratio reached over 90% after heat treatment at 1073 K under vacuum. Under atmospheric conditions, NaCl induced phase transformation in clay minerals, whereas under vacuum, decontamination progressed through rapid ion exchange in clay minerals. It was revealed that rapid ion exchange in vacuum is facilitated by the sublimation of NaCl and the expansion of interlayer spacing during heating. Differences in interlayer spacing during heat treatment under atmospheric and vacuum conditions were explained by deprotonation and the resulting changes in layer charge. The novel phenomenon we discovered is a promising solution for the decontamination of soil contaminated with radioactive Cs.
