[1A10-15] Environmental Remediation

[1A10] Enhanced desorption of cesium from vermiculitized biotite by hydrothermal treatment with eluting cations

*Xiangbiao Yin¹, Hideharu Takahashi¹, Yusuke Inaba¹, Kenji Takeshita¹ (1. Tokyo Institute of Technology)

Keywords:Cesium desorption, hydrothermal treatment, volume reduction, ion exchange

The objectives of present study are to clarify how Cs fixation on vermiculite is influenced by structure change caused by Cs sorption at different loading levels and how Cs desorption is affected by various replacing cations induced at different treating temperature. As a result,after five cycles of treatment at 250℃ with 0.01M Mg²⁺, ~100% removal of saturated Cs was achieved. X-ray diffraction analysis results suggested that Cs desorption was completed through enhanced diffusion of Mg²⁺ cations into collapsed interlayer space under hydrothermal condition resulting in subsequent interlayer decollapse and readily release of Cs⁺. The results were expected to provide new insights to explore available decontamination technology for Fukushima Cs-contaminated soils.