Evaluation of microscopic changes and binding in the adsorption reaction of Cs on clay minerals: a systematic investigation over a wide adsorption concentration range

Abstract

Clay minerals control the environmental behaviors of various elements because they are widely distributed in the Earth's surface layer and adsorb many cations. One such element is radioactive cesium (Cs) released from the Fukushima Daiichi Nuclear Power Plant accident, which was fixed in the soil surface layer due to its strong adsorption on clay minerals. However, the details of the adsorption reaction of clay minerals remain unclear due to the complex structure.In this study, we focused on the fact that the adsorption site changes with the concentration of Cs adsorbed on clay minerals, aiming to systematically clarify the microstructural changes and Cs binding properties over a wide range of adsorption concentrations through a combination of experiments and simulations. The results showed that the adsorption structure changes with increasing Cs concentration and that Cs forms ionic bonds regardless of these changes.