Investigation of environmental behavior of multiple ions based on systematic understanding of adsorption reaction on clay minerals

Yamaguchi, Akiko  

The adsorption reaction on clay minerals is an important chemical reaction that controls the environmental behaviors of various ions at the Earth's surface, but the details are unknown due to the complexity of the reaction, such as the diversity of clay mineral compositions and the existence of multiple adsorption sites. In this study, we focused on the adsorption structure on clay minerals at the atomic level, and clarified it in detail by combining X-ray absorption fine structure (XAFS) methods and first-principles calculations. In particular, XAFS measurements of radium, which has the largest ionic radius among alkaline earth metals and has been difficult to measure at the atomic level, were successfully performed, and new knowledge was obtained by comparing the results with those of other elements.