Yamamoto Takahiro, Takigawa Tomoaki, Fujimura Takuya, Shimada Tetsuya, Ishida Tamao, Inoue Haruo, Takagi Shinsuke
Japan Atomic Energy Agency, 765-1 Funaishikawa, Tokai-mura, Naka-gun, Ibaraki 319-1184, Japan.
Phys Chem Chem Phys. 2019 May 8;21(18):9352-9356. doi: 10.1039/c9cp00457b.
How can radioactive Cs+ ions be removed from aqueous solution? From this perspective, the adsorption of Cs+ was investigated by using five types of clay minerals possessing different charge exchange capacities. The fixation ability for Cs+ depended on the charge exchange capacity of the clay minerals. Phlogopite and vermiculite, where the number of charges is almost equal to half the number of siloxane ditrigonal cavities in the structure, exhibited a strong Cs+ fixation ability among these clay minerals. In these clay minerals, effective interlayer collapse, which leads to quasi-irreversible adsorption of Cs+, is expected from the introduction of Cs+ into the layer space. This is named the "cavity-charge matching effect". This study clarifies why only phlogopite and vermiculite can fix Cs+ quite strongly among various types of clay minerals. These findings are beneficial for removing radioactive Cs+ ions from the environment using clay minerals through the cavity-charge matching effect.
如何从水溶液中去除放射性铯离子？从这个角度出发，利用五种具有不同电荷交换容量的粘土矿物对铯离子的吸附进行了研究。铯离子的固定能力取决于粘土矿物的电荷交换容量。金云母和蛭石，其电荷数几乎等于结构中硅氧烷双三角穴数量的一半，在这些粘土矿物中表现出很强的铯离子固定能力。在这些粘土矿物中，通过将铯离子引入层间空间，有望实现有效的层间塌陷，从而导致铯离子的准不可逆吸附。这被称为“穴-电荷匹配效应”。本研究阐明了为什么在各种类型的粘土矿物中只有金云母和蛭石能非常强烈地固定铯离子。这些发现对于利用粘土矿物通过穴-电荷匹配效应从环境中去除放射性铯离子是有益的。
