Abstract
Natural clay mineral, allophane, was tried to be used for removal of cesium ion from aqueous solution. The removal performance of allophane was evaluated by atomic absorption spectrometry in batch test and flow test compared to that of the other clay minerals, such as zeolite, montmorillonite, and kaolinite. The adsorption ability of the allophane for cesium ion was significantly lower than that of zeolite due to its lower cation exchange capacity. On the other hand, water quickly passed though the funnel filled with allophane compared to the other clay minerals. Allophane has somewhat adsorption ability for cesium ion and appropriate water-permeability. The allophane can be an excellent adsorbent when it is appropriately filled in the funnel or column. Furthermore, elusion of cesium ion from the allophane to water was inhibited when the allophane absorbing cesium ion was dispersed in silica gel by the sol-gel method. The same effect was observed for ion of lead used for radiation shielding. This can be a first step toward the development of the disposal of radioactive wastes.
