Adsorption Property of Cesium onto Modified Macroporous Silica-Calix[4]arene-crown Based Supramolecular Recognition Materials

The adsorption behavior of Cs(I), one of the heat generators, in HNO3 medium was investigated at 298 K. The impact of U(VI), some typical elements, and temperature on the adsorption of Cs(I) was evaluated. It was performed by macroporous silica-based 1,3-[(2,4-diethylheptylethoxy)oxy]-2,4-crown-6-calix[4]arene (Calix[4]arene-R14) impregnated supramolecular recognition materials (Calix[4] + M)/SiO2-P. They were modified with tri-n-butyl phosphate (TBP), octanol (Oct), and methyloctyl-2-dimethylbutanemide (MODB). The excellent adsorption ability and high selectivity of (Calix[4] + M)/SiO2-P for Cs(I) except Rb(I) and U(VI) were confirmed. The adsorption ability of Cs(I) onto the modified supramolecular recognition materials was (Calix[4] + Oct)/SiO2-P > (Calix[4] + TBP)/SiO2-P > (Calix[4] + MODB)/SiO2-P. The chromatographic separation of Cs(I) from a 4.0 M HNO3 solution containing La(III), Sr(II), Ru(III), Cs(I), Rb(I), U(VI), Mo(VI), Zr(IV), Gd(III), and Pd(II) was carried out with a (Calix[4] + TBP)/SiO2-P packed column. Cs(I) was eluted effectively with water. The possibility and feasibility of effective partitioning of Cs(I) from highly active liquid waste by the (Calix[4] + M)/SiO2-P materials was evaluated.