Effective separation of cesium with a new silica-calix[4]biscrown material by extraction chromatography

Abstract To separate Cs(I), a new silica-calix[4]biscrown hybrid material, 1,3-calix[4]arene-bis(naph-crown-6) (CalixBNaphC)@SiO 2 -P, was synthesized by impregnation in situ and immobilization of agent into the pores of the SiO 2 -P particles. The materials were characterized by SEM images, FT-IR spectra, nitrogen adsorption-desorption isotherms and 29 Si solid-state CP/MAS NMR. The adsorption of Cs(I) and some typical metals onto CalixBNaphC@SiO 2 -P was investigated by examining the effect of contact time and HNO 3 concentration in the range of 0.4–6.0 M. Enrichment and recovery of Cs(I) in batch experiments were performed by six adsorption and desorption cycles. The removal of Cs(I) was more than 99.1%. Based on the batch results, the chromatographic separation of Cs(I) from 3.0 M HNO 3 was conducted by CalixBNaphC@SiO 2 -P packed column. The effective separation of Cs(I) was achieved utilizing 3.0 M HNO 3 and water as eluents. A new process entitled PCEC ( P artitioning of C esium by E xtraction C hromatography) for individual separation of Cs(I) was developed.