Adsorption of Sr²⁺ on Dolomite and Analcime

The adsorption behavior and the effect of various experimental conditions on Sr²⁺ adsorption on dolomite and analcime were investigated respectively with batch sorption method, and XRD, FT-IR and SEM were carried out. The results show that dolomite and analcime can adsorb Sr²⁺ effectively, and the adsorption increases with the increase of initial pH and decreases with the increase of ionic strength. The adsorption equilibrium both are achieved after 6 d. The adsorption processes both are well described by pseudo-second-order kinetics model, which indicates that the adsorption processes may be chemical adsorption. As the increase of the initial concentration of Sr²⁺, the K_d of Sr²⁺ on dolomite increases first and then decreases, and the K_d of Sr²⁺ on analcime decreases. With the increase of humic acid, the K_d of Sr²⁺ on dolomite decreases, but the K_d of Sr²⁺ on analcime increases slightly. Langmuir and Freundlich isotherm model results show that the adsorption mechanism of Sr²⁺ on dolomite is relatively complex, and it is monolayer for analcime. The results can provide basic data and reference for the site selection of high level waste.