白云石与方沸石对Sr2+的吸附行为研究

采用静态实验法研究了黏土岩的组成矿物白云石和方沸石对Sr²⁺的吸附行为，考察了时间、初始pH值、初始浓度、离子强度以及腐殖酸对吸附的影响，并利用XRD、FT-IR和SEM对材料进行了表征。结果表明：两种材料均能有效吸附Sr²⁺，初始pH值升高会促进吸附，离子强度增大会抑制两种材料对Sr²⁺的吸附；吸附均在6 d时达到平衡，吸附过程均符合准二级动力学模型，说明吸附均以化学吸附为主；随着Sr²⁺初始浓度的增加，白云石吸附Sr²⁺的吸附分配比呈先增加后降低的趋势，方沸石吸附Sr²⁺的吸附分配比不断降低；腐殖酸会抑制白云石吸附Sr²⁺，对方沸石吸附Sr²⁺的过程略有促进；Langmuir和Freundlich模型拟合结果显示，白云石吸附Sr²⁺的吸附机理较为复杂，而Sr²⁺在方沸石上的吸附过程为单分子层吸附。上述结果可为高放废物地质处置的选址工作提供基础数据和参考。

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.