本文主要以放射性核素在氧化物、磷酸盐和黏土矿物表面上吸附研究为例,概括了放射性核素在固液界面上吸附行为研究的系统方法。主要分为以下7个步骤进行介绍:(1)吸附剂结构、形貌、拓扑性质的表征;(2)吸附剂表面电荷性质表征;(3)表面质子化和去质子化反应的平衡常数;(4)pH、离子强度、吸附质浓度和天然有机质等对放射性核素在固液界面吸附影响;(5)放射性核索在固液界面上的微观形态和空间结构等信息;(6)利用表面配位模型探讨放射性核素在固液界面的吸附机理;(7)采用先进光谱表征技术和量子计算技术对所得吸附机理进行分子或原子水平上的论证。
In this paper, the sorption of radionuclides on oxides, phosphates and clay minerals has been reviewed to clarify the different steps necessary to obtain reliable sorption data and tried to describe the usefulness of structural investigation at molecular level. The presentation mainly includes the following sections: (1) physicochemical characterization of sorbent~s structure and morphology; (2) the surface charge density of sorbent in aqueous solution; (3) the equilibrium constants of protonation and deprotonation on the sorbent~s surface; (4) the influences of pH, ionic strength and organic matters on the sorption behaviors of radionuclides~ (5) the speciation and structure of radionuclides at solid-water interface; (6) surface complexation model and its application in evaluating the sorption mechanism of radionuclides; (7) the proofs from advanced spectroscopy technologies in this field.