叶腊石对水溶液中铀的吸附研究

Sorption of uranium from aqueous solution with pyrophyllite

开展铀吸附研究,特别是铀在黏土矿物上的吸附行为研究,对处置库安全评价十分必要.叶腊石是自然界常见的黏土矿物,但是对叶腊石和铀相互作用的研究还较少.本文采用批式实验的方法研究了pH、离子强度等对铀在叶腊石上吸附行为的影响,还探讨了该吸附反应的热力学和动力学特性.结果表明,铀在叶腊石上的吸附受pH影响较大,受离子强度影响较小.铀在叶腊石上的吸附过程符合准二级动力学方程,Freundlich模型可以更好地拟合铀在叶腊石上的吸附行为.叶腊石吸附铀是一个自发进行的吸热反应.

The research about uranium sorption, especially sorption on clays, is necessary for the safety assessment of repository. Pyrophyllite is a kind of common clay, but the study about interaction between uranium and pyrophyllite is still rare. In this paper, we investigated how p H, solid-liquid radio and ion concentration influenced the sorption efficiency of uranium on pyrophyllite with batch experiments and studied the thermodynamic and dynamic laws of the sorption. The results showed that the sorption was strongly p H-dependent and ion concentration had little impact on sorption. The sorption process can be described by a pseudo-second-order rate model. Freundlich model fitted the sorption data better than Langmiur model. The sorption of pyrophyllite to uranium was a spontaneous and endothermic reaction.