Eu(Ⅲ)在白云石上的吸附行为  

Sorption Behavior of Eu(Ⅲ)on Dolomite

作　　者：张寒 贺含毅 刘军[1] 李洪辉[2] 赵帅维[2] 贾梅兰[2] 杨吉军[1] 刘宁[1] 廖家莉[1] 杨远友[1] ZHANG Han;HE Han-yi;LIU Jun;LI Hong-hui;ZHAO Shuai-wei;JIA Mei-lan;YANG Ji-jun;LIU Ning;LIAO Jia-li;YANG Yuan-you(Key Laboratory of Radiation Physics and Technology of the Ministry of Education,Institute of Nuclear Science and Technology,Sichuan University,Chengdu 610064,China;China Institute for Radiation Protection,Taiyuan 030006,China)

机构地区：[1]四川大学原子核科学技术研究所,辐射物理及技术教育部重点实验室,四川成都610064 [2]中国辐射防护研究院,山西太原030006

出　　处：《核化学与放射化学》2021年第5期418-425,I0005,共9页Journal of Nuclear and Radiochemistry

基　　金：国家自然科学基金资助项目(21876123)。

摘　　要：采用静态吸附法研究了Eu(Ⅲ)在塔木素粘土岩主要成分白云石上的吸附行为,探讨了时间、温度、pH值、离子强度、固液比、Eu(Ⅲ)初始浓度、腐殖酸等因素对吸附的影响。结果表明:Eu(Ⅲ)在白云石上的吸附强烈依赖于溶液pH值。当pH<7时,Eu(Ⅲ)的吸附率随溶液离子强度的增加而减小,表明Eu(Ⅲ)在白云石上的吸附以离子交换为主;当pH>7时,则以内层表面配位反应为主。腐殖酸的加入和温度的升高均会促进Eu(Ⅲ)的吸附,其吸附是一个自发吸热的过程,且较好地符合准二级动力学和Freundlich吸附模型,揭示该过程以化学吸附和非均相吸附为主。上述研究结果还表明白云石在塔木素粘土岩吸附Eu(Ⅲ)的过程中非主导作用,这更好地理解了白云石在塔木素粘土岩吸附Eu(Ⅲ)过程中的贡献,为我国高放废物地质处置库选址及安全性评价提供参考。The Eu(Ⅲ)sorption on dolomite was investigated by batch sorption experiments,and the influence of time,temperature,pH value,ionic strength,solid-to-liquid ratio,initial Eu(Ⅲ)concentration,humic acid and other factors on adsorption was researched.The results show that the sorption of Eu(Ⅲ)on dolomite is strongly dependent on the pH value of the solution.When pH<7,the Eu(Ⅲ)sorption decreases with increasing ionic strength of the solution,demonstrating that ion exchange is the main process under acidic condition.When pH>7,the inner-sphere surface complexation dominates the sorption process.Moreover,rising temperature,as well as the addition of humic acid,can promote the adsorption of Eu(Ⅲ),which is spontaneous endothermic process.The Eu(Ⅲ)sorption on dolomite can be well fitted by Pseudo-second-order model and Freundlich isotherm model,indicating a chemical and heterogeneous sorption.The results reported here are important in gaining a better understanding of the contribution of dolomite in the process of Eu(Ⅲ)sorption on Tamusu clay,with useful implications on the final site selection and safety evaluation of China high-level radioactive waste geological repository.

关 键 词：Eu(Ⅲ) 白云石 高离子强度 吸附行为 离子交换 

分 类 号：TL93[核科学技术—辐射防护及环境保护]