高岭土负载钛酸钙复合材料对放射性废水中U(Ⅵ)的吸附性能与机理  

Adsorption Performance and Mechanism of Kaolin Loaded Calcium Titanate for U(Ⅵ) in Radioactive Wastewater

作　　者：李冠超 孙功明 钟丽艳 李小燕[2] 毕明亮 LI Guan-chao;SUN Gong-ming;ZHONG Li-yan;LI Xiao-yan;BI Ming-liang(Radiation Environment Monitoring Center of Guangdong Province Nuclear Industry Geological Bureau,Guangzhou 510800,China;State Key Laboratory of Nuclear Resources and Environment,East China University of Technology,Nanchang 330013,China)

机构地区：[1]广东省核工业地质局辐射环境监测中心,广州510800 [2]东华理工大学核资源与环境国家重点实验室,南昌330013

出　　处：《有色金属（冶炼部分）》2022年第12期109-115,123,共8页Nonferrous Metals（Extractive Metallurgy)

基　　金：国家自然科学基金资助项目(41761090)。

摘　　要：利用一锅法制备了高岭土负载钛酸钙复合材料,研究了其对放射性废水中的U(Ⅵ)的吸附性能和机理。探讨了反应温度、U(Ⅵ)初始浓度、接触时间、固液比等对其吸附废水中U(Ⅵ)的影响,并进行了吸附动力学、热力学和等温吸附分析。结果表明,高岭土负载钛酸钙复合材料对废水中U(Ⅵ)有较好的吸附效果。当溶液pH=3.5、固液比0.4 g/L、反应时间60 min、反应温度25℃时,U(Ⅵ)的去除率达到最大值94.7%,最大吸附量为197.6 mg/g。高岭土负载钛酸钙吸附U(Ⅵ)的过程是一个自发且不可逆的吸热反应过程,符合准二级动力学模型和Freundlich等温吸附模型,表明其对U(Ⅵ)的吸附是物理吸附和化学吸附并存,以非均匀吸附为主的过程。Kaolin loaded calcium titanate(KCT) was prepared, and adsorption performance and mechanism of KTC for U(Ⅵ) in radioactive wastewater were studied.Effects of reaction temperature, initial concentration of U(Ⅵ),contact time, and dosage of KCT on adsorption of U(Ⅵ)were investigated.The adsorption kinetics, thermodynamics and adsorption isotherm were conducted.The results show that KCT has a good adsorption capability on U(Ⅵ)in solution.The maximum adsorption rate and adsorption capacity is 94.7% and 197.6 mg/g respectively under the conditions including pH value of solution of 3.5,dosage of KCT of 0.4 g/L,reaction time of 60 min, and reaction temperature of 25 ℃.The adsorption isotherm, kinetics and thermodynamic studies show that the adsorption of U(Ⅵ)by KCT is a spontaneous and irreversible endothermic reaction process, which conforms to the pseudo-second-order kinetic model and Freundlich isothermal adsorption models, indicating that the adsorption of U(Ⅵ)is a process of coexistence of physical and chemical adsorption, and is dominated by heterogeneous adsorption.

关 键 词：高岭土 钛酸钙 铀 吸附 

分 类 号：X52[环境科学与工程—环境工程] X703