β-环糊精改性介孔二氧化硅材料对U(Ⅵ)的去除机制  

Removal Mechanism of U(Ⅵ)byβ-cyclodextrin Modified Mesoporous Silica Material

作　　者：朱奥琦 谢水波[2] 司子彦 刘迎久[2] 莫官海 ZHU Aoqi;XIE Shuibo;SI Ziyan;LIU Yingjiu;MO Guanhai(School of Civil Engineering,University of South China,Hengyang 421001,China;Hunan Provincial Key Laboratory of Pollution Control and Resources Technology,University of South China,Hengyang 421001,China)

机构地区：[1]南华大学土木工程学院,湖南衡阳421001 [2]南华大学污染控制与资源化技术湖南省重点实验室,湖南衡阳421001

出　　处：《原子能科学技术》2020年第10期1753-1761,共9页Atomic Energy Science and Technology

基　　金：国家自然科学基金资助项目(11475080)。

摘　　要：以三乙氧基(3-异氰酸丙基)硅为交联剂,通过后接枝法合成了β-环糊精改性介孔二氧化硅(SBA-15-CD)材料。通过静态吸附试验研究了溶液pH值、SBA-15-CD投加量、吸附时间、温度等因素对SBA-15-CD吸附U(Ⅵ)的影响。通过扫描电镜(SEM)、X射线粉末衍射(XRD)、BET比表面分析、傅里叶红外光谱(FT-IR)和X射线光电子能谱(XPS)对材料进行表征分析,并探讨了SBA-15-CD吸附U(Ⅵ)的机制。结果表明,当U(Ⅵ)初始浓度为5 mg/L、温度为30℃时,SBA-15-CD吸附U(Ⅵ)的最佳条件为:pH=5、SBA-15-CD投加量0.20 g/L、吸附平衡时间30 min,在此条件下,平衡吸附量为24.4 mg/g,U(Ⅵ)去除率为98.3%。吸附过程符合准二级动力学模型和Langmuir等温模型,即以化学吸附为主,且主要是通过表面的羟基、酯基和氨基与U(Ⅵ)配位。30℃下SBA-15-CD的饱和吸附量达330 mg/g,升高温度有利于吸附的进行。SBA-15-CD具有良好的重复使用性能。Aβ-cyclodextrin modified mesoporous silica(SBA-15-CD)material was synthesized by post-grafting using triethoxy(3-isocyanatopropyl)silicon as a crosslinking agent.The effects of solution pH,SBA-15-CD dosage,adsorption time and temperature on the adsorption of U(Ⅵ)on SBA-15-CD were studied by static adsorption test.Scanning electron microscopy(SEM),X-ray powder diffraction(XRD),BET specific surface analysis,Fourier transform infrared spectroscopy(FT-IR)and X-ray photoelectron spectroscopy(XPS)were used to characterize the material and explore the adsorption mechanism of U(Ⅵ)on SBA-15-CD.The experimental results show that when the initial concentration of U(Ⅵ)is 5 mg/L and the temperature is 30℃,the optimal conditions for SBA-15-CD to adsorb U(Ⅵ)are:pH=5,0.20 g/L of SBA-15-CD dosage,and 30 min of time.Under the optimum condition,the equilibrium adsorption amount is 24.4 mg/g,and the U(Ⅵ)removal rate is 98.3%.The adsorption process conforms to the pseudo-second-order kinetic model and the Langmuir isotherm model,that is,the chemical adsorption is the main one,and it is mainly adsorbed by the coordination of hydroxyl,ester and amino groups on the surface with U(Ⅵ).The saturation adsorption capacity of SBA-15-CD reaches 330 mg/g at 30℃.Increasing the temperature is favorable for the adsorption,and SBA-15-CD has good reusability.

关 键 词：介孔二氧化硅 Β-环糊精 U(Ⅵ) 吸附 

分 类 号：O647.33[理学—物理化学] X591[理学—化学]