羧基纤维介孔硅对Th(Ⅳ)的高效去除

Efficient Removal of Th(Ⅳ) by Carboxyl Fiber Mesoporous

采用后嫁接法合成了羧基功能化纤维介孔硅材料。利用扫描电子显微镜(SEM)和热重分析表征了材料的形貌和热稳定性。结果表明,羧基功能化纤维介孔硅材料为纤维结构的球状体,孔径约为11 nm、比表面积约416 m2/g,经羧基官能团修饰后材料整体结构没有明显变化,热稳定性能良好。吸附测试表明COOH-F-SiO_2吸附Th(Ⅳ)速度非常快,120 min内可达到平衡。当pH=3.5;msorbent/Vsolution=0.4 mg/m L,Th(Ⅳ)初始浓度[Th]initial=100 mg/L时,COOH-F-SiO_2对Th(Ⅳ)离子的最大吸附容量达115.5 mg/g。COOH-F-Si O2吸附Th(Ⅳ)离子符合Langmuir(R2>0.992 9)模型,Th4+以单分子层吸附为主。在多种复杂金属离子环境下,仍具有对Th(Ⅳ)离子较高的选择吸附速率。

The carboxyl functionalized fibrous mesoporous silica was synthesized by posterior grafting. The morphology and thermal stability of the materials were characterized by scanning electron microscopy （SEM） and thermogravimetric analysis. Results show that the carboxyl functionalized mesoporous silica fiber material had the structure of fiber globule, with aperture around 11 nm, specific surface area of about 416 m^2/g. The material did not change significantly overall structure when modified by carboxyl functional groups, and thermal stability was good. Adsorption tests showed that the adsorption Th（Ⅳ） of COOH-F-SiO2 was very fast and could be balanced within 120 rain. The lnaximum adsorption capacity of Th（IV） ions on COOH-F-SiO2 was 115.5 mg/g at the condition of pH 3. 5, m sorbent/Vsolutlon =0. 4 mg/mL, and Th （ Ⅳ ） initial concentration [ Th ]initial= 100 mg/L. The adsorption of Th （IV） by COOH-F-SiO2 was in line with the Langmuir （R^2 〉 0.992 9） model, and Th^4＋ was mainly absorbed environments, the adsorption rate of Th（IV） ion was by monolayer. In many complex metal ion still higher.