摘要:
随着核能的大力发展,开发环境友好型生物基吸附剂对放射性核素污染控制具有重要意义。采用混合交联法制备一种新型单宁酸复合海藻酸钠(TA/SA)微球,考察了TA和SA质量比、溶液pH、U(Ⅵ)初始浓度、接触时间和温度等因素对TA/SA吸附U(Ⅵ)行为的影响,并进行了吸附动力学和热力学研究,探讨了TA/SA微球对U(Ⅵ)的吸附机理。结果表明,TA和SA的最佳质量比为1∶2,pH对TA/SA微球吸附U(Ⅵ)效果的影响较小。在U(Ⅵ)质量浓度为50 mg/L,TA/SA微球投加量为0.1 g/L,溶液pH=4,温度为323 K,吸附时间为2 h时,TA/SA微球对U(Ⅵ)的最大吸附量为263.42 mg/g。TA/SA微球对U(Ⅵ)的吸附行为符合准二级反应动力学模型和Freundlich等温吸附模型,TA/SA微球对U(Ⅵ)的吸附是一个自发吸热过程,且反应可分为表面吸附、中孔内扩散和微孔内扩散3个阶段。TA/SA表面呈不规则沟壑状,内部是大量开孔的三维网状结构,还原反应在TA/SA微球对U(Ⅵ)的吸附中起主导作用。
关键词:
单宁酸,
海藻酸钠,
吸附,
放射性核素,
铀
Abstract:
With the rapid development of nuclear energy, the development of environmentally friendly bio-based adsorbents is of great significance for controlling radioactive nuclide pollution. A novel tannic acid and sodium alginate (TA/SA) composite microsphere was prepared using a mixed crosslinking method. The effects of TA/SA mass ratio, solution pH, initial concentration of U(Ⅵ), contact time, and temperature on the adsorption behavior of U(Ⅵ) by TA/SA microspheres were investigated, and the adsorption kinetics and thermodynamics were studied. The adsorption mechanism of TA/SA microspheres on U (Ⅵ) was also explored. The results showed that the optimal mass ratio of TA to SA was 1∶2, and pH had little effect on the adsorption of U(Ⅵ) by TA/SA microspheres. When the mass concentration of U(Ⅵ) was 50 mg/L, the dosage of TA/SA microspheres was 0.1 g/L, the solution pH was 4, the temperature was 323 K, and the contact time was 2 hours, the maximum adsorption capacity of TA/SA microspheres for U(Ⅵ) was 263.42 mg/g. The adsorption behavior conformed to the quasi second order kinetic model and Freundlich isotherm adsorption model. The adsorption of U(Ⅵ) by TA/SA microspheres was a spontaneous endothermic process, and the reaction could be divided into three stages, including surface adsorption, mesopore diffusion, and micropore diffusion. TA/SA microspheres had an irregular grooved surface and a three-dimensional network structure with numerous openings inside. The reduction reaction played a dominant role in the adsorption of U (Ⅵ) by TA/SA microspheres.
Key words:
tannins,
sodium alginate,
adsorption,
radioactive nuclide,
uranium
中图分类号:
刘清, 黄健滨, 李伟凡, 招国栋, 杨景景. 单宁酸复合海藻酸钠微球富集U(Ⅵ)的性能[J]. 工业水处理, 2025, 45(1): 58-65.
Qing LIU, Jianbin HUANG, Weifan LI, Guodong ZHAO, Jingjing YANG. Performance of U(Ⅵ) enrichment by tannic acid sodium and alginate composite microspheres[J]. Industrial Water Treatment, 2025, 45(1): 58-65.