响应面法优化改性β-环糊精聚轮烷对Th(IV)的动态吸附

Optimization of Thorium (IV) ions Dynamic Adsorption onto a Mono-modified β-Cyclodextrin Polyrotaxane Using Response Surface Methodology (RSM)

通过使用响应面分析法(RSM)的Box-behnken设计来优化聚轮烷对Th(IV)的吸附过程,考察pH、吸附时间、初始浓度和吸附剂用量等因素对吸附过程的影响;同时对各种相互影响因素建模和拟合,并对实验数据进行处理。实验结果表明:各独立因素均为Th(IV)吸附过程的显著因素,通过相关系数和方差分析发现预测值和实验值基本一致,在pH值=3.72,吸附时间为35.4 min,钍离子初始浓度为22.8 mg/L,吸附剂用量为30 mg时,Th(IV)的最大吸附量为13.62 mg/g。Langmuir,Freundlich和Dubinin-Radusckevich(D-R)的等温吸附模型表明,吸附过程更符合Langmuir等温吸附模型,且为自发吸附过程。综上可知,聚轮烷在水相低浓度Th(IV)吸附方面是一种优良的吸附材料。

The adsorption of Th（IV） using mono-modified β-cyclodextrin polyrotaxane was optimized by Box-behnken design of response surface methodology（RSM）. The effect of a function of pH,contact time,initial Th（IV） concentration as well as adsorbents dosage was investigated. Moreover,after all interaction variables fitted and modeled,then we analyses and performed the statistic results of this work. According to the results all the single effect contribute obviously significant to the adsorption of Th（IV）. By analysis the variance（ANOVA） and correlation coefficients,the results showed that the predicted conformation was according with the experimental data well. The best experimental condition was as follow： pH = 3. 72,equilibrium time 35. 4min,initial adsorbate concentration 22. 8 mg/L,adsorbents dosage 30 mg. Under the optimum condition adsorbing capacity of Th（IV） was reached 13. 62 mg/g. Adsorption data were modeled by Langmuir,Freundlich and Dubinin-Radusckevich（D-R）adsorption isotherms. Thermodynamic studies revealed that PR was an excellent sorbent material for adsorption Th（IV） ions from low concentration aqueous system.