季铵功能化的金属有机骨架对水中双氯芬酸钠的高效吸附与去除

摘要

A quaternary ammonium functionalized MIL-101(Cr)named MIL-101(Cr)-NMe 3was synthesized and explored as a novel adsorbent for the fast removal of diclofenac sodium(DCF) in water. The adsorption process of kinetics,adsorption isotherms,thermodynamics,and adsorbent regeneration were investigated. And the effects of key parameters such as pH value and ionic strength on the adsorption of DCF were also studied. The results showed that the adsorption of DCF on MIL-101(Cr)-NMe3was very fast. Most of DCF were adsorbed in the first 30 min. The adsorption kinetics of DCF on MIL-101(Cr)-NMe 3obeyed pseudo-second-order kinetics. The adsorption isotherms of DCF on MIL-101(Cr)-NMe3fitted well to the Langmuir adsorption model. And the maximum adsorption capacity was 310.6 mg/g at 20 ℃. The analysis of the adsorption mechanism showed that the electrostatic interaction and π-π stacking interac-tion between DCF and MIL-101(Cr)-NMe3were responsible for the efficient adsorption. Regen-eration experiments indicated that the used MIL-101(Cr)-NMe3was recycled at least five times without significant loss of adsorption capacity. The fast adsorption kinetics,high adsorption capacity,and excellent reusability made MIL-101(Cr)-NMe3attractive for removal DCF from aqueous solution.%通过两步合成法制备了季铵功能化的金属有机骨架 MIL-101(Cr)即 MIL-101(Cr)-NMe3,并考察了该材料对双氯芬酸钠(DCF)的吸附行为.通过不同浓度的 DCF 在 MIL-101(Cr)-NMe3吸附剂上的动力学数据,以及在不同温度下的吸附平衡等温线和MIL-101(Cr)-NMe3吸附剂的重复使用性能考察,发现该材料对DCF的吸附过程符合准二级动力学方程,吸附平衡等温线符合Langmuir等温吸附模型,在20 ℃下的最大吸附量为310.6 mg/g,5次循环使用后吸附量未明显减少.MIL-101(Cr)-NMe3对 DCF的吸附作用机理可归结为静电相互作用和 π-π 相互作用,吸附效果远大于未修饰氨基的 MIL-101(Cr).可以预见该材料对水中 DCF的去除具有良好的应用前景.