树脂基UiO-66复合材料的制备及其去除水中配位态重金属EDTA-Cu的性能

Fabrication of a polymer-based UiO-66 composite for the removal of EDTA-Cu coordination compounds from water

以超高交联氨基吸附树脂(NDA-802)为载体,通过原位生长的方式将金属有机框架材料UiO-66(Zr)负载于载体孔内,制备树脂基UiO-66复合材料(UiO 66@NDA)。通过吸附等温线、吸附动力学、pH影响、离子竞争以及循环再生等序批式实验考察该新型复合吸附剂对水中Cu与配合剂乙二胺四乙酸(EDTA)配位化合的EDTA-Cu的净化性能。结果表明:降低温度有利于UiO-66@NDA对EDTA-Cu的吸附,且Freundlich模型可以较好地描述复合吸附剂对EDTA-Cu的吸附行为;该复合吸附剂在300 min时基本达到平衡,动力学行为符合准二级动力学方程;pH对吸附影响较大,当pH约为4时,UiO-66@NDA对EDTA-Cu显示出最佳的吸附性能;水中共存的Cl-和NO-3的浓度对UiO 66@NDA吸附EDTA-Cu影响较小,而SO_(4)^(2-)浓度的升高会对EDTA-Cu的去除产生较大的抑制作用;该复合吸附剂用0.85 mol/L NaCl和1.25 mol/L NaOH的混合液脱附后可以重复利用。

A polymer-based UiO-66 composite(UiO-66@NDA)was fabricated by loading the metal-organic frame material UiO-66(Zr)into the pores of ultra high cross-linked amino adsorption resin(NDA-802)by in-situ growth method.The adsorption isotherm experiments,adsorption kinetics experiments,pH-influenced experiments,ion competition experiments and recycling regeneration experiments were carried out to investigate the purification performance of this new composite adsorbent for EDTA-Cu coordinated with Cu and ethylene diamine tetraacetic acid(EDTA)in water.Results showed that reducing reaction temperature was beneficial for EDTA-Cu adsorption on UiO-66@NDA,and the adsorption behavior was more consistent with the Freundlich model.This composite adsorbent could reach equilibrium within 300 min and its kinetic behavior was well fitted by pseudo-second-order model.pH value had a large effect on the adsorption,and UiO-66@NDA showed the best adsorption performance for EDTA-Cu when pH was 4.The concentrations of Cl-and NO-3 that coexist in water had little effect on the adsorption of EDTA-Cu by UiO-66@NDA,while the increase of SO_(4)^(2-)concentration had a greater inhibition on the adsorption of EDTA-Cu.When the 0.85 mol/L NaCl solution and 1.25 mol/L NaOH solution was employed as the regenerant,the composite adsorbent could be employed for repeated use after desorption.