ZIF-8-DMTD@ALG 气凝胶制备及对 Pb(Ⅱ)、Cd(Ⅱ)吸附性能研究

文章利用合成后改性法将2,5-二巯基-1,3,4-噻二唑(DMTD)引入沸石咪唑酯骨架材料(ZIF-8)，通过共混法将其与海藻酸钠(ALG)复合成功制备出ZIF-8-DMTD@ALG气凝胶。ZIF-8-DMTD@ALG气凝胶解决了粉末状吸附剂易团聚和难以回收的问题，DMTD的引入为ZIF-8-DMTD@ALG气凝胶带来丰富的官能团，从而提高其吸附性能。静态批量吸附实验表明：ZIF-8-DMTD@ALG气凝胶对Pb(Ⅱ)和Cd(Ⅱ)的吸附均遵循准二级动力学模型和Langmuir吸附等温模型；Langmuir模型拟合出的ZIF-8-DMTD@ALG对Pb(Ⅱ)和Cd(Ⅱ)的最大吸附容量分别达到352.101、170.592 mg/g。离子强度实验和循环吸附实验表明ZIF-8-DMTD@ALG气凝胶具有良好的耐盐性能和再生能力。表征技术和批量吸附实验结果揭示了ZIF-8-DMTD@ALG气凝胶主要通过络合作用吸附Pb(Ⅱ)和Cd(Ⅱ)，少量的离子交换和静电作用也对吸附做出了贡献。该研究结果表明ZIF-8-DMTD@ALG气凝胶具有制备简单、回收容易和吸附能力强等优点，在实际污水处理领域有良好的应用前景。

In this paper, 2,5-dimercapto-1,3,4-thiadiazole(DMTD) was introduced into zeolitic imidazolate framework material (ZIF-8) by post-synthesis modification method, and then combined with sodium alginate(ALG) by blending method to prepare ZIF-8-DMTD@ALG aerogels. ZIF-8-DMTD@ALG aerogels solve the problems that powder adsorbents are easy to agglomerate and difficult to recover. The introduction of DMTD brings abundant functional groups to ZIF-8-DMTD@ALG aerogels and improves their adsorption performance. The static batch adsorption experiments showed that the adsorption of Pb(Ⅱ) and Cd(Ⅱ) by ZIF-8-DMTD@ALG aerogels followed the quasi-second-order kinetic model and Langmuir adsorption isothermal model. The maximum adsorption capacities of ZIF-8-DMTD@ALG for Pb(Ⅱ) and Cd(Ⅱ) obtained by Langmuir model reached 352.101 mg/g and 170.592 mg/g, respectively. Ionic strength experiments and cyclic adsorption experiments showed that ZIF-8-DMTD@ALG aerogels had good salt resistance and regeneration ability. Characterization techniques and batch adsorption experiments revealed that ZIF-8-DMTD@ALG aerogels mainly adsorbed Pb(Ⅱ) and Cd(Ⅱ) through complexation, and a small amount of ion exchange and electro-