基于氮硫多功能有机配体的金属有机骨架（MOFs）材料的合成及对水体中高氯酸盐的高效吸附研究

Various treatment technology is applied for perchlorate removal, because it affects thyroid hormone function by inhibiting the uptake of iodide anion into the thyroid gland. Adsorption is one of the important treatment methods for oxyanion removal from water. The porous Metal Organic Frameworks (MOFs) materials with special structure and function will be expected based on the diverse coordination fashion and unique electron-rich nitrogen/surfur-containing ligands. By introducing various functionalites into MOFs, it is helpful for MOFs to effectively adsorb contaminants from the water. MOFs composition and properties are tailored or tuned by ligands functionaliztion, metal ion alteration, metal-ligand coordination enhance, composite modification, and so on. Then the polyfunctional MOFs material is applied to the adsorption of perchlorate from aqueous solution. The interactions mechanism between MOFs and perchlorate will be explored and summarized by the density functional theory, molecular simulation and diverse methods of characterization. The kinetics and isotherms for the adsorption of oxyanion onto MOFs will be determined on various environmental conditions. The high-efficiency adsorption for perchlorate onto MOFs and regneeration of adsorbent will be also analyzed. The fixed reactor with MOFs as adsorbent will be manufactured to probe into the dynamic adsorption. In order to optimize the removal efficiency during the continuing adsorption, the process parameters of this reactor and the environmental impact factors will be investigated. Furthermore, the mathematical modeling about the continuing adsorption will be studied, which will be helpful to make the theory about MOFs adsorption apply to the water treatment.

含有高氯酸盐水体的摄入易引起甲状腺生理功能紊乱，各种降解技术的开展得到关注。吸附是水体中微量高氯酸盐阴离子污染物去除的重要手段之一。富氮硫配体丰富的配位方式和独特的富电子结构，有利于金属有机骨架（MOFs）合成特殊电子分布的功能结构。本项目从修改有机配体、改变金属中心、形成复杂金属有机联接的π键、合成新型混合体等角度尝试合成水相中高稳定性的多功能基团的MOFs材料。在此基础上，考察MOFs吸附水体中高氯酸盐的构效关系，利用表征手段分析高效吸附的原理，探讨吸附过程的动力学、热力学机理，分析MOFs对水中高氯酸盐的吸附效率及再生效率，探索高效吸附的数学模型，提高自然水体环境中的高氯酸盐的吸附性。通过设计固定床反应器进行动态吸附研究，探讨持续吸附高氯酸盐阴离子的效果，确定连续流处理工艺的最佳设计和运行参数。最后建立数学模型为深化反应器处理机理的规律性认识和工艺进一步优化提供参考。

吸附法是目前开发研究投资省、运行费用低、操作管理简单的最有效的废水脱除稳定性阴离子的方法之一。金属有机骨架(MOFs)是一类具有广阔应用前景的多孔材料，可使材料具有各种纳微尺度的骨架型规整孔道结构、超大的比表面积和孔隙率及小的固体密度，有利于其在水相中对稳定性的高氯酸盐的吸附去除。.本项目选择含氮硫多功能基团的阳离子性MOFs为吸附材料，合成水相中高稳定性的高效吸附MOFs材料，基本骨架结构为Cu-(4,4’-bipy)2，并通过O-Cu-O将基本骨架连接，Cu(Ⅰ)和4,4’-联吡啶构成主链，氨基磺酸和α,β-烷基磺酸作为有机配体嵌插在主体骨架之间起支撑作用，合成分层多孔的三斜晶体结构。合成材料属阳离子型MOFs材料，表面带有正电荷，且在非过碱性环境中为稳定的悬浮状态，材料有利于高氯酸盐类阴离子性的污染物的静电吸附捕捉。MOFs材料对水体中的ClO4-展现了较好的去除效果。室温条件下，在较大的pH范围内（2-11），MOFs材料ASC和ESC对ClO4-的去除率分别可达到98%和80%左右。阳离子型MOFs材料对水体中ClO4-的吸附满足Langmuir模型，伪一阶动力学反应方程式，整个反应过程为自发性放热反应，低温状态有利于反应的正向进行。吸附主要来源于静电吸附和离子交换的共同作用。阴离子共存体系中的选择性吸附实验表明，材料似乎只对四面体结构的含氧无机阴离子具有特殊的选择性。有机磺酸盐溶液再生法是比较适合两种阳离子型MOFs材料再生的方法，两者的再生率分别为80%和60%左右。高水稳定性的层状MOFs材料，对水体中高氯酸盐等离子的去除存在较大的发展空间。