光引发制备壳聚糖改性絮凝剂及其对重金属去除机理研究

项目名称： 光引发制备壳聚糖改性絮凝剂及其对重金属去除机理研究

项目编号： No.51508268

项目类型： 青年科学基金项目

立项/批准年度： 2016

项目学科： 其他

项目作者： 孙永军

作者单位： 南京工业大学

项目金额： 20万元

中文摘要： 重金属污染已影响到人们的生活环境，并导致环境质量恶化，成为亟待解决的水污染问题。传统絮凝剂由于重金属捕集能力弱，已难以在混凝过程中实现重金属的高效去除，开发新型高效多功能絮凝剂势在必行。近年来，天然绿色絮凝基材壳聚糖备受关注，但壳聚糖存在溶解性差、分子量低、重金属螯合能力欠缺等不足，是制约对重金属高效去除的关键因素。这些不足主要根源于现有的壳聚糖改性方法和接枝共聚引发方式。因此，本项目提出开展壳聚糖的接枝改性研究，以强化壳聚糖的重金属螯合捕集能力和吸附架桥能力。通过分子定位修饰技术将强螯合基团和可聚合双键引入壳聚糖单体中，再经紫外光引发制备改性壳聚糖和丙烯酰胺的接枝共聚絮凝剂，并研究壳聚糖大分子的定位修饰技术和紫外光引发接枝共聚相关机理机制。在此基础上，深入研究和探讨絮凝剂的结构与重金属捕集-絮凝性能之间的构-效关系，进而探明絮凝剂对重金属的螯合捕集-絮凝作用机理、影响因素及变化规律。

中文关键词： 絮凝剂；光聚合；壳聚糖；重金属；水处理

英文摘要： Heavy metal pollution has been threatening people's living environment and led to the deterioration of environmental quality, becoming a problem badly in need of solutions. The weak heavy metal chelating ability of traditional flocculants cannot guarantee a high efficient removal of heavy metals in the coagulation process, which makes the development of new efficient multi-flocculants imperative and necessary. In recent years, chitosan, the natural green flocculating material, draws public attention, but its shortcomings of poor solubility, low molecular weight, and weakness of chelating heavy metals are key factors affecting the high removal efficiency of heavy metals. These deficiencies are mainly rooted in the chitosan modification method and initiation processes of graft copolymerization. Therefore, this project proposed to carry out the research of modified chitosan to enhance the capabilities of heavy metal chelation-trapping and strengthen the ability of adsorption bridging. First, the stronger chelating group and polymerizable double bonds are introduced into the chitosan monomers by the molecular orientation modification technology. And then the graft copolymerization of modified chitosan and acrylamide is initiated by UV irradiation. Meanwhile, the related mechanisms of the molecular orientation modification technology and UV irradiation graft copolymerization technology are investigated. On this basis, the relationship between flocculants structure and the capacity of heavy metal chelating-flocculation performance is researched and discussed, and thus the mechanisms of heavy metal chelating-flocculation, influencing factors, and variation rules are explored and demonstrated.

英文关键词： flocculant;photo polymerization;chitosan;heavy metal;water treatment