一维磁性微球组装链状结构的制备及对重金属离子的吸附性能研究

With the rapid development of industry，the heavy metal pollution becomes more and more serious. Adsorption is widely applied in disposing heavy metal waste water due to its ease of operation and high efficiency. The fast and efficient separation of adsorbents is critical to industrial applications. Magnetic microspheres could be separated effectively by magnetic field, thus possessing special advantages as adsorbents. In our previous research, magnetic microspheres with high specific saturation magnetization were prepared by polymerization-induced colloidal aggregation. To further improve the separation efficiency and meet the requirements of industrial applications, one-dimensional chains composed of magnetic microspheres will be prepared by magnetic-field-induced assembly in this project. The surfaces of the magnetic chains are modified by polydopamine shell which exhibits high adsorption capacities to heavy metal ions. The adsorption capacity of polydopamine modified magnetic chains for various ions ( Cu2+，Pb2+，Cd2+，Hg2+，Zn2+ )will be evaluated. Desorption of the adsorbed ions is conducted in acid solutions. The adsorbent prepared in this project offers several advantages such as high adsorption capacity, rapid separation and recycle capacity. The successful carry out of this project will promote the industrial applications of magnetic adsorbents and improve the processing efficiency of heavy metal waste water, which is of great significance to the sustainable development of economy.

随着我国工业的快速发展，重金属污染日益加剧。吸附法具有操作简便、效率高、能耗低等优点，在重金属废水处理领域应用广泛。吸附材料能否被快速分离对其工业化应用十分关键。磁性微球能被磁场定向分离，在吸附材料领域具有独特优势。申请人前期利用聚合诱导胶体聚集法制备了具有高比饱和磁化强度的磁性微球。为适应工业化应用对分离速度的要求，本项目将在前期工作基础上，利用磁场诱导磁性微球组装为一维链状结构，从而集合多个微球所受的磁吸引力，进一步加快磁分离速度。之后在链状结构表面修饰能与金属离子高效结合的聚多巴胺壳层，考察其对多种金属离子（Cu2+，Pb2+，Cd2+，Hg2+，Zn2+）的吸附性能，并利用酸性溶液对吸附的离子进行解吸，构建具有高吸附容量、可快速分离和循环利用的吸附体系。该项目有望推进磁性吸附材料在重金属废水处理领域的工业化应用，提高工业重金属废水处理效率，对实现经济的可持续发展具有重要意义。

随着我国工业的快速发展，重金属污染日益加剧，严重危害人民群众的身体健康。开发低成本、高效率的重金属废水处理方法，对保护生态环境、实现经济的可持续发展具有重要意义。本项目通过磁场诱导磁性脲醛微球组装为一维链状结构，经二氧化硅修饰后高温去除脲醛树脂，得到的磁性链状颗粒具有很高的比饱和磁化强度（56.9 emu/g），能在磁场中被快速分离。磁性链状颗粒表面经聚多巴胺修饰后（MC-PDA）对重金属离子具有良好的吸附性能，对五种金属离子（Cu2+、Pb2+、Cd2+、Hg2+、Zn2+）的吸附容量分别为117.0、182.6、78.8、97.4、310.4 mg/g。MC-PDA颗粒用于重金属污染处理具有吸附容量高、磁分离速度快和可循环利用的优点；另外，MC-PDA颗粒对亚甲基蓝也具有良好的吸附性能（吸附容量：48.7 mg/g）。利用PDA壳层的还原性原位生成Ag纳米颗粒得到MC-PDA-Ag颗粒，吸附亚甲基蓝后通过Ag纳米颗粒催化降解，可以更有效地对亚甲基蓝进行洗脱。重复12次吸附-降解洗脱循环后，MC-PDA-Ag颗粒的吸附容量仍然保留了初始值的76%以上，从而构建了集染料吸附分离/催化降解于一体的新型染料吸附体系。本项目的研究工作有望推进磁性吸附材料在重金属和染料污染处理领域的工业化应用。