基于溶剂热法制备的新型多孔含磷氧基螯合树脂处理含铀废水的研究

With the rapid development of nuclear power, the damage of waste water containinguranium is increasing prominently. Thus, to develop adsorbent which can treat waste water containing uranium efficiently has very important scientific and practical significance for the rapid and healthy development of the China nuclear industry. Macroporous chelating resin bearing phosphine oxide groups not only has rich pore structure, but provides phosphine oxide groups which has good coordination ability with uranyl ions under high acidity. Consequently, taking macroporous chelating resin bearing phosphine oxide group as the adsorption medium has a potential application prospect in the field of the treatment of waste water containing uranium. Macroporous chelating resins bearing phosphine oxide groups were prepared by way of solvothermal method in the presence of vinyl monomer bearing phosphine oxide groups, resulting in phosphine oxide groups could be distributed uniformly around the skeleton of porous polymer. Compared with traditional adsorbent materials, macroporous chelating resins bearing phosphine oxide groups as sorbents to deal with waste water containing uranium might solve the problems including lower adsorption capacity and poor selectivity. The effect of solvothermal conditions on adsorption properties and microstructures will be studied, and the relationship between structures and sorption properties will be explored. The adsorption mechanism of uranium by macroporous chelating resin bearing phosphine oxide groups would be discolsed by means of extend X ray absorption fine structure analysis, X-ray photoelectron spectroscopy analysis, transmission electron microscope analysis and dynamic adsorption model analysis. The results of this work are expected to provide a certain theoretical basis to deal with waste water containing uranium.

随着核电的快速发展，含铀废水的危害日愈凸显，研制能高效处理含铀废水的吸附介质对我国核工业健康快速发展具有重要的科学和现实意义。多孔含磷氧基螯合树脂不仅具有丰富的孔道结构，同时还带有在高酸度下与铀酰离子具有较强配位能力的磷氧基团，以其为吸附介质在处理含铀废水领域具有潜在的应用前景。本项目拟以含磷氧基不饱和化合物为单体，经溶剂热聚合技术制备出多孔含磷氧基螯合树脂吸附剂，实现磷氧基团在聚合物骨架上的均匀分布，拟突破传统吸附材料处理含铀废水时存在的吸附容量低和选择性差等瓶颈。深入研究溶剂热聚合参数对多孔含磷氧基螯合树脂结构和吸附性能的影响，探讨多孔含磷氧基螯合树脂吸附铀的构效关系；通过扩展X射线吸收精细结构光谱、X射线光电子能谱和透射电镜等分析手段，结合吸附动力学模型，揭示多孔含磷氧基螯合树脂吸附铀的作用机理。预期成果将为解决含铀废水处理难问题提供一定的理论依据。

随着核电的快速发展，铀矿的需求量越来越大，而铀矿的开采和铀水冶过程中会产生大量的含铀废水。含铀废水不仅会污染地表水，还会渗透进入地下污染地下水，同时会进入生物体内，从而造成很大的危害，因此，铀污染水体的修复问题亟待研究解决。本项目以含磷氧基不饱和化合物为聚合单体，采用溶剂热聚合技术制备出一系列多孔含磷氧基螯合树脂，并将其应用于处理含铀废水的研究。本研究特别筛选出一种对铀具有高吸附容量和高选择性的含磷氧基螯合树脂P（EGDMA-VPA），详细考察了其对铀的吸附行为。结果表明P（EGDMA-VPA）不仅具有丰富的孔隙率和较高的稳定性，同时具有高浓度的磷氧基团。P （EGDMA-VPA）在4 mol L-1的硝酸介质下对铀酰离子的单分子层饱和吸附容量分别为215.9 mg g-1，动力学研究表明铀酰离子在吸附剂上的吸附过程服从准二级模型；热力学研究表明铀酰离子在吸附剂上的吸附属于自发和吸热的过程。P （EGDMA-VPA）在强酸介质中对铀酰离子不仅具有较好的选择性能，同时还具有较好的重复使用性能。XPS结果表明，吸附剂在强酸介质中对铀的吸附主要依靠P=O键与铀的络合来实现的。DFT计算结果表明吸附剂中1个P=O基团结合1个UO2(NO3)2为最稳定结构。项目成果将为解决含铀废水处理难问题提供一定的理论依据。