亲水性镧锕分离配体的设计制备及其在高放废液处理中的应用研究

With the development of nuclear energy, safe disposal of spent nuclear fuel especially high level liquid waste (HLLW) is essential for the sustainable development of nuclear energy. Highly efficient ligand for actinide separation is a difficult and hot field of dealing HLLW. This project aims to design and selective highly more complexing ability of hydrophilic sulfonated ligands toward actinide ions at the molecular simulation level. Based on the theoretical results, we will synthesize these hydrophilic sulfonated ligands in experiment. Then we investigate the interaction mechanism of sulfonated ligands with actinides/lanthanides as well as their back extraction behavior by combining computational chemistry and experimental techniques, which is expected to obtain the relationship between the chemical structure of the ligands and complexing ability of selectivity. This project is devoted to develop a new method based on TALSPEAK process of dealing HLLW to back extract the actinides from lanthanides using hydrophilic ligands in highly acidic HLLW.

随着核能的快速发展，乏燃料后处理尤其是高放废液的安全处理与处置已成为制约核能可持续发展的关键。开发新型高效的锕系元素分离配体是目前高放废液处理的热点和难点研究课题之一。本项目拟以亲水性磺酸化官能团修饰刚性邻菲罗啉骨架及其衍生物，通过理论模拟从分子水平上设计并筛选出对锕系具有较高络合能力和选择性的亲水性配体。在此基础上，实验合成磺酸化配体，进而采用理论和实验结合的方法研究磺酸化配体与镧、锕离子的相互作用机理和反萃行为，建立配体结构与络合性能及选择性之间的关系。基于处理高放废液的TALSPEAK流程，提出从酸性高放废液中反萃锕系离子的可行解决方案。

本项目围绕亲水性镧锕分离配体的设计制备及其在高放废液处理中的应用研究，经过四年的努力达到了预期科研目标。首先，我们理论设计了磺酸化邻菲罗啉二酰胺类配体，研究了其与Am(III)和Eu(III)离子的配位结构、成键性质和络合反应机理，探讨了配体的结构与结合能力以及萃取选择性的关系。随后，我们实验合成了磺酸化邻菲罗啉二酰胺类配体，通过红外光谱、电喷雾电离质谱和紫外-可见光谱等方法研究了Eu(III)与此配体在水溶液中的配位化学行为，实现了水溶液中镧锕离子的高效分离。同时，我们也研究了二硫代酰胺类配体与Am(III)与Eu(III)离子的萃取行为，其镧锕选择性主要由金属-硫键的共价性所决定。此外，针对羟基化亲水性配体，我们利用多种理论手段探究了三种不同桥连骨架配体对镧锕分离的影响。这些工作阐明了镧锕离子与亲水性配体的配位结构和成键性质，为设计具有高效镧锕分离性能的亲水性配体提供了理论依据。本项目的执行也为TALSPEAK流程从酸性高放废液中反萃锕系离子提供可行的方案。