功能化纳米零价铁的构筑及其对放射性核素238U(VI)的去除性能和机理研究

Large amounts of radionuclides are inevitably released into the environment with the development of nuclear power energy, which is dangerous to natural environment and human health. Due to its special surface effect and small size effect, nanoscale zero-valent iron (nZVI) has excellent adsorption performance and high redox activity, which has shown great potential in environmental pollution control in recent years. However, nZVI can be easily oxidized and form aggregates when exposured to atmospheric conditions, which limited its application in radioactive pollution management. In this project, we will synthesize functional nZVI material with high chemical stability, excellent dispersibility and higher selectivity by surface modification and porous material supporting method. The effect of the nZVI materials on the removal of radionuclide 238U(VI) will be studied intensively to understand the interaction mechanism of radionuclide with nZVI materials, especially the effect of structures and functional groups on the interaction between radionuclides and nZVI materials. The mechanism of radionuclide on the solid interfaces will be studied by advanced spectroscopy techniques and theoretical calculations at molecular level. The expected investigation results will provide a new kind of material, method and technique for the effective removal of radionuclide, and provide a scientific theoretical support for the controlling of radioactive contamination.

核能利用过程中产生的放射性核素不可避免的释放到环境中，给自然环境和人类健康带来重大危害。纳米零价铁因其特有的表面效应和小尺寸效应，具有优越的吸附性能和很高的还原活性，近年来在环境污染治理方面展现出巨大的潜能。然而，纳米零价铁易氧化和团聚的缺陷，限制了其在环境放射性污染治理中的应用。本项目拟通过表面修饰和多孔材料负载的方法制备化学稳定性高、分散性好、选择性强的功能化纳米零价铁材料，系统研究不同环境条件下其对放射性核素238U(VI)的去除效果，揭示纳米零价铁材料结构和功能基团等性质与放射性核素作用的关系和规律，进一步借助先进的谱学技术表征以及理论计算，在分子水平上阐明功能化纳米零价铁材料对放射性核素的吸附和还原的界面作用机理。本项目预期研究成果为放射性核素的有效去除提供一种新材料、新技术和新方法，为放射性污染治理提供科学的理论依据和技术支持。

核工业发展所消耗的核燃料会不可避免地将大量含铀（U(VI)）废水排放到自然界，给生态和环境带来一定的威胁，因而去除水环境中的U(VI)成为一项迫切的任务。纳米零价铁材料被广泛用于U(VI)的去除，但是单纯的纳米零价铁存在稳定性差、去除效果差等不足。本项目通过表面钝化技术与负载技术制备了硫化纳米零价铁和多孔材料（生物炭、水滑石、海绵和MXene）负载的纳米零价铁，并将其用于水中U(VI)的高效去除。通过宏观实验探明了反应时间、温度、pH、背景离子浓度等因素对材料去除U(VI)的影响。进一步通过微观光谱分析阐明了功能化纳米零价铁材料对U(VI)的吸附和还原的界面作用机理。部分相关研究成果发表在J. Environ. Chem. Eng.，J. Clean. Prod.，化学学报，中国科学：化学等期刊上，其中1篇论文（J. Clean. Prod., 2021, 319: 128641）被评为高被引论文。上述研究成果为功能化纳米零价铁材料的构筑及其对放射性核素U(VI)的高效去除和界面作用机理提供实验与理论依据。近三年发表SCI论文6篇，联合培养博士研究生1名，硕士研究生6名。