使用新型多孔性硅基无机离子筛吸附剂去除放射性核素锶的研究

Radioactive nuclides removal technology from contaminated water plays an important role in the defense of radioactive contamination, which is quite important to ensure the safe development of nuclear energy. Fukushima nuclear accident in 2011 lead to a large quantity of contaminated water containing radioactive nuclides as Cs, Sr and other radionuclides leaked to environment, which was a serious threat to environment and society. Radionuclide removal technology is currently a hot research topic worldwide. However, the existing strontium adsorbents still have many shortcomings in selectivity, stability, mechanical strength and properties for chromatographic separation application. .This work will develop several novel porous silica–based inorganic adsorbents which can be used for efficient removal of strontium from radioactive wastewater. Ion sieve material based on SnP2O7 which has high selectivity on strontium will be synthesized and impregnated into porous silica supports. We will investigate the main physicochemical characteristics of the silica-based inorganic adsorbent and study the adsorption properties and mechanism towards Sr and typical coexisting elements for efficient elimination of strontium. Based on the treatment experiments using simulated wastewater, the applicability of the adsorbents will be evaluated and their performances will be improved. Through the above work, it is expected to develop novel inorganic adsorbents and provide scientific and technological basis for effective removal of strontium from the radioactive wastewater produced in nuclear industry.

污染废水中放射性核素的去除技术是防御放射性污染扩大的重要手段，对核能安全发展具有极其重要的意义。2011年日本福岛核电重大事故造成大量含Cs、Sr等放射性核素的污染水泄露，对生态环境带来了严重的威胁，放射性核素的去除技术成为全球范围内的研究热点。现有的除锶吸附剂在选择性、稳定性、机械强度和水力学性能等方面仍存在不少缺点。.本项目以构建高效率，低成本的针对不同类型的含锶放射性废水的净化处理技术体系为目标，将对锶具有极高选择性的基于焦磷酸锡的锶离子筛担载在多孔性二氧化硅中，研制出能够迅速高效去除放射性锶的新型高效无机吸附剂材料。并对其主要的物化特性进行表征，研究吸附剂对锶及主要共存元素的吸附性能以及作用机理，通过采用模拟废水的净化处理实验评价各种吸附剂的适合性并进行性能优化，为实现放射性废水中锶的快速高效去除提供科学根据和技术基础。

2011年日本福岛核电重大事故造成大量含放射性铯、锶等放射性同位素的污染水泄漏，对生态环境带来了严重的威胁。尤其是常用的沸石类无机吸附剂去除锶的效率很低，因此开发合成简便、性能优异的锶吸附材料，高效地从高盐度溶液中选择性分离锶是目前核安全领域的研究热点。. 本研究以申请人团队研发的多孔SiO2为载体，采用溶胶-凝胶和化学液相接枝的方法成功合成了新型吸附剂Na2TinO2n+1/SiO2和Zr(HPO4)2·nH2O/SiO2。所合成的吸附材料具有良好的吸附性能和水力学特性，以及较强的耐辐照性。在吸附反应的1h内，吸附剂对Sr2+的吸附效率超过90%。合成的地质聚合物微球（NaA Zeolite Microspheres）和气凝胶态的磷酸锆在有竞争离子（Na+, K+, Mg2+, Ca2+）存在的情况下对Sr2+具有很好的选择性，并在柱实验中表现出优异的动态吸附性能，具有非常高的实际应用价值。鉴于钛酸钠不同的晶型特征，通过烧结使用后的吸附剂，使捕捉Sr2+后的钛酸钠（即钛酸锶）晶体结构发生变化，逐步转变为钙钛矿稳定结构, 从而实现了锶的原位固化。. 通过研究人员在吸附领域不断探究与创新，解决了高效新型多功能吸附剂的开发、吸附剂应用在污染水处理体系中的耐久性以及放射性污染水处理系统技术适用性的综合评价和技术优化的关键科学问题。