沸石材料吸附水中放射性锶和铯的研究进展

Progress in adsorption of radioactive strontium and cesium from aqueous solution on zeolite materials

放射性锶和铯是核工业生产过程中重要的核裂变产物,也是放射性废水中含量较多的放射性污染物,具有较长的半衰期和持续的生物毒性。本文综述了近几年国内外采用天然沸石、合成沸石和复合沸石吸附去除水中放射性锶、铯的研究进展。重点阐述了海藻酸盐、聚丙烯腈、炭材料以及磁改性金属与沸石构成的复合吸附材料对水中放射性锶、铯的吸附。复合沸石可以解决沸石粒径小、难分离、稳定性差等难题,强化了沸石的实用性。从吸附平衡时间、最大吸附容量、酸碱耐受度等方面归纳了沸石材料对水中放射性锶、铯的吸附特性,并分析总结了三类沸石的优缺点。最后,针对沸石材料在处理放射性锶、铯废水中的应用,展望了未来的研究方向,指出可以在降低原水浓度、开发组合工艺和加强模型模拟等方面的研究进行完善,从而推动沸石材料未来在工程技术领域的应用。

Radioactive strontium and cesium are the most important nuclear fission products in the process of nuclear industry and the most abundant radioactive pollutants in nuclear waste water. They have long half-life and persistent biological toxicity. This paper reviewed the latest advances at home and abroad in removing radioactive strontium and cesium from aqueous solutions by natural zeolites, synthetic zeolites and composite zeolites. It focused on the adsorption of radioactive cesium and strontium in aqueous solution by composite adsorbents, which are the compounding of alginate, polyacrylonitrile,carbon materials or magnetically modified metal on zeolites. The composite zeolites could solve the problems of small in particle size, difficult in separation, poor in stability, and enhance the applicability of the zeolite. The adsorption characteristics of zeolite materials on radioactive strontium and cesium in aqueous solution were summarized from the aspects of adsorption equilibrium time, maximum adsorption capacity and acid-base tolerance. The advantages and disadvantages of the three types of zeolites were analyzed and summarized. Furthermore, future research directions are prospected aiming at the application of zeolite materials in the treatment of radioactive cesium and strontium from aqueous solution. It is pointed out that the research on reducing raw water concentration, developing combined process and strengthening model simulation can promote the application of zeolite materials in engineering technology in future.