摘要/Abstract
随着核工业的快速发展，大量放射性元素铀被排放到环境中，造成严重的环境污染并给人类健康带来重大危害.层状双金属氢氧化物（LDHs）因其具有比表面积大、离子交换能力强以及独特的纳米结构等优点，在铀酰离子的去除及环境水污染处理方面展现出巨大潜力.同时，将层状双金属氢氧化物进行改性可大大增加活性位点，进一步提高材料对放射性元素铀的吸附性能.详细介绍了层状双金属氢氧化物及复合材料的制备及改性方法，通过光谱分析技术阐述了层状双金属氢氧化物对环境中铀酰离子的吸附效果以及作用机理.最后，对层状双金属氢氧化物在治理水污染中的应用前景给出个人见解，以期为今后的环境治理工作的深入研究和实际应用提供参考依据.
关键词: 层状双金属氢氧化物, 复合材料, 铀, 环境污染, 吸附
With the rapid development of nuclear industry, nuclear energy, as a kind of low-carbon energy, has been widely used in the world. However, in the development and application of nuclear energy, a large amount of radionuclides, especially the radioactive uranium, have been inevitably discharged into the environment, causing serious environmental pollution and having great harm to human health. Layered double hydroxides (LDHs) have become the excellent adsorbents in environmental pollution treatments due to easy preparation, large specific surface area, the unique nanostructure and excellent ion exchange capacity. Hence, the preparation of layered double hydroxides and their composites for the efficient removal of radioactive uranium is one of the hot issues in the field of environmental science, which include coprecipitation, ion exchange, hydrothermal method, the urea hydrolysis method, aerogel, microwave-crystallization and separate nucleation/crystallization isolation method. Besides the aforementioned methods, other reported synthesis methods of LDHs include the secondary intercalation method (an intercalation method involving dissolution and the re-coprecipitation method), reconstruction method based on the "memory effect", N2 protection synthesis, mechanochemical synthesis, surface synthesis, template synthesis, and others. The modification methods of layered double hydroxides can be divided into calcination, intercalation and compounding method, which significantly increase the active sites and further improve the adsorption performance of the materials to radioactive uranium. In addition, the adsorption mechanism has been thoroughly investigated with spectroscopic analysis techniques such as Fourier transformed infrared spectroscopy (FT-IR), X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS) and Extended X-ray absorption fine structure (EXAFS). In conclusion, the review briefly discuss the application prospects of layered double hydroxides and their composites in the treatment of water pollution, which provide definitive reference values for the further research and practical application of environmental management in the future.
Key words: layered double hydroxides, composites, U (VI), environmental pollution, adsorption
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