Layered Double Hydroxides as Promising Adsorbents for Purification of Radioactive Polluted Water: A Review

A critical review of the last decade’s literature on the synthesis, modification, and properties of layered double hydroxides (LDHs) regarding their use as sorbents for the removal of radionuclides from aquatic environments has been conducted. The evaluation of their adsorption capacity against U(VI), ¹³⁷Cs, ⁹⁰Sr, ⁶⁰Co, ^152+154Eu(III), and ²⁴¹Am has been performed on the basis of the analysis of the effect of the LDH preparation method, the nature of the metal ions in the material layers and compounds intercalated into their interlayer space. It is shown that magnetic composites of LDHs chelated forms have significant advantages for a practical use for the removal of both cationic and, especially, anionic forms of uranium(VI) from aquatic environments. Zn,Al-LDHs intercalated with the inorganic compounds, namely hexacyanoferrate(II) anions and copper(II) hexacyanoferrate, are found to be the most effective for the sorption extraction of ¹³⁷Cs and ⁹⁰Sr radionuclides.