Anionic radionuclides generated during nuclear power production and waste management, including iodine ( 129 I), selenium ( 79 Se), and technetium ( 99 Tc) exhibit high mobility in subsurface environments due to their negative charge and weak interactions with common geomaterials.The effective immobilization of these radionuclides is therefore a critical issue for the long-term safety of radioactive waste disposal and environmental remediation.Layered double hydroxides (LDHs), characterized by positively charged brucite-like layers and exchangeable interlayer anions, have attracted increasing attention as promising materials for the sequestration of mobile anionic contaminants.This mini-review provides a comprehensive overview of recent advances in the application of LDHs for the immobilization of anionic radionuclides.The major immobilization mechanisms of LDHs-including interlayer anion exchange, surface complexation, and the structural "memory effect" associated with thermal treatment and rehydration-are systematically discussed in relation to radionuclide uptake behavior.Interlayer anion exchange enables rapid initial sequestration of oxyanions but may be influenced by competing background anions, whereas surface complexation can lead to stronger and more stable inner-sphere binding depending on radionuclide speciation and surface chemistry.The coexistence of multiple immobilization pathways confers LDHs with considerable versatility under varying geochemical conditions, including changes in pH, ionic strength, and solution composition.Finally, this review discusses current challenges and future perspectives for the practical application of LDH-based materials in radioactive waste management, highlighting their potential role as effective barriers for anionic radionuclide containment in environmental and geological systems.
Lee et al. (Fri,) studied this question.