Sorption of tracer amounts of 137Cs and 90Sr radionuclides from model solutions of various compositions onto synthetic titanosilicates, framework ivanyukite and layered SL3, both synthesized at the...

The article presents the distribution coefficient (K_d) values of ¹³⁷Cs and ⁹⁰Sr tracer radionuclides in solutions of sodium and calcium salts for a wide range of commercially available inorganic sorbents: natural and synthetic aluminosilicates, manganese, titanium and zirconium oxyhydrates, titanium and zirconium phosphates, titanosilicates of alkali metals, and ferrocyanides of transition metals. The results were obtained using a standard technique developed by the authors for evaluating the efficiency of various sorption materials towards cesium and strontium radionuclides. It was shown that bentonite clays and natural and synthetic zeolites are the best for decontaminating low-salt natural water from cesium radionuclides, and ferrocyanide sorbents are the choice for decontaminating high-salt-bearing solutions. The manganese (III, IV) oxyhydrate-based MDM sorbent is the most effective for removing strontium from natural water; for seawater, the barium silicate-based SRM-Sr sorbent is the first-in-class. Results of the study provide a possibility of making a reasonable choice of sorbents for the most effective treatment of natural water and technogenic aqueous waste contaminated with cesium and strontium radionuclides.

The characteristics of various sorbents based on tetraoctyldiglycolamide (TODGA) in sorption of REE(III), Th(IV), and U(VI) ions from nitric acid solutions were studied. The static capacity of the...

The ability of natural and modified montmorillonite clays from Belgorod oblast to sorb Cs, Sr, U, and Pu radionuclides was studied. The clays were modified by treatment with metal (Li+, Na+, K+, Mg2+,...

The static capacity (SC) of the AXIONIT MND40T grade solid extractant (TVEX) based on a macroporous styrene-divinylbenzene copolymer and an extractant, tetraoctyldiglycol diamide (TOGDA), were determined during the sorption of actinide ions (Th, U, Np, and Pu) in various oxidation states in 3 M HNO₃, HCl, HClO₄ media. Despite the fact that a clear relationship between the SC value, the actinide oxidation state, and the type of acid was not found, in most cases there is the highest capacity of the sorbent in nitric acid solutions. In hydrochloric and perchloric acid media, the SC values, as a rule, decrease by several times. In general, the capacity of the AXIONIT MND40T sorbent decreases in the following order: An(IV) ˃ An(III) ˃ An(VI), where An is the actinide. The determination of the TODGA/An molar ratio in the solid phase of the sorbent showed that in all cases, except for the sorption of Pu(IV) from 3 M HNO₃, the ratio was greater than 3, while in the REE(III) extraction with TODGA from nitric acid solutions, the molar ratio TODGA/metal at saturation was 3.

Equilibrium and kinetic characteristics of template mesoporous silicas containing phosphonic acid residues in sorption of various actinide ions were studied. The sorption equilibrium involving these...