Modern Sorption Materials for Cesium and Strontium Radionuclide Extraction from Liquid Radioactive Waste

Abstract

The paper describes the main types of sorption materials used to remove cesium and strontium radionuclides from low-level and intermediate-level liquid radioactive waste (LRW). It mainly focuses on sorbents produced at an industrial or pilot scale in Russia. Based on a developed standardized technique, it presents the experimental values for 137Cs and 90Sr distribution coefficients (Kd ) accounting for various types of sorbents. The study demonstrates that based on the developed technique, sorption characteristics of various types of sorption materials can be compared in an unbiased manner and most effective sorbents can be reasonably selected to treat liquid radioactive waste of various salt and radionuclide composition.

Hydrothermal synthesis and sorption performance to Cs(I) and Sr(II) of zirconia-analcime composites derived from coal fly ash cenospheres

“…Such high Sr 2+ sorption parameters of the small-sized zirconia-analcime composites are comparable with those for the known specific Sr 2+ sorbents, such as hydrated antimony pentoxide [44,45], titano-and zirconosilicates [46,47]. A number of distribution coefficients for Cs + and Sr 2+ sorption for different inorganic sorbents produced in Russia [48] are given in Table 3.…”

“…Distribution coefficients (K D ) for Cs + and Sr 2+ sorption on different inorganic sorbents in 0.1 mol/L NaNO 3 , pH = 5−6[48].…”

New Sorbents Based on Polyacrylonitrile Fiber and Transition Metal Ferrocyanides for 137Cs Recovery from Various Composition Solutions

“…In addition, it should be noted that previously, under similar conditions, when extracting from 0.1 and 1 mol/L solutions of sodium nitrate with pH 6 [19,24] and seawater [16], a large number of sorbents of various types were tested: organic ion exchange resins, natural and synthetic aluminosilicates and zeolites, oxyhydrates, phosphates, titanosilicates, ferrocyanide sorbents, carbon sorbents. Papers [16,19,24] present detailed comparative tables of 137 Cs distribution coefficients. When comparing our results with those presented, it is seen that the effectiveness of obtained sorbents is not inferior to the effectiveness of existing materials.…”

“…However, it should be noted that sorbents based on AMP are prone to adsorption of 40 K, which leads to an overestimation of the result of measuring 137 Cs activity; therefore, sorbents based on transition metal ferrocyanides are preferable [4]. Transition metal ferrocyanides can be used to extract 137 Cs in pure form [12] or deposited on a support: PAN fiber (KNiFC-PAN) [4,13,14], silica gel (SiO 2 -KMCHCF [15], FSS [16], FC-Cu-EDA-SAMMS [17]), aluminosilicates (Niket-k) [18,19], chitin-containing materials (FFCG-SO 4 -FC [20], Mikoton-Cs [21], CFC Zn-K, CFC Cu-K, CPC Ni-K [22]), hydrated zirconium dioxide (Thermoxide 35) [16,23,24], activated carbon (C/NiHCFe, C/InHCFe, C/CuHCFe) [25], cellulose support (Anfezh [16,19,26], Uniket [18], NKF-C [27,28], FN and FN-50 [19,29]), natural minerals (diatomite (FND) [19,24], tripolite [30], clinoptilolite (NPF-CL) and quartz-glauconite concentrate (NPF-GL) [23,31,32]) and others. Zeoliteimidazole frameworks [33], mesoporous silica gels [34], aerogels [35], and hydrogels [36], which showed high sorption characteristics in cesium recovery, should be mentioned as new promising supports.…”