New Sorbents and Their Application for Deactivation of Liquid Radioactive Waste

The article deals with the methods of obtaining sorbents and the possibilities of their application for deactivation of liquid radioactive waste. A method for obtaining nanodispersion of nickel-potassium ferrocyanides is proposed. The mechanism of formation of nanoparticles and a diffuse layer on the surface of nickel-potassium ferrocyanides nanocrystals is considered. The increased sorption of cesium (K_d > 100000, ml/g), in addition to ion exchange, is associated with the inclusion of cesium ions in the structure of the surface layer of ferrocyanide nanocrystals, which is due to the presence of octahedral cavities in the crystal lattice of nickel-potassium ferrocyanides, which contain water molecules, The efficiency of the proposed sorbents based on iron oxide micro- and nanotubes and iron (III) hydroxide nanoparticles modified with nickel-potassium ferrocyanides, whose size is mainly 1–100 µm, is shown. To decontaminate liquid radioactive waste containing complementary substances of organic nature, plasma-chemical treatment is used, which results in the formation of a dispersion containing nanoparticles of metals and metal oxides that show increased affinity for strontium and transition metals. The integrated use of this dispersion in combination with montmorillonite allows for effective treatment of multicomponent liquid radioactive waste. To increase the strontium recovery rate while maintaining high efficiency of cesium and transition metals recovery, it is advisable to apply preliminary plasma chemical treatment followed by the use of sorbents based on ferrocyanide-modified iron (III) oxides/hydroxides. The choice of the deactivation algorithm depends on the composition of liquid radioactive waste to be treated.