Sorption of radionuclides from solutions with composite materials based on Mikoton natural biopolymer

Abstract

Composite sorbents based on Mikoton natural biopolymer, selective to 90Sr, were prepared, and features of 90Sr sorption with these sorbents were discussed. The inorganic compound used as modifier is deposited on the surface of fibers of Mikoton biopolymer in the form of single crystals and polycrystals. Certain physicochemical parameters of the sorption were determined: static exchange capacity, constants of sorption equilibrium, etc. Deposition of BaSO4 on the surface of biopolymer fibers increases the sorption capacity toward 90Sr in solutions containing sulfate ions, and deposition of MnO2 enhances the sorption of 90Sr from solutions with high concentrations of salts. The influence of the chemical composition and pH of solution was studied in detail. The calculated low value of ΔG0 of radionuclide sorption is attributed to the simultaneous occurrence of several parallel processes in the system, some of which are energy-consuming. The Mikoton-Cs sorbent {composite of Mikoton biopolymer with K2Cu[Fe(CN)6]} appeared to be only weakly sensitive to variation of the chemical composition of the solution in a wide range of salt concentrations.