Interaction of radionuclides with some functional derivatives of chitosan in solutions

New derivatives of low- and high-molecular-weight chitosan (LMWC and HMWC), containing various functional groups, were prepared. The solubility of the compounds in aqueous solutions at pH 1–10 and the sorption and complexation of radionuclides with these compounds were studied. Water-insoluble preparations based on LMWC and HMWC efficiently sorbed ⁹⁰Y and ²³³UO₂²⁺ with the distribution coefficients K _d > 10³ ml g⁻¹ at a phase contact time of 1 h and V/m = 100. The water-soluble preparations based on LMWC showed high complexing power toward ²³³UO₂²⁺ and virtually completely retained hydrolyzed U(VI) species in solutions in a wide pH range. In the presence of N-sulfosuccinyl-LMWC (N-SSLMWC), ²³³UO₂SO₄ solutions with pH 8–9 and U(VI)/N-SSLMWC weight ratio of 0.5 remained stable for 200 days, with no precipitation of hydrolyzed ²³³UO₂²⁺ species.