Removal of 90Sr from nitric acid solutions with sorbents based on di-tert-butyldicyclohexyl-18-crown-6

A series of impregnated sorbents based on di-tert-butyldicyclohexyl-18-crown-6 (DTBDCH18C6), various diluents (1-octanol, nitrobenzene, telomeric alcohol n3), and supports (Porolas-Т, LPS-500, hydrophobized silica gel) for removing tracer and weighable amounts of Sr ions from nitric acid solutions were prepared. The distribution coefficient of tracer amounts of 90Sr on all the synthesized sorbents increases with an increase in the HNO3 concentration in the range 1–7 M. The most pronounced increase in the sorption occurs with an increase in the HNO3 concentration to 3 M. The maximal distribution coefficient of 90Sr (Kd = 158 cm3 g–1) is reached for the sorbent based on DTBDCH18C6 and 1-octanol in 7 M HNO3. Experiments on sorption of weighable amounts of Sr2+ ions show that the static capacity of all the prepared sorbents for Sr in nitric acid solutions amounts to 4.3, 9.2, and 8.4 mg g–1 for the sorbents based on 1-octanol, nitrobenzene, and telomeric alcohol n3, respectively. The synthesized sorbents are suitable for radioanalytical determination of Sr radionuclides in liquid radioactive waste and in radioactively contaminated natural objects.