The Evaluation of the Effectiveness of Adsorbents Based on Acrylamide Hydrogels and Cryogels for Water Purification from Radioactive Contaminants

The article presents the assessment results on the effectiveness of polymer hydrogel and cryogel-based adsorbents for treating natural waters from radioactive contaminants. Nine polymer gels were synthesized, their physico-chemical properties studied, and the processes of selective adsorption of radioactive elements such as ¹³⁷Cs, ⁹⁰Sr, and other chemical elements in aqueous solutions were investigated using polymer gels. The effectiveness of radioactive element adsorption from aqueous solutions by polymer hydrogels and cryogels was evaluated by placing different pure samples of the synthesized gels in radioactively contaminated aqueous solutions. At the same time, the activity of the aqueous solution was measured before placing the polymer gel into it. Then, the polymer gel was placed in the aqueous solution for 3 days. Afterward, the activity of the polymer gel was measured after it was extracted from the aqueous solution. The best adsorption characteristics and selectivity with respect to ¹³⁷Cs was demonstrated by hydrogels AM:AA/3-2.4 × 10^-8 mg/g, AM:AA/2-4.1 × 10^-9 mg/g, and AM:AA/5-3.7 × 10^-9 mg/g. Cryogel MAA:AM-7.0 × 10^-8 mg/g, hydrogel AM:AA/2-5.1 × 10^-8 mg/g, and hydrogel AM:AA/5-1.5 × 10^-8 mg/g exhibit the highest selectivity for ⁹⁰Sr. An adsorption potential has been demonstrated by the synthesized polymer gels with respect to such chemical elements as K, Fe, Ni, and U.