Treatment of spent decontamination solutions based on citric acid with composite polyacrylonitrile: transient metal oxidic nanoparticles sorbents

Composite sorbents based on the nanoparticles of NiO, NiO–TiO 2 and ZrO 2 –TiO 2 embedded in polyacrylonitrile were chosen for the treatment of spent decontamination solutions based on citric acid. Active oxidic materials were prepared by photoinduced synthesis (NiO, NiO–TiO 2 ) or hydrolytic method (ZrO 2 –TiO 2 ). Weight distribution ratios for radionuclides 241 Am, 60 Co, 137 Cs and 90 Sr/ 90 Y were investigated during the experiments performed in pH range 2–12. High sorption capacities up to 9 mmol g –1 for 137 Cs were found by sorption isotherm experiments. Dynamic experiments were carried out with simulated spent decontamination solutions containing citric acid. Elution of > 85% radionuclide waste with mineral acids or complexing agents was in 5–6 times lower volume compared to treated spent solution.