Studying the Efficiency of Model Liquid Radioactive Waste Treatment from Ruthenium Radionuclides by Sorption, Membrane and Precipitation Methods

This article discusses the effect of Fe(III) hydroxoforms at a concentration of 1 mg/dm3 on the treatment efficiency of model liquid radioactive waste (LRW) containing boric acid at a concentration of 5 g/dm3 from ruthenium radionuclides by ion exchange and ultrafiltration methods. The study shows that the presence of Fe(III) hydroxoforms in the studied solutions decreases the efficiency of 106Ru extraction from aqueous solutions by the ion exchange method, while the treatment efficiency in case of ultrafiltration with membranes at a cut off limit 1 and 10 kDa depends on the pH of the solution. The study also evaluates possible application of sorption, membrane and precipitation methods in treating model LRW containing boric acid, as well as organic complexing agents from ruthenium radionuclides. 106Ru could not be removed from the studied solutions in one stage by ion exchange resins applied in the study, as did ultrafiltration. Yet, the coprecipitation method was applied successfully to treat the studied solutions from 106Ru to a level below the threshold established to refer waste to the LRW category. However, organic complexones present in the solutions decrease considerably the treatment efficiency provided by this method.