Removing radioactive caesium from solns. and suspensions etc. - by filtering, recycling retentate to batch containers, feeding permeate to ion exchange, and adding permeate to previous retentate

摘要

In removing radioactive Cs from suspension, solns. and similar liqs., (a) the liq. is brought to a uniform compsn., opt. after processing from a dry pre-prod., (b) the liq. is conditioned w.r.t. temp. and filtered, and the retentate, harmful to an ion-exchanger, is recycled into a batch container, (c) the Cs-contg. permeate is fed to an ion-exchange, where the Cs bonds to the ion-exchange material, and the permeate freed from Cs is recycled to the retentate in the batch container, and (d) this circulation is maintained until the contamination of the liq. in the mixing container has fallen below a pre-determined level. The novelty is (e) the ion-exchanger material is a support coated with NH4-Cu hexacyanoferrate complex, (f) the support, not taking part in the exchange of Cs ions, is highly porous spheres of synthetic material, with large surface and with high binding capacity to the ion-exchange material, and (g) the spheres have dia. 0.4-1.2 mm. USE/ADVANTAGE - The materials to be treated are foods and fodders. The claimed use is the decontamination of whey powder, by dissolving the powder in water in ratio 1:4. subjecting to ultrafiltration, when the protein is retained in the retentate and a lactose-salt soln. is fed as permeate to the ion-exchange, and the soln. formed after removal of Cs from permeate and retentate is spray dried. The prod. is not affected by the ion-exchange material. Filtration, ion-exchange and withdrawal of the decontaminated prod. can be continuous. High loading of the ion-exchanger is obtd., with very low activity in the treated prod..