Highly Promising Method for the Decontamination of Europium from Americium Using an Extraction Chromatography Resin Containing a Tripodal Diglycolamide and SO₃Ph-BTP as Eluent

Separation of Am3+ from Eu3+ was demonstrated by extraction column chromatography using a tripodal diglycolamide ligand (T-DGA). A clean separation was achieved by selective complexation of Am3+ in the feed with 2,6-bis(5,6-di(sulfophenyl)-1,2,4-triazin-3-yl)pyridine (SO3Ph-BTP) with a separation factor of about 2000. The extraction chromatography resin material with particle size in the range of 175-250 mu m contained only 7.4% T-DGA ligand (53 mu mol/g) and is one of the most efficient materials used for this purpose until date. Parameters such as feed acidity and SO3Ph-BTP concentration were varied, while keeping the other parameters constant for getting the best optimized condition for the separation of Am3+ from Eu3+ ions. The optimized feed condition was 0.1 M HNO3 containing 10 mM SO3Ph-BTP for the clean separation of Am3+ from the Eu3+ fraction. In the feed solution containing Eu3+ and Am3+, the latter was complexed with SO3Ph-BTP and, therefore, was not retained on the column, whereas the uncomplexed Eu3+ could be efficiently held onto the column. Finally, the loaded Eu3+ from the column was eluted with 0.1 M HEDTA (N-(2-hydroxyethyl)ethylenediamine-N,N',N'-triacetic acid), giving a sharp and narrow elution curve. The radiation stability of the resin was excellent up to 1000 KGy gamma dose, and an identical separation efficiency of the resin was noted with the irradiated resin column, as was obtained with the pristine resin.