Radionuclide extraction with different ionic liquids

10 ionic liquids based on 3 different cations and 5 anions were investigated for radionuclide extraction from aqueous solutions. While uranium and 210Po were extracted with satisfying yields irrespective of the feed solution pH, 234Th, 226Ra and 210Pb extraction yields were rather low. The contact time necessary for near to complete extraction was determined as well as the conditions for successful back-extraction. The loading capacities of the ionic liquids for uranium were very high and depended on the uranyl counter-ion. From the leaching of the ionic liquids into the aqueous phase the predominant extraction mechanisms were derived.