Studies on uranium(VI) pertraction across a N,N,N′N′-tetraoctyldiglycolamide (TODGA) supported liquid membrane

Solvent extraction and pertraction behaviour of uranium(VI) is reported here using N,N,N'N'-tetraoctyldiglycolamide (TODGA) as the extractant. The nature of the extracted species from solvent extraction measurements conformed to UO2(NO3)2 center dot TODGA. The transport behaviour of UO22+ was investigated from a feed containing 3.0 M HNO3 into a receiver phase containing 0.1 M HNO3 across a PTFE flat sheet supported liquid membrane (SLM) containing TODGA in n-dodecane as the carrier solvent. Effects of feed acidity, carrier extractant concentration, membrane pore size and U concentration in the feed on the transport rates were investigated. Membrane diffusion coefficients were measured using two different methods and were compared. The Do value was calculated to be 2.98 x 10(-6) cm(2)/s using Danesi's model while the thickness of the aqueous diffusion layer in the feed compartment was measured to be (8.12 +/- 0.72) x 10(-3) CM. Influence of metal ion concentration on flux was also investigated. (C) 2009 Elsevier B.V. All rights reserved.