A Novel Liquid Emulsion Membrane Containing TODGA as the Carrier Extractant for Am Recovery from Acidic Wastes

The recovery of Am has been investigated by Liquid Emulsion Membrane (LEM) containing 0.1 M N,N,N′,N′-tetraoctyl-3-oxapentane diamide (TODGA) + 0.5 M di-n-hexyloctanamide (DHOA) in n-dodecane as extractant. Span 80 (sorbitan monooleate) was used as the surfactant for making the emulsion while 3 M HNO3 and 0.1 M acetate buffer (at pH 4.75) were used as the external and internal phases, respectively. Optimized conditions indicated 2% Span 80 was required for making the emulsions. The effect of different experimental conditions such as varying feed acidity, varying volume ratio, different strippants, and varying TODGA concentration have been studied for the quantitative removal of Am from acidic solution. The higher transport rate has been observed which can be attributed to the higher surface area per unit volume available for mass transport. Demulsification was possible by heating the emulsions to 80°C. Actual acidic radioactive waste has also been tested for the recovery of americium. The results show the applicability of ELM for the removal of Am(III) from waste solutions with a faster rate of transport as compared to those reported previously.