Studies on Permeation of Nd (III) through Supported Liquid Membrane Using DNPPA plus TOPO as Carrier

The transport behavior of Nd (III) through a supported liquid membrane (SLM) containing PTFE as support with organophosphorus extractant dinonyl phenyl phosphoric acid (DNPPA) carrier has been studied. The effect of neutral donors such as TOPO (tri-n-octyl phosphine oxide) TBP (tri-n-butyl phosphate), TEHP (tris 2-ethylhexyl phosphate) and Cyanex 923 (a mixture of four trialkyl phosphine oxides) in combination with DNPPA on transport of Nd (III) from HCl across SLM has been examined and the following trend was observed: TOPO>Cyanex 923>TBP>TEHP. The effect of experimental variables such as feed acidity (0.5 to 5M HCl), neodymium metal ion concentration (6.94x10(-4) to 6.94x10(-3)M), DNPPA concentration (0.2 to 0.6M), stripping reagents in the receiving phase on Nd (III) transport across SLM were investigated. The percentage transport of Nd (III) was 97% after 6hr run with 0.6 MDNPPA+0.13 MTOPO as carrier. The permeability of Nd (III) decreased with increase in HCl and Nd (III) concentration in the feed solution. The transport of Nd (III) decreased with increase in membrane thickness as well as with decrease in pore size. Under optimized conditions transport behavior of other rare earths was also investigated independently, the trend observed was: La>PrNd>Sm>Eu>Gd>Tb>Dy>Ho>Er>Tm>LuY.