Liquid-liquid extraction and flat sheet supported liquid membrane studies on Am(Ⅲ) and Eu(Ⅲ) separation using 2,6-bis(5,6-dipropyl-1,2,4-triazin-3-yl)pyridine as the extractant

摘要

Solvent extraction and supported liquid membrane transport studies for the preferential removal of Am3* from feeds containing a mixture of Am~(3+) and Eu~(3+) was carried out using 2,6-bis(5,6-dipropyl-1 ,2,4-triazin-3-yl)pyridine (n-Pr-BTP) as the extractant. Diluent plays an important role in these studies. It was observed that the distribution coefficients deteriorate significantly for both Am~3+ and Eu~3+ though the separation factors were affected only marginally. The transport studies were carried out at pH 2.0 in the presence of NaNO_3 to result in the preferential Am~(3+) transport with high separation factors. Effect of different experimental parameters, viz. feed composition, stripping agents, diluents of the organic liquid membrane and membrane pore size was studied on the transport and separation behaviour of Am~(3+) and Eu~(3+). The supported liquid membrane studies indicated about 85% Am~(3+) and 6% Eu~3+ transport in 6 h using 0.03 M n-Pr-BTP in n-dodecane/1-octanol (7:3) diluent mixture for a feed containing 1 M NaNO_3 at pH 2 and a receiver phase containing pH 2 solution as the strippant. Consequently, a permeability coefficient of (1.75 ± 0.21) × 10~(-4) cm s~(-1) was determined for the Am3* transport. Stability of the n-Pr-BTP and its SLM was also studied by carrying out the distribution and transport experiment after different time intervals.