Separation of Eu(III) with supported dispersion liquid membrane system containing D2EHPA as carrier and HNO 3 solution as stripping solution

Abstract

The Eu(III) separation in supported dispersion liquid membrane (SDLM), with polyvinylidene fluoride membrane (PVDF) as the support and dispersion solution containing HNO 3 solution as the stripping solution and Di(2-ethylhexyl) phosphoric acid (D2EHPA) dissolved in kerosene as the membrane solution, was studied. The effects of pH value, initial concentration of Eu(III) and different ionic strengths in the feed phase, volume ratio of membrane solution and stripping solution, concentration of HNO 3 solution, concentration of carrier, different stripping agents in the dispersion phase on the separation of Eu(III) were also investigated, respectively. As a result, the optimum separation conditions of Eu(III) were obtained as the concentration of HNO 3 solution was 4.00 mol/L, concentration of D2EHPA was 0.160 mol/L, and volume ratio of membrane solution to stripping solution was 30:30 in the dispersion phase, and pH value was 5.00 in the feed phase. Ionic strength had no obvious effect on the separation of Eu(III). Under the optimum conditions studied, when initial concentration of Eu(III) was 1.00×10 −4 mol/L, the separation rate of Eu(III) was up to 94.2% during the separation period of 35 min. The kinetic equation was developed in terms of the law of mass diffusion and the theory of interface chemistry. The results were in good agreement with the literature data.