Using polyvinylidene fluoride membrane (PVDF) as a support, kerosene as a membrane solvent, di(2-ethylhexyl) phosphoric acid (D2EHPA) as a flowing carrier, the Gd(III) separation in a renewal supported liquid membrane (RSLM) was investigated. The effects of pH in the feed phase, volume ratio of membrane solution to HCl solution, concentration of HCl solution and concentration of carrier in the renewal phase on separation of Gd(III) have also been studied, respectively. As a result, the optimum separation conditions of Gd(III) were obtained as that concentration of HCl solution was 4.00 mol/L, concentration of D2EHPA was 0.160 mol/L, and volume ratio of membrane solution to HCl solution was 4∶3 in the renewal phase, and pH was 4.80 in the feed phase. When initial concentration of Gd(III) was 1.00×10^－4 mol/L, the separation rate of Gd(III) was up to 95.7% in 35 min. The kinetic equation of Gd(III) separation in RSLM was developed in terms of the law of mass diffusion and the theory of interface chemistry.

Key words: renewal supported liquid membrane, di(2-ethylhexyl) phosphoric acid, gadolinium(III), renewal phase