Transport of Co(II) Ions through Di(2-ethylhexyl) Phosphoric Acid-CCl4 Supported Liquid Membranes

Abstract

A liquid membrane transport study of Co(II) using di(2-ethylhexyl) phosphoric acid (D2EPHA) as carrier and CCl₄, as diluent supported on polypropylene microporous film has been carried out. The carrier concentration in the membrane and HCl concentration in the stripping phase have been varied to see the effect on transport of Co(II) ions across the membrane. Maximum flux and permeability values of 1.23 × 10^?5 mol · m^?2 · s^?1 and 7.66 × 10^?11 m²/s, respectively, at a 0.87 mol/dm³ carrier concentration in the membrane have been found. At 1 mol/dm³ HCl concentration in the stripping phase the flux and permeability have maximum values of 1.4 mol · m^?2 · s^?1 and 5.27 × 10^?11 m²/s, respectively. The distribution coefficient of Co(II) ions into organic phase has been found to increase with increasing carrier concentration. The diffusion coefficient determined varies from 13.73 × 10^?11 to 0.83 × 10^?11 m²/s, which is the reverse order of the values of the distribution coefficient and explains the permeability of the Co(II) D2EPHA complex through the membrane.