Recovering copper ions from industrial environments by supported liquid membranes: parameters and mechanism
Résumé
The technique of supported liquid membranes (SLM) was used to study the facilitated
extraction of Cu(II) ions from acidic solutions, with tri-octhyl amine (TOA), methyl Cholate (MC) and Trin-octyl phosphine oxide (TOPO) as carriers , toluene as organic phase and a flat film of polyvinylidene
difluoride (PVDF) as hydrophobic support (0.45 μm pore) . The macroscopic parameters, permeability P
and initial flux J0 related to facilitated extraction of these ions have been determined, for the three carriers
and different initial concentrations of Cu (II) ions, we have observed a net evolution of these parameters. To
explain extraction phenomena of these ions by this membrane type (SLM), a mechanism based on the
complexation of Cu (II) ions by the carrier and the diffusion of the formed complex through the SLM
organic phase has been developed. Experimental results verify this mechanism and allow to find the
optimum carrier, and to determine the values of microscopic parameters, association constant Kass and
apparent diffusion coefficient D*, relating to the migration of the complex substrate-carrier, through the
membrane phase