MODELING OF MASS-TRANSFER IN FACILITATED SUPPORTED LIQUID MEMBRANE-TRANSPORT OF GOLD(III) USING PHOSPHOLENE DERIVATIVES AS CARRIERS

An experimental study of gold(III) transport through solid-supported l iquid membranes using phospholene derivatives as carriers has been per formed using batch experiments. A model is reported describing the tra nsport mechanism which consists of a diffusion process through a feed aqueous diffusion layer, a fast interfacial chemical reaction and a di ffusion of HAuCl4L and HAuCl4L2 through the membrane. The mathematical equations describing the rate of transport are derived and correlate the membrane permeability coefficient to diffusional and equilibrium p arameters as well as the chemical composition of the system, such as e xtractant concentration in the membrane phase and HCl concentration in the feed phase. The experimental data are explained with the derived equations, and the diffusion resistances to mass transfer are evaluate d. The influence in the transport of stirring speed in the feed phase, the nature of the diluent and stripping agent, and the type of polyme ric support have been also discussed. (C) 1998 Elsevier Science B.V.