Mathematical modelling and simulation of cotransport phenomena through flat sheet-supported liquid membranes

A mathematical model of cotransport phenomena of metal ions across flat sheet-supported liquid membranes (FSSLM) is developed in the transient. The initial conditions of the FSSLM system, the physical characteristics of the membrane (porosity, tortuosity and thickness), the kinetics of the chemical reaction in the feed-membrane interface and the diffusion in the membrane phase are taken into account by the model. By using the electroneutrality principle, an expression of the concentration of cotransport species with the metal is deduced in terms of the temporal variation of the metal concentration in the feed phase. From the proposed model, the maximum percentage of metal transported is derived. Finally, a simulation is performed for the case of the transport of metal anions in alkaline solution and is checked against experimental data corresponding to the transport of Au(CN)(2)(-) in alkaline solution by LIX 79. The proposed model reproduces this transport phenomenon with great accuracy. (C) 2004 Elsevier B.V. All rights reserved.