Ion transport modelling through nanofiltration membranes

The aim of this work is to study the transport mechanism of ions through na nofiltration membranes. A model based on extended Nernst-Planck and film th eory equations is reported. This model can be characterized by three transp ort parameters: the water permeability L-p, the salt transmittance Phi and the effective salt transfer coefficient K-eff. The knowledge of the feed an d permeate concentration and of the permeate volumetric flux enable us to c alculate these transport parameters. The model is used to estimate cadmium salts rejection by a NANOMAX 50 membrane. Experimental and calculated resul ts are shown to be in good agreement. The model is then successfully extend ed to experimental data reported in the literature. (C) 1999 Elsevier Scien ce B.V. All rights reserved.