Separation Science and Technology, Vol.34, No.10, 1947-1962, 1999
Modeling of solvent and ionic fluxes in electronanofiltration
Electronanofiltration (ENF) is a new membrane separation process that uses an additional electric field between the permeate and retentate sides during nanofiltration. A recently published pioneering work gives the performance with single and mixed ionic solutions containing one monovalent cation and one or two anions (mono- or/and divalent). It appears that the electric field leads to a net increase of cation flux and it decrease of anion permeation at the same time if the cathode is placed on the permeate side. In relation with the well-known dependence of solvent flux on transmembrane pressure, these data open up potential applications of ENF for new integrated operations of ion separation/concentration. In this paper a semiempirical model accounting for permeate and ionic fluxes is proposed. Based on the Stefan-Maxwell approach, a simple set of linearized equations is developed that fits experimental data at various transmembrane pressure (Delta P), electric fields (Delta U), and concentrations (C).