Separation of multicomponent liquid systems containing non-volatile compounds (e.g. salts, sugars or proteins) became an important and interesting case of the application of pervaporation (PV) process. The aim of this work was to evaluate the influence of NaCl on the performance of PV removal of methyl acetate (MeAc) from water using hydrophobic membrane. The selective and transport properties were determined for a hydrophobic PDMS membrane (PERVAP 1060-Sulzer Chemtech Membrane Systems, Germany) in contact with pure water, binary water-MeAc and ternary water-MeAc-NaCl systems. Vacuum pervaporation experiments were performed at 25 degrees C. The concentration range for the binary system was 0-6 wt.% MeAc aqueous solution, whereas the composition of the ternary system was changed in the range 0-6 wt.% MeAc and 0-4 mol NaCl/kg H2O. It was found that NaCl, as a non-volatile compound, was not transported on the permeate side of the membrane. The obtained results showed that the presence of electrolyte in the feed solution caused simultaneously the decrease of the water flux and the increase of MeAc flux, thus increasing the membrane selectivity and the overall performance of the separation process. Such behavior of the membrane system can be explained by the salting-out effect and described using the Setschenov empirical equation. In contact with binary mixture (I wt.% MeAc) selectivity coefficient alpha = 160 and permeate flux of MeAc J(MeAc) = 202 g m(-2) h(-1) were found, whereas in contact with ternary mixture (1 wt.% MeAc, 4 mol NaCl/kg) alpha = 450 and J(MeAc) = 430 g m(-2) h(-1). The value of the pervaporation salting-out coefficient (k(s)(pv) = 0. 151 dM(3) mol(-1)) found in this work for lower NaCl concentration range (i.e. up to 2 mol dm(-3)), was well placed in the range of the k(s) values (0. 114-0.287 dm(3) mol(-1)) calculated by Segatin et al. using several different models. For the higher concentration region of NaCl some modifications of Setschenov equation, accounting for the hydration and solvation interactions between ions and water molecules as well as non-electrolyte self-interactions, should give much better correlation. (C) 2006 Elsevier B.V. All rights reserved.