Based on theorical analysis of existing models and on experimental observat
ions, a model that allows us to connect the permeate flux to the intrinsic
separation factor taking account of the terms of the minimal and maximal se
paration factors, was established. The experiments covering a large range o
f permeate flux (from several 10(-9) mu L/(m(2).s) to several 10(-3) mL/(m(
2).s)) permit us to determine the values of maximal separation and minimal
separation, as well as the solute transport parameter for the solutions of
sodium chloride and sodium sulfate.