Revista de Chimie, (2015), 66(3), pp .328 to 332 MATHEMATICAL MODELLING OF SOME PRECESSES OF SEPARATION THROUGH MEMBRANE – DYNAMIC MODELS. Daniela Elena Pascu, Aurelia Cristina Nechifor, Mihaela Pascu (Neagu), Gina Alina Traistaru, A.A. Bunaciu, Luoana Florentina Pascu and Ghe. Nechifor