THE INFLUENCE OF HYDROSTATIC-PRESSURE ON THE SELECTIVITY OF ELECTROMEMBRANE SYSTEMS UNDER THE LIMITING CONDITIONS OF THE CONCENTRATION POLARIZATION

The influence of small hydrostatic pressure gradients on the selectivi ty of electromembrane systems under the limiting conditions of concent ration polarization is studied at various initial solution concentrati ons on either side of the membrane under study using the rotating memb rane disk. The analysis of variance and regressive analysis show that the membrane selectivity considerably (by 12-17%) decreases when the p ressure on the side of the solution being concentrated exceeds 0.003 M Pa; whereas no significant changes in the selectivity occur at the rev erse direction of the pressure gradient. The nontrivial effect involvi ng asymmetry of the influence of small hydrostatic pressure gradients on the selectivity of polarized electromembrane systems proves the nec essity of accounting for barofiltration processes at the interface bet ween the membrane and the solution being concentrated.