SELECTIVITY OF ION-EXCHANGE MEMBRANES AS A FUNCTION OF HYDROSTATIC-PRESSURE

A procedure is developed for determining the selectivity of ion-exchan ge membranes under conditions limiting concentration polarization. The procedure is based on the use of a rotating membrane disk (RMD). Samp les of domestic and foreign membranes are tested. An excess hydrostati c pressure is found to affect most of the membranes studied. The membr ane selectivity increases in the presence of excess pressure on the si de of the desalination chamber and decreases in its presence on the ba ck side.