TRANSPORT CHARACTERISTICS OF THE RO THIN-FILM COMPOSITE MEMBRANES

The transport correlations by which one can predict the effect of pressure and solute concentration of the feed solution on membrane performance for the system sodium chloride-water-RO thin film composite membranes have been studied. As the scientific basis for specification and predicting technique the Kimura-Sourirajan analysis, based on a generalised capillary flow model was used. The effect of solute concentration of the feed solution (in the range 0.03-0.16 molality) and operating pressure (in the range of 1000-5000 kPa) on pure water permeability constant (A) and transport parameter (Dam/K-delta) for the thin film composite membranes FT 30 BW, MPD HT and HR-95 were established. The results are compared with the corresponding data obtained for cellulose acetate and aromatic polyamide membranes.