CONTROL OF CONCENTRATION POLARIZATION IN REVERSE OSMOSIS DESALINATION OF WATER

Concentration polarization has been studied in a thin channel reverse osmosis test device under laminar flow conditions. Experiments were performed with cellulose acetate membranes and aqueous sodium chloride solutions at 1500 psig hydrostatic pressure, results of which were in agreement with an earlier theoretical analysis of P.L.T. Brian. In order to simulate the high flux conditions expected of future desalination membranes, comparable reverse osmosis measurements were made using aqueous tetrabutylammonium chloride solution with a high-water-permeability polyelectrolyte complex resin membrane which displays significant retention of this electrolyte. It has been demonstrated that concentration polarization can be controlled with small expenditure of energy in laminar flow and thin channels for membrane permeation fluxes up to 60 gallons/sq. ft. day and a fractional feed water recovery of more than 50%. © 1969.