Concentration polarization in the reverse osmosis desalination of sea water

Abstract This paper presents data which show the effect of concentration polarization on the product rate and product quality for reverse osmosis system operating on sea water feed. The system was the same 1″ diameter tubular design pioneered by Sidney Loeb while at the University of California, Los Angeles. The tests were conducted on asymmetric cellulose acetate membranes of the Loeb-Sourirajan type. Membranes cured at temperatures of 83°C, 88°C, and 92°C were tested at 1000 psi operating pressure for a range of Reynolds numbers from 1000 to 42,000. The applicability of the Brian equation for use in the turbulent flow regime is checked. The possibility of adapting this equation for use in the laminar region by use of a correction term cw/c0w which can be estimated from a graph is discussed. Figs. 3, 4, and 5 present direct experimental evidence for the performance of tubular membranes as a function of bulk brine velocity.