REVERSE OSMOSIS OF COTTAGE CHEESE WHEY 2. Influence of Flow Conditions

Abstract

SUMMARY— Flow conditions in tubular, cellulose‐acetate reverse osmosis membranes were varied by changing the flow rate and by inserting turbulence promoters (rods with intermittently‐spaced rings cemented to them) in the tubes. In general, increasing the flow velocity increased the permeation rate. Turbulence promoters were most effective in increasing permeation rate under conditions that, in their absence, permitted fouling of the membrane surface by macrosolutes from the feed. When the feed contained macrosolutes, increasing the flow velocity or use of turbulence promoters increased retention of lactose and potassium. Modifying the flow conditions to increase turbulence improves performance of reverse osmosis membranes by increasing both permeation rate and retention.