APPLICATION OF LOW-PRESSURE REVERSE-OSMOSIS MEMBRANE FOR ZN2-WATER( AND CU2+ REMOVAL FROM WASTE)

Reverse osmosis (RO) is a pressure-driven operation which normally req uires more than 690 kPa (100 psig) for effective removal of metal ions from their solvents. This paper, however, illustrates the feasibility of using complexation and low-pressure RO membranes for the removal o f Zn2+ and Cu2+ by applying pressures significantly below 690 kPa. The results show that the use of EDTA is a reliable method for increasing the percentage removal of both Zn2+ and Cu2+ with sulphonated polysul phone RO membranes. The percentage removal of metal ions of Zn2+ was s lightly greater than that for Cu2+. Copyright (C) 1996 IAWQ. Published by Elsevier Science Ltd.