REMOVAL OF LEAD, COPPER AND NICKEL IONS FROM WASTEWATER BY FORWARD OSMOSIS PROCESS

Chemical

Abstract

In this study the application of a novel forward osmosis (FO) process for the removal of Pb(II), Cu(II), and Ni(II) metal ions from wastewater is briefly described. Polyamide (thin film composite (TFC))used as flat sheet forward membrane for heavy metal rejection under orientation membrane of active layer facing feed solution and using NaCl of different concentration as the draw solution. The operating parameters studied were draw solutions concentration (5 - 100 g/l), feed solutions concentration (5 - 200 mg/l), pH of feed solution (4 - 8), constant pressure and temperature were maintained at 0.2 bar and 25 °C respectively. It was found that the water flux increases with increasing draw solution concentration, and decreases with increasing feed solution concentration and pH of feed solution. For different type of heavy metal used as feed solution, the order of water flux was Pb+2> Cu+2> Ni+2. For binary and ternary feed solution, the water flux decreased with time and increasing with the concentration of feed solution due to decreasing of driving force. Forward osmosis can be used to recover water from wastewater contaminated by heavy metals with a rejection efficiency more than 99%, 97% and 87% for Pb+2, Ni+2, and Cu+2metal ions respectively.