APPLICATION OF CELLULOSE ACETATE MEMBRANES FOR REMOVAL OF TOXIC METAL IONS FROM AQUEOUS SOLUTION

In this study, we investigated the transport of heavy metals ions through a polymer inclusion membrane (PIM) containing cellulose acetate (CA) as support, calix[4]resorcinarenes (RC) as carriers, 2-nitrophenyloctanoate (NPOT) and 2-nitrophenyloctylether (NPOE) as plasticizers. The effects of several transport conditions including, pH, PIM thickness, plasticizers amount and carriers concentration were studied. The optimal transport conditions for Pb(II), Cu(II) and Zn(II) were found to be 10.8 mM of carriers, 0.13 mL/g of CA for NPOE, a pH of 5.1 and 1.5 for feeding and receiving phases respectively. Our experiments revealed a facilitated counter-transport mechanism for ions transfer and showed that such PIMs can be reused for five consecutive cycles without appreciable deterioration. We characterized PIMs structure by several techniques and determined their water content and porosity. Applying these optimized transport conditions to remove metal ions from municipal wastewater samples, we found an overall removal efficiency of 87%, 86%, 75%, 72%, and 71% for Pb(II), Ni(II), Cd(II), Cu(II) and Zn(II) respectively. Of interest, the residual concentrations of these heavy metal ions were below the permissible limits according to the Algerian standards for wastewaters quality.