Facilitated transport of Cr(VI) through a novel activated composite membrane containing Cyanex 923 as a carrier

This paper describes the facilitated transport of Cr(VI) through a novel Activated Composite Membrane (ACM) containing Cyanex 923 as a carrier. The ACM was prepared by immobilization of the Cyanex 923 on a polysulfone support by means of interfacial polymerisation. The prepared ACM was characterized by using scanning electron microscopy (SEM) and atomic force microscopy (AFM) techniques and contact angle measurements. The effect of feed phase composition, carrier concentration of the casting solution and stripping phase composition on the transport of Cr(VI) was investigated. When the feed phase contained 1 X 10(-3) M Cr(VI) at pH 1.0, 99% of Cr(VI) was transported through the ACM (prepared with 3% carrier solution) by using 1 M NaOH as a stripping phase. Furthermore, Cr(VI) was preferably transported in the presence of various metal ions (i.e., Cr(III), Ni(II), Cu(II), Zn(II), Cd(II), Co(II), etc.) and sulphate and nitrate ions had no negative effect on the transport of Cr(VI). The results also showed that transport efficiency of the ACM was reproducible and it could be efficiently used in the long-term separation processes instead of supported liquid membrane (SLM). (C) 2009 Elsevier B.V. All rights reserved.