Multivariate optimization approach for Cu(II) ions selective extraction from a mixture of six metal cations via benzyl bis(thiosemicarbazone)

Copper(II) ion is an environmental contamination, which has been tested and assessed over the past few years from both the toxicological and human health viewpoints [1]. It has been well reported that the accumulation of copper in human body causes brain, skin, pancreas and heart diseases [2]. Therefore, various methods for the recovery of Cu(II) ions from the aqueous solutions have been used. The main aim of this work is to investigate the competitive extraction of Cu(II) ion from an aqueous solution containing Mn(II), Co(II), Ni(II), Cu(II), Zn(II) and Pb(II) metal cations using benzylbis(thiosemicarbazone) (I) as carrier. Taguchi design approach for screening and central composite design (CCD) for optimization was carried out and optimum conditions were determined. Under the optimal conditions, Cu(II) ions were extracted of 93.35% from the mixture of six metal cations solution, and other cations remained in source aqueous phase (Fig. 1).