Synergistic separation of copper(II) in sulfate solutions through outer-sphere coordination of dinonylnaphthalene disulfonic acid

Synergistic extraction is a promising strategy to achieve the separation and concentration of metal ions from complex effluents. Herein, the selective extraction behaviors of Cu(II) with 2-ethylhexyl pyridine-4-carboxylate ester (LII) and dinonylnaphthalene disulfonic acid (H2DNNDS) have been investigated. The extraction of impurity ions including Al(III), Fe(III), Mn(II), Mg(II) and Ca(II) can be effectively depressed at the high molar ratio of...