Competitive adsorption of Pb(II), Cu(II) and Zn(II) onto xanthate-modified magnetic chitosan

► The competitive adsorption of Pb(II), Cu(II) and Zn(II) onto a novel xanthate-modified magnetic chitosan (XMCS) in single and ternary systems were investigated. ► In single system, the adsorption of Pb(II), Cu(II) and Zn(II) followed the Langmuir model. ► In ternary system, the combined action of the metals was found to be antagonistic. ► The FTIR and XPS studies showed that the thiol and amino group participated in the adsorption of Pb(II), Cu(II) and Zn(II).