Separation and concentration of trace Pb(II) by the porous resin loaded with α-zirconium phosphate crystals

Crystalline α-zirconium phosphate (α-ZrP) has been loaded in the pores of porous spherical polymer beads by impregnation of ZrOCl ₂·8H₂O and hydrolysis of the zirconium salt followed by the hydrothermal reaction with phosphoric acid. The physicochemical properties of the α-ZrP loaded resin have been investigated in terms of X-ray diffraction, pore distribution, surface area and the distribution of α-ZrP in the polymer beads. The scanning electron microscope observation indicates that α-ZrP crystals distribute uniformly in the resin pore. The adsorption characteristics of the α-ZrP resin for the metal ions including Pb(II), Cd(II), Cu(II), Zn(II), Fe(III), Al(III) and Ca(II) have been examined. The present resin has revealed unexpectedly high selectivity toward the adsorption of Pb(II) and hence, interference from common metal ions (Na ⁺, Ca²⁺) is not significant. Due to the remarkable selectivity, fast kinetics and chemical stability, the present α-ZrP resin has been effectively applied to the separation and enrichment of trace Pb(II) from aqueous solution.