Selective adsorption of lead(II) from aqueous solution

Adsorptive separation of Pb(II) from aqueous solution containing Pb(II) and other heavy metals (Cu(II), Zn(II) and Cd(II)) has been investigated, using three adsorbents, such as an iminodiacetic acid-chelating resin (CR11) and Fe-based adsorbents (goethite and magnetite). Batchwise adsorption of Pb(II) and other metal ions in single metal system and multi-components system was carried out with varying parameters, such as pH, time and initial concentrations of metals. CR11 possesses the highest adsorption ability for these metals, while the selectivity of individual metal is little. Goethite possesses selectivity for Pb(II) and Cu(II), and magnetite possesses selectivity for Pb(II), though the adsorption capacity for the metals is less than those with CR11. The kinetics of the adsorption of metals with all adsorbents is of pseudo-second-order, and the magnetite is revealed to have the fastest adsorption kinetics. The three adsorbents can be applied for chromatographic separation for these metals. The magnetite is feasible for selective separation of Pb(II), although complete elution cannot be achieved.