Adsorption of Pb(II) Ions from Aqueous Solutions Using a Low Grade Iron Ore as an Effective Adsorbent

Abstract

The use of banded hematite quartzite (BHQ), a low-grade iron ore, as an adsorbent for the removal of lead(II) ions from aqueous solutions was studied. X-Ray diffraction (XRD) studies of BHQ ore showed the presence of hematite and quartz as the major mineral phases, while FT-IR studies showed the presence of Si-OH and Fe-OH sites capable of exhibiting strong adsorption properties. SEM/EDS studies indicated that the particles of the materials were relatively fine and contained Fe, Si and 0, together with trace amounts of Al. Batch adsorption studies demonstrated that BHQ exhibits a significant capacity towards the adsorption of Pb(II) ions from aqueous solution. The parameters of the adsorption process investigated in this study included the effect of agitation time, initial Pb(II) ion concentration, adsorbent dosage, pH and temperature. The adsorption of Pb(II) ions onto BHQ increased as the pH of the aqueous medium increased from 1.8 to 6.5. Maximum removal of Pb(H) ions (99.8%) from aqueous solutions with an initial Pb(II) ion content of 10 mg/l occurred at pH 5.0. The sorptions data for Pb(II) ions were correlated using the Langmuir and Freundlich isotherms, thereby allowing an analysis of the equilibrium data obtained at room temperature. The Langmuir isotherm indicated monolayer formation on the adsorbent surface.