Adsorptive Properties of Mn-Substituted Goethite Particles for Aqueous Solutions of Lead, Copper, and Zinc

Abstract

The substitution of Mn for Fe in the goethite (α-FeOOH) framework and the excess addition of Mn beyond the solid-solubility limit, approximately 1.5 mol%Mn, contribute to the change of adsorptive properties for metal ions, Pb^II, Cu^II, and Zn^II, in aqueous solutions. Removal of Pb^II from the metal solution at pH 4 was enhanced by the excess addition of Mn in the synthetic process for Mn-substituted goethite. This enhancement was caused by the formation of a new composite adsorbent, α-(Fe, Mn)OOH particles with (Fe, Mn)₃O₄ precipitates on their surfaces.