Akimoto NAKAMURA

Preferential adsorption of heavy metal ions on Goethite (ƒ¿-FeOOH) particles

Kazunori SATO

Goethite(ƒ¿-FeOOH) has been known as a strong adsorbent for heavy metal ions in aqueous environment. Substitution of foreign metals elements for Fe3+ ions in the goethite lattice can affect the color, shape, and the unit-cell dimension of goethite particles. An influence of the foreign-metal substitution in goethite has been studied on the preferential adsorption of Pb(II) ions. Among the foreign metals elements investigated in this study: Mn, Ni, Ga and Cr, Mn (20mol%)-substituted goethite showed the highest ability for the adsorption of Pb(II) ions in an aqueous solution of Pb(II), Cu(II), and Zn(II) ions. The effect of anisotropy in goethite particles was also investigated on the preferential adsorption of Pb(II) ions for the samples prepared from Fe(NO3)3 ,Fe2(SO4)3 and FeSO4. Crystallograhic anisotropy in the prepared goethite particles was caused by the starting reagent and the synthetic conditions. This anisotropy greatly affected adsorptive properties of goethite for Pb(II), Cu(II), and Zn(II) ions.