Oxidation of green rust suspensions containing different chromium ion species

The oxidation of hydrosulphate green rust (GR2(SO42-)) suspension containing different chromium ion species was investigated by X-ray diffraction, X-ray absorption spectroscopy and transmission electron microscopy. The pH, oxidation-reduction potential and amount of dissolved oxygen in aqueous solutions were measured during the reactions. The results show that the addition of Cr(III)(2)(SO4)(3) solution suppresses the transformation of GR2(SO42-) into iron oxyhydroxides and oxides in aqueous solution, while the addition of Na2Cr(VI)O-4 solution promotes the transformation of GR2(SO42-) in which Cr(VI) is reduced to Cr(III); alpha-FeOOH particles were refined by the addition of the chromium ions. (C) 2009 Elsevier Ltd. All rights reserved.