Oxidation of green rust suspensions containing different chromium ion species

Abstract

The oxidation of hydrosulphate green rust (GR2(SO 4 2−)) 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(SO 4) 3 solution suppresses the transformation of GR2(SO 4 2−) into iron oxyhydroxides and oxides in aqueous solution, while the addition of Na 2Cr(VI)O 4 solution promotes the transformation of GR2(SO 4 2−) in which Cr(VI) is reduced to Cr(III); α-FeOOH particles were refined by the addition of the chromium ions.