Influence of montmorillonite on Fe(II) oxidation products
Source: Clay Minerals, Volume 33, Number 2, 1 June 1998 , pp. 205-212(8)
Publisher: Mineralogical Society
Abstract:Goethite and maghemite are the stable species of Fe oxyhydroxides-oxides formed in acidic and alkaline environments from the oxidation of Fe(II) perchlorate solutions. The influence of montmorillonite on the oxidation products of 0.02 M ferrous perchlorate at pHs of 6.0 and 8.0 was studied by X-ray diffraction, infrared and transmission electron microscopic analyses. Increased rate of OH consumption during the oxidation at constant pH indicated that the presence of montmorillonite accelerated the rate of Fe(II) oxidation. The presence of montmorillonite, with high surface reactivity, at an initial montmorillonite/Fe (w/w) ratios of 1.4 and 3.4 retarded the formation of goethite, lepidocrocite and maghemite, and maghemite and goethite, and promoted the formation of ferrihydrite and lepidocrocite at pHs of 6.0 and 8.0, respectively. Kaolinite, on the other hand, with relatively low surface reactivity had no influence on the nature of the Fe(II) oxidation products formed at either pH.
Document Type: Research article
Affiliations: 1: Dipartimento di Scienze Chimico-Agrarie, Universita di Napoli Federico II, 80055 Portici, Italy 2: Department of Soil Science, University of Saskatchewan, 51 Campus Drive, Saskatoon SK S7N 5A8, Canada 3: Department of Soil Science,niversity of Saskatchewan, 51 Campus Drive, Saskatoon SK S7N 5A8, Canada
Publication date: 1998-06-01