• journal_title：Clays and Clay Minerals
• Contributor：Fabienne Favre ; Joseph W. Stucki ; Pascal Boivin
• Publisher：Clay Minerals Society
• Date：2006-
• Format：text/html
• Language：en
• Identifier：10.1346/CCMN.2006.0540407
• journal_abbrev：Clays and Clay Minerals
• issn：0009-8604
• volume：54
• issue：4
• firstpage：466
• section：Articles

The aim of this study was to compare the redox properties of oxides and smectite structural Fe (Fe_Str). Structural Fe in smectite often accounts for about half of the Fe pool in soils and sediments, and is naturally reduced by indigenous bacteria. This reaction is, however, seldom taken into account in environmental studies. The equation for the oxidation-reduction of Fe_Str and its application to the calculation of the standard electrode potential of Fe_Str, E₀, are discussed on the basis of literature review. The resulting redox properties were used in a new analysis of previously reported field monitoring data. This agreed well with experimental observations that remained unexplained, and showed that if equilibrium conditions prevail, the Fe_Str pool in soils will reduce prior to the Fe in oxides. The Fe_Str pool is, therefore, likely to play a major role in controlling the bio-geochemistry of temporarily water-logged soils, and this reaction should be taken into account in further studies.