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The Impact Of Small Organic Acids On Iron And Manganese Mineral Transformations And The Fate Of Trace Metals, Elaine Denise Flynn
The Impact Of Small Organic Acids On Iron And Manganese Mineral Transformations And The Fate Of Trace Metals, Elaine Denise Flynn
Arts & Sciences Electronic Theses and Dissertations
Iron and manganese oxides are ubiquitous in soils and sediments and play a critical role in the geochemical distribution of trace elements and heavy metals through adsorption and coprecipitation. At redox interfaces, biogeochemical processes generate conditions with coexisting dissolved Fe(II) and solid-phase Fe(III). In such systems, Fe(II) induces the recrystallization of iron oxides through coupled mineral growth and dissolution due to electron transfer as oxidative adsorption of Fe(II) and reductive dissolution of Fe(III) occur. Aqueous Mn(II) adsorption onto Mn(III/IV) oxides also likely involves oxidation although likely through different mechanisms than that of the Fe system because of the potential for …
Ion Interactions At The Mineral-Water Interface During Biogeochemical Iron And Manganese Cycling, Margaret A. G. Hinkle
Ion Interactions At The Mineral-Water Interface During Biogeochemical Iron And Manganese Cycling, Margaret A. G. Hinkle
Arts & Sciences Electronic Theses and Dissertations
The biogeochemical cycling of iron and manganese involves the reductive dissolution and oxidative precipitation of Fe(III) and Mn(IV/III) oxides. Biogenic Fe(III) and Mn(IV/III) oxides are often characterized by high surface areas and therefore high sorptive capacities. As a result, these minerals can substantially alter the chemistry of natural waters and the availability of micronutrients in soils and sediments by scavenging trace metals. Recent research indicates that the adsorption of aqueous Fe(II) onto Fe(III) oxides involves oxidative adsorption, electron transfer, and subsequent reductive dissolution at another surface site [a process collectively referred to as `electron transfer-atom exchange' (ET-AE)]. Aqueous Mn(II) adsorption …