The eastern part of the Adelaide Geosyncline contains well preserved glaciomarine sequences of the Sturtian glaciation (:750–700 Ma) including calcareous or dolomitic siltstone, manganiferous siltstone, dolostone and diamictite units and the associated Braemar ironstone facies. The ironstone facies occurs as matrix to diamictites and as massive to laminated ironstones and comprises abundant Fe ...

Recent studies have suggested that a chromian spinel can be formed under natural hydrothermal conditions; however, the required conditions, process, and associated redistribution of Cr are still poorly understood. Here, formation was performed by Fe-Cr hydroxides alteration with an Fe2+(aq) supply at 150, 170, 200 °C 5 MPa simulating diagenetic process. The flow-through system enabled to leache...

Magnetite (Fe3O4) is a commonly found in the environment and can form via several pathways, including biotic and abiotic reduction of Fe oxides and the oxidation of Fe and Fe. Despite extensive research, the redox behavior of magnetite is poorly understood. In previous work, the extent and kinetics of contaminant reduction by magnetite varied by several orders of magnitude between studies, two ...

Magnetite nanoparticles are redox active constituents of subsurface and corrosive environments. In this study, we characterized the aggregation and sedimentation behavior of well characterized magnetite nanoparticle clusters using dynamic light scattering (DLS), UV-vis-NIR spectroscopy, and small angle X-ray scattering (SAXS). Both unfunctionalized (NaOH-magnetite) and tetramethylammonium hydro...

Nanocomposite cation exchange membranes (CEMs) were prepared by adding various amounts of functionalized silica-coated magnetite nanoparticles to the sulfonated polyethersulfone (sPES) polymeric matrix. The particles were synthesized first by the co-precipitation method (M0). Different surface modifications were then carried out on them by grafting three functional groups of mercaptopropyl, pro...

Humic substances (HS) are redox-active compounds that are ubiquitous in the environment and can serve as electron shuttles during microbial Fe(III) reduction thus reducing a variety of Fe(III) minerals. However, not much is known about redox reactions between HS and the mixed-valent mineral magnetite (Fe3O4) that can potentially lead to changes in Fe(II)/Fe(III) stoichiometry and even dissolve ...

Ž . Although dissimilatory iron reducing bacteria DIRB are capable of reducing a number of metals in oxides and soluble forms, the factors controlling the raterextent of magnetite reduction and the nature of the mineral products resulting from magnetite reduction are not well understood. This study was carried out to investigate mechanisms and biogeochemical processes occurring during magnetite...