Journal ArticleDOI
Surface catalysis of uranium(VI) reduction by iron(II)
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In this article, the authors investigated the kinetic effect of specific adsorption interactions on the chemical reduction of uranyl (UVIO22+) by ferrous iron, and derived a rate law for surface-catalyzed U(VI) reduction by Fe(II), d[U(VI)] dt =−k[≡ Fe III OFe II OH 0 ][U( VI)] ads where the bimolecular rate constant k has a value of 399 ± 25 M−1 min−1 at 25°C.About:
This article is published in Geochimica et Cosmochimica Acta.The article was published on 1999-10-01. It has received 647 citations till now. The article focuses on the topics: Uranyl & Reaction rate constant.read more
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Dissertation
Mineralisation and biomineralisation of radionuclides
TL;DR: In this paper, the authors used a self-organising map to identify areas of promising and active research as well as less researched interdisciplinary areas in the field of radionuclide degradation.
Journal ArticleDOI
Determining the kinetics of discrete aqueous redox reaction sub-steps using computational methods: Application to reactions of plutonyl (PuO2+/2+) with Fe2+, Fe3+, and hydroxyl radical (•OH)
Will M. Bender,Udo Becker +1 more
TL;DR: In this article, the authors used collision theory and quantum-mechanical modeling to analyze the energy, as well as atomic charges and spins, as a function of distance between the two reactants.
Journal ArticleDOI
Hydroxyl groups bridge the electron transfer from Fe(II) to carbon tetrachloride.
TL;DR: In this article , the rate of reductive dechlorination of carbon tetrachloride (CT) by Ferrous Hydroxyl Complex (FHC) increased with increasing OH- dosage.
Journal ArticleDOI
Natural attenuation of dissolved uranium within a small stream of central Japan
TL;DR: In this paper, the authors investigated the natural attenuation of the uranium (U) load in the surface water within a humid forest in Japan, and the results indicated that U, which within the study area is derived from pegmatites at a mine, is attenuated by uptake onto the surface of organic material and uptake by amorphous material that forms over time within dams.
Reaction-based modeling of quinone-mediated bacterial iron(III) reduction
Abstract: This paper presents and validates a new paradigm for modeling complex biogeochemical systems using a diagonalized reaction-based approach. The bioreduction kinetics of hematite (α-Fe2O3) by the dissimilatory metal-reducing bacterium (DMRB) Shewanella putrefaciens strain CN32 in the presence of the soluble electron shuttling compound anthraquinone-2,6-disulfonate (AQDS) is used for presentation/validation purposes. Experiments were conducted under nongrowth conditions with H2 as the electron donor. In the presence of AQDS, both direct biological reduction and indirect chemical reduction of hematite by bioreduced anthrahydroquinone-2,6-disulfonate (AH2DS) can produce Fe(II). Separate experiments were performed to describe the bioreduction of hematite, bioreduction of AQDS, chemical reduction of hematite by AH2DS, Fe(II) sorption to hematite, and Fe(II) biosorption to DMRB. The independently determined rate parameters and equilibrium constants were then used to simulate the parallel kinetic reactions of Fe(II) production in the hematite-with-AQDS experiments. Previously determined rate formulations/parameters for the bioreduction of hematite and Fe(II) sorption to hematite were systematically tested by conducting experiments with different initial conditions. As a result, the rate formulation/parameter for hematite bioreduction was not modified, but the rate parameters for Fe(II) sorption to hematite were modified slightly. The hematite bioreduction rate formulation was first-order with respect to hematite ”free“ surface sites and zero-order with respect to DMRB based on experiments conducted with variable concentrations of hematite and DMRB. The AQDS bioreduction rate formulation was first-order with respect to AQDS and first-order with respect to DMRB based on experiments conducted with variable concentrations of AQDS and DMRB. The chemical reduction of hematite by AH2DS was fast and considered to be an equilibrium reaction. The simulations of hematite-with-AQDS experiments were very sensitive to the equilibrium constant for the hematite-AH2DS reaction. The model simulated the hematite-with-AQDS experiments well if it was assumed that the ferric oxide “surface” phase was more disordered than pure hematite. This is the first reported study where a diagonalized reaction-based model was used to simulate parallel kinetic reactions based on rate formulations/parameters independently obtained from segregated experiments.
References
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Book
Critical Stability Constants
TL;DR: Erratum to: Aminocarboxylic Acids to: Iminodiacetic Acid Derivatives to: Peptides to: Aliphatic Amines to: Protonation Values for other Ligands.
Book
Solutions, Minerals and Equilibria
Robert M. Garrels,C. L. Christ +1 more
TL;DR: In this article, the authors provide a thorough, up-to-date coverage of controls on the chemical quality of surface and ocean waters. But they do not provide a detailed analysis of the results of their experiments.
Book
Fourier Transform Infrared Spectrometry
TL;DR: The theory and instrumentation for Fourier transform infrared spectrometry are discussed, and important areas of chemistry include atmospheric monitoring, surface chemistry, and on-line identification of chromatographically separated materials.
Book
Vogel's textbook of quantitative chemical analysis
TL;DR: In this paper, the principles of reaction in solution are discussed and the basis of separarative methods are discussed, as well as the safety units of Reagent Purity and Reagent Reactions in Solution.
Journal ArticleDOI
Uranium solution-mineral equilibria at low temperatures with applications to sedimentary ore deposits
TL;DR: The Gibbs free energies, enthalpies and entropies of 42 dissolved uranium species and 30 uranium-bearing solid phases have been critically evaluated from the literature and estimated when necessary for 25°C.