Journal ArticleDOI
Arsenate and Chromate Retention Mechanisms on Goethite. 1. Surface Structure
TLDR
In this paper, the authors used Extended X-ray absorption fine structure (EXAFS) spectroscopy to deduce the local coordination environment of two environmental contaminants, arsenate and chromate, on the mineral goethite (α-FeOOH).Abstract:
The molecular structure of ions retained on mineral surfaces is needed to accurately model their sorption process and to determine their stability. Extended X-ray absorption fine structure (EXAFS) spectroscopy was used in this study to deduce the local coordination environment of two environmental contaminants, arsenate and chromate, on the mineral goethite (α-FeOOH). Based on the oxyanion−Fe distances, it was concluded that three different surface complexes exist on goethite for both oxyanions: a monodentate complex, a bidentate-binuclear complex, and a bidentate-mononuclear complex. At low surface coverages, the monodentate complex was favored while at higher coverages the bidentate complexes were more prevalentthe bidentate-binuclear complex appears to be in the greatest proportion at these highest surface coverages. Therefore, modeling efforts for chromate or arsenate retention on goethite need to consider a monodentate complex at very low coverages, both the monodentate and bidentate complexes at in...read more
Citations
More filters
Journal ArticleDOI
Zinc Speciation in Contaminated Sediments: Quantitative Determination of Zinc Coordination by X-ray Absorption Spectroscopy
TL;DR: In this article, the authors used X-ray absorption spectroscopy (XAS) to quantify the various proportions of the different ligation spheres of zinc in the sediments of Lake DePue (Illinois, USA), an environment contaminated by smelting operations.
Journal ArticleDOI
Adsorption of Oxyanions from Industrial Wastewater using Perlite-Supported Magnetite.
TL;DR: Perlite-supported magnetite is suitable for treating real wastewaters: it can remove several oxyanions simultaneously from the considered industrial wastewater, but the adsorption order changes due to the presence of interfering anions.
Journal ArticleDOI
Sensing and Approaching Toxic Arsenate by Shewanella putrefaciens CN-32.
TL;DR: The conventional view about arsenic as a chemotactic inhibitor to microbes is reversed by revealing the positive chemotaxis of Shewanella to As(V), and it is observed that such a sense is governed by an energy taxis mechanism and mediated by several methyl-acceptingChemotaxis proteins (MCPs), rather than a specific MCP.
Journal ArticleDOI
Reactivity of As and U co-occurring in Mine Wastes in northeastern Arizona.
Johanna M. Blake,Sumant Avasarala,Abdul-Mehdi S. Ali,Michael N. Spilde,Juan S. Lezama-Pacheco,Drew E. Latta,Kateryna Artyushkova,Anastasia G. Ilgen,Christopher Shuey,Christopher Nez,José M. Cerrato +10 more
TL;DR: The reactivity of co-occurring arsenic and uranium in mine wastes was investigated using batch reactors, microscopy, spectroscopy, and aqueous chemistry to suggest that As and U can be released under environmentally relevant conditions in mine waste, which is applicable to risk and exposure assessment.
ReportDOI
EBS Radionuclide Transport Abstraction
TL;DR: In this article, the authors developed and analyzed the EBS RT abstraction model, consistent with Level I and Level II model validation, as identified in ''Technical Work Plan for: Near-Field Environment and Transport: Engineered Barrier System: Radionuclide Transport Abstraction Model Integration'' (BSC 2005 [DIRS 173617]).
References
More filters
Book
Environmental Chemistry of Soils
TL;DR: In this article, an introduction to modern soil chemistry describes chemical processes in soils in terms of established principles of inorganic, organic, and physical chemistry, providing an understanding of the structure of the solid mineral and organic materials from which soils are formed.
Book
Iron Oxides in the Laboratory: Preparation and Characterization
Udo Schwertmann,R. M. Cornell +1 more
TL;DR: In this paper, the main aim of the second edition is to present reliable, well-tested, up-to-date methods of synthesizing pure iron oxides, including monodispersed particles, presently of great interest to industry.
Journal ArticleDOI
Theoretical X-ray Absorption Fine Structure Standards
John J. Rehr,John J. Rehr,J. Mustre de Leon,S. I. Zabinsky,S. I. Zabinsky,R. C. Albers,R. C. Albers +6 more
Journal ArticleDOI
Surface chemistry of ferrihydrite: Part 1. EXAFS studies of the geometry of coprecipitated and adsorbed arsenate
TL;DR: In this article, the As and Fe K-edges were collected from samples of two-line ferrihydrite with adsorbed (ADS) and coprecipitated (CPT) arsenate prepared over a range of conditions and arsenate surface coverages.