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
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Journal ArticleDOI
INCORPORATION OF Mo6+ IN FERRIHYDRITE, GOETHITE, AND HEMATITE
TL;DR: In this article, the authors investigated the relation between Mo content and its structural incorporation in hematite, goethite, and six-line ferrihydrite by a combination of X-ray absorption spectroscopy (XAS), powder Xray diffraction (pXRD), and inductively-coupled plasma optical emission spectrometry (ICP-OES).
Book
Sorption of Arsenic, Mercury, Selenium onto Nanostructured Adsorbent Media and Stabilization via Surface Reactions
TL;DR: Han et al. as discussed by the authors evaluated the ability of novel nanostructured adsorbent media (NTAs, iron sulfides (FeS2 and FeS)) to remove arsenic, selenium and mercury from ash and scrubber pond effluents.
Journal ArticleDOI
Two-dimensional MXene for efficient arsenic removal from aqueous solutions: experimental and molecular dynamics simulation
Ahmad Kayvani Fard,Tarik Rhadfi,Gordon McKay,Yehia Manawi,Viktor Kochkodan,One Sun Lee,Muataz Ali Atieh +6 more
TL;DR: In this paper, a 2D titanium carbide nanosheet was used as a nanoadsorbent for the removal of toxic arsenic species from water, which exhibited high sorption capacities and fast kinetics for As(III) removal from water.
Book ChapterDOI
Processes and conditions affecting elevated arsenic concentrations in groundwaters of Tulare Basin, California, USA
S. Gao,K.K. Tanji,G.S. Bañuelos +2 more
TL;DR: In this article, high concentrations of arsenic (As) in the shallow and deep groundwaters of the Tulare Basin in California, USA, pose a hazardous risk to drinking water supplies and the complexities of interactions among multi aquifers and water flow present challenges in identifying the source of As and its movement.
Journal ArticleDOI
Iron Vacancy Accelerates Fe(II)-Induced Anoxic As(III) Oxidation Coupled to Iron Reduction.
TL;DR: In this article , the authors show that As(III) oxidation can be facilitated by Fe oxyhydroxides (i.e., goethite) under anoxic conditions coupled with the reduction of structural Fe(III).
References
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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.