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
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Arsenic in Alluvial Aquifers in the Meghna Basin, Southeastern Bangladesh : Hydrogeological and Geochemical Characterisation
TL;DR: Elevated levels of arsenic (As) in Bangladesh groundwater has emerged as a massive calamity exposing a large population to the risk of As toxicity from drinking water sources and agricultural prod....
Journal ArticleDOI
Extraction of Arsenic and Heavy Metals from Contaminated Mine Tailings by Soil Washing
Myoung-Jin Kim,Tae-Suk Kim +1 more
TL;DR: In this article, a soil washing technique has been used to treat mine tailings contaminated heavily with arsenic and heavy metals at Jingok mine, which is one of the abandoned mines in Korea.
Journal ArticleDOI
Enhancing corrosion stability and shelf life of nanoscale zero-valent iron via encapsulation in porous Ze-TiO2 matrix: An interface for simultaneous oxidation and adsorption of As(III)
TL;DR: In this paper, the nano-titania layer imparts a hydrophilic character to an otherwise hydrophobic substrate of zeolite, enhancing rate of As(III) adsorption.
Book ChapterDOI
XAFS for Characterization of Nanomaterials
Maria Katsikini,E. C. Paloura +1 more
TL;DR: X-ray absorption fine structure (XAFS) spectroscopy studies the modification of the X-ray absorbing coefficient, above the absorption edge of a specific element, due to the presence of neighboring atoms and delivers information on materials nano- and electronic structure as mentioned in this paper.
Journal ArticleDOI
Competitive kinetics of Ni(II)/Co(II) and Cr(VI)/P(V) adsorption and desorption on goethite: A unified thermodynamically based model
TL;DR: In this article , an integrated thermodynamic-kinetic model was developed to predict the binary competitive adsorption of Ni(II)-Co(II), Cr(VI)-P(V), and P(V)-Cr(VI) on goethite under various conditions.
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.