Microscale Investigation of Arsenic Distribution and Species in Cement Product from Cement Kiln Coprocessing Wastes

To improve the understanding of the immobilization mechanism and the leaching risk of Arsenic (As) in the cement product from coprocessing wastes using cement kiln, distribution and species of As in cement product were determined by microscale investigation methods, including electron probe microanalysis (EPMA) and X-ray absorption spectroscopy. In this study, sodium arsenate crystals (Na3AsO412H2O) were mixed with cement production raw materials and calcined to produce cement clinker. Then, clinker was mixed water to prepare cement paste. EPMA results showed that As was generally distributed throughout the cement paste. As content in calcium silicate hydrates gel (C-S-H) was in low level, but higher than that in other cement mineral phases. This means that most of As is expected to form some compounds that disperse on the surfaces of cement mineral phases. Linear combination fitting (LCF) of the X-ray absorption near edge structure spectra revealed that As in the cement paste was predominantly As(V) and mainly existed as Mg3(AsO4)2, Ca3(AsO4)2, and Na2HAsO4.

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Neptunium Reactivity During Co-Precipitation and Oxidation of Fe(II)/Fe(III) (Oxyhydr)oxides

Geosciences ◽

10.3390/geosciences9010027 ◽

2019 ◽

Vol 9 (1) ◽

pp. 27 ◽

Cited By ~ 2

Author(s):

Hannah E. Roberts ◽

Katherine Morris ◽

J. Frederick W. Mosselmans ◽

Gareth T. W. Law ◽

Samuel Shaw

Keyword(s):

Green Rust ◽

Solution Chemistry ◽

Natural Environments ◽

Edge Structure ◽

X Ray ◽

End Point ◽

Mineral Phases ◽

Oxidation In Air ◽

Co Precipitation ◽

X Ray Absorption

Fe(II) bearing iron (oxyhydr)oxides were directly co-precipitated with Np(V)O2+ under anaerobic conditions to form Np doped magnetite and green rust. These environmentally relevant mineral phases were then characterised using geochemical and spectroscopic analyses. The Np doped mineral phases were then oxidised in air over 224 days with solution chemistry and end-point oxidation solid samples collected for further characterisation. Analysis using chemical extractions and X-ray absorption spectroscopy (XAS) techniques confirmed that Np(V) was initially reduced to Np(IV) during co-precipitation of both magnetite and green rust. Extended X-Ray Absorption Fine Structure (EXAFS) modelling suggested the Np(IV) formed a bidentate binuclear sorption complex to both minerals. Furthermore, following oxidation in air over several months, the sorbed Np(IV) was partially oxidised to Np(V), but very little remobilisation to solution occurred during oxidation. Here, linear combination fitting of the X-Ray Absorption Near Edge Structure (XANES) for the end-point oxidation samples for both mineral phases suggested approximately 50% oxidation to Np(V) had occurred over 7 months of oxidation in air. Both the reduction of Np(V) to Np(IV) and inner sphere sorption in association with iron (oxyhydr)oxides, and the strong retention of Np(IV) and Np(V) species with these phases under robust oxidation conditions, have important implications in understanding the mobility of neptunium in a range of engineered and natural environments.

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Determination of the As(III)/As(V) Ratio in Soil by X-ray Absorption Near-edge Structure (XANES) and Its Application to the Arsenic Distribution between Soil and Water

Analytical Sciences ◽

10.2116/analsci.19.891 ◽

2003 ◽

Vol 19 (6) ◽

pp. 891-896 ◽

Cited By ~ 36

Author(s):

Yoshio TAKAHASHI ◽

Naoya OHTAKU ◽

Satoshi MITSUNOBU ◽

Kouichi YUITA ◽

Masaharu NOMURA

Keyword(s):

Edge Structure ◽

X Ray ◽

Arsenic Distribution ◽

X Ray Absorption ◽

Soil And Water

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Chemical and orientational imaging of polymeric samples

Proceedings, annual meeting, Electron Microscopy Society of America ◽

10.1017/s0424820100168074 ◽

1994 ◽

Vol 52 ◽

pp. 68-69

Author(s):

H. Ade ◽

B. Hsiao ◽

G. Mitchell ◽

E. Rightor ◽

A. P. Smith ◽

...

Keyword(s):

Ethylene Terephthalate ◽

National Laboratory ◽

Brookhaven National Laboratory ◽

Carbonyl Groups ◽

Aromatic Rings ◽

Edge Structure ◽

X Ray ◽

Scanning Transmission ◽

Polymeric Samples ◽

X Ray Absorption

We have used the Scanning Transmission X-ray Microscope at beamline X1A (X1-STXM) at Brookhaven National Laboratory (BNL) to acquire high resolution, chemical and orientation sensitive images of polymeric samples as well as point spectra from 0.1 μm areas. This sensitivity is achieved by exploiting the X-ray Absorption Near Edge Structure (XANES) of the carbon K edge. One of the most illustrative example of the chemical sensitivity achievable is provided by images of a polycarbonate/pol(ethylene terephthalate) (70/30 PC/PET) blend. Contrast reversal at high overall contrast is observed between images acquired at 285.36 and 285.69 eV (Fig. 1). Contrast in these images is achieved by exploring subtle differences between resonances associated with the π bonds (sp hybridization) of the aromatic groups of each polymer. PET has a split peak associated with these aromatic groups, due to the proximity of its carbonyl groups to its aromatic rings, whereas PC has only a single peak.

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In Vivo Investigation of the Distribution and the Local Speciation of Selenium inAlliumcepa L. by Means of Microscopic X-ray Absorption Near-Edge Structure Spectroscopy and Confocal Microscopic X-ray Fluorescence Analysis

Analytical Chemistry ◽

10.1021/ac060380s ◽

2006 ◽

Vol 78 (22) ◽

pp. 7616-7624 ◽

Cited By ~ 49

Author(s):

Ewa Bulska ◽

Irena A. Wysocka ◽

Małgorzata H. Wierzbicka ◽

Kristof Proost ◽

Koen Janssens ◽

...

Keyword(s):

Fluorescence Analysis ◽

Edge Structure ◽

X Ray ◽

X Ray Absorption

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Full-Field Calcium K-Edge X-ray Absorption Near-Edge Structure Spectroscopy on Cortical Bone at the Micron-Scale: Polarization Effects Reveal Mineral Orientation

Analytical Chemistry ◽

10.1021/acs.analchem.5b04898 ◽

2016 ◽

Vol 88 (7) ◽

pp. 3826-3835 ◽

Cited By ~ 12

Author(s):

Bernhard Hesse ◽

Murielle Salome ◽

Hiram Castillo-Michel ◽

Marine Cotte ◽

Barbara Fayard ◽

...

Keyword(s):

Cortical Bone ◽

Edge Structure ◽

Full Field ◽

Polarization Effects ◽

X Ray ◽

X Ray Absorption

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Local structure and cation distribution analysis of Mn1-xZnxFe2O4 powders by X-ray Absorption Near Edge Structure Spectroscopy

Radiation Physics and Chemistry ◽

10.1016/j.radphyschem.2021.109628 ◽

2021 ◽

pp. 109628

Author(s):

Jaru Jutimoosik ◽

Pinit Kidkhunthod ◽

Theerachai Bongkarn ◽

Rattikorn Yimnirun

Keyword(s):

Cation Distribution ◽

Local Structure ◽

Distribution Analysis ◽

Edge Structure ◽

X Ray ◽

X Ray Absorption

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Database of ab initio L-edge X-ray absorption near edge structure

Scientific Data ◽

10.1038/s41597-021-00936-5 ◽

2021 ◽

Vol 8 (1) ◽

Author(s):

Yiming Chen ◽

Chi Chen ◽

Chen Zheng ◽

Shyam Dwaraknath ◽

Matthew K. Horton ◽

...

Keyword(s):

High Throughput ◽

Scattering Theory ◽

Research Community ◽

Metal Compounds ◽

Edge Structure ◽

X Ray ◽

Initial Release ◽

Computational Workflow ◽

X Ray Absorption

AbstractThe L-edge X-ray Absorption Near Edge Structure (XANES) is widely used in the characterization of transition metal compounds. Here, we report the development of a database of computed L-edge XANES using the multiple scattering theory-based FEFF9 code. The initial release of the database contains more than 140,000 L-edge spectra for more than 22,000 structures generated using a high-throughput computational workflow. The data is disseminated through the Materials Project and addresses a critical need for L-edge XANES spectra among the research community.

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Theoretical and experimental investigation of point defects in cubic boron nitride

MRS Advances ◽

10.1557/adv.2017.53 ◽

2017 ◽

Vol 2 (29) ◽

pp. 1545-1550 ◽

Cited By ~ 1

Author(s):

Nicholas L. McDougall ◽

Jim G. Partridge ◽

Desmond W. M. Lau ◽

Philipp Reineck ◽

Brant C. Gibson ◽

...

Keyword(s):

Boron Nitride ◽

Cubic Boron Nitride ◽

Optical Emission ◽

Wide Band ◽

Wide Band Gap ◽

Edge Structure ◽

X Ray ◽

Substitutional Defects ◽

X Ray Absorption ◽

Annealing Experiments

ABSTRACTCubic boron nitride (cBN) is a synthetic wide band gap material that has attracted attention due to its high thermal conductivity, optical transparency and optical emission. In this work, defects in cBN have been investigated using experimental and theoretical X-ray absorption near edge structure (XANES). Vacancy and O substitutional defects were considered, with O substituted at the N site (ON) to be the most energetically favorable. All defects produce unique signatures in either the B or N K-edges and can thus be identified using XANES. The calculations coupled with electron-irradiation / annealing experiments strongly suggest that ON is the dominant defect in irradiated cBN and remains after annealing. This defect is a likely source of optical emission in cBN.

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