XAFS Investigation for As(V) Co-Precipitation Mechanism with Ferrihydrite
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- TOKORO Chiharu
- School of Creative Science and Engineering, Faculty of Science and Engineering, Waseda University
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- KOGA Hajime
- School of Creative Science and Engineering, Faculty of Science and Engineering, Waseda University
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- ODA Yuji
- School of Creative Science and Engineering, Faculty of Science and Engineering, Waseda University
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- OWADA Shuji
- School of Creative Science and Engineering, Faculty of Science and Engineering, Waseda University
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- TAKAHASHI Yoshio
- Graduate School of Science, Hiroshima University
Bibliographic Information
- Other Title
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- XAFSによるFerrihydriteへのAs(V)共沈機構の考察
- XAFS ニ ヨル Ferrihydrite エ ノ As V キョウチン キコウ ノ コウサツ
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Abstract
XRD/XAFS analysis were conducted to investigate the As(V) co-precipitation mechanism with ferrihydrite (γ-FeOOH). In As(V) co-precipitation with ferrihydrite, XRD results showed that As(V) complexation to the surface of ferrihydrite was dominant when the initial molar ratio of As/Fe was less than 0.25, whereas surface precipitation of amorphous ferric arsenate was formed when the initial molar ratio of As/Fe was more than 0.5.<BR>Both of XANES and EXAFS analysis on K-edge of As showed As(V) co-precipitates with ferrihydrite was the mixture of As(V) adsorbed ferrihydrite and amorphous ferric arsenate. Molar ratio of amorphous ferric arsenate in As(V) co-precipitates was estimated to be more than 0.5 when the initial molar ratio of As/Fe was more than 0.5. These results are in good agreement with the XRD results. EXAFS analysis assuming one surface complex for As-Fe bond showed the coordination number of As to Fe in As(V) co-precipitates increased with increasing the initial molar ratio of As/Fe. Moreover, EXAFS analysis assuming three kinds of surface complexes for As-Fe bond showed the coordination number for 2.85 Å of the atomic distance of As-Fe increased and it for 3.24 Å of the atomic distance of As-Fe decreased with increasing the initial As/Fe molar ratio. All experimental data obtained in this study showed As(V) co-precipitation mechanism shifted gradually from As(V) complexation to the surface of ferrihydrite toward amorphous ferric arsenate with increase in the initial molar ratio of As/Fe.
Journal
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- Journal of MMIJ
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Journal of MMIJ 127 (4_5), 213-218, 2011
The Mining and Materials Processing Institute of Japan
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Keywords
Details 詳細情報について
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- CRID
- 1390001205279997312
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- NII Article ID
- 10028160391
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- NII Book ID
- AA12188381
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- COI
- 1:CAS:528:DC%2BC3MXnvFKqtbY%3D
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- ISSN
- 18840450
- 18816118
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- NDL BIB ID
- 11069251
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- Text Lang
- en
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- Data Source
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- JaLC
- NDL
- Crossref
- CiNii Articles
- KAKEN
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- Abstract License Flag
- Disallowed