|
|
 |
|||||||||||||||||
|
|||||||||||||||||
 |
|||||||||||||||||
| JOURNAL HOME | HELP | CONTACT PUBLISHER | SUBSCRIBE | ARCHIVE | SEARCH | TABLE OF CONTENTS |
1 Department of Earth Sciences and Williamson Research Centre for Molecular Environmental Science, University of Manchester, Oxford Road, Manchester M13 9PL, UK
2 CLRC Daresbury Laboratory, Daresbury, Warrington WA4 4AD, UK
3 Department of Chemistry, University of Kalyani, Kalyani, West Bengal, 741 235, India
* E-mail: andrew.gault{at}man.ac.uk
Knowledge of the solid-phase speciation of As in Bengali sediments associated with hazardous As-rich groundwaters is crucial to understanding the processes controlling As release. The local coordination environment of As in such a sediment has been probed using K-edge As EXAFS. This revealed that As exists predominantly in its oxidized form, As(V), probably adsorbed as bidentate arsenate tetrahedra on metal (Fe and/or Al) oxide/hydroxide surfaces, although incorporation of As into a metal oxide structure cannot be ruled out. Arsenic was found to occur in several different coordination environments and this, together with the low concentration (<10 µg g–1) of As in the sediment prevented the unambiguous assignment of the second coordination sphere. The EXAFS analysis of the sediment after incubation under anaerobic conditions in the presence of added electron donor for metal reduction indicated changes in the relative concentrations of different solid-phase As species, providing circumstantial evidence for differential susceptibility to microbial action.
KEYWORDS: speciation, arsenic, West Bengal, India, EXAFS
This article has been cited by other articles:
|
|
 |
|
  J.M. Charnock, D.A. Polya, A.G. Gault, and R.A. Wogelius Direct EXAFS evidence for incorporation of As5+ in the tetrahedral site of natural andraditic garnet American Mineralogist, November 1, 2007; 92(11-12): 1856 - 1861. [Abstract] [Full Text] [PDF]
|
|
|
|
 |
|
 H. A. L. Rowland, A. G. Gault, J. M. Charnock, and D. A. Polya Preservation and XANES determination of the oxidation state of solid-phase arsenic in shallow sedimentary aquifers in Bengal and Cambodia Mineralogical Magazine, October 1, 2005; 69(5): 825 - 839. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
C. Pascua, J. Charnock, D. A. Polya, T. Sato, S. Yokoyama, and M. Minato Arsenic-bearing smectite from the geothermal environment Mineralogical Magazine, October 1, 2005; 69(5): 897 - 906. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
E. Valsami-Jones and D. A. C. Manning Environmental Mineralogy: introduction to a thematic set of papers arising out of sessions held at IMA 2002, Edinburgh, UK Mineralogical Magazine, December 1, 2003; 67(6): 1123 - 1125. [Full Text] [PDF]
|
|
| JOURNAL HOME | HELP | CONTACT PUBLISHER | SUBSCRIBE | ARCHIVE | SEARCH | TABLE OF CONTENTS |
