X-ray Microspectroscopy and Chemical Reactions in Soil Microsites
- Dean Hesterberg *a,
- Martine C. Duffb,
- Joe B. Dixonc and
- Michael J. Vepraskasa
- a Dep. of Soil Science, Box 7619, North Carolina State Univ., Raleigh, NC 27695-7619
b Savannah River National Lab., Washington Savannah River Company, Bldg. 773-42A, Aiken, SC 29808
c Dep. of Soil and Crop Sciences, Texas A&M Univ., 370 Olsen Blvd., College Station, TX 77843. Assigned to Associate Editor Ganga Hettiarachchi
Soils provide long-term storage of environmental contaminants, which helps to protect water and air quality and diminishes negative impacts of contaminants on human and ecosystem health. Characterizing solid-phase chemical species in highly complex matrices is essential for developing principles that can be broadly applied to the wide range of notoriously heterogeneous soils occurring at the earth's surface. In the context of historical developments in soil analytical techniques, we describe applications of bulk-sample and spatially resolved synchrotron X-ray absorption spectroscopy (XAS) for characterizing chemical species of contaminants in soils, and for determining the uniqueness of trace-element reactivity in different soil microsites. Spatially resolved X-ray techniques provide opportunities for following chemical changes within soil microsites that serve as highly localized chemical micro- (or nano-)reactors of unique composition. An example of this microreactor concept is shown for micro-X-ray absorption near edge structure analysis of metal sulfide oxidation in a contaminated soil. One research challenge is to use information and principles developed from microscale soil chemistry for predicting macroscale and field-scale behavior of soil contaminants.Please view the pdf by using the Full Text (PDF) link under 'View' to the left.
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