Microscopically Focused
Synchrotron X-ray Investigation of
Selenium Speciation in Soils
Developing on Reclaimed Mine
Lands
Amy L. Ryser
Daniel G. Strawn
Matthew A. Marcus
Sirine Fakra
Jodi L. Johnson-Maynard
Gregory Möller
10.1021/es051674i.s001
https://acs.figshare.com/articles/journal_contribution/Microscopically_Focused_Synchrotron_X_ray_Investigation_of_Selenium_Speciation_in_Soils_Developing_on_Reclaimed_Mine_Lands/3243940
Chemical speciation determines Se solubility and therefore
its bioavailability and potential for transport in the
environment. In this study we investigated the speciation
of Se in soil developed on reclaimed mine sites in the U.S.
Western Phosphate Resource Area (WPRA) using micro-X-ray absorption near-edge structure (μ-XANES) spectroscopy
and micro-X-ray fluorescence (μ-XRF) mapping. Selenium
was nonuniformly distributed in the soils and positively
correlated with Fe, Mn, Cu, Zn, and Ni. Sixteen points of
interest (POI) from three soil samples were analyzed with
μ-XANES spectroscopy. The XANES data indicated that
Se is present in the soils in at least three oxidation states,
Se(−II, 0), Se(IV), and Se(VI). Selenides or elemental Se
dominated 7 of the 16 POI. Selenate was the dominant species
at only one of the POI. The remaining eight POI were
composed of both Se(IV) and Se(VI), with minor Se(−II, 0)
contributions. The results of this research suggest that
the reduced Se species in the soil parent material are
oxidizing to Se(VI), one of the more mobile species of Se in
the environment. This information can be used to better
predict and manage Se availability in soils.
2006-01-15 00:00:00
16 POI
XANES data
WPRA
soil samples
Selenium Speciation
Reclaimed Mine Lands Chemical speciation
XRF
Se species
soil parent material
oxidation states
Western Phosphate Resource Area
Se availability
Se solubility
U.S
mine sites