TITLE:
Characterization of Chromium in Contaminated Soil Studied by SEM, EDS,XRD and Mossbauer Spectroscopy
AUTHORS:
L. R. Reyes-Gutiérrez, E. T. Romero-Guzmán, A. Cabral-Prieto, R. Rodríguez-Castillo
KEYWORDS:
Cr(VI), soil contamination, Mossbauer, EDS, SEM, DRX
JOURNAL NAME:
Journal of Minerals and Materials Characterization and Engineering,
Vol.7 No.1,
March
20,
2008
ABSTRACT: Chromium is important from the environmental point of view since its behavior and toxicity
properties depend on its oxidation states. The Cr(VI) concentration in wells of Buenavista,
Guanajuato, Mexico, is higher than the permissible level of it for drinking water, 0.05mg/L. The
objective of this research was to determine the elution of chromium with deionized water from
contaminated soil samples and to determine the oxidation state of Fe, which is an element that
can limit the mobility of chromium. These results will be considered in a pump and treat
remediation scheme for this site. Chromium contaminated soil samples were obtained from an
industrial area of Leon, Guanajuato, México. O, Na, Mg, K, Al, Si, Ca, Cr and Fe were found in
the chemical analysis by EDS of the contaminated samples. In the soluble species only O, Na, S,
Ca and Cr were found. The oxidation state of iron was determined by Mossbauer spectroscopy
(MS) in the soil contaminated with chromium, in the soil washed with deionizer water and also in
the soluble samples. CaCrO4 was found in the soluble fraction, as a single crystalline phase by XRD. MS indicated that at least two iron species were present, one insoluble and the other
sparingly soluble.