title: Time-resolved XANES speciation studies of chromium on soils during simulated contamination.
abstract: Time-resolved synchrotron X-ray absorption near edge structure (XANES) spectroscopy was used to study changes of chromium speciation in soils upon soil-water interaction. The time resolution was 30-45 min. In a flow-column apparatus operated near the synchrotron beamline, two different types of soil were treated with potassium-dichromate solution, and soil samples were taken and directly analysed by XANES. The results provide insight into different equilibrium times of a few hours, depending on the type of soil. The XANES speciation analyses, based on a model comprising insoluble Cr(III) and Cr(VI) compounds, show how the fate of Cr species on soils can be followed close to real-time. Since the method allowed the soils to be investigated close to real-time, sampling in the field and preservation before analysis were made redundant. This study benefits the development of corresponding in situ remediation techniques.
authors.affiliation: Centre for Materials and Surface Science and Department of Physics, La Trobe University, Kingsbury Drive, Bundoora, Victoria 3086, Australia. p.kappen@latrobe.edu.au
authors.forename: P
authors.initials: P
authors.lastname: Kappen
authors.forename: E
authors.initials: E
authors.lastname: Welter
authors.forename: P H
authors.initials: PH
authors.lastname: Beck
authors.forename: J M
authors.initials: JM
authors.lastname: McNamara
authors.forename: K A
authors.initials: KA
authors.lastname: Moroney
authors.forename: G M
authors.initials: GM
authors.lastname: Roe
authors.forename: A
authors.initials: A
authors.lastname: Read
authors.forename: P J
authors.initials: PJ
authors.lastname: Pigram
mesh_terms: D002857:Chromium / Q000032:analysis* / Q000737:chemistry; D011192:Potassium Dichromate / Q000737:chemistry; D012680:Sensitivity and Specificity; D012989:Soil Pollutants / Q000032:analysis* / Q000737:chemistry; D012996:Solutions / Q000737:chemistry; D013052:Spectrometry, X-Ray Emission / Q000379:methods*; D013997:Time Factors
chemical_list: D012989:Soil Pollutants; D012996:Solutions; D002857:Chromium; D011192:Potassium Dichromate