Whittleston, RA, Stewart, DI, Mortimer, RJG et al. (4 more authors) (2011) Chromate reduction in Fe(II)-containing soil affected by hyperalkaline leachate from chromite ore processing residue. Journal of Hazardous Materials, 194. 15 - 23 . ISSN 0304-3894
Abstract
Highly alkaline (pH 12.2) chromate contaminated leachate (990 μmol L−1) has been entering soils below a chromite ore processing residue disposal (COPR) site for over 100 years. The soil immediately beneath the waste has a pH of 11 → 12.5, contains 0.3 → 0.5% (w/w) chromium, and 45 → 75% of the microbially available iron is Fe(II). Despite elevated pH, a viable microbial consortium of Firmicutes dominated iron reducers was isolated from this COPR affected soil. Soil pH and Cr concentration decrease with distance from the waste. XAS analysis of soil samples indicated that Cr is present as a mixed Cr(III)–Fe(III) oxy-hydroxide phase, suggesting that the elevated soil Cr content is due to reductive precipitation of Cr(VI) by Fe(II). Microcosm results demonstrate the capacity of COPR affected soil to abiotically remove all Cr(VI) from the leachate within 40 days. In air oxidation experiments less than 2% of the total Cr in the soil was remobilised despite significant Fe(II) oxidation. XAS analysis after air oxidation showed no change in Cr-speciation, indicating the Cr(III)-containing phase is a stable long term host for Cr. This work suggests that reductive precipitation of Cr(VI) is an effective method of contaminant immobilisation in soils where microbially produced Fe(II) is present.
Metadata
Item Type: | Article |
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Authors/Creators: |
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Dates: |
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Institution: | The University of Leeds |
Academic Units: | The University of Leeds > Faculty of Environment (Leeds) > School of Earth and Environment (Leeds) The University of Leeds > Faculty of Engineering & Physical Sciences (Leeds) > School of Chemical & Process Engineering (Leeds) The University of Leeds > Faculty of Engineering & Physical Sciences (Leeds) > School of Civil Engineering (Leeds) |
Depositing User: | Symplectic Publications |
Date Deposited: | 05 Feb 2013 10:59 |
Last Modified: | 15 Nov 2016 21:23 |
Published Version: | http://dx.doi.org/10.1016/j.jhazmat.2011.07.067 |
Status: | Published |
Publisher: | Elsevier |
Identification Number: | 10.1016/j.jhazmat.2011.07.067 |
Open Archives Initiative ID (OAI ID): | oai:eprints.whiterose.ac.uk:74934 |