Leaching Behavior of Cr(III) in Stabilized/Solidified Soil
The leaching behavior of chromium was studied using batch leaching tests, surface complexation modeling and X-ray absorption near edge structure (XANES) spectroscopy. A contaminated soil sample containing 1330 mg-Cr kg{sup -1} and 25 600 mg-Fe kg{sup -1} of dry soil was stabilized/solidified (S/S) with 10% cement, 25% cement, 10% lime and a mixture of 20% flyash and 5% lime. The XANES analysis showed that Cr(III) was the only Cr species in untreated soil and S/S-treated samples. The leachate Cr concentration determined using the toxicity characteristic leaching procedure (TCLP) was reduced from 5.18 mg l{sup -1} for untreated soil to 0.84 mg l{sup -1} for the sample treated with 25% cement. The Cr leachability in untreated and treated soil samples decreased dramatically as the pH increased from 3 to 5, remained at similar levels in the pH range between 5 and 10.5, and further decreased at pH > 10.5. Modeling results indicated that the release of Cr(III) was controlled by adsorption on iron oxides at pH < 10.5, and by precipitation of Ca{sub 2}Cr{sub 2}O{sub 5} {center_dot} 6H{sub 2}O at pH > 10.5.
- Research Organization:
- Brookhaven National Lab. (BNL), Upton, NY (United States). National Synchrotron Light Source
- Sponsoring Organization:
- Doe - Office Of Science
- DOE Contract Number:
- DE-AC02-98CH10886
- OSTI ID:
- 914208
- Report Number(s):
- BNL-78776-2007-JA; CMSHAF; TRN: US0801602
- Journal Information:
- Chemosphere, Vol. 64, Issue 3; ISSN 0045-6535
- Country of Publication:
- United States
- Language:
- English
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