TY - JOUR
T1 - Leaching behavior of Cr(III) in stabilized/solidified soil
AU - Jing, Chuanyong
AU - Liu, Suqin
AU - Korfiatis, George P.
AU - Meng, Xiaoguang
PY - 2006/6
Y1 - 2006/6
N2 - 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-1 and 25 600 mg-Fe kg-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-1 for untreated soil to 0.84 mg l-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 Ca2Cr2O5 · 6H2O at pH > 10.5.
AB - 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-1 and 25 600 mg-Fe kg-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-1 for untreated soil to 0.84 mg l-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 Ca2Cr2O5 · 6H2O at pH > 10.5.
KW - Chromium
KW - Leaching
KW - Stabilization/solidification
KW - Surface complexation model
KW - XANES
UR - http://www.scopus.com/inward/record.url?scp=33744544618&partnerID=8YFLogxK
UR - http://www.scopus.com/inward/citedby.url?scp=33744544618&partnerID=8YFLogxK
U2 - 10.1016/j.chemosphere.2005.12.039
DO - 10.1016/j.chemosphere.2005.12.039
M3 - Article
C2 - 16466774
AN - SCOPUS:33744544618
SN - 0045-6535
VL - 64
SP - 379
EP - 385
JO - Chemosphere
JF - Chemosphere
IS - 3
ER -