TY - JOUR
T1 - Thermal detoxification and bloating of chromium(VI) with bentonite
AU - Wei, Y. L.
AU - Hsieh, H. F.
AU - Peng, Y. S.
AU - Yang, J. C.
AU - Wang, H. Paul
AU - Lin, C. Y.
AU - Shih, W. L.
AU - Hsu, C. C.
N1 - Funding Information:
The authors thank Professor J.-F. Lee and the staff at the NSRRC of Taiwan for their assistance during the XAS experimentation. This project was sponsored by the National Science Council of Taiwan ( NSC 89-2211-E-029-008 ).
PY - 2010/7/1
Y1 - 2010/7/1
N2 - This study stabilizes and bloats Cr(VI)-sorbed bentonite by heating at high temperature. Cr leaching decreases with increasing temperatures. Heating the sample at 1100 °C results in a non-detectable Cr concentration in the leachate, equivalent to a Cr leaching percent less than 0.001% (i.e., Cr TCLP concentration < 0.018 mg of Cr L-1 of leachate). Morphology observed with a scanning electron microscopy indicates the occurrence of sintering of the sample heated at 1100 1°C. The heated samples also show the occurrence of a vesicant process at 1100 1°C. X-ray absorption spectroscopy results indicate that heating at 500 °C for 4h can convert approximately 87% Cr(VI) into Cr(III) that is negligibly toxic; Cr2O3 was detected to be the most abundant Cr species. After heating at higher temperatures, namely 900-1100 °C, almost all doped Cr(VI) is reduced to Cr(III) as inferred from the height of the pre-edge peak of XANES spectra and/or from XANES simulation.
AB - This study stabilizes and bloats Cr(VI)-sorbed bentonite by heating at high temperature. Cr leaching decreases with increasing temperatures. Heating the sample at 1100 °C results in a non-detectable Cr concentration in the leachate, equivalent to a Cr leaching percent less than 0.001% (i.e., Cr TCLP concentration < 0.018 mg of Cr L-1 of leachate). Morphology observed with a scanning electron microscopy indicates the occurrence of sintering of the sample heated at 1100 1°C. The heated samples also show the occurrence of a vesicant process at 1100 1°C. X-ray absorption spectroscopy results indicate that heating at 500 °C for 4h can convert approximately 87% Cr(VI) into Cr(III) that is negligibly toxic; Cr2O3 was detected to be the most abundant Cr species. After heating at higher temperatures, namely 900-1100 °C, almost all doped Cr(VI) is reduced to Cr(III) as inferred from the height of the pre-edge peak of XANES spectra and/or from XANES simulation.
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U2 - 10.1016/j.nima.2009.10.130
DO - 10.1016/j.nima.2009.10.130
M3 - Article
AN - SCOPUS:78650283891
SN - 0168-9002
VL - 619
SP - 108
EP - 111
JO - Nuclear Instruments and Methods in Physics Research, Section A: Accelerators, Spectrometers, Detectors and Associated Equipment
JF - Nuclear Instruments and Methods in Physics Research, Section A: Accelerators, Spectrometers, Detectors and Associated Equipment
IS - 1-3
ER -