In-situ EXAFS study of copper in the electrokinetic remediation process.
The speciation of copper in the early stage of the electrokinetic remediation (EKR) process has been studied by extended X-ray absorption fine structure (EXAFS) spectroscopy in the present work. By in-situ EXAFS, we found that copper in a contaminated soil possessed a Cu-O bond distance of 1.98 A with a coordination number (CN) of 5.8. In the second shell, the bond distance of Cu-(O)-Cu was 2.87 A with a CN of 6.4. However, possibly due to the fact that incompact copper atoms in the outer shells were distorted by EKR, the Cu-(O)-Cu (2nd shell) bond distance and the CN of copper in the contaminated soil decreased by 0.08 A and 5.4, respectively in the early stage of the EKR process. Interestingly, after prolonging the contact time to about 80 minutes, the 1st-shell copper atoms were also perturbed by EKR. This work is an example of usefulness of the in-situ EXAFS spectroscopy for detailed studies of the speciation of copper in the contaminated soil during EKR process.
Liu
S H
SH
Department of Environmental Engineering, National Cheng Kung University, Tainan, Taiwan.
Wang
H P
HP
Wang
H C
HC
Yang
Y W
YW
D003300:Copper / Q000737:chemistry* / Q000302:isolation & purification; D004563:Electrochemistry / Q000379:methods*; D007700:Kinetics; D012989:Soil Pollutants / Q000032:analysis* / Q000302:isolation & purification; D013052:Spectrometry, X-Ray Emission / Q000379:methods
D012989:Soil Pollutants; D003300:Copper