Remediation of chromium-contaminated soil by electrokinetics and electrokinetics coupled with CaAl-LDH permeable reaction barrier.
The remediation of Cr(VI)-contaminated soil was investigated by electrokinetic (EK) and permeable-reactive-barrier assisted electrokinetic (EK-PRB). The medium of PRB was hydrocalumite (CaAl-LDH). The results showed that removal efficiency of hexavalent chromium (Cr(VI)) in EK-PRB and EK system was 96.49 and 85.50%, respectively. Simultaneously, the removal efficiency of total chromium (TCr) was 69.34 and 40.97% after 120-h treatment. The XRD, FTIR, and XPS analyses indicated that the reactive barrier media of CaAl-LDH successfully captured the chromium. Besides, the migration rate of chromium in EK-PRB was relatively faster than EK, since the media of PRB captured chromium in-time and reduced the influence of chromium accumulation on the migration of chromium. Moreover, the trivalent chromium (Cr(III)) was generated in EK/EK-PRB, and the chromium was stabilized in soil with the chemical speciations of oxidizable and residual fractions. Therefore, the treatment of EK-PRB and EK both increased the removal of chromium and decreased its environmental risks.
['Xu|Yunfeng|Y|', 'Xia|Wei|W|', 'Hou|Hetian|H|', 'Zhang|Jia|J|', 'Qian|Guangren|G|']
D000537:Aluminum Oxide D002122:Calcium Chloride D002857:Chromium D055664:Electrochemical Techniques D052918:Environmental Restoration and Remediation D007700:Kinetics D008903:Minerals D012987:Soil D012989:Soil Pollutants
Chromium-contaminated soil Electrokinetics CaAl-LDH Permeable-reactive-barrier Soil water