Remediation of a hexachlorobenzene-contaminated soil by surfactant-enhanced electrokinetics coupled with microscale Pd/Fe PRB.
Treatment of soils contaminated with chlorinated hydrophobic organic compounds (CHOCs) remains a challenge for environmental scientists worldwide. In this study surfactant-enhanced electrokinetics (SEEK) was coupled with permeable reactive barrier (PRB) composed of microscale Pd/Fe to treat a hexachlorobenzene (HCB)-contaminated soil. A nonionic surfactant, Triton X-100 (TX-100), was selected as the solubility-enhancing agent. Five bench-scale tests were conducted to investigate the performance of EK-PRB on HCB removal from soils. Results showed that the HCB removal was generally increased by a factor of 4 by EK coupled with PRB compared with EK alone (60% versus 13%). In the EK-PRB system, HCB was removed from soil through several sequential processes: the movement driven by electroosmotic flow (EOF) in the anode column, the complete adsorption/degradation by the reactive Pd/Fe particles in PRB, and the consequent movement by EOF and probable electrochemical reactions in the cathode column. TX-100 was supposed to be a superior enhancement agent for HCB removal, not only in the EOF movement process but also in the Pd/Fe degradation process. This study indicates that the combination of SEEK and Pd/Fe PRB is efficient and promising to remove CHOCs from contaminated soils.
Wan
Jinzhong
J
Environmental Science Research Institute, Huazhong University of Science and Technology, Wuhan 430074, PR China.
Li
Zhirong
Z
Environmental Science Research Institute, Huazhong University of Science and Technology, Wuhan 430074, PR China.
Lu
Xiaohua
X
Environmental Science Research Institute, Huazhong University of Science and Technology, Wuhan 430074, PR China. Electronic address: hust-esri2009@hotmail.com.
Yuan
Songhu
S
Environmental Science Research Institute, Huazhong University of Science and Technology, Wuhan 430074, PR China. Electronic address: yuansonghu@mail.hust.edu.cn.
D004563:Electrochemistry / Q000379:methods*; D052918:Environmental Restoration and Remediation / Q000379:methods*; D006581:Hexachlorobenzene / Q000737:chemistry*; D007501:Iron / Q000737:chemistry*; D007700:Kinetics; D010165:Palladium / Q000737:chemistry*; D012989:Soil Pollutants / Q000737:chemistry*; D013501:Surface-Active Agents / Q000737:chemistry*
D012989:Soil Pollutants; D013501:Surface-Active Agents; D006581:Hexachlorobenzene; D010165:Palladium; D007501:Iron