Roles of surfactant, oxidant and activator on enhanced electrokinetic-persulfate technique for the removal of hydrophobic organic compounds in soil: A review

Researchers have explored electrokinetic remediation (EKR) for two decades due to its applicability, cost-effectiveness, flexibility, and wider scope for the soil remediation of organic and inorganic contaminants. The integration of the EKR technique with persulfate-based advanced oxidation has received considerable attention recently. Persulfate (PS) can degrade into strong oxidants, such as sulfate (SO4 center dot-) and hydroxyl radicals ((OH)-O-center dot), which can degrade most of the hydrophobic organic contaminants (HOCs) in soil. Various studies have discussed the efficiency, synergistic effects, and futuristic scope of the EKR-PS technique. However, research on the challenges and limitations of the EKR-PS technique is limited. This review summarizes bench-scale studies of EKR-PS techniques, where new knowledge and insights have emerged, particularly regarding the role of surfactants, oxidants, and activators in the effective degradation of HOCs in low-permeability soils. We emphasize that it is essential to update our understanding of the enhanced EKR-PS technique in order to apply it to the remediation HOCs at the field level. Future research directions are also discussed.

Automated summary

Researchers have explored electrokinetic remediation (EKR) for two decades and recently discovered its integration with persulfate-based advanced oxidation as an effective method for soil remediation. However, research on the challenges and limitations of this technique is limited. This review summarizes bench-scale studies of EKR-PS techniques, emphasizing the importance of updating our understanding of this technique for field-level application in the remediation of hydrophobic organic contaminants (HOCs) in low-permeability soils. Future research directions are also discussed.