A comprehensive review of soil remediation contaminated by persistent organic pollutants using electrokinetic: Challenging enhancement techniques

• Published in: Journal of environmental management 2024-12, Vol.373, p.123587, Article 123587
• Main Authors: Fardin, Ali Barati, Jamshidi-Zanjani, Ahmad, Saeedi, Mohsen
• Format: Article
• Language: English
• Subjects: Electrokinetic; Enhancement techniques; Numerical modeling; Operational consideration; Persistent organic pollutants
• ISSN: 0301-4797; 1095-8630; 1095-8630
• DOI: 10.1016/j.jenvman.2024.123587

The hydrophobic, hard-to-naturally-decompose compounds, including polycyclic aromatic hydrocarbons (PAHs), polychlorinated biphenyls (PCBs), and pesticides, are categorized as persistent organic pollutants (POPs). POPs are toxic/hazardous and present serious risks to human health. Electrokinetic (EK) remediation is highly flexible and cost-effective, suitable for both in-situ and ex-situ applications. It effectively targets a wide range of contaminants, including metals and organic compounds, especially in low-permeability and low-hydraulic conductivity soils, where traditional methods are less effective. This technology is easy to install and can be combined with other strategies for enhanced remediation in complex soil environments. This paper underscores EK remediation as a promising method for addressing soil pollution caused by these organic pollutants, especially in low-permeability soil. The present review starts with the classification, toxicity effects, and source of POPs in the environment. Theoretical aspects and fundamentals of EK, including transport mechanisms and principles, are also reviewed. The theoretical underpinnings of effective factors are comprehensively explored, such as surface charge, zeta potential, pHpzc, and numerical modeling of transport fluxes. Moreover, a comprehensive examination is undertaken regarding the operation and design considerations of the EK process, encompassing factors like pH, electrode arrangement, electrolyte, and voltage. Subsequently, it is highlighted that EK has the potential to come in synergistically in contact with other remediation technologies to augment the POPs’ degradation. Various enhancement techniques are also explored, including solvent extraction, chemical oxidation, bioremediation, and permeable reactive barriers to combine with EK. Each method is examined in terms of its advantages, limitations, recent developments, and ongoing research. Finally, the potential and challenges associated with enhanced EK methods combined with other techniques for the removal of POPs were reviewed. [Display omitted] •The challenges of enhancement techniques combined with EK were deeply discussed.•Degradation mechanisms of POPs through enhancement techniques were reviewed.•Chemical oxidation combined with EK can be more efficient for POPs remediation.•Scalability and environmental impact of EK were reviewed.•The operational and design factors for soil remediation using EK were studied.