Extraction agents for the removal of polycyclic aromatic hydrocarbons (PAHs) from soil in soil washing technologies

• Published in: Environmental pollution (1987) Vol. 184; pp. 640 - 649
• Main Authors: Lau, Ee Von, Gan, Suyin, Ng, Hoon Kiat, Poh, Phaik Eong
• Format: Journal Article
• Language: English
• Published: Kidlington Elsevier Ltd 01.01.2014; Elsevier
• Subjects: Applied sciences; Chemical Fractionation - methods; Cyclodextrins - chemistry; Decontamination. Miscellaneous; Earth sciences; Earth, ocean, space; Engineering and environment geology. Geothermics; Environmental Restoration and Remediation - methods; Exact sciences and technology; Extraction agents; Plant Oils - chemistry; Pollution; Pollution, environment geology; Polycyclic aromatic hydrocarbons (PAH); Polycyclic Aromatic Hydrocarbons - analysis; Polycyclic Aromatic Hydrocarbons - chemistry; Soil; Soil - chemistry; Soil and sediments pollution; Soil Pollutants - analysis; Soil Pollutants - chemistry; Solubility; Solutions - chemistry; Solvents - chemistry; Surface-Active Agents - chemistry; Extraction agents; Polycyclic aromatic hydrocarbons (PAH); Soil; Hydrocarbon; Oligoholoside; Vegetable oil; Washing; Surfactant; Polycyclic aromatic compound; Mutagen; Soil pollution; Macrocycle; Persistent organic pollutant; Biosurfactant; Carcinogen; Organic solvent; Cyclodextrin; Decontamination; Teratogen; Microemulsion; Humic acid; Organic compounds
• ISSN: 0269-7491; 1873-6424
• DOI: 10.1016/j.envpol.2013.09.010

Polycyclic aromatic hydrocarbons (PAHs) in soil have been recognised as a serious health and environmental issue due to their carcinogenic, mutagenic and teratogenic properties. One of the commonly employed soil remediation techniques to clean up such contamination is soil washing or solvent extraction. The main factor which governs the efficiency of this process is the solubility of PAHs in the extraction agent. Past field-scale soil washing treatments for PAH-contaminated soil have mainly employed organic solvents or water which is either toxic and costly or inefficient in removing higher molecular weight PAHs. Thus, the present article aims to provide a review and discussion of the alternative extraction agents that have been studied, including surfactants, biosurfactants, microemulsions, natural surfactants, cyclodextrins, vegetable oil and solution with solid phase particles. These extraction agents have been found to remove PAHs from soil at percentages ranging from 47 to 100% for various PAHs. •The alternative and advancement in extraction agents to remove PAHs from soil using soil washing technology is summarised.•The soil regulations for PAH level in various countries are summarized for reference to researchers.•The concentration levels of PAHs in soil at present and the need for soil remediation is presented. The efficiency of the extraction agent plays a significant role in soil washing of PAH-contaminated soil.