Removal of PAHs from highly contaminated soils found at prior manufactured gas operations

• Published in: Journal of hazardous materials 2000-12, Vol.80 (1), p.159-174
• Main Authors: Khodadoust, Amid P, Bagchi, Rajesh, Suidan, Makram T, Brenner, Richard C, Sellers, Neal G
• Format: Article
• Language: English
• Subjects: 1-Pentanol; 2-Propanol; 2-Propanol - chemistry; acetone; Applied sciences; Co-solvent; Coal Tar - chemistry; Decontamination. Miscellaneous; Earth sciences; Earth, ocean, space; Engineering and environment geology. Geothermics; Environmental Pollution - analysis; Environmental Pollution - prevention & control; Ethanol; Ethanol - chemistry; Exact sciences and technology; Gases; Industrial Waste; Industry; Pentanols - chemistry; Pollution; Pollution, environment geology; Polycyclic aromatic hydrocarbons (PAHs); Polycyclic Aromatic Hydrocarbons - chemistry; Soil and sediments pollution; Soil Pollutants; Solvent washing; Solvents - chemistry; Waste Management - methods
• ISSN: 0304-3894; 1873-3336
• DOI: 10.1016/S0304-3894(00)00286-7

Removal of PAHs from highly contaminated soil found at a manufactured gas site was evaluated using solvent washing with mixed solvents. The following solvents were considered as water miscible co-solvents in mixed solvents: ethanol, 2-propanol, acetone, and 1-pentanol. In batch solvent extraction of soil, ethanol and 2-propanol were selected as primary components of mixed solvents in addition to 1-pentanol. Using ternary solutions containing either ethanol or 2-propanol with a volume fraction of 1-pentanol ranging from 5 to 25% and a water volume fraction ranging from 5 to 30%, ethanol was more effective than 2-propanol in extracting PAHs from soil. A solvent mixture of 5% 1-pentanol, 10% water and 85% ethanol was selected as the extraction solvent. Using a 1 g:4 ml soil:solvent extraction ratio, extraction kinetics showed that from 65 to 90% of the extractable PAHs were removed within an hour of contact between soil and solvent. Using this 1 g:4 ml extraction ratio, PAHs were removed in a three-stage cross-current solvent washing process where the same batch of soil was extracted with clean solvent for 1 h in each stage. PAH removals in three-stage cross-current solvent washing were comparable to PAH removals obtained with Soxhlet extraction.