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Abstract: Coal tar, creosote, and similar viscous non-aqueous phase liquids (NAPLs) behave in alluvial soils in a manner significantly different from that of less viscous NAPLs, such as gasoline and [...]

A simple and reproducible method which provides the simultaneous determination of PAHs and hetero-PAHs (N,S,O) and their metabolites in contaminated soils has been developed. Contaminants extracted from the soil sample were separated by polarity and acid-base characteristics using solid phase extraction (SPE) on silica gel and a strong basic anion exchange material. A subfraction containing PANHs and neutral metabolites was subsequently fractionated into neutral and basic compounds using a strong acidic cation exchange material. The identification and quantification was performed using different GC and HPLC methods. A method validation was carried out for 21 PAHs, 22 hetero-PAHs, and 19 metabolites in a five-level matrix calibration. Uncontaminated soil (AhA1-layer/compost mixture) was spiked with the chosen standard compounds. The method showed good linearity (coefficient of correlation) and high precision (coefficient of variation) for major and minor compounds over a wide range of concentration as well as high sensitivity (limit of detection). The method was successfully applied to different authentic tar oil contaminated sites. Aside from the typical tar oil PAHs, hetero-PAHs and metabolites predominantly with ketonic or quinonic structure were identified on a mg/kg concentration level.

Solvent extraction of organic wood preservative, creosote, yielded three classes of creosote contituents namely polycyclic aromatic hydrocarbons (PAHs), phenolics and heterocyclics, that inhibit the fluoranthene-degrading activity of Sphingomonas paucimobilis strain EPA505. The integration of a pretreatment step prior to inoculation of strain EPA505 could help increase the effectiveness of strain EPA505 to degrade fluoranthene.

Results from the bioremediation of creosote-contaminated soil reveal that the partition coefficients of [14C]naphthalene, which are related to the mass of organic carbon in the soil, are unaltered even as the average molecular weight of the residual creosote is increased by 10% to 36%. The partition coefficients for the creosote contaminant yield about 3500 to 4040 mL/g of organic carbon from both bioremediated and nonbioremediated soil samples when partitioning is used to model the total contributions of the nonaqueous phase contaminant and the soil organic matter.

Factorial studies were used to analyze interactions between phenanthrene, fluorene, p-cresol, pentachlorophenol, carbazole, dibenzothiophene and dibenzofuran during aerobic biodegradation in groundwater. The results showed that substrate interaction had the greatest effect on the more hydrophobic and recalcitrant compounds. Interaction among independent factors also took place.