The influence of entrainers on the extraction of polycyclic aromatic hydrocarbons from contaminated soils

The extraction of polycyclic aromatic hydrocarbons (PAH) with supercritical carbon dioxide from contaminated soils can be improved by the use of entrainer. In comparison to alcohols or alkanes, water yields good results as moisture of the soil due to its low solubility in the supercritical fluid. Thus, water is only slowly driven out of the soil and can therefore influence the adsorption of the contaminants on the soil particles even at longer extraction times. The agglomeration of soil with elevated water content results in an optimum humidity for the extraction of contaminated soil in the range of 8 - 15 %.