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Release of polycyclic aromatic hydrocarbons from contaminated soils by surfactant and remediation of this effluent by Penicillium spp
Author(s) -
Pinto Linda J.,
Moore Margo M.
Publication year - 2000
Publication title -
environmental toxicology and chemistry
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.1
H-Index - 171
eISSN - 1552-8618
pISSN - 0730-7268
DOI - 10.1002/etc.5620190706
Subject(s) - pyrene , chrysene , chemistry , environmental chemistry , phenanthrene , soil water , environmental remediation , bioavailability , critical micelle concentration , soil contamination , pulmonary surfactant , polycyclic aromatic hydrocarbon , contamination , micelle , organic chemistry , aqueous solution , environmental science , ecology , bioinformatics , biochemistry , soil science , biology
Studies in which surfactants have been employed to increase the bioavailability of soil‐bound polycyclic aromatic hydrocarbons (PAHs) have not yielded consistent results. Surfactant mobilization of high molecular weight (MW) PAHs from contaminated soils has not been extensively studied; therefore, the purpose of this research was to compare the extent of release of freshly added high MW 14 C‐PAH with aged PAH from four different PAH‐contaminated soils using a nonionic detergent, Tween 80, and to determine whether Tween 80‐solubilized 14 C‐PAH in soil washings could be degraded by indigenous microorganisms or by added Penicillium spp. Only very high concentrations of Tween 80 (>1,000 times the critical micelle concentration [CMC] for 3 of 4 soils) were able to mobilize bound 14 C‐pyrene, ‐chrysene, and ‐benzo[ a ]pyrene. The concentration of surfactant required to release 50% of bound 14 C‐PAH (the SC50 value) ranged from 5 to 30 g/L depending on soil type; a modest correlation was found (0.512) between the fraction of organic carbon in the soil and the SC50 value. At 10 4 × CMC, Tween 80 released an average of 75% of bound 14 C‐PAH and 64% of the aged PAH, indicating that the 14 C‐PAH release only slightly overestimated PAH mobilization from weathered soil. An exception was one soil that had been previously remediated in which <30% of the PAHs were released. The PAH structure had a negligible effect on the mobilization by surfactant because the solubilization curves for all three PAHs were very similar. Tween 80‐solubilized 14 C‐pyrene readsorbed to soil when the surfactant concentration dropped below 10 3 × CMC. Greater than 90% of the 14 C‐pyrene in the soil washing effluent could be removed by the addition of spores of active PAH‐oxidizing Penicillium spp. plus nutrients. In contrast, <10% of 14 C‐pyrene was oxidized by the indigenous soil bacteria under the same conditions.