| humic acid toxicity in biologically treated soil contaminated with polycyclic aromatic hydrocarbons and pentachlorophenol. | contaminated soil from a land treatment unit at the libby groundwater superfund site in libby, mt, was amended with 14c pyrene and incubated for 396 days to promote biodegradation and the formation of soil-associated bound residues. humic and fulvic acids were extracted from the treated soil microcosms and analyzed for the presence of pyrene residues. biologic activity promoted 14c association with the fulvic acid fraction, but humic acid-associated 14c did not increase with biologic activity. t ... | 2005 | 16170453 |