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Impact of imposed anaerobic conditions and microbial activity on aqueous‐phase solubility of polycyclic aromatic hydrocarbons from soil
Author(s) -
Pravecek Tasha L.,
Christman Russell F.,
Pfaender Frederic K.
Publication year - 2005
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 - 10.1897/04-109r.1
Subject(s) - chemistry , pyrene , anthracene , environmental chemistry , fluoranthene , polycyclic aromatic hydrocarbon , aqueous two phase system , aqueous solution , anaerobic exercise , bioavailability , hydrocarbon , organic chemistry , physiology , bioinformatics , biology
The influence of anaerobic conditions on aqueous‐phase polycyclic aromatic hydrocarbon (PAH) bioavailability was investigated in laboratory microcosms. Highly aged (>70 years), PAH‐contaminated soil was incubated under anaerobic conditions by using various anaerobic headspaces, anaerobic headspaces with an oxygen‐scavenging complex (titanium(III) citrate) in the aqueous phase, or anaerobic headspaces with electron‐acceptor amendments in the aqueous phase. Incubation of soil solely under anaerobic conditions resulted in increased aqueous concentrations of all PAHs tested (fluoranthene, pyrene, benz[ a ]anthracene, and benzo[ a ]pyrene). Benz[ a ]anthraoene and benzo[ a ]pyrene extractable concentrations were above aqueous solubility, by as much as an order of magnitude for the latter. The degree of solubility increase observed was a function of molecular weight of the PAH regardless of initial soil concentration, suggesting formation of stable PAH‐soluble organic matter associations. The soil samples incubated aerobically for 90 d before imposition of anaerobic conditions did not release PAHs to the aqueous phase. Methanogenic organisms and sulfate‐reducing bacteria were seen to have the most significant effect on increases in aqueous‐phase PAHs. Polycyclic aromatic hydrocarbons made more soluble under anaerobic conditions was available to be degraded or transformed under aerobic conditions.