Microbial bioavailability of pyrene in three laboratory-contaminated soils under aerobic and anaerobic conditions.

Changes in bioavailability of pyrene in three uncontaminated soils were examined under aerobic and anaerobic conditions. Three soils were aerobically aged with pyrene and [(14)C]pyrene for 63 days, then incubated with water, nitrate, or sulfate under aerobic or anaerobic conditions for one year. Under aerobic conditions, microorganisms in two soils mineralized 58-82% of the added [(14)C]pyrene.

Impact of imposed anaerobic conditions and microbial activity on aqueous-phase solubility of polycyclic aromatic hydrocarbons from soil.

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).