title: Impacts of microbial redox conditions on the phase distribution of pyrene in soil-water systems.
abstract: Variations in the soil/sediment organic matter (SOM)-hydrophobic organic contaminant (HOC) bindings upon microbially mediated redox conditions were examined. While the extractability of pyrene associated with soil declined after its biodegradation began during aerobic incubation, its variations were almost constant (+/-3.0-4.4%) during anoxic/anaerobic incubations. The dissolved organic matter released from the soil incubated under highly reduced conditions became more humified and aromatic, had a higher average molecular weight, and was more polydispersed compared to that obtained from oxic incubation, similar to the SOM alterations in the early stage of diagenesis (humification). The concentrations of pyrene in the aqueous phase increased significantly during the soil incubations under highly reduced conditions due to its favorable interaction with the altered DOM. Our results suggest that the microbially mediated redox conditions have significant impacts on SOM and should be considered for the transport, fate, bioavailability, and exposure risk of HOCs in the geo-environments.
authors.affiliation: Environmental Engineering, Konkuk University, 1 Hwayang-dong, Gwangjin-gu, Seoul 143-701, Korea. hankim@konkuk.ac.kr
authors.forename: Han S
authors.initials: HS
authors.lastname: Kim
authors.forename: J Chadwick
authors.initials: JC
authors.lastname: Roper
authors.forename: Frederic K
authors.initials: FK
authors.lastname: Pfaender
mesh_terms: D000332:Aerobiosis; D000693:Anaerobiosis; D001673:Biodegradation, Environmental; D004463:Ecology; D004784:Environmental Monitoring / Q000379:methods; D006812:Humic Substances; D010084:Oxidation-Reduction; D010316:Particle Size; D011721:Pyrenes / Q000032:analysis / Q000737:chemistry*; D012987:Soil / Q000032:analysis; D012988:Soil Microbiology; D012989:Soil Pollutants / Q000032:analysis / Q000737:chemistry*; D014874:Water Pollutants, Chemical / Q000032:analysis / Q000737:chemistry*
chemical_list: D006812:Humic Substances; D011721:Pyrenes; D012987:Soil; D012989:Soil Pollutants; D014874:Water Pollutants, Chemical; C030984:pyrene