Factors regulating PAH transformations in disturbed coastal sediments
- State Univ. of New York, Stony Brook, NY (United States). Marine Sciences Research Center
Important limitations to bacterial transformations of polycyclic aromatic hydrocarbon (PAH) compounds in sediments include compound structure, dissolved concentration and oxygen availability. Here the authors present evidence suggesting that dissolved concentration is as important as structure in controlling degradation in radiolabeled sediments in flow through microcosms. Results from experiments where the mineralization rates of naphthalene phenanthrene and benzo[a]pyrene were related to the degree of oxygenation of suboxic sediments via sediment resuspension, showed that differences between mineralization rates and percent maximum degradation never varied by more than a factor of two between naphthalene and phenanthrene, despite phenanthrene having sixteen-fold greater hydrophobicity. The results also showed that dissolved naphthalene concentrations in the overlying water from frequently resuspended sediments were much farther below equilibrium predictions than dissolved concentrations of phenanthrene and B[a]P. The authors postulate that kinetic limitations to desorption into the aqueous phase limits the biodegradation of naphthalene to a greater extent than for phenanthrene and B[a]P. Results from experiments relating desorption from sediment to mineralization in side-by-side comparisons showed that labeled sediments undergoing resuspension in microcosms desorbed much less naphthalene than phenanthrene, and that the amount desorbed was largely underpredicted by a kinetic radial diffusion model, especially for naphthalene. Desorption rate limitation in the system may help to explain the similar degree of mineralization of naphthalene and phenanthrene seen in the experiments.
- OSTI ID:
- 462554
- Report Number(s):
- CONF-961149-; TRN: IM9719%%24
- Resource Relation:
- Conference: 17. annual meeting of the Society of Environmental Toxicology and Chemistry: partnerships for the environment - science, education, and policy, Washington, DC (United States), 17-21 Nov 1996; Other Information: PBD: 1995; Related Information: Is Part Of SETAC 17. annual meeting -- Abstract book. Partnerships for the environment: Science, education, and policy; PB: 378 p.
- Country of Publication:
- United States
- Language:
- English
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