Aerobic biodegradation of selected polycyclic aromatic hydrocarbons and associated metabolites in soils
- Utah State Univ., Logan, UT (United States). Utah Water Research Lab.
A simple microcosm approach, utilizing measurements of oxygen consumption, was used to investigate the biodegradability of several polycyclic aromatic compounds (PAHs), including phenanthrene and anthracene, and two known biochemical metabolites 1-hydroxy-2-naphthoic acid (1H2NA), 2,3-dihydroxy naphthalene (23DHN) in soil. The microcosms consisted of 100 mL glass vials fitted with Mininert{reg_sign} valves and typically contained about 40 g of soil. Several soils were used including one soil obtained from a coal-tar creosote contaminated site, All compounds were added directly to the soil, without a carrier solvent, resulting in a soil concentration of approximately 200 ppm. Headspace concentrations of oxygen, converted to percent of theoretical oxygen demand (%ThOD) by subtracting appropriate controls at each sampling time, were analyzed over time using a gas chromatograph equipped with a thermal conductivity detector. In non-contaminated soil, several hydrocarbons displayed an acclimation period prior to the onset of accelerated oxygen consumption resulting in a characteristic S-shaped biodegradation curve. However, in the creosote-contaminated soil, no significant acclimation period was observed for phenanthrene, anthracene, and the two corresponding biochemical metabolites, 1H2NA and 23DHN. Both metabolites demonstrated slightly slower rates of oxygen utilization than the parent compounds. The Microtox{reg_sign} bioassay was used to examine the relative toxicity of the test compounds. The anthracene metabolite, 23DHN, was found to be more toxic than the phenanthrene metabolite, 1H2NA. Characterization of the toxicity potential and oxygen consumption rates provides useful information for evaluating bioremediation as a treatment alternative for PAH contaminated soils.
- OSTI ID:
- 203611
- Report Number(s):
- CONF-9511137--; ISBN 1-880611-03-1
- Country of Publication:
- United States
- Language:
- English
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