Effectiveness of in site biodegradation for the remediation of polycyclic aromatic hydrocarbons at a contaminated oil refinery, Port Arthur, Texas

Due to the character of the original source materials and the nature of batch digitization, quality control issues may be present in this document. Please report any quality issues you encounter to digital@library.tamu.edu, referencing the URI of the item.Includes bibliographical references (leaves 31-35).Issued also on microfiche from Lange Micrographics.The effectiveness of bioremediation for the removal of polycyclic aromatic hydrocarbons (PAHs) from sediments contaminated with highly weathered petroleum was evaluated at a contaminated oil refinery. The sediments were chronically contaminated with crude oil and Bunker C fuel oil for the past 20 years. Two treatments, Inipol EAP-22 (INIPOL) and basic nutrients with indigenous organisms (BNIO), were compared to a control (CONTROL) plot over an 11 week period. In site PAH biodegradation was quantified by plotting the time dependence of PAH to 17α,21β-hopane concentration ratios. 17α,21β-hopane, a nondegradable, C30 triterpane, was used as a natural internal standard. Sediment characterization was performed to determine the effect of geologic conditions on PAH biodegradation rates. Total Ion Chromatograms (TICs) of extracted oil showed high concentrations of an unresolved complex mixture that did not change over the 11 week period. The particle size of the sediments from the plots averaged 51% and 34% for clay and silt content, respectively. Sediment mineralogy was dominated by kaolinite and smectite. [PAH]/[Hopane] ratios indicate no significant PAH degradation in either the INIPOL, BNIO, or CONTROL plots over the 11 week period. This data indicates that bioremediation was unsuccessful at this site due to the extreme weathered state of the oil, the limited bioavailability of the PAH compounds, and the potential toxicity of the petroleum. The use of hopane as a natural internal standard was important in quantifying the effectiveness of bioremediation due to the high spatial variability in initial oil concentrations