Project Information

Title: Pilot studies of bioremediation of the Exxon Valdez oil in Prince William Sound Beaches 11100836

Project Year and Number: 2011: 11100836

Other Fiscal Years and Numbers for this Project: 2012: 11100836-A, 2010: 10100128

Principal Investigator (PI): Michel Boufadel

Managing Agency: NOAA

Assisting Personnel: Jacqui Michel

Research Location: Prince William Sound

Restoration Category: Research

Injured Resources Addressed: Not Specified

Abstract: Oil from the Exxon Valdez persists on initially polluted beaches and contains a considerable fraction of the toxic compounds polycyclic aromatic hydrocarbons (PAHs). The results of the “Oil biodegradation” project by Albert Venosa revealed that more than 80% of the total PAHs (TPAHs) biodegrade within six months when exposed to an environment rich with dissolved oxygen and nutrients. Results from the “Limiting factors” project by Michel Boufadel revealed that the nutrient concentration was an order of magnitude lower than needed for optimal oil biodegradation. It was also found that the dissolved oxygen concentration at oiled pits was, in general, less than 1.0 mg/L. Therefore, anoxic conditions exist, which means that aerobic biodegradation of oil is not occurring. Therefore, both oxygen and nutrient limitations are occurring. While the Venosa study demonstrated oil biodegradability, the actual rate of oil biodegradation in the field when provided with sufficient oxygen and nutrient can be evaluated only through a pilot study of bioremediation, as we are proposing herein. Due to the high dilution for chemicals applied onto the beach surface, we evaluated the delivery of oxygen and nutrient solutions into the beaches subsurface through tracer studies. The tracer experiments revealed that the tracer delivered into the subsurface travelled distances of meters with minimal dilution. Therefore, we are proposing herein to pursue the same approach for delivering solutions of hydrogen peroxide, sodium nitrate, and sodium tripolyphosphate. Sediment samples will be obtained at various times from various locations and will be analyzed for oil composition. Surrogate measures for oil biodegradation include microbial population and the nutrient concentration. The selection of the beaches for the study will be made based on the “Limiting Factor project” and the “Spatial oil distribution” project by Jacqui Michel. Findings from the latter project will be relied upon to upscale the pilot scale results of this study.


Proposal: View (2,210 KB)

Reports:
Annual Report FY11: View (770 KB)
Final Report: View (18,476 KB)

Publications from this Project: None Available