2003 Progress Report: Resolving the Unresolved Complex Mixture in Petroleum Residues in Environmental MatricesEPA Grant Number: R830393
Title: Resolving the Unresolved Complex Mixture in Petroleum Residues in Environmental Matrices
Investigators: Reddy, Christopher M.
Institution: Woods Hole Oceanographic Institution
EPA Project Officer: Carleton, James N
Project Period: September 1, 2002 through August 31, 2004
Project Period Covered by this Report: September 1, 2002 through August 31, 2003
Project Amount: $224,955
RFA: Futures Research in Natural Sciences (2001) RFA Text | Recipients Lists
Research Category: Ecological Indicators/Assessment/Restoration , Land and Waste Management , Hazardous Waste/Remediation
The objective of this research project is to use comprehensive two-dimensional gas chromatography (GC x GC) to study the unresolved complex mixture of petroleum hydrocarbons in environmental samples.
The greatest emphasis has been placed on two local sites in Cape Cod, MA, where studies on the long-term fate of petroleum hydrocarbons in salt marsh sediments are underway. The barge Florida spilled approximately 700,000 liters of diesel fuel on September 16, 1969, and marsh sediments near Wild Harbor were severely impacted. A sediment core collected in 2000 revealed that oil still persists at sediment depths of 8 to 20 cm. On October 9, 1974, the barge Bouchard 65 spilled an undetermined amount of its cargo (also diesel fuel) and contaminated Winsor Cove, which is located about 4 km north of Wild Harbor. GC x GC/flame ionization detector analysis has revealed that the hydrocarbon composition at these two sites is quite different (although traditional one-dimensional gas chromatography indicates a very similar fingerprint). Hence, GC x GC has provided increased resolution that was previously unattainable and can allow for more refined studies on weathering processes. We believe that the environmental conditions at the two sites have lead to these differences. Significant amounts of naphthalenes and larger aromatics remain at the Wild Harbor site because the oil resides in buried anoxic sediments and are not fully exposed to environmental weathering (mainly water washing). At the Winsor cove site, aromatics are greatly reduced in concentration because the oil remained in the near-surface sediments, where water washing likely has occurred. At both sites, branched and cyclic alkanes comprise the majority of the remaining petroleum hydrocarbons. The n-alkanes at both locations have been biodegraded.
Future efforts will focus on analyzing some additional field samples, but mainly, we will analyze laboratory-based microbial degradation cultures. A significant amount of time will be devoted to interpreting the results and preparing several manuscripts on this work.