PAH Distribution in the 1994 and 1997 Mobile Burn Products and Determination of the Diesel PAH Destruction Efficiencies

In 1994 and 1997, several U.S. and Canadian government agencies jointly conducted a series of mesoscale burns in Mobile Bay, Alabama, to study various aspects of in situ diesel fuel burning. Samples were taken from the oil, residue and the smoke plume during each burn and analysed by capillary gas Chromatograph/mass spectrometry (GC/MS). Analysis results reveal that the PAH distribution patterns in the diesel, residue, and soot samples are significantly different from each other. A simple model based on mass balance of individual petroleum ?AHs pre- and post-burn is proposed to estimate the destruction efficiencies of the total petroleum PAHs. The average destruction efficiency of the total diesel PAHs from three 1994 Mobile burns was estimated to be greater than 99%. The high molecular weight PAHs with five or more rings were found to be largely generated by combustion. These studies demonstrated that under certain circumstances, in situ burning is an effective measure to minimise the impact of an oil spill on the environment and to reduce the damage of an oil spill to the ecological system.