Quantitative characterization of PAHs in burn residue and soot samples and differentiation of pyrogenic PAHs from petrogenic PAHs - the 1994 mobile burn study

Various aspects of in situ diesel fuel burning were examined when a series of mesoscale burns were conducted in Mobile Bay, Alabama in 1994. During each burn, samples were taken from the oil residue and the smoke plume and were analysed for PAHs and other hydrocarbons by gas chromatography/mass spectrometry. Quantitative results for the PAH composition and relative distribution of five alkylated PAH homologues and an additional 14 EPA-defined unsubstituted priority PAHs in the smoke particulate were obtained. The high temperature reached during each burn resulted in nearly complete destruction of the diesel. The burn residue and soot produced from the burns were estimated to account for 0.1-0.3 per cent and 8-14 per cent of the diesel by weight, respectively. The data helped in the estimation of the destruction efficiencies of the diesel PAHs and in the assessment of the environmental impact of an in situ burn. It was concluded that overall, in situ burning can help to mitigate the environmental impacts of an oil spill by consuming much of the spilled oil and thereby significantly reduce the total amount of PAHs in the oil. 31 refs., 7 tabs., 6 figs