Characterization of emissions and residues from simulations of the Deepwater Horizon surface oil burns

Abstract

The surface oil burns conducted by the U.S. Coast Guard from April to July 2010 during the Deepwater Horizon disaster in the Gulf of Mexico were simulated by small scale burns to characterize the pollutants, determine emission factors, and gather particulate matter for subsequent toxicity testing. A representative crude oil was burned in ocean-salinity seawater, and emissions were collected from the plume by means of a crane-suspended sampling platform. Emissions included particulate matter, aromatic hydrocarbons, polychlorinated dibenzodioxins/dibenzofurans, elements, and others, the sum of which accounted for over 92% by mass of the combustion products. The unburned oil mass was 29% of the original crude oil mass, significantly higher than typically reported. Analysis of alkanes, elements, and PAHs in the floating residual oil and water accounted for over 51% of the gathered mass. These emission factors, along with toxicity data, will be important toward examining impacts of future spill burning operations.

Keywords: Deepwater Horizon; Emissions; In situ burns; Oil spill.

Figure 1.

Typical emission results during a burn.

Figure 2.

PM size fractions by mass.

Figure 3.

(a) Particle number distributions corrected for sampling losses and background levels, averaged over the first part of the burn and the boilover phases; and (b) burn averaged volume distributions as measured and corrected for sampling line losses.

Figure 4.

Bright field TEM image of the aggregate for Figures 5 and 6.

Figure 5.

An HAADF image of the aggregate shown in Figure 4, as described in the text.

Figure 6.

Elemental analysis maps of the aggregate of Figs. 4 and 5 for the color-coded elements. C red, O = green, S = blue.

Figure 7.

PAH concentrations on PM from burning oil. Data from Gullett et al. (2016) [6], Evans et al. (2001) [37], Fingas et al. (1996) [9], Wang et al. (1999) [58], Simon et al. (2012) [57], Devai et al. (1998) [59].

Figure 8.

Fate of combusted oil into products, by weight.