Chemical composition of floating and sunken in-situ burn residues from the Deepwater Horizon oil spill. Issue 1 (15th July 2016)

• Record Type: Journal Article
• Authors: Stout, Scott A.; Payne, James R.
• Is Part Of: Marine pollution bulletin. Volume 108:Issue 1/2(2016:Jul.)
• Page Start: 186
• Page End: 202
• Publication Date: 2016-07-15
• Subjects: Oil spill -- In-situ burning -- Hopane -- Polycyclic aromatic hydrocarbons -- Mass loading; Marine pollution -- Periodicals; Marine Biology -- Periodicals; Water Pollution -- Periodicals; Mer -- Pollution -- Périodiques; Publications périodiques; Pollution des mers; Lutte antipollution; Electronic journals; 363.7394
• DOI: 10.1016/j.marpolbul.2016.04.031
• Languages: English
• ISSNs: 0025-326X

Abstract

Abstract: In-situ burning during the Deepwater Horizon oil spill generated tens of thousands of barrels of in-situ burn (ISB) residues in the northern Gulf of Mexico (GoM), most or all of which eventually sank to the seafloor. Chemical analyses showed that floating and sunken (~ 1400 m deep) ISB residues (1) exhibited distinct n -alkanes and UCM profiles inconsistent with vapor-pressure driven evaporation, (2) were relatively enriched in pyrogenic PAHs, particularly less stable (mostly) linear PAH isomers formed during burning, and (3) had lost petroleum biomarkers, relative to their volatility. PAH concentrations in ISB residues indicate that between 26, 800 and 37, 800 kg of total PAHs (TPAH51) and 2880 and 4060 kg of 16 Priority Pollutant PAHs were potentially deposited on the seafloor in discrete ISB residue particles. Despite this additional benthic impact, ISB reduced the total mass loadings of PAH from the burned oil to the GoM by 89% (ignoring any re-deposition from atmospheric emissions). Graphical abstract: Highlights: In-situ burning of oil created discrete residues that ultimately sunk to seafloor. Chemical features of burn residues were distinguishable from unburned oil. Pyrogenic PAHs were enriched in burn residues. In-situ burning reduced total mass loading of PAH to Gulf of Mexico. Sunken burn residues added PAHs to the deep benthos.