Photochemical Fate of Oil Dispersants Used in the Gulf Oil Spill Clean-Up

摘要

Following the explosion of the BP Deepwater Horizon Oil Rig in the Gulf of Mexico, the company utilized COREXIT 9500A and 9527A dispersants as a clean-up mechanism in order to separate the oil plume into smaller particles. Smaller oil particles minimize the surface oil from reaching land and enhance biodegradability. Concern surrounding the toxicity of these dispersants has arisen because of their use in unprecedented quantities in the deepwater environment, where natural degradation processes are not well understood. In addition to deepwater application, surface application was also utilized in the cleanup effort. The dispersant chemicals that were surface applied are subject to sunlight exposure, giving rise to direct photolysis and sunlight driven photochemical degradation of the constituents in COREXIT. The photochemistry of COREXIT and its individual components are not well studied, and the kinetics of these pathways are important in achieving an overall mass balance of dispersant application in oil cleanup operations. Possible byproduct formation from these degradation pathways should also be studied, as the byproducts could be toxicologically relevant.