Determining Kinetics for Simulated Sunlight-Exposed Oil Compounds

Understanding of the fate of oil in the environment is of utmost importance; however, accurate, predictive models are still in very early stages. To aid in the development of these models, photodegradation of selected polycyclic aromatic hydrocarbons (PAHs) in an n-alkane hydrocarbon matrix was followed for individual PAHs and mixtures of PAHs similar to that found in the Deepwater Horizon spill. Tetracene in tetradecane photodegraded quickest of all observed PAHs, with a loss of 99% after only one hour of irradiation. Binary mixtures of PAHs showed different degradation amounts, including changes in PAH kinetics. These results suggest that the formation of dimers or aggregates as well as photosensitization reaction is important in the degradation of PAHs in oil. Kinetics of PAH photodegradation and PAH sensitized photodegradation will be presented. This information will provide a better understanding of the fate of oil in environmental systems.