We investigated the effects of an oil dispersant (COREXIT� EC9500A) and sediment sorption on photodegradation and ozonation of two oil polycyclic aromatic compounds (PAHs) under simulated Gulf Coast ground level conditions. Batch sorption/desorption tests showed that increasing dispersant concentration from 0 to 1360 mg/L progressively decreased physicochemical availability of PAHs sorbed on sediments, resulting in prolonged weathering rates of the PAHs. Ozone oxidation kinetic tests showed that the dispersant at 18 mg/L inhibited degradation of the PAHs by up to 21%. Increasing the dispersant concentration to 180 mg/L further decreased the ozone oxidation rates by up to 44%. The presence of the dispersant at 18 and 180 mg/L retarded photodegradation of the PAHs by ~5% and remarkably decreased the evaporation losses of phenanthrene and pyrene, resulting in elevated persistence of the PAHs in the seawater. Effects of salinity, pH, and dissolved organic matter on the weathering rates are also investigated.

Effects of oil dispersants and sediment sorption on photodegradation and ozonation of persistent oil compounds in the Gulf Coast ecosystems

245th National Meeting (2013)

The official archive and repository for all ACS Meetings & Expositions abstracts and select posters or presentations.