title: Effects of oil dispersant on ozone oxidation of phenanthrene and pyrene in marine water.
abstract: This work investigated effects of a popular oil dispersant (Corexit EC9500A) on oxidation of phenanthrene and pyrene (two model polycyclic aromatic hydrocarbons) in Gulf coast seawater under simulated atmospheric ozone. The degradation data followed a two-stage pseudo-first order kinetics, a slower initial reaction rate followed by a much faster rate in longer time. The ozonation rate for pyrene was faster than that for phenanthrene. The presence of 18 and 180 mg/L of the dispersant inhibited the first-order degradation rate by 32-80% for phenanthrene, and 51-85% for pyrene. In the presence of 18 mg/L of the dispersant, the pyrene degradation rate increased with increasing ozone concentration, but decreased with increasing solution pH and temperature, while remained independent of ionic strength. For the first time, the results indicate that atmospheric ozone may play a significant role in the weathering of dispersed persistent oil components in natural and engineered systems.
authors.affiliation: School of Environment, Guangzhou Key Laboratory of Environmental Exposure and Health, Guangdong Key Laboratory of Environmental Pollution and Health, Jinan University, Guangzhou, 510632, China; Environmental Engineering Program, Department of Civil Engineering, Auburn University, Auburn, AL, 36849, USA. Electronic address: yanyangong@jnu.edu.cn.
authors.forename: Yanyan
authors.initials: Y
authors.lastname: Gong
authors.affiliation: Environmental Engineering Program, Department of Civil Engineering, Auburn University, Auburn, AL, 36849, USA. Electronic address: zhaodon@auburn.edu.
authors.forename: Dongye
authors.initials: D
authors.lastname: Zhao
mesh_terms: D006863:Hydrogen-Ion Concentration; D007700:Kinetics; D009821:Oils / Q000737:chemistry*; D010084:Oxidation-Reduction; D010126:Ozone / Q000737:chemistry; D059392:Petroleum Pollution / Q000032:analysis*; D010616:Phenanthrenes / Q000737:chemistry; D011721:Pyrenes / Q000032:analysis* / Q000737:chemistry; D012623:Seawater / Q000032:analysis*; D013696:Temperature; D014874:Water Pollutants, Chemical / Q000032:analysis*; D018508:Water Purification
chemical_list: D009821:Oils; D010616:Phenanthrenes; D011721:Pyrenes; D014874:Water Pollutants, Chemical; C031181:phenanthrene; D010126:Ozone; C030984:pyrene
keywords: Marine pollution; Oil dispersant; Oil weathering; Ozonation; PAHs