title: Effects of oil dispersant and oil on sorption and desorption of phenanthrene with Gulf Coast marine sediments.
abstract: Effects of a model oil dispersant (Corexit EC9500A) on sorption/desorption of phenanthrene were investigated with two marine sediments. Kinetic data revealed that the presence of the dispersant at 18 mg/L enhanced phenanthrene uptake by up to 7%, whereas the same dispersant during desorption reduced phenanthrene desorption by up to 5%. Sorption isotherms confirmed that at dispersant concentrations of 18 and 180 mg/L, phenanthrene uptake progressively increased for both sediments. Furthermore, the presence of the dispersant during desorption induced remarkable sorption hysteresis. The effects were attributed to added phenanthrene affinity and capacity due to sorption of the dispersant on the sediments. Dual-mode models adequately simulated sorption isotherms and kinetic data in the presence of the dispersant. Water accommodated oil (WAO) and dispersant-enhanced WAO increased phenanthrene sorption by up to 22%. This information is important for understanding roles of oil dispersants on the distribution and transport of petroleum PAHs in seawater-sediments.
authors.affiliation: Environmental Engineering Program, Department of Civil Engineering, Auburn University, Auburn, AL 36849, USA.
authors.forename: Yanyan
authors.initials: Y
authors.lastname: Gong
authors.affiliation: Environmental Engineering Program, Department of Civil Engineering, Auburn University, Auburn, AL 36849, USA.
authors.forename: Xiao
authors.initials: X
authors.lastname: Zhao
authors.affiliation: Bureau of Ocean Energy Management, GOM Region, Office of Environment, New Orleans, LA 70123, USA.
authors.forename: S E
authors.initials: SE
authors.lastname: O'Reilly
authors.affiliation: Environmental Engineering Program, Department of Civil Engineering, Auburn University, Auburn, AL 36849, USA; Institute of Environmental Science, Taiyuan University of Science and Technology, Taiyuan, Shanxi 030024, China.
authors.forename: Tianwei
authors.initials: T
authors.lastname: Qian
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: D019015:Geologic Sediments / Q000737:chemistry*; D060851:Gulf of America; D007700:Kinetics; D008956:Models, Chemical; D010578:Petroleum / Q000032:analysis*; D059392:Petroleum Pollution; D010616:Phenanthrenes / Q000032:analysis / Q000737:chemistry*; D012623:Seawater / Q000737:chemistry; D013501:Surface-Active Agents / Q000737:chemistry*; D014874:Water Pollutants, Chemical / Q000032:analysis / Q000737:chemistry*
chemical_list: D010578:Petroleum; D010616:Phenanthrenes; D013501:Surface-Active Agents; D014874:Water Pollutants, Chemical; C031181:phenanthrene
keywords: Oil dispersant; Oil spill; Polycyclic aromatic hydrocarbon; Sediment; Sorption