title: Effects of oil dispersant on solubilization, sorption and desorption of polycyclic aromatic hydrocarbons in sediment-seawater systems.
abstract: This work investigated effects of a prototype oil dispersant on solubilization, sorption and desorption of three model PAHs in sediment-seawater systems. Increasing dispersant dosage linearly enhanced solubility for all PAHs. Conversely, the dispersant enhanced the sediment uptake of the PAHs, and induced significant desorption hysteresis. Such contrasting effects (adsolubilization vs. solubilization) of dispersant were found dependent of the dispersant concentration and PAH hydrophobicity. The dual-mode models adequately simulated the sorption kinetics and isotherms, and quantified dispersant-enhanced PAH uptake. Sorption of naphthalene and 1-methylnaphthalene by sediment positively correlated with uptake of the dispersant, while sorption of pyrene dropped sharply when the dispersant exceeded its critical micelle concentration (CMC). The deepwater conditions diminished the dispersant effects on solubilization, but enhanced uptake of the PAHs, albeit sorption of the dispersant was lowered. The information may aid in understanding roles of dispersants on distribution, fate and transport of petroleum PAHs in marine systems.
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: Environmental Engineering Program, Department of Civil Engineering, Auburn University, Auburn, AL 36849, USA.
authors.forename: Yanyan
authors.initials: Y
authors.lastname: Gong
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. Electronic address: zhaodon@auburn.edu.
authors.forename: Dongye
authors.initials: D
authors.lastname: Zhao
mesh_terms: D000327:Adsorption; D019015:Geologic Sediments / Q000737:chemistry*; D007700:Kinetics; D008962:Models, Theoretical; D009281:Naphthalenes / Q000032:analysis / Q000737:chemistry; D059392:Petroleum Pollution / Q000032:analysis; D011084:Polycyclic Aromatic Hydrocarbons / Q000032:analysis / Q000737:chemistry*; D012623:Seawater / Q000737:chemistry*; D012995:Solubility; D014872:Water Movements; D014874:Water Pollutants, Chemical / Q000032:analysis / Q000737:chemistry*; D018508:Water Purification / Q000379:methods
chemical_list: D009281:Naphthalenes; D011084:Polycyclic Aromatic Hydrocarbons; D014874:Water Pollutants, Chemical; C025968:1-methylnaphthalene
keywords: Dispersant; Oil; Oil spill; Polycyclic aromatic hydrocarbon; Sediment; Sorption