title: Impact of mixing time and energy on the dispersion effectiveness and droplets size of oil.
abstract: The effects of mixing time and energy on Alaska Northern Slope (ANS) and diluted bitumen Cold Lake Blend (CLB) were investigated using EPA baffled flask test. Dispersion effectiveness and droplet size distribution were measured after 5-120 min. A modeling method to predict the mean droplet size was introduced for the first time to tentatively elucidate the droplet size breakup mechanism. The ANS dispersion effectiveness greatly increased with dispersant and mixing energy. However, little CLB dispersion was noted at small energy input (ε = 0.02 Watt/kg). With dispersant, the ANS droplet size distribution reached quasi-equilibrium within 10 min, but that of CLB seems to reach quasi-equilibrium after 120 min. Dispersants are assumed ineffective on high viscosity oils because dispersants do not penetrate them. We provide an alternative explanation based on the elongation time of the droplets and its residence in high intensity zones. When mixing energy is small, CLB did not disperse after 120 min, long enough to allow the surfactant penetration. Our findings suggest that dispersants may disperse high viscosity oils at a rougher sea state and a longer time. The latter could determine how far offshore one can intervene for effective responses to a high viscosity oil spill offshore.
authors.affiliation: Center for Natural Resources Development and Protection, Department of Civil and Environmental Engineering, New Jersey Institute of Technology, Newark, NJ, 07102, USA.
authors.forename: Zhong
authors.initials: Z
authors.lastname: Pan
authors.affiliation: Center for Natural Resources Development and Protection, Department of Civil and Environmental Engineering, New Jersey Institute of Technology, Newark, NJ, 07102, USA.
authors.forename: Lin
authors.initials: L
authors.lastname: Zhao
authors.affiliation: Center for Natural Resources Development and Protection, Department of Civil and Environmental Engineering, New Jersey Institute of Technology, Newark, NJ, 07102, USA. Electronic address: boufadel@gmail.com.
authors.forename: Michel C
authors.initials: MC
authors.lastname: Boufadel
authors.affiliation: Center for Offshore Oil, Gas and Energy Research, Department of Fisheries and Oceans Canada, Bedford Institute of Oceanography, Dartmouth, NS, B2Y 4A2, Canada.
authors.forename: Thomas
authors.initials: T
authors.lastname: King
authors.affiliation: Center for Offshore Oil, Gas and Energy Research, Department of Fisheries and Oceans Canada, Bedford Institute of Oceanography, Dartmouth, NS, B2Y 4A2, Canada.
authors.forename: Brian
authors.initials: B
authors.lastname: Robinson
authors.affiliation: National Risk Management Research Laboratory, Office of Research and Development, U.S. Environmental Protection Agency, 26 West Martin Luther King Boulevard, Cincinnati, OH, 45268, USA.
authors.forename: Robyn
authors.initials: R
authors.lastname: Conmy
authors.affiliation: Wealth from Oceans National Research Flagship, CSIRO, Australian Resources Research Centre, Kensington, Australia.
authors.forename: Kenneth
authors.initials: K
authors.lastname: Lee
mesh_terms: D000413:Alaska; D004784:Environmental Monitoring / Q000379:methods; D052918:Environmental Restoration and Remediation / Q000379:methods*; D006838:Hydrocarbons; D060106:Lakes; D010578:Petroleum / Q000032:analysis*; D059392:Petroleum Pollution; D013501:Surface-Active Agents; D013997:Time Factors; D014783:Viscosity; D014874:Water Pollutants, Chemical / Q000032:analysis*
chemical_list: D006838:Hydrocarbons; D010578:Petroleum; D013501:Surface-Active Agents; D014874:Water Pollutants, Chemical; C006647:asphalt
keywords: Dispersion effectiveness; Droplet size distribution; Mixing energy; Mixing time; Viscosity