Dispersion, sorption and photodegradation of petroleum hydrocarbons in dispersant-seawater-sediment systems.
This work examined effects of model oil dispersants on dispersion, sorption and photodegradation of petroleum hydrocarbons in simulated marine systems. Three dispersants (Corexit 9500A, Corexit 9527A and SPC 1000) were used to prepare dispersed water accommodated oil (DWAO). While higher doses of dispersants dispersed more n-alkanes and PAHs, Corexit 9500A preferentially dispersed C11-C20 n-alkanes, whereas Corexit 9527A was more favorable for smaller alkanes (C10-C16), and SPC 1000 for C12-C28 n-alkanes. Sorption of petroleum hydrocarbons on sediment was proportional to TPH types/fractions in the DWAOs. Addition of 18mg/L of Corexit 9500A increased sediment uptake of 2-3 ring PAHs, while higher dispersant doses reduced the uptake, due to micelle-enhanced solubilization effects. Both dispersed n-alkanes and PAHs were susceptible to photodegradation under simulated sunlight. For PAHs, both photodegradation and photo-facilitated alkylation were concurrently taking place. The information can facilitate sounder assessment of fate and distribution of dispersed oil hydrocarbons in marine systems.
Environmental Engineering Program, Department of Civil Engineering, Auburn University, Auburn, AL 36849, USA.
Xiao
X
Zhao
Environmental Engineering Program, Department of Civil Engineering, Auburn University, Auburn, AL 36849, USA.
Wen
W
Liu
Environmental Engineering Program, Department of Civil Engineering, Auburn University, Auburn, AL 36849, USA.
Jie
J
Fu
Environmental Engineering Program, Department of Civil Engineering, Auburn University, Auburn, AL 36849, USA.
Zhengqing
Z
Cai
Environmental Engineering Program, Department of Civil Engineering, Auburn University, Auburn, AL 36849, USA.
S E
SE
O'Reilly
Environmental Engineering Program, Department of Civil Engineering, Auburn University, Auburn, AL 36849, USA. Electronic address: zhaodon@auburn.edu.
Dongye
D
Zhao
D019015:Geologic Sediments; D006838:Hydrocarbons; D010578:Petroleum; D059392:Petroleum Pollution; D010782:Photolysis; D012623:Seawater; D014874:Water Pollutants, Chemical
D006838:Hydrocarbons; D010578:Petroleum; D014874:Water Pollutants, Chemical
Dispersant; Oil sorption; Oil spill; PAH; Petroleum hydrocarbon; Photodegradation