Effects of Oil and Dispersant on Formation of Marine Oil Snow and Transport of Oil Hydrocarbons

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• 作者：Jie Fu ; Yanyan Gong ; Xiao Zhao ; S. E. O鈥橰eilly ; Dongye Zhao
• 刊名：Environmental Science & Technology
• 出版年：2014
• 出版时间：December 16, 2014
• 年：2014
• 卷：48
• 期：24
• 页码：14392-14399
• 全文大小：418K
• ISSN：1520-5851

文摘

This work explored the formation mechanism of marine oil snow (MOS) and the associated transport of oil hydrocarbons in the presence of a stereotype oil dispersant, Corexit EC9500A. Roller table experiments were carried out to simulate natural marine processes that lead to formation of marine snow. We found that both oil and the dispersant greatly promoted the formation of MOS, and MOS flocs as large as 1.6鈥?.1 mm (mean diameter) were developed within 3鈥? days. Natural suspended solids and indigenous microorganisms play critical roles in the MOS formation. The addition of oil and the dispersant greatly enhanced the bacterial growth and extracellular polymeric substance (EPS) content, resulting in increased flocculation and formation of MOS. The dispersant not only enhanced dissolution of n-alkanes (C9鈥揅40) from oil slicks into the aqueous phase, but facilitated sorption of more oil components onto MOS. The incorporation of oil droplets in MOS resulted in a two-way (rising and sinking) transport of the MOS particles. More lower-molecular-weight (LMW) n-alkanes (C9鈥揅18) were partitioned in MOS than in the aqueous phase in the presence of the dispersant. The information can aid in our understanding of dispersant effects on MOS formation and oil transport following an oil spill event.