Degradation of petroleum hydrocarbons in seawater by simulated surface-level atmospheric ozone: Reaction kinetics and effect of oil dispersant. (October 2018)

• Record Type: Journal Article
• Authors: Ji, Haodong; Gong, Yanyan; Duan, Jun; Zhao, Dongye; Liu, Wen
• Is Part Of: Marine pollution bulletin. Volume 135(2018)
• Page Start: 427
• Page End: 440
• Publication Date: 2018-10
• Subjects: Atmospheric ozone -- Ozonation -- Oil spill -- Oil dispersant -- Oil weathering -- Petroleum hydrocarbon; Marine pollution -- Periodicals; Marine Biology -- Periodicals; Water Pollution -- Periodicals; Mer -- Pollution -- Périodiques; Publications périodiques; Pollution des mers; Lutte antipollution; Electronic journals; 363.7394
• DOI: 10.1016/j.marpolbul.2018.07.047
• Languages: English
• ISSNs: 0025-326X

Abstract

Abstract: Oil degradation by surface-level atmospheric ozone has been largely ignored in the field. To address this knowledge gap, this study investigated the ozonation rate and extent of typical petroleum compounds by simulated surface-level ozone, including total petroleum hydrocarbons (TPHs), n -alkanes, and polycyclic aromatic hydrocarbons (PAHs). Moreover, the work explored the effect of a prototype oil dispersant, Corexit EC9500A, on the ozonation rate. Rapid oxidation of TPHs, n -alkanes and PAHs was observed at various gaseous ozone concentrations (i.e. 86, 200 and 300 ppbv). Generally, the presence of the oil dispersant enhanced ozonation of the oil compounds. The addition of humic acid inhibited the reaction, while increasing salinity accelerated the degradation. Both direct ozonation by molecular ozone and indirect oxidation by ozone-induced radicals play important roles in the degradation process. The findings indicate that ozonation should be taken into account in assessing environmental fate and weathering of spilled oil. Graphical abstract: Highlights: Surface-level atmospheric ozone plays an important role in weathering of oil. Oil dispersant Corexit EC9500A can accelerate ozonation of oil hydrocarbons. Oil dispersant Corexit EC9500A enhances generation of hydroxyl radicals. Both direct and indirect ozonation account for degradation of oil hydrocarbons. Higher pH and humic acid may inhibit ozonation of oil hydrocarbons.