Oil dispersion and aggregation with suspended particles in a wave tank

• Published in: Journal of environmental management 2021-01, Vol.278 (Pt 2), p.111572, Article 111572
• Main Authors: Yu, Yue, Qi, Zhixin, Xiong, Deqi, Sun, Ruiyang, Fu, Sinan, Li, Wenxin
• Format: Article
• Language: English
• Subjects: Breaking wave; Oil type; Oil-particle aggregate; Oils; Particulate Matter; Sunken oil; Temperature; Viscosity; Water Pollutants, Chemical - analysis; Wave tank
• ISSN: 0301-4797; 1095-8630
• DOI: 10.1016/j.jenvman.2020.111572

Suspended particulate matter (SPM) in marine environments plays an important role in determining the fate of spilled oil via the generation of oil-particle aggregates (OPAs). A series of mesoscale wave tank experiments and sedimentation tests were conducted to fill the knowledge gap on how the turbulent mixing, temperature, and oil type affect the dispersion of spilled oil and properties of OPAs. Generally, the oil dispersing efficiency was significantly enhanced by high wave energy, which also led to effective oil sinking, large size of OPAs and wide distribution of trapped oil. Nonlinear fitting results indicated that the oil sinking efficiency followed an exponential growth over time. The effect of temperature on oil dispersion and formation of OPAs is primarily attributed to its influence on oil viscosity and interfacial tension. Viscous oils are more likely to interact with particles above 25 °C. However, below 20 °C, a specific oil viscosity that will bring about the maximum OPAs exists. Excessive oil viscosity will lead to a weak binding between oil and SPM and a centralized distribution of trapped oil. Furthermore, spilled oil with a high asphaltene can interact more effectively with particles. Our finding suggested that early prevention of offshore oil sinking is key in summer. [Display omitted] •Increase of wave energy promotes more oil to disperse and interact with the particles.•Oil with medium viscosity has a higher risk of sinking as temperature rises.•Increase of the mixing time and turbulent energy expedite more large oil droplets trapped in the aggregates.