Influence of Kaolin on the Formation and Sedimentation of Oil-Colloidal Particle Aggregates in Marine Environments

Spilled oil in the marine environment is dispersed into droplets under the action of waves and currents, forming oil-colloidal particle aggregates (0cPAs) in the presence of clay particles in the ocean. Kaolin, which is a typical representative of clay particles, was investigated for its influence on the morphology and sedimentation characteristics of OcPAs in this work. Results have displayed that OcPAs exist mainly in the forms of single drop, double drops, and multiple drops, and their morphology is mainly affected by the turbulence intensity and kaolin concentration in seawater. Furthermore, it is observed that under medium- and high-turbulence intensity, the larger the fractal dimension of OcPAs is, the smaller the settling velocity becomes. The results suggest that the spilled oil can be removed from the sea surface by adding clay particles to promote the formation of OcPAs with large particle size and rapid settling velocity.