Exploring the Role of Nanobubbles in the Fate and Transport of Spilled Oil on Shorelines

Abstract

Nanobubbles (NBs) generated by wave breaking and shearing are abundant and stable in the ocean. However, few studies have focused on the effects of NBs in the fate and transport of pollutants in the shoreline environment. In this study, the properties of NBs were determined, as well as the influencing factors. The role of NBs in the fate and transport of spilled oil were further investigated. The results showed that NBs significantly increased the concentration of dissolved oxygen as well as changed the pH, zeta potential, and surface tension of the water. Low salinity favored the generation of NBs, while high salinity inhibited this process. The surface active materials played a positive role in the generation and stabilization of NBs. With the assistance of external energy, the bulk NBs enhanced the efficiency in oil detachment from the surface of the substrate. At the same time, the surface NBs on the substrate obstructed the downward transport of oil colloids. Considering the behavior between the NBs in two different phases and the oil droplets, the oil droplets tended to bind to the NBs. This study demonstrates that NBs can play a significant role in the environmental behaviors of pollutants in the coastal areas.