Effects of Properties of Montmorillonite on the Formation of Oil-Mineral Aggregates

Spilled oil can collide with suspended minerals in the water column to form oil-mineral aggregates (OMA) under the wave action, which can bring a threat to the marine environment and life. In this paper, the effects of concentration, size and contact angle of montmorillonite on the formation of OMA were investigated by the baffled flask tests. The increase in mineral concentration can lead to the increase in the oil droplet size trapped in OMA, OMA density and oil content in OMA. The increase in mineral size has the same result as the increase in mineral concentration, except for the opposite result in oil content in OMA. Minerals with a larger contact angle can trap larger and more oil droplets and formed OMA has a lower density. The average density of formed OMA was 1700–2000 kg/m3 in this study. The oil content in OMA grows with time and becomes stable after 240 min, and it was about 15–50% of initially added oil under different conditions.