Flotation mechanism and performance of air/condensate bubbles for removing oil droplets in the presence of acetic acid

Flotation technology is widely utilized to remove emulsified oil droplets from Produced water. Organic acid adsorption on the oil droplet surface affects bubble attachment, reducing oil removal efficiency. This investigation exploited the principle of similar dissolution to synthesize condensate bubbles (CB). The surface properties of oil droplets and CB and air bubbles (AB) were appraised using FTIR, zeta potential, interfacial tension, and contact angle measurements. The research also investigated the effects of acetic acids (AA) on the adhesion of oil droplets to AB and CB along with the underlying mechanism via the Extended Derjaguin-Landau-Verwey-Overbeek (EDLVO) interaction theory and the Stefan-Reynolds model of liquid film thinning, integrated with adhesion times. Flotation efficiency and kinetic dissimilarities between AB and CB were also examined. The results indicated that CB exhibits superior lipophilic hydrophobicity compared to AB, reduced induction and spreading times upon oil droplet attachment, and maximized oil removal efficiency. Furthermore, CB could mitigate the impact of AA on adhesion. The interaction barriers between CB and oil droplets were minimal, and the thinning rate of the hydration film was quicker than in AB. The conventional first-order model proved effective in fitting the AB flotation, whereas a delay constant was applied to the model of the CB flotation rate.