Which method is commonly used to remove emulsified oil from wastewater?

Dissolved air flotation (DAF) is commonly used to remove emulsified oil from wastewater due to its effective mechanism of separating oil droplets from the water phase. In this process, air is dissolved in the wastewater under pressure, and when released, microbubbles form. These bubbles attach to the emulsified oil droplets, causing them to rise to the surface where they can be skimmed off. This method is particularly efficient for treating wastewater with low concentrations of oil and allows for the removal of fine solid particles as well.

Other methods like chemical precipitation may not effectively address emulsified oils and are more suited for removing suspended solids or specific contaminants. Filtration can remove larger particles but may not be effective against very fine emulsified oils, while bioremediation relies on biological processes to degrade contaminants over time, which may not rapidly address the presence of emulsified oil directly in wastewater. Therefore, dissolved air flotation is recognized as a specialized and effective method for treating wastewater containing emulsified oils.