Dissolved air flotation is a solid–liquid separation process based on the attachment of fine air bubbles to suspended particles. These microbubbles reduce the overall density of the solids, causing them to float to the surface where they can be removed as scum. The process is especially useful for removing oil, grease, algae, and other low-density contaminants that do not readily settle. https://wxyosun.com/Dissolved-Air-Flotation.html