Which of the following are true about the flotation method for waste management? A. It is a water-treatment process that clarifies wastewaters by removing suspended matter such as oil or solids. B. The removal is achieved by dissolving air under pressure and then releasing it at atmospheric pressure in a flotation tank. C. Flotation is a separation technique that uses gas bubbles as a transport medium.

Flotation is a water-treatment process that clarifies wastewater by removing suspended matter such as oil or solids.

The removal works by dissolving air under pressure and then releasing it at atmospheric pressure inside a flotation tank.

As a separation technique it uses rising gas bubbles as the transport medium to carry particles up.

The lighter oil and solids attach to the bubbles and float to the surface as a froth.

The floated layer is then skimmed off, leaving clarified water below.

Dissolved air flotation is widely used in oil refineries and paper mills.