What process involves dissolving air into wastewater under high pressure to float solids?

The process that involves dissolving air into wastewater under high pressure to float solids is known as Dissolved Air Flotation (DAF). In this method, air is saturated into the wastewater at high pressure, and then, when the pressure is released, the dissolved air forms tiny bubbles. These bubbles attach to suspended solids, making them less dense and allowing them to rise to the surface. As a result, a layer of scum is formed which can be easily removed. This technique is commonly used for the removal of fats, oils, greases, and other types of suspended solids in wastewater treatment, enhancing the efficiency of solid separation.

In contrast, activated sludge refers to a biological treatment process where microorganisms break down organic matter, but does not specifically utilize air flotation for solids separation. Comminution involves grinding or crushing solids to manage solids in a treatment process but is unrelated to air dissolution. Filtration is a physical separation process that removes particles from liquid but does not involve the use of pressurized air to float solids.