What process is described as dissolving air into wastewater, followed by releasing it to aid in floating solids to the surface?

The process described in the question is known as Dissolved Air Flotation (DAF). This technique involves saturating wastewater with air under pressure. When this pressurized water is released into a flotation chamber, the drop in pressure causes air to come out of solution, forming tiny bubbles. These bubbles attach to suspended solids in the wastewater, causing them to rise to the surface. This floating mass can then be easily removed, typically by skimming off the surface.

This method is particularly effective for separating organic materials, fats, oils, and greases from the wastewater, making it an important process in the treatment of industrial and municipal effluents. In contrast, filtration primarily focuses on passing liquid through a filter medium to remove solids, while aeration introduces air into water to promote aerobic biological activity. Coagulation involves chemical processes to aggregate particles into larger clumps, which is distinctly different from the flotation mechanism utilized in DAF.