Dissolved air flotation (DAF) is a water treatment process that clarifies wastewater by removing suspended solids. The removal is achieved by dissolving air in the water or wastewater under pressure and then releasing the air at atmospheric pressure in a flotation tank.
DAF are incorporated when the sludge is less dense than water, or is neutrally buoyant. DAF uses billions of micro-bubbles that attach themselves to the flocs and carry them to the surface. These bubbles, known as “whitewater”, are removed by a mechanical skimmer within the DAF unit that skims away floating sludge.