Dissolved Air Flotation is a liquid or solid separation process in which microscopic air bubbles (10-10O`i) become attached to solid particles suspended in liquid, causing the solid particles to float. In a OAF system air is dissolved into liquid under pressure The dissolved air remains in solution until the pressure is release, to atmospheric pressure, causing the air to come out of solution in the form of microscopic air bubbles. The bubbles are mixed intimately with the wastewater and become attached to the solids in the waste stream causing the air solids agglomerate to float to the liquid surface where a solids (float) blanket formed. Surface skimmers then remove the float blanket.