For saturation of water treated with atmospheric air in a dissolved air flotation (DAF) system and the production of microbubbles, air was introduced through the suction pipe of a centrifugal pump. The operating conditions of the centrifugal pump were adjusted to avoid the occurrence of cavitation phenomena. The novel technique was applied for the treatment of oily water in a DAF pilot prototype. A central composite rotational design (CCRD) was used to determine the high efficiency of the separation process. In addition to this high degree of oil-water separation, the technique reduces space and energy costs in comparison to conventional processes of saturation of the effluent treated with compressed air.