Dissolved Air Flotation (DAFETP)

Dissolved air flotation (DAF) is a process for removing suspended particles from liquid by bringing particles to the surface of the liquid. The influent feed liquid can be raw water, wastewater or liquid sludge. The flotation system consists of four major components: air supply, pressurizing pump, saturator (retention tank), and flotation chamber. According to Henry’s law, the solubility of a gas in an aqueous solution increases with increasing pressure.


Dissolved air flotation (DAF) has been successful in treating industrial wastewaters. In many cases, such as in poultry effluent treatment, DAF proves to be an effective pretreatment technology by reducing the organic load of the wastewater. DAF units have been widely in use in treating refinery and mining industry effluents. In both the cases DAF combined with chemical flocculation has proven to be very effective in removing particles from the effluents.

Thus, DAF should not be considered as a separate process, but integrated into design and operation of the overall treatment system. Recent technological advances in DAF include DAFRapide, AquaDAF and high rate DAF. DAF is considered as one of the most powerful tools to remove light and difficult-to-treat colloidal suspensions, precipitates or fine dispersions.