T Tjandra, Freyssinet Australia Pty Ltd
Dissolved Air Flotation (DAF) Tanks are used to clarify waste waters by removing suspended solids, oils and other contaminants. A pressurised stream of air saturated, clarified water is mixed with the sewage effluent in the DAF separation chamber. With the release of pressure dissolved air comes out of the solution producing a cloud of microscopic bubbles. These bubbles attach to the solids, floating them to the surface to be mechanically skimmed and removed from the tank. The clarified effluent overflows from the DAF tank via an over / under weir to the next stage of treatment.