Influent stream is mixed with a side stream that is recirculated from the final effluent chamber. Side stream is saturated with air and the mixture is introduced into the contact chamber of the DAF unit. Heavy particles settle into the first section of conical bottom of the unit while the suspended matter is carried by micro air bubbles on the liquid surface.

Accumulated scum is then removed and conveyed to the sludge collection chamber by the action of a chain and flight mechanism. The liquid portion of the influent flows downwards through a lamella settler where remaining particles are separated and settle into the second section of the conical bottom of the unit. Settled particles are removed from two individual discharge ports installed at the lower bottom of the unit. Purified effluent flows through pipe(s) to the effluent chamber. Water level in the unit is adjusted with the use of overflow telescopic nozzles installed into the effluent chamber. A special multistage – multiphase pump is used to recirculate effluent to the inlet.

Compressed or atmospheric air is delivered to the recirculation pump and saturation of the air-water mixture is performed into the pressure vessel. Final purified effluent overflows through the discharge pipe.