A recirculation pump redirects part of the clarified water at the outlet of the DAF unit to a pressurization/saturation system. The recirculated water is pressurized by the pump to approximately 6 bar and mixed with pressurized air. Under these pressure conditions, the air is dissolved in the water. Depressurization occurs inside the DAF unit, resulting in the generation of micro air bubbles.

Dissolved air micro bubbles allow the removal of solids and flocs that do not have sufficient buoyancy. The bubbles are between 30-50 microns in diameter, essential dimensions for efficient flotation. The bubbles quickly attach to particles of similar and larger dimensions and rise to the surface.

This mixture of water and bubbles is homogeneously distributed in the inlet compartment of the DAF unit under laminar conditions and the floated particles are redirected directly to the dewatering system at the top of the unit, where they are removed by a specially designed skimmer system.

The settlable matter flows down to the sediment compartment at the bottom of the DAF unit and is discharged through the sludge extraction system.

The clarified water leaves the unit through an adjustable supernatant system. Part of this clarified water stream will be redirected by the recirculation pump to enter the compression and saturation system described above.

:Advantages

• High quality of treated water.
• Adaptability of equipment and coagulation-flocculation and pH adjustment system, exclusive for each type of water and requirements of contaminant concentrations in the clarified water.
• Fast start-up.
• Thicker sludge, therefore less sludge production and lower management and treatment costs.
• Footprint reduced.
• Easy to operate.