How Does a DAF Equipment Work

Solid Liquid Separator April 16, 2025 Dissolved Air Flotation

A dissolved air flotation unit operates by introducing a large quantity of microbubbles into the wastewater. These tiny air bubbles attach to fine oil droplets and suspended solids, causing them to float to the surface, where they are separated from the water. This process enables effective oil-water separation.

DAF units are known for their high treatment efficiency and compact footprint, making them ideal for treating oily wastewater with low oil concentrations but complex water compositions.

How the DAF Unit Operates

An integrated wastewater treatment system functions like a precision-engineered “mini purification plant.” Here's how it typically operates:

Pre-treatment (Screening)
The system starts with a screening unit or grit chamber that acts as a "large sieve," intercepting larger suspended solids and debris in the wastewater to protect downstream components from clogging or damage.
Biological Treatment
It then uses biological treatment methods, leveraging the strong “digestive power” of microorganisms to break down and convert organic pollutants into harmless substances, significantly reducing key contamination indicators such as Chemical Oxygen Demand (COD) and Biochemical Oxygen Demand (BOD).
Physical Separation (Sedimentation & Filtration)
Physical methods such as sedimentation and filtration are employed to further remove residual suspended solids and partially dissolved substances, ensuring the water is deeply purified.
Disinfection
Finally, a disinfection stage kills harmful pathogens and microorganisms in the treated water to ensure it meets stringent discharge standards.

In industrial applications such as textile dyeing plants, where production processes generate wastewater containing small amounts of oil and complex contaminants, a DAF system proves especially effective. Compared with traditional sedimentation methods, DAF provides faster and more thorough separation of oil and solids, resulting in significantly higher effluent quality.