Dissolved Air Floatation (DAF) Systems
Wastewater treatment system using fine air bubbles to float suspended solids, oils, and emulsified contaminants to the surface for skimming — available in circular and rectangular configurations.
Dissolved Air Flotation (DAF) is a wastewater treatment technology that clarifies wastewater by removing suspended matter such as oil, emulsified oil, and solids simultaneously. The process works by dissolving air in wastewater under pressure and then releasing it at the inlet of the flotation tank. The released air forms micro-sized bubbles which adhere to the suspended particles, lowering their specific gravity and causing them to float to the surface where they are removed by a skimming device.
AIRFIN DAF systems offer very low retention times of 5–15 minutes with separation efficiency of 95–98 % depending on industry. High loading rates of 10–20 m/h are standard, with advanced process variants operating successfully up to 40–45 m/h. The system produces a very thick float sludge of 2–3 % total solids, which can be dewatered directly without intermediate thickening.
DAF systems often require no polymer as the process does not need a large, dense floc. Coagulant dosages may also be reduced compared to conventional settling. Flocculation times are shorter, start-up is rapid (typically under 30–60 minutes to steady state), and the overall footprint is significantly smaller than conventional flocculation and gravity sedimentation systems.
Available in both circular and rectangular configurations, AIRFIN DAF systems are fabricated in Mild Steel, MS+FRP, and Stainless Steel (SS304, SS316) as per site requirements. Pre-fabricated units are available for easy installation. Applications span food and beverage, oil refineries, pulp and paper, municipal wastewater, textile and tanning, dairy, meat, poultry, and fish processing industries.
Key features
- Clarifies wastewater by removing suspended matter, oil, and emulsified oil simultaneously
- Dissolves air in wastewater under pressure and releases it at the flotation tank inlet to form micro-sized bubbles
- Micro bubbles adhere to solid particles, lowering their specific gravity and floating them to the surface for skimming
- Very low retention time of 5–15 minutes compared to conventional settling
- High loading rate typically 10–20 m/h, with advanced variants operating up to 40–45 m/h
- Produces very thick float sludge of 2–3 % total solids — can be dewatered without intermediate thickening
- Often no polymer required as DAF does not need a large dense floc
- Shorter flocculation times compared to gravity separation
- Rapid start-up typically under 30–60 minutes to reach steady state
- Smaller footprint compared to conventional flocculation and gravity sedimentation
- Available in both circular and rectangular configurations
- Available in Mild Steel, MS+FRP, and Stainless Steel (SS304, SS316) as per requirement
Outcomes
- Separation efficiency of 95–98 % for TSS, free oil, and emulsified oil removal depending on industry
- Excellent Giardia and Cryptosporidium removal efficiencies of approximately 2–2.5 log depending on temperature
- Very thick float product eliminates the need for intermediate sludge thickening before dewatering
- Small footprint and low retention time reduce civil construction costs compared to conventional clarifiers
- Pre-fabricated units available for quick site installation and commissioning
Who it's for
Food and beverage industry, oil refineries and petrochemicals, pulp and paper mills, municipal wastewater plants, textile and tanning industries, dairy and meat processing, poultry and fish processing, mining industry, and any facility requiring simultaneous removal of suspended solids and oils from wastewater.
Applications
Food & beverage industry
Removal of fats, oils, grease, and suspended solids from food and beverage process wastewater.
Oil refineries & petrochemicals
Separation of free and emulsified oil from refinery and petrochemical process effluent.
Pulp & paper mills
Clarification of process water and effluent in pulp production and papermaking.
Municipal wastewater plants
Primary or tertiary treatment for suspended solids and contaminant removal in municipal STPs.
Textile & tanning industries
Removal of dyes, chemicals, and suspended matter from textile and tannery effluent.
Dairy & meat processing
Separation of fats, proteins, and solids from dairy, meat, poultry, and fish processing wastewater.
Focus areas
- Waste Water Treatment
- Engineering & Fabrication
- Food, Beverage & Distillery
