Dissolved air flotation description
Dissolved air flotation is a water treatment process that clarifies wastewater by removal of suspended solids, oils, greases, BOD, COD, and metals.
This is achieved by dissolving air in the wastewater under pressure and then releasing the air at atmospheric pressure in a flotation tank.
The released air forms tiny bubbles which adhere to the suspended matter causing it to float to the surface of the water where it can then be removed by a skimming device, ready to dewater for proper disposal.
To improve solids removal coagulant/flocculants are added to coax suspended solids and colloidal particles into clumping together.

Dissolved air flotation principle
Dissolved air flotation (DAF) systems remove suspended solids, fats, oils, greases and non-soluble organics by dissolving air into pressurized water. Here’s how this highly efficient dissolved air flotation process works:
Water enters the WWW™ DAF system through the influent header box to reduce the water’s velocity and distribute it across the length of the vessel. To optimize the treatment process, we design the influent header box with multiple injection points, allowing the introduction of whitewater — a highly saturated pressurized stream of air and DAF effluent that sometimes includes flocculant.
The whitewater forms micro-bubbles and as the wastewater enters the flotation zone, the micro-bubbles attach to the particle surface, lowering the particle density enough to cause suspended solids, fats, oils, greases and non-soluble organics to separate from the wastewater and rise to the surface. The now separated solids, fats, oils, greases and non-soluble organics are skimmed and removed by a chain-and-flight skimmer into the sludge hopper.
Dissolved air flotation technical sheet
| DAF Model | Qm3/h | Piping Connections | Physical Dimensions(m) | Weight (Kg) | Operating Weight (Kg) |
|---|---|---|---|---|---|
| DAF-003 | 3 |
Inlet: DN50 Outlet: DN50 Sludge: DN100 Vent: DN100 |
L/L1: 3.7/2.8 W/W1: 2.4/1.16 H/H1: 2.2/1.7 |
1500 | 5000 |
| DAF-005 | 5 |
Inlet: DN80 Outlet: DN80 Sludge: DN100 Vent: DN80 |
L/L1: 4/3 W/W1: 2.4/1.16 H/H1: 2.2/1.7 |
1600 | 7000 |
| DAF-010 | 10 |
Inlet: DN100 Outlet: DN100 Sludge: DN100 Vent: DN100 |
L/L1: 4.65/3.8 W/W1: 2.7/1.36 H/H1: 2.4/1.9 |
2000 | 12000 |
| DAF-015 | 15 |
Inlet: DN125 Outlet: DN100 Sludge: DN150 Vent: DN100 |
L/L1: 5.6/4.5 W/W1: 2.9/1.66 H/H1: 2.5/2 |
2200 | 18000 |
| DAF-020 | 20 |
Inlet: DN150 Outlet: DN150 Sludge: DN150 Vent: DN100 |
L/L1: 5.9/4.8 W/W1: 3.2/1.96 H/H1: 2.5/2 |
3000 | 22000 |
| DAF-030 | 30 |
Inlet: DN150 Outlet: DN150 Sludge: DN150 Vent: DN100 |
L/L1: 6.8/5.5 W/W1: 3.2/2.16 H/H1: 2.7/2.2 |
3800 | 32000 |
| DAF-040 | 40 |
Inlet: DN200 Outlet: DN150 Sludge: DN150 Vent: DN100 |
L/L1: 8/6.7 W/W1: 3.6/2.6 H/H1: 2.7/2.2 |
5000 | 45000 |
| DAF-050 | 50 |
Inlet: DN200 Outlet: DN150 Sludge: DN150 Vent: DN100 |
L/L1: 8.4/7 W/W1: 3.6/2.6 H/H1: 2.7/2.2 |
5500 | 55000 |
| DAF-060 | 60 |
Inlet: DN250 Outlet: DN200 Sludge: DN150 Vent: DN100 |
L/L1: 9.9/8.4 W/W1: 3.8/2.8 H/H1: 2.9/2.4 |
6000 | 66000 |
| DAF-070 | 70 |
Inlet: DN250 Outlet: DN200 Sludge: DN150 Vent: DN100 |
L/L1: 10.4/9 W/W1: 3.8/2.8 H/H1: 2.9/2.4 |
6500 | 75000 |
| DAF-080 | 80 |
Inlet: DN250 Outlet: DN250 Sludge: DN150 Vent: DN100 |
L/L1: 10.8/9.4 W/W1: 4/3 H/H1: 2.9/2.4 |
7500 | 100000 |
| DAF-100 | 100 |
Inlet: DN300 Outlet: DN250 Sludge: DN150 Vent: DN100 |
L/L1: 12.1/10.6 W/W1: 4.2/3.2 H/H1: 2.9/2.4 |
9000 | 110000 |
| DAF-120 | 120 |
Inlet: DN300 Outlet: DN250 Sludge: DN150 Vent: DN100 |
L/L1: 12.5/11.4 W/W1: 4.4/3.4 H/H1: 2.9/2.4 |
10000 | 130000 |
Dissolved air flotation process flow
Dissolved air flotation advantage
The effectiveness of DAF units lies in their ability to handle a variety of wastewater streams, making them indispensable across multiple industries.
Whether in industrial settings dealing with complex contaminants or municipal systems facing large volumes of urban runoff, DAF units prove their versatility and efficiency.
They are particularly renowned in industries such as food and beverage production, where they handle organic matter and fats with ease, and in the oil and gas sector, where the separation of hydrocarbons is critical.
Furthermore, the technology is adaptable, with configurations allowing for the introduction of various chemicals to optimize performance based on specific treatment needs.
Beyond their application flexibility, DAF units offer significant advantages including high removal efficiency, low operating costs, flexibility in operation, and a compact footprint.
This makes them a viable solution even for facilities with space constraints or those looking to upgrade their existing wastewater treatment infrastructure.
However, it’s important to note that the complexity of these systems often necessitates skilled operators to manage and maintain optimal performance.
Proper pre-treatment steps such as Coarse Screening, homogenization, sand removal, and coagulation-flocculation are also essential to ensure maximum efficiency and longevity of the DAF units.

Dissolved air flotation feature
The environmental impact of DAF systems is generally positive, particularly in minimizing water pollution.
By enabling the removal of over 90% of harmful components from industrial effluents, DAF systems contribute to cleaner water bodies and reduced environmental pollution.
Moreover, reduced chemical usage and advancements in energy-efficient designs further enhance the sustainability of DAF technology.
Dissolved Air Flotation systems have solidified their place as an indispensable tool in modern water treatment processes.
Their ability to efficiently remove suspended solids from diverse wastewater streams makes them particularly valuable across industries with stringent water quality requirements.
As technological innovations continue to evolve, DAF systems are poised to become even more cost-effective and environmentally sustainable, bolstering their role in the global effort to safeguard water resources.

Dissolved air flotation application
Wastewater TreatmentDAF systems find applicability across multiple industrial sectors, addressing specific water treatment needs.
Dissolved-air flotation processes have diverse applications across multiple industrial settings.
Common industries benefiting from DAF technology include:
Food and Beverage: The food processing industry utilizes DAF systems to treat wastewater containing high concentrations of fats, oils, and food particles.
Pulp and Paper: DAF is employed to handle process water and to remove suspended solids, enhancing the quality of effluents.
Petroleum and Petrochemical: In these sectors, DAF systems act to remove oils and greases from produced water, significantly reducing environmental impact.
Wastewater Treatment Plants: Municipal treatment facilities use DAF to optimize sludge management and enhance overall treatment efficiency.
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