Dissolved Air Flotation (DAF): Powerful Particle Separation in Wastewater Treatment
Dissolved Air Flotation (DAF) is a physico-chemical process for separating suspended and other floatable substances from industrial wastewater. In the process, fine air bubbles are generated and attach to particles such as paint residues, oils, fats, plastics and other suspended contaminants. The resulting particle-air agglomerates rise to the water surface, where they can be removed continuously by an automatic scraper system.
Unlike sedimentation, DAF uses the buoyancy generated by fine air bubbles to separate contaminants. This makes the process particularly suitable for light, emulsified or finely dispersed contaminants that are difficult to separate by conventional sedimentation. The short hydraulic retention time also enables compact system designs.
Technical Operating Principle of DAF Technology
In a DAF system, a portion of the treated water is pressurised and saturated with air. When the pressure is subsequently released in a controlled manner, microscopic air bubbles are formed. These bubbles attach to suspended particles and form stable particle-air agglomerates that rise to the water surface.
Bubble size, pressure level and recirculation rate can be adjusted according to the application. The addition of suitable flocculants or precipitants can further improve the separation of fine and emulsified contaminants. This enables DAF systems to achieve consistent treatment performance even when wastewater composition varies.
High-Performance Flotation from OKO-tech
OKO-tech develops flotation systems for demanding industrial wastewater treatment applications. Depending on the wastewater characteristics and treatment objectives, the systems can separate oils, fats, suspended solids, paint particles and other floatable or flocculated contaminants.
Optimised hydraulics, controlled air dissolution and automated process control support stable flotation performance. Depending on the application, the treatment concept can also help reduce chemical and energy consumption while supporting economical operation.
Typical Applications
DAF is particularly suitable for applications in:
- Paint shops and surface treatment
- Food and beverage production
- Metalworking
- Plastics processing and recycling
- Chemical industry
The process can be integrated into compact continuous-flow systems as well as modular treatment concepts. OKO-tech selects and combines the appropriate treatment stages according to the wastewater characteristics, required treatment objectives and operating conditions.
