What is the primary function of DAF (dissolved air flotation) systems?

The primary function of DAF (dissolved air flotation) systems is to effectively separate and remove suspended solids, fats, oils, greases, and biochemical oxygen demand (BOD) from wastewater. In this process, air is dissolved in the water under pressure and then released at atmospheric pressure in a flotation tank. This causes micro-bubbles to form and attach to the particles, causing them to rise to the surface, where they can be easily skimmed off.

This method is particularly effective for treating wastewater with significant quantities of fats and oils, which may not settle well in traditional sedimentation processes. By focusing on the removal of these specific contaminants, DAF systems help improve the overall quality of effluent before it is discharged or further treated, thereby playing a crucial role in the wastewater treatment process.

The other options, while relevant to wastewater treatment, do not encapsulate the primary purpose of DAF systems. For instance, reducing sludge volume, removing nutrients, or increasing oxygenation does not represent the main operational capability of DAF technology.