Dissolved Air Floatation Unit

DAF Unit in Action

The dissolved air is causing the sludge to float and is being skimmed off to the sludge hopper.

DAF Unit in Action

The clarified effluent is removed from the center layer of the DAF unit and overflows through the weir pipe and flows to disinfection and final disposal or reuse.

DAF Unit

What is a WSI DAF? The WSI DAF (Dissolved Air Floatation) unit is responsible for the separation of TSS (Total Suspended Solids). (See drawing to the right.)

A major advantage of using a WSI DAF unit over a traditional settling clarifier is that the very small or light particles, which settle slowly by gravity, can be removed more completely and in a shorter time period while using a smaller footprint than existing settling clarifiers.

For example, the typical amount of suspended solids exiting a BCR (Bio Chip Reactor) range from 200-250mg/l TSS (Total Suspended Solids). The DAF unit, will remove these solids down to a range of 10mg/l TSS prior to final filtration. A percentage of the clean water coming from the front of the DAF unit is re-circulated and pressurized while adding dissolved oxygen and then discharging to a manifold located on the bottom of each DAF unit.

Such a design completely eliminates the concerns of sludge bulking problems that may happen in a secondary clarifier for both the suspended growth process and the attached growth system.

Compared to other older technologies, still being used today, the DAF unit is a very simple and efficient process.

WSI will design a DAF for almost any application ranging in sizes from 50 GPM to several thousand GPM meeting the most demanding requirements.

Give us a call and we can design just the right DAF for your project!