Dissolved Air Flotation (DAF) Clarifiers

M.W. Watermark DAF Clarifier (Dissolved Air Flotation)

M.W. Watermark DAF Clarifier (Dissolved Air Flotation)

The M.W. Watermark Dissolved Air Flotation (DAF) clarifier is a very effective tool in removing suspended solids, fats, oils, metals and non-soluble BOD from a waste stream.

In a DAF clarifier, microscopic air bubbles are produced and mixed with the incoming wastewater. The air bubbles attach themselves to the contaminants, which gives them buoyancy. The buoyant mixture of particles and air bubbles float to the surface and are removed by a skimming mechanism.

Air bubble production is achieved by pressurizing a portion of the clean effluent and recycling it back to the influent to be mixed with the waste stream. As the super saturated water enters the DAF the pressure is removed and millions of microscopic air bubbles are produced. The bubbles become entrained in the solids, rise to the surface and form a bed of material that is skimmed into an isolated chamber.

The effluent quality of a DAF is greatly improved with chemical pre-treatment. Our Snake-Blend™ and CAT systems offer the latest in design technologies. Removal rates for FOG and TSS are typically 95% to 97% with proper chemical pretreatment.

The Snake-Blend™ system is an effective way to introduce and mix a chemical recipe using water turbulence in a series of winding pipes. The design features winding, clog free mixing zones for ideal mixing of the chemistry. The design is compact and has no moving parts.

M.W. Watermark Snake-Blend™ System - Chemical Pre-Treatment for a DAF Clarifier

M.W. Watermark Snake-Blend™ System

The Chemical Addition Tank (CAT) system is designed based on flow and retention time. They are typically used when greater contact time and mixing are required to effectively mix the chemistry. The systems are custom designed to match the flow requirement of the DAF and are offered in A-36 carbon, 304 or 316 stainless steel. Mixers and chemical pumps are supplied as standard.

M.W. Watermark Chemical Addition Tank - CAT - Chemical Pre-Treatment for a DAF Clarifier

M.W. Watermark Chemical Addition Tank (CAT-70)

Proudly manufactured and assembled in the U.S.A. Pilot units are available for rental or purchase. 

Contact M.W. Watermark for details

M.W. Watermark DAF Brochure
DAF Sizing Drawing
DAF Specifications Document
Industrial Wastewater Questionnaire

Learn More on Our Blog…

“Dissolved Air Flotation Clarifier (DAF) or Oil-Coalescing Separator (OCS)?” – Read more.

“Slant Plate or Dissolved Air Flotation (DAF) Clarifier?” – Read more.

“How to Improve Removal Efficiencies in a DAF Clarifier” – Read more.

“Dissolved Air Flotation: A Cost Effective Clarification Technique” – Read more.

Visit our Industries and Applications pages to learn more about utilizing a DAF for laundry wastewater recycling. 

Need feed pumpstanks or an electrical control cabinet? M.W. Watermark can supply everything you need for a complete wastewater treatment system.

Looking for a Slant Plate (Inclined Plate) Clarifier? Visit our SPC webpage.

Does you spec call for a Low Profile Clarifier (LPC) design? We can provide that as well. Just ask!

DAF Clarifier Adjustable Skimmer Image - M.W. Watermark

Adjustable Skimmer
DAF Clarifier Adjustable Weir Image - M.W. Watermark

Adjustable Wier
M.W. Watermark Chemical Addition Tank - CAT 132 - Chemical Pre-Treatment for a DAF ClarifierM.W. Watermark CAT-132
M.W. Watermark Chemical Addition Tank - CAT 132 - Chemical Pre-Treatment for a DAF Clarifier

M.W. Watermark Chemical Addition Tanks (CAT-70)M.W. Watermark Chemical Addition Tanks (CAT-70)
M.W. Watermark DAF Overview Video
DAF Chemical Pre-Treatment Equipment Video

DAF Product Features

Our systems each come standard with features that improve efficiency and make them easier to use. These include:

  • Construction in A-36 carbon, 304 or 316 stainless steel, welds are dye penetrant tested.
  • Compact design saves floor space.
  • Variable speed flight and chain skimmer design that allows for the driest float cake possible.
  • Adjustable effluent weir disc for easy adjustment of water level.
  • Highly efficient air system produces dissolved air without the need for a dedicated air supply.
  • Nema 4 and Nema 7 control packages available.
  • Operator friendly.

DAF Applications

Our DAF treatment systems can be used across a wide range of industries for a variety of applications, including:

  • Algae Removal
  • Aircraft Maintenance
  • Automotive
  • Ballast Water Treatment
  • Biodiesel Process Water
  • Canning Plants
  • Chemical Processing Plants
  • Dairy Products
  • Durable Goods
  • Fiber Recovery
  • Fiber Recovery
  • Food Processing
  • Frozen Food Processing
  • Heavy Metals Removal
  • Hydro-Frac Flow Back Water
  • Meat Packing
  • Military Wash Racks
  • Mining
  • Oil Refinery Waste
  • Paint Manufacturing
  • Pet Foods
  • Petro-Chemical
  • Poultry Processing
  • Power Plants
  • Prepared Water
  • Pulp and Paper
  • Railroads
  • Refinery
  • Storm Water Treatment
  • Vehicle and Fleet Cleaning

Available Options

In addition to the standard features, our DAF clarifiers can also be equipped with:

  • Chemical Pre-Treatment
  • Expanded Float Chamber
  • Feed and Effluent Pump Systems
  • Sludge/Float Pump Systems
  • Nema 7 Control Panel
  • Sludge Auger
  • Expanded Effluent Chamber
  • Walkway

System Design

Inlet Diffusion Chamber
The raw influent enters the DAF with the pressurized recycle flow through a distribution baffle that spans the entire width of the tank. Initial mixing takes place as the two flows merge.

Separation Chamber
As the pressurized recycle flow reaches atmospheric pressure, millions of small bubbles form and attach themselves to the contaminants in water, floating them to the surface.

Skimmer
A flight skimmer system moving in a concurrent direction skims the float from atop the separation chamber into a float collection chamber. The skimmer system includes an adjustable speed gear motor to adjust the speed of the skimmer blades.

Solids Chamber
Heavy solids that settle descend into a bottom sludge chamber. The sides are pitched to provide near complete removal of the sludge.

Effluent Chamber
Clean water passes under a strategically placed retention baffle and into the effluent chamber. A portion of the clean effluent water is recycled back to the influent and mixed with the incoming waste stream, with the balance discharged.

Pressurization Pump System
A portion of the effluent stream is directed to an air aspirating pump that generates highly saturated dissolved air efficiently and reliably. The pump eliminates the need for a dedicated air source. The pressurized recycle flow exits the pump and is mixed with the influent raw waste stream.

Specification Table

daf specification table

*Information subject to change without notice, dimensions are approximate, values may vary based on process conditions.

Contact us for more information by calling or filling out our online form.