Dissolved Air Flotation system

The DAF water treatment process clarifies wastewater and is typically used in a wide range of industrial applications to maintain environmental compliance and mitigate the financial impact of trade effluent charges.

The system is used for the reduction of Chemical Oxygen Demand (COD) present in fat, grease, oil, colour organic matter, biological sludges, and colloidal material.

Hire and pilot trials

WPL can provide hire equipment to keep sites operational and within consent and pilot units to identify the precise equipment required for your operation.

Why choose a WPL DAF:

  • Compact design and  small footprint in comparison to other technologies
  • Higher quality effluent discharged to sewer further reducing trade effluent charges
  • Reduced sludge volume with higher dry solids content
  • Can be used for recovery and recycling of non-emulsified oils with no further treatment required

Low operation and maintenance

  • Energy efficient treatment of wastewater
  • Reinforced plastic components reduce wear and corrosion
  • White water system utilises a pressure vessel to negate the need for diffusers within the floatation tank
  • Fully automated control system, removes the need for manual operation
  • Can be integrated with site BMS (building management systems)
  • Full integrated monitoring of final discharge to sewer or further treatment

Modular

  • Fully integrated treatment package for adaptation into existing process streams
  • Multiple systems installed in parallel for higher or variable flows
  • Discreet independent modules for each element of the process train
  • Transportable and fitted on site with a ‘plug and play’ approach to design, with options for access and portability

Chemical

  • Multiple chemical injection and sampling points to site requirement
  • Full dosing packages designed by site requirement

Robust

  • Constructed in grade 304 or 316 stainless steel
  • Flocculation and coagulation units manufactured in medium-density polyethylene (MDPE) to ensure an extended life
  • CE marked and built to European norms

Image of WPL dissolved air flotation DAF wastewater treatment tank with engineer

Typical industrial trade effluent applications:

  • Abattoirs, meat and poultry wastewater treatment
  • Brewery, winery and soft drink manufacture wastewater treatment
  • Baking and confectionery, ready meals and vegetable production and packaging manufactures wastewater treatment
  • Commercial laundry wastewater treatment
  • Cosmetics manufactures production and packaging wastewater treatment
  • Dairy inc milk, cream, yoghurt and cheese processing and packaging wastewater treatment
  • Fish processing wastewater treatment
  • Paper mills wastewater treatment
  • Petrochemical wastewater treatment
  • Pharmaceutical wastewater treatment
  • Textile manufacture wastewater treatment
  • Waste recycling centre wastewater treatment

Standard technical specification

Download the WPL DAF datasheet within the Assets section on this page.


Efficient wastewater and process water treatment through flotation with micro bubbles

The system is a purely physical process which operates on a simple design philosophy. Incoming effluent may require pre-treatment as necessary; for example the addition of chemical coagulant(s) and/or flocculant(s) may be required.

Adjustment of pH may also be necessary to ensure optimum operating conditions.

Process diagram of the WPL DAF wastewater treatment

 

(A) The incoming effluent enters the flotation vessel where it comes into contact with recycled, treated effluent (sometimes termed white water). The percentage of the total effluent flow into which air is dissolved under pressure and subsequently recycled will be determined by effluent specific factors.

(B) Once this saturated effluent enters the flotation tank, the pressure is released back to atmospheric. This immediately results in the recycled flow becoming supersaturated, generating micro bubbles as the dissolved air comes out of solution.

(C)These micro bubbles attach to the solids or chemical flocculants entering the vessel, causing them to float to the surface where they are retained and subsequently removed by a mechanical skimmer.

(D1) Within the rectangular flotation tank, the skimmer mechanism consists of a series of paddles or flights which run on a plastic corrosion-resistant chain, and skim just below the surface of the tank removing the float into a trough for recovery. To eliminate the risk of sludge build-up on the flotation tank floor, the design may also incorporate a floor scraper on larger systems.

(D2) Where solids normally sink, they collect in the hopper and are removed via a manual or automated valve, dependent on the effluent.

(E) The final treated effluent discharges to either drain or for further treatment