DAF

Still floating, not sinking. Although invented in Norway more than 100 years ago, Dissolved Air Flotation is still one of the most proven and effective physical/chemical technologies for treating a variety of wastewater.

Contaminants are removed using a dissolved air-in-water solution produced by injecting air under pressure into a recycle stream of clarified DAF effluent. This recycle stream is then combined and mixed with incoming wastewater in an internal contact chamber where the dissolved air comes out of the solution in the form of micron-sized bubbles that attach to the contaminants. The bubbles and contaminants rise to the surface and form a floating bed of material that is removed by a surface skimmer into an internal hopper for further handling.

Selected References

FARA WWTP

New state of the art treatment plant for Fredrikstad og Hvaler

Design Load

Qdim: 2170 m³/h
Qmax: 6600 m³/h
TN: 1500 kg/d
TP: 167 kg/d
BOD: 6200 Kg/d

Technologies

Pumping station
Pre-treatment
MBBR
Dissolved air flotation
CoMag system

Effluent Requirements

TN: 85% removal or 6 mg/l
TP: 95% removal or 0,2 mg/l
BOD: 80% removal or 25 mg/l

Project Data

Awarded: 2022
Completion: 2027

Oppegård Drinking Water Plant

   

Design Load

Qdim; 750  m³/h

Technologies

Complete rebuilding of the flotation system including rehabilitation and strengthening of the concrete pool. New inlet arrangement with distribution of dispersion water, new baffles in steel, new sludge roller, bottom scraper and new arrangement for emptying sludge.

Project Data

Awarded: 2017
Completion: 2018

UGRA WWTP

New State of the art treatment plant for Ullensaker Municipality

Design Load

PE: 125 000
Qmaxdim: 1 900 m³/h    
BOD: 7470 kg/d
TN: 1530 kg/d

Technologies

Pumping station
Pre-treatment
MBBR
Dissolved air flotation
Sand filtration

Effluent Requirements

TN: 70 %removal
TP: 98% removal
BOD: 70% removal or 25 mg/l

Project Data

Awarded: 2020
Completion: 2025

Enga WWTP

Upgrading existing plant for Sandefjord Municipality

Design Load

PE: 103 500
Qmaxdim: 3200 m³/h
BOD: 6210 kg/d

Technologies

Pumping station
MBBR
Dissolved air flotation

Effluent Requirements

TP: 90% removal
BOD: 70% removal or 25 mg/l

Project Data

Awarded: 2018
Completion: 2025

Søbyholmen WWTP

   

Design Load

PE: 4000
Qmaxdim: 57 m³/h
BOD: 180 kg/d
COD: 360 kg/d

Technologies

Pumping station
Pre-treatment
MBBR
Dissolved air flotation
Sludge dewatering

Effluent Requirements

TP: 90% removal
BOD: 90% removal or 10 mg/l

Project Data

Awarded: 2020
Completion: 2022