Water treatment

All water can be made clean, it is just a question of how much we are willing to pay. It is important to find a balance between that which is technically possible, and cost.

The treatment group is an experimentally oriented research group working in close cooperation with SINTEF with most of the projects targeting development of new treatment processes as well as optimization of treatment processes both for:

  • drinking water,
  • industrial process water (for instance in aquaculture),
  • municipal and industrial wastewater and
  • sludge treatment.

The department is particularly strong in areas of research concerning the removal of humic substances in drinking wate and the removal of nutrients in wastewater (phosphate by chemical precipitation and nitrogen by nitrification/denitrification in biofilm processes); as well as particle separation processes (coagulation, flocculation, flotation, granular media filtration and membrane filtration).

Membrane filtration

Currently the focus of our activities is membrane filtration — a unit process that probably will revolutionise the water and wastewater treatment sector during the next decades. On the applied research side, the group has put a lot of emphasis on biofilm processes and has developed “the moving bed biofilm process” that is now commercialised and become very popular in practice all over the world.


In the area of water hygiene the research has been focused on rapid techniques for detection of bacteria in contaminated water aiming at development of rapid techniques for determining bacterial water quality and disinfection efficiency, and for assessment of bacterial viability. Disinfection of water and wastewater is another research activity, and the group works both with traditional (ozone, UV) and new (e.g. membrane technology) disinfection processes for removal of microorganisms (virus, bacteria, protozoa) from water. See also Treatment of produced water (pdf)

Membrane technology

One of the main research areass for the water and wastewater treatment group is the application of membrane technology in drinking water treatment and wastewater treatment. The current activity includes;

  • Hybrid membrane bioreactors (MBR)
  • Ozononation-biofilm-membran processes for the removal of NOM in drinking water
  • MF/UF filtration of water and wastewater
  • Coagulation and MF/UF separation
  • Membrane contactors for gas transfer (ozone)

Drinking water

Research topics and activity include:


  • Coagulation/directfiltration
  • Membranefiltrering
  • Ozonation-biofiltration

Coagulants and flocculants

  • Inorganic
  • Organic polymers

Disinfection (hygienic barriers)

  • Ozonation
  • Membranefiltration

Corrosion control

  • Carbonatisation
  • Activated silica addition

Membrane technology

  • Nanofiltration
  • Coagulation/ultra- og microfiltration

Water chemistry and hygiene

Research topics within water chemistry and water hygiene includes:

Rapid techniques for detection of bacteria

  • Assessment of bacterial viability
  • Assessment of disinfection efficiency

Disinfection (bacteria, virus, protozoa)

  • Ozone
  • UWater chemistry and hygiene

Wastewater treatment


Primary treatment

Grovfiltrering, Kjemisk primærrensing

Secondary treatment

Kaldnesprosessen, Koagulerings prosesser, Koagulanter and flokkulanter

Tertiary treatment

Phosphate removal

Chemical, Biological

Nitrogen removal

Moving bed process (Kaldnes process)

Membrane filtration


Sludge treatment

Thermal sludge hydrolysis

Water and wastewater engineering

EU projects

TECHNEAU: drinking water treatment

EUROMBRA: development of MBR technolgy for treatment of municipal wastewater

Hybrid MBR process


We are currently working on the development of a hybrid MBR process combinig a moving bed biofilm reactor with a submerged membrane reactor for the separation of biomass/particulates.

MF/UF with coagulation pretreatment

The removal of NOM from drinking water is of major concenr in Norway. One of our projects is the development of a treatment process combining MF/UF filtration in a submerged membrane configuration with coagulation pretreatment.