Membrane filtration

Membranes remove unwanted components and ensure stable water quality. They consist of porous films, with defined pore diameters.

A membrane is a material that allows some substances to pass through and retains others - a selective barrier. A given membrane material retains components of a certain size or with certain chemical properties. In membrane filtration of water, pressure is used to get purified water through the membrane, while retaining unwanted components.

Water filtration membranes can be characterised by pore size. The pore size determines which components are retained (as shown in the figure below). The type of membrane filtration process is chosen based on wanted water quality.

AkvaFresh offers facilities for ultrafiltration, nanofiltration and reverse osmosis. The main components in membrane filtration plants are pre-filtration / pre-treatment, pump(s), and membrane modules with a total membrane area given by the needed water capacity. Our plants have fully automated processes with programmable logic control (PLC).

AkvaFresh offers facilities for ultrafiltration, nanofiltration and reverse osmosis. The main components for the membrane filtration plants are pre-filtration / pre-treatment, pump(s) and membrane modules with a total size based on the desired water capacity. Our plants are fully automatically operated processes with programmable logic control (PLC).

 

What are membranes able to remove?

1. Particle removal:

  • Turbidity, totally suspended substances
  • Mineral particles, sand, clay and soil, colloids (0.1–1 μm)
  • Organic particles derived from living microorganisms; algae, protozoa, etc. (1–100 μm)

2. Organic pollution; colour and humus (NOM)

3. Biological pollution; parasites, bacteria and viruses:

  • Salmon lice (Lepeophtherius salmonis salmonis) 540–850 up to 5000–10.000 μm
  • Gyrodactulus salaris 500 μm
  • Paramoeba perurans (AGD) 20–30 μm
  • Ichthyobodo sp. 7 μm
  • Aeromonas salmonicida 0,5–6 μm
  • Yersinia ruckeri (Yersiniose) 1–3 μm
  • Moritella viscosa (Winter ulcers) 0,5–2,5 μm
  • SGP-virus (Salmon Gill Poxvirus) 0,3 μm
  • ILA-virus 0,09–0,13 μm
  • IPN-virus 0,06 μm

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