Water pre-treatment for RO

Water pre-treatment for RO increases the lifespan of RO membranes

Pre-treatment (for RO or UF) is necessary to remove suspended impurities, dissolved solids, colloids, minerals, oxidants and living organisms from raw water prior to the membranes. Inadequate pretreatment for RO membranes will causes higher backwash rates, CIP of the membranes and so shorter lifetimes of the expensive membranes and so higher operational costs.

Requirements of the customer

  • Lower CIP usage, and costs
    CIP usage has four main cost factors:
    • Water
    • Energy
    • Time
    • Chemicals
  • Less downtime
  • Increasing the lifespan of he membranes
  • Lower operational expenses


  • Reliable pre-filtration package
  • Small footprint ad easy operation

Dutch Filtration will give you:

  • The knowledge to improve your processes
  • Save costs on CIP usage
  • Increase the life span of Membranes
  • Standard and custom build filter equipment
  • Turn Key filtration projects
  • In house design and production
  • (Onsite) testing to obtain process data
  • 24/7 customer service, personal and quick response

Products water pre-treatment or RO












We also provide the following products and services

  • Cartridge filter housings (vertical and horizontal

  • Bag filter housings

  • Training and Start-up
  • Spare parts
  • Rentals

Pre-treatment for Reverse Osmosis

RO plants supplies large amounts of water used for commercial processes such as food and beverage industry, but also drinking water for the public sector. Reverse Osmose (RO), Nanofiltration (NF) and Ultrafiltration (UF) are being applied to surface water, seawater, wastewater and groundwater. Most of the times these source waters have high loadings of particulate matters, organic substances and other solids. Many researches and tests have shown that UF, NF and RO can handle a certain dirt load and SDI, so a proper filtration system for pretreatment is crucial for membranes. Pretreatment protects your RO system against heavy loads by particles or colloids, oxidants, minerals and living organism.

Increasing the lifespan of RO membranes

If a RO plant doesn’t use the right pretreatment the following problems can occur:

Fouling: Feedwater in most RO Systems is heavily polluted with many microscopic contaminants, such as bacteria, microorganisms, viruses. These contaminants are collected in large quantity and blocks the RO membrane. The pressure drops caused by the lower permeate flow. This will shorten the live of the membrane and because cleaning is necessary the operating costs will increase. Pretreatment can help to slow the process of collection of contaminants.

Scaling: Scaling occurs when water has high levels of minerals, sulfates and carbonates. Resulting in plugging the membrane element or within the flow channels. It lowers the permeate flow and causes a pressure drop. The RO operation will suffer and the quality of the water will decrease.

Particles: Some damages can occur when particles hit the membranes because of plumbing errors or a hard start. Another disadvantage of particles is that the membrane becomes clogged with solid particles. More pressure is needed for a continuous flow, this will lead to higher energy costs.

Effect of Chemicals: Most RO plants are built with relatively thin membranes for improvement of permeate flow. A disadvantage of these thin membranes is they can easily be damaged by chemicals like chlorine.

 The effects of these problems are:

  • Shortening the life of the membrane
  • Poor water quality
  • Higher operational costs

Pre-treatment for UF

If the intake water contains high levels of turbidity, organics and bacteriological activity, it is better to add an extra filtration step after the prefiltration and before RO. This extra filtration step is an UF filtration system. It is still necessary to use the pre-filtration before the UF filtration, these filters protect the UF fibers from harmful objects.

Dutch Filtration can help you to choose the best solution for your pre-treatment.


Experience & Innovation

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