Pre-filtration, ultrafiltration, reverse osmosis (RO), and disinfection in desalination

Water treatment UAE

Absolutely, the process you’ve outlined—utilizing pre-filtration, ultrafiltration, reverse osmosis (RO), and disinfection—is a common and effective method for desalination based on reverse osmosis. Let’s break down each stage:

  1. Pre-filtration:
    • This stage involves the removal of larger particles, debris, sediments, and any substances that could potentially damage or clog the subsequent filtration systems.
    • Typically employs multimedia filters, cartridge filters, or other filtration methods to remove larger impurities.
  2. Ultrafiltration:
    • Ultrafiltration (UF) is a finer filtration process that uses membranes with smaller pore sizes compared to pre-filtration.
    • Removes suspended solids, colloidal particles, bacteria, and larger organic molecules.
    • Helps in protecting the RO membranes by further purifying the water before it enters the RO stage.
  3. Reverse Osmosis (RO):
    • RO is the core process in desalination, involving a semi-permeable membrane that separates salts, minerals, and impurities from water.
    • Applies pressure to force water through the membrane while rejecting salts and contaminants.
    • Produces freshwater by allowing purified water to pass through while concentrating salts in the reject stream.
  4. Disinfection:
    • After the water passes through the RO stage, disinfection ensures the removal or inactivation of any remaining microorganisms or pathogens.
    • Common disinfection methods include chlorination, ultraviolet (UV) treatment, ozonation, or a combination of these methods to ensure the water meets safety standards.


This multi-stage process ensures thorough purification and desalination of the water, starting from the removal of larger particles and progressing to the separation of salts and impurities through RO, ultimately followed by disinfection to ensure the water’s safety for consumption or other uses.

This comprehensive approach not only produces desalinated water but also helps prolong the lifespan and efficiency of the RO membranes by reducing fouling and potential damage from larger particles and contaminants.