Desalination

Reverse osmosis (RO) is a water purification technology that uses a semipermeable membrane to remove ions, molecules, and larger particles including bacteria from industrial and drinking water. In reverse osmosis, an applied pressure is used to overcome osmotic pressure. A good quality pre-treatment process is instrumental to the successful operation of a seawater reverse osmosis (SWRO) plant. The compounds that are susceptible to foul the reverse osmosis (RO) membranes are inorganic suspended solids, sand, oil, clays, bacteria, and dissolved organic matters. In order to prevent the fouling, a pre-treatment of the raw water needs to be conducted. The pre-treatment technologies are commonly grouped into two categories, conventional and non-conventional. Both of these treatments are currently applied in SWRO plants in the world. The traditional conventional methods of treating seawater intended for processing via SWRO includes sedimentation (following in-line coagulation), media filtration and cartridge filtration. While conventional processes have been widely used for SWRO pre-treatment, the need for careful design and close operator control has resulted in the increasing popularity of using ultrafiltration (UF) and microfiltration (MF). To ensure the successful operation of both popular options, the protection by mechanical coarse filtration (100-300 microns) has proven to be the most efficient and economical. Among the different strainers used to protect the UF/MF membranes or media filters, automatic screen filter is the leading choice of desalination systems design engineers. The main advantages are the precise filtration of the determined particles, the easiness of self-cleaning and the savings in capital and operation costs. Yamit offers several types of filters for this application based on the suction scanner or brush cleaning technologies.