Three French companies are meeting the water demands of large populations through the use of seawater desalination.Distillation and reverse osmosis are two competing techniques in the desalination of seawater. While each method has pros and cons, both provide a vital service in making seawater drinkable. Three French water companies (Saur, Degremont and Sidem) are working to improve the quality of fresh water created by both these methods and have invested heavily in the Mediterranean and Middle East markets with these technologies.
Las Palmas, Spain
Desalination technology has brought fresh water and hence industrial and commercial development to areas of the world that otherwise might have remained unproductive. Not only has development been enhanced by this technology but, more importantly, the health and welfare of many people have been improved by the supply of sanitary fresh water supplies.
Once considered a viable technology only for desalination, membrane processes are increasingly employed for removal of bacteria and other microorganisms, particulate material and natural organic material that can impart color, tastes and odors to the water.
Though both the cation and the anion resin are responsible for the quality of a deionization (DI) system effluent, it is the cation resin that is the big contributor to leakage. Improving the leakage characteristics of DI cation will reduce effluent conductivity, drop the pH and ultimately lead to better silica performance from the system.
Off the coast of Washington, 32 families on Guemes Island were faced with an aging well that was drawing salt water into its system. Because groundwater is scarce on the island, residents had to rely on what little rain water soaks into the ground.
The increasingly broad range of requirements for water quality has motivated the water treatment industry to refine existing techniques, combine methods and explore new water purification technologies including desalination.
Reverse osmosis plants increasingly are being installed in outlying and remote areas. By providing water they can sustain life and/or provide irrigation to previously remote areas without readily available fresh water sources.
Membrane filtration, widely used in chemical and biotechnology processes, is already established as a valuable means of filtering and cleaning wastewater and industrial process water.
As competition for limited water supplies increases, sea water treated by reverse osmosis will become more viable.