Demineralisation Water Preparation
Demineralisation is the process of removing mineral contents in water. Water naturally contains dissolved mineral salts, these salts when present in the boiler water can either cause corrosion or scaling in the piping systems. Furthermore, many industrial processes (such as IT, chemicals and food and beverage industries) require low levels of salinity in production water.
Reverse Osmosis: RO is a process used to purify concentrated solutions of disolved minerals and salts and is used in desalination plants. The technology involves forcing water through a semipermiable membrane under high pressure, leaving the disolved salts and other solutes behind on the surface of the membrane. Source: water-technology.net
RO is used to demineralise water used for cooling systems, boiler systems and some specific manufacturing processes (in food and beverages for example). This continual treatment process does not require chemicals, except for cleaning of the membranes. This process of salt removal is mostly used in Western countries.
Ion Exchange Resins (IX): these resins are polymers which are capable of exchanging particular ions within the polymer with the liquid they are in contact with. For example to remove Ca2+ and Mg2+ a resin containing Na+ cations may be used; when the water flows through the resin the Ca2+ and Mg2+ remain in the resins which release Na+ instead. This type of treatment is more widespread in Asia.