Ion exchange resins are used to remove dissolved particles from liquids. Therefore, functional groups are bonded to the polymer beads. These functionalized polymers adsorb particular anions or cations from the liquid and discharge others. Water treatment is the best-known and biggest field of application for ion exchange resins. In household, such applications are used among others to soften water. They ensure that the calcium ions responsible for water hardness are replaced by sodium ions.
Ion exchange resins are also used in industry, for example in power generation. There, Lewatit is used in the production of ultra-pure boiler feed water and steam to avoid incrustations and corrosion. This improves the efficiency, operating reliability and lifetime of power plants.