Ion exchange is a special kind of solid adsorption process, it is by ion exchange agent for the electrolyte solution. General ion exchange agent is a water-insoluble solid particulate matter, that ion exchange resins. It can draw from the electrolyte solution of a cation or anion, while the self-contained in another sign of the ions with same charge and other quantities for them, and released into the solution to this is the so-called ion exchange. According to the type of ion exchange, ion exchange agents can be divided into cation exchanger and anion exchanger into two categories.
As a mature water treatment process, the ionic exchange has widely been used in the production of purified water, highly purified water and demineralized water. It can be used to remove the all kinds of ion and anion by taking advantage of exchange absorbance property of cationic and anionic exchange resin. It can be divided into cation bed, anion bed and combined bed. The salt can be remove by the combination of the beds to attain the design requirement in water treatment. Ion exchange equipment is a requisite for the production of highly purified water, and finds its wide applications in medicine, chemical engineering, electronics, electroplating, and boiler. The electric resistivity can reach 1-18MΩ.CM after combinations with RO, EDI equipment.