【Introduction】

Ion exchange system through the anion and cation exchange resins in water of various anions and cations for replacement of a traditional water treatment process, anion and cation exchange resins in different proportions can be formed with the sun-bed ion exchange systems, ion exchange anion bed Mixed bed ion exchange system and the (re-bed) system.The total salt content in water 400mg / l or less，according to different requirements, water quality between the 1.0-0.2us/cm.。If the total salt content in water 500mg / l or more，can be combined with electrodialysis desalination，water quality higher。

【Word Principle】
By ion-exchange method， the water was able to state the positive ion，anion removed to sodium chloride (NaCl) on behalf of inorganic salts in water， water desalination in the basic reaction can be expressed by the following equation：
◆ cation exchange column (Yang bed): R-H + Na + → R-Na-H +
◆ anion exchange column (anion bed): R-OH + Cl - → R-Cl + OH? _
◆ Yang, known as anion exchange columns in series after the re-bed, the overall reaction can be written as:
     RH+ROH+NaCl??-----RNa+RCl+H2O
     This can be seen, the water, NaCl?? already were on the resin replaced by H + and OH_, it reached the role of salt removal.

◆ Mixed ion exchange column (mixed bed)： mixed bed is the cation and anion resin at a certain ratio (1:2 for cation and anion exchange resin to reach the end while at the same time renewable) into the mixed column from，in fact，two kinds of resin Arising after exchange of H + and OH ions is very small synthesis of ionization of water molecules，there is almost no sun beds used alone or when used alone produced anion bed inverse exchange phenomenon，it can make the exchange reaction was carried out thoroughly，so mixed Water quality is better than bed cation and anion beds consisting of multiple beds in series can achieve the water quality，the system can take very high purity product water。