Ion exchange mixed bed equipment

Ion exchange mixed bed equipmentThe system is a traditional water treatment process that replaces various anions and cations in water through anion and cation exchange resins. By combining anion and cation exchange resins in different proportions, ion exchange cation bed systems, ion exchange anion bed systems, and ion exchange mixed bed (compound bed) systems can be formed. The mixed bed (composite bed) system is usually used as the terminal process for producing ultrapure water and high-purity water after water treatment processes such as reverse osmosis. It is one of the irreplaceable means for preparing ultrapure water and high-purity water at present. The conductivity of its effluent can be lower than1uS/cmBelow, the resistivity of the effluent water reaches1MΩ.cmAs mentioned above, depending on different water qualities and usage requirements, the resistivity of the effluent can be controlled within1~18.2MΩ.cmBetween. Ion exchange technology is widely applied in the field of water treatment, including the preparation of industrial ultrapure water and high-purity water for electronics and power, chemical engineering, electroplating, boiler feed water, and pharmaceutical use. Compared with the reverse osmosis devices introduced in recent years, it can thoroughly remove ionic impurities. It has low requirements for the pretreatment of water. The equipment has the advantages of low cost and so on. At present, there are no alternative devices for ion exchange technology in the preparation of high-purity water. The total salt content of the influent is400mg/lAt the following times, the effluent water quality varies according to different user requirements1.0-0.2us/cmBetween. If the total salt content of the influent water is500mg/lWhen the above is applied, it can be combined with an electrodialyzer for desalination, and the quality of the effluent can be further improved.

Ion exchange mixed bed equipmentThe working principle of resin

By using the ion exchange method, the cations and anions in water in ionic form can be removed, such as sodium chloride(NaCl)Representing inorganic salts in water, the basic reactions of water desalination can be expressed by the following equation:

1Cation exchange resinR-H+Na+ R-Na+H+

2Anion exchange resinR-OH+Cl- R-Cl+OH-

3The overall reaction equation for cation and anion exchange resins can be written as: RH+ROH+NaCl-RNa+RCL+H2O

From this, it can be seen that in the waterNaClIt has been respectively applied to the resinH+andOH-It is replaced, and the reaction products are onlyH2OTherefore, the effect of removing salt from water has been achieved.

Ion exchange mixed bed equipmentPretreatment of resin

Pretreatment of cation exchange resin

First, rinse the resin with clean water, and then use4~5%theHClandNaOHAlternate soaking in sequence in the exchange column2~4For a few hours, rinse with a large amount of clean water between acid and alkali until the effluent is nearly neutral. Repeat this process2~3Each time, the amount of acid and alkali used is the volume of the resin2Double. The last processing application4~5%theHClProceed with the solution, drain the acid completely, and rinse with clean water until neutral, then it is ready for use.