In the production of ion exchange resins, a small amount of organic oligomers and some inorganic impurities are often contained. In the initial stage of use, it will gradually dissolve and release, affecting the quality of the effluent or the quality of the product. Therefore, the new resin must be pretreated before use, as follows:
1. After the ion exchange resin
is loaded into the system, backwash the resin layer with clean water at an expansion rate of 50% to 70% until the water is clear, odorless, and free of finely divided resin.
2. Pass the resin layer at a flow rate of 2 m/h with about 2 times the resin volume of 4 to 5 % HCl solution. After all the inlets, soak for 4-8 hours, drain the acid solution, rinse with clean water until the effluent is neutral, and the flushing flow rate is 10 ~ 20 m / h.
3. Using a solution of about 2 times the volume of the resin in 2 to 5 % NaOH, pass in and soak as above the HCl solution. Drain the alkali liquor, rinse with clean water until the effluent is neutral, and the flushing flow rate is the same as above.
If the acid or alkali solution can be repeated 2 to 3 times, the effect is better.
For the pre-treated resin, the amount of regenerant should be appropriately increased during the first operation to ensure sufficient regeneration of the resin.