Filling and Pretreatment of Anion and Cation Resins in Mixed Bed
The specific operations are as follows:
Clean the bed and put water 1-2 meters deep (ensure that the water surface is higher than the resin layer):
1. The design height shall be filled with resin (the final height of resin shall be subject to re ecology).
2. After installing the cation exchange resin, backwash to make the resin surface smooth, and then install the anion exchange resin; Two steps have been taken to prevent backwashing and disordered resin layers (for the convenience of seeing the height of anion and cation resins), and to ensure that the water surface is higher than the resin surface, and then:
2.1 Inject 3-3.5% HCl solution from the bottom and discharge from the top. It does not matter if the resin layer is disordered (it does not matter if the resin layer is disordered). The flow rate is 3-3.5m/h. When the discharged solution has about 2% acid, stop the acid flow, soak it for more than 2 hours, and then clean it with deionized water until the effluent is neutral.
2.2. 2-3% NaOH is introduced from the alkali inlet and discharged from the bottom at a flow rate of 3-3.5m/h until about 2% of the alkali in the effluent leaks out. Stop alkali introduction and soak it for more than 2 hours, and then wash it with deionized water until it is neutral.
2.3 Backwash the mixed bed and control the backwashing expansion rate of 80% - 100% until there is an obvious layering surface for the anion and cation resins. Observe whether the height of the anion and cation resins is appropriate and determine the height before regeneration.
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