Some questions about using ion exchange resins in water treatment

In water treatment using  Ion Exchange Resins, there are a number of points that need special attention. Here are some:

1. Use Care when performing backwashing

During backwashing, if the water flow is not adequate for the specific product or the operation is incorrect, resins may be washed out of the reactor and lost. This is the main reason why resins are found in trenches and wastewater ponds.

2. Inspect regularly your vessels to make sure the nozzles or liquid distribution parts are intact

If the nozzles or other liquid distribution parts are damaged, the resins will leak out of the equipment, and then enter the subsequent equipment or water supply system. Therefore, the operation of the downstream equipment will be disturbed, and the quality of the produced water may be impacted.

3. Always monitor the quality and the amount of water produced. When operating Mixed Bed, select Saprelite resin types allowing good separation of anionic and cationic components.

4. Prevent suspended solids from entering the ion exchange system.

If turbidity of the influent water is too high, it will lead to blockage of the resin bed, fouling of the resins and potential precipitation in the beads. The suspended solids often contain salts of multi-valent metal ions which are prone to precipitation.

5. When using sulfuric acid regeneration, prevent calcium sulfate precipitation:

Sulfuric acid is commonly used to regenerate cationic resin. If the concentration of sulfuric acid is too high at the start and the flow rate is too slow, calcium sulfate will precipitate on the surface of the resin particles. To prevent this problem, a stepwise concentration increase of sulfuric acid during regeneration as well as sufficient flow are recommended.

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