Treatment of wastewater from cation-anion resin regeneration
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Can acid or base be added to the wastewater generated from the regeneration of cationic and anionic resins for reuse? If possible, the concentrations of sodium and chloride ions gradually increase during this process. At what concentrations of sodium and chloride ions can they no longer be reused?
I’ve never heard that recycled wastewater can be reused; it usually goes into a neutralization tank for neutralization before being discharged into the sewage treatment system
Reused wastewater usually contains salts, and it seems that using acids and bases to recover them is not worthwhile; therefore, such recovery is rarely carried out.
After neutralization in acid and alkali wastewater, it is sent to a wastewater treatment plant for centralized treatment and comprehensive utilization.
For resin regeneration wastewater, nanofiltration units can be used to separately purify and recover acids and bases. It can generate significant economic value and environmental benefits. Generally, recycled hydrochloric acid with a high concentration (greater than 1%) is collected and purified using nanofiltration to remove more than 95% of calcium, magnesium ions, pigments, and other large-molecule impurities, with a recovery rate of over 80%. It is also possible to collect recycled alkali waste solutions with a high concentration (greater than 1%), purify them using nanofiltration to remove more than 93% of macromolecular impurities such as pigments, with a recovery rate of over 80% as well. The purified dilute hydrochloric acid can be supplemented with some concentrated hydrochloric acid for use in the next regeneration process. The purified weak alkaline solution can also be reused for the next regeneration by simply adding some liquid alkali to it.
Why can’t we use recycled water for replenishment? The amount of such water isn’t large at all, so it’s completely fine to use it for this purpose
The reclaimed water from our company is neutralized and then incorporated into the river water supply network for use
Is the water COD in your area up to standard?
Use electrochemical treatment instead of resin tanks. Electrochemical treatment directly extracts calcium and magnesium ions from water. There is no water production or waste discharge, and salt is also saved. If you have any needs, feel free to contact me; we can discuss it further to see if electrochemical equipment would be suitable for your situation. WeChat: 15028870590