Regarding the issue of the saline denitration membrane, the problem of free chlorine in the saline before it enters the membrane
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Our company uses activated carbon to remove free chlorine, but it cannot eliminate it completely; there is still a level of 0.1 or so units of free chlorine remaining after the safety filter. This causes significant damage to the denitration membrane. Is there a better method? Everyone, share your experiences for everyone to learn from*
Sodium hyposulfite is better for removing free chlorine
Sulfite is generally added to remove free chlorine.
No sodium hydrosulfite added at the front and no online ORP monitoring? Relying on security personnel to eliminate all free chlorine is clearly not sufficient.
In our facility, sulfite is added first to remove free chlorine, and only then is the activated carbon filter used. Moreover, online ORP detection devices were installed before and after the activated carbon filter.
In my opinion, activated carbon does not have a significant effect on absorbing free chlorine; after using it for some time, it was found that it merely served as a buffer. Subsequent modifications involved removing the activated carbon and adjusting the amount of sodium sulfite added to maintain stability in the system’s ORP. The key factor is the role of sodium sulfite, while the role of activated carbon is minimal.
Sodium sulfite should be added in a quantified amount before the activated carbon tower, with an excess of sodium sulfite present after the tower. Increase the analysis frequency as necessary.