Amount of sodium sulfite added

The amount of sodium sulfite is increased; brackish water raises the sulfate content, which in turn increases the consumption of barium chloride by the primary brine, and the load on other denitrification processes also increases

In the process of removing free chlorine, it is definitely a process involving an excess of sodium hypochlorite. After an excess of sodium hydride is present, during the brine treatment step, the pH value decreases to some extent as a result of the re-salting process, and some free chlorine is regenerated; the excess sodium hydride is then used to remove this free chlorine. If there is an excess of sodium hydride, under slightly alkaline conditions, it should have no effect.

It is reasonable to say that this will partially lower your pH value while generating some free chlorine again. We have encountered this situation in actual production, and we never understood why free chlorine appears again after the pH drops – is it due to the reversible reaction between sodium hypochlorite and free chlorine? Also, can adding sodium hypochlorite when the pH is low effectively remove free chlorine?

Note: The original question is: 1. Is sodium sulfite in excess? What is the amount of excess? 2. What are the effects if the amount is excessive? 3. If the excess amount is too large, should any action be taken? What are the good methods for dealing with it? 4. Comparison of the solubilities of barium sulfite, calcium sulfite, barium sulfate, and calcium carbonate in saline solution.

The current brine treatment process involves adding hydrochloric acid followed by sodium sulfite after using Kay membrane, in order to destroy the chlorate ions in the brine and thereby remove free chlorine and protect the secondary purification resin

Adding an excess of sodium sulfite increases the sulfate content in the brine, causing unnecessary problems for the primary brine!

Excessive addition of sodium sulfite is detrimental to the removal of algae and other contaminants from brine.

These substances are all precipitates and belong to insoluble substances; sulfites can dissolve in acid. I don’t have any information on this topic :(

Personally, I think sodium sulfite and sodium hypochlorite are truly natural rivals; it seems that where there’s a rivalry, they end up meeting. In order to protect brine treatment equipment from corrosion by hypochlorite, a large amount of sodium hydroxide and sodium sulfite must be added during the dechlorination of weak brine. Yet hypochlorite cannot be detected directly; instead, an indirect detection method using the redox potential is employed. As is well known, the ORP value can sometimes be negative, but chemical analysis methods are still able to detect hypochlorite. Why is that? It’s because there are no better detection methods yet. In an effort to protect the membrane and the chelating resin, people adopted a strategy of preferring to eliminate ten thousand cases by mistake rather than let even one case escape, and thus they added sodium sulfite in large quantities. As a result, the sulfate concentration in the brine became very high; this practice was particularly evident at Binhua, where the annual costs associated with nitrate removal were quite high. Everyone here is an expert, a top professional in the field, and a highly knowledgeable scholar. Could we discuss the calculation method for ORP here? Can anyone theoretically explain at what ORP value perchlorate no longer exists, according to theory? And then explain why we still have to go to great lengths to reduce the ORP to a negative value Everyone is welcome to discuss; I’ll learn something too!

Reply to 1# tcs1789@163.com: We are also facing the same issue now. Has your problem been resolved? How is this resolved? What kind of effects will an excessive amount of sodium sulfite have?