By-product salts in the context of ion-exchange membrane caustic and diaphragm caustic
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Gentlemen, I have a chemical plant in my industrial park. In Shandong, strict controls are in place on the total salt content of wastewater discharged outside the plant. Inside the plant, water-free wastewater is processed, resulting in a large amount of sodium chloride with a purity of over 95%; the content of insoluble substances is 0.5%, sulfate ions are 0.5%, and sodium carbonate is also 0.5%. After dissolution, the COD concentration is around 500, and it can be reduced further. I believe many industries also generate sodium chloride as a by-product; disposing of it as hazardous waste is too costly. Is there any market for it? I’m considering setting up my own membrane caustic or chlor-alkali production facilities, so that the low-concentration caustic solution and chlorine produced can be used directly for wastewater treatment. I seek advice from experts! ! !
Those who are interested can contact me via QQ 743370224
This method is feasible; diaphragm alkalis result in a relatively lower quality of brine. If ion-exchange membrane alkalis are to be used, careful consideration should be given
The organic content in salt is relatively high; therefore, care must be taken during salt purification to keep the organic content within acceptable limits. It is recommended to use ion exchange membrane devices; domestic ones are already quite mature, and the investment required is not high. Moreover, the quality of these devices is good, and it is easy for customers to accept selling them outside the company as well, in addition to using them within the company itself.
If organic substances can’t be reduced, then membrane and ion exchange membranes are of no use. The requirements for brine used with membranes are low, but **that’s no longer allowed, unless you can find a way to reduce energy consumption or something similar**. For ion exchange membranes, the TOC level must be below 10; there isn’t a specific requirement regarding COD. But as you mentioned, it’s possible to reduce this value further – by how much exactly?