How to deal with the concentrated water from electrodialysis?
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Our company's products will produce organic acid salts during the fermentation process and there are inorganic salts in the fermentation medium. After electrodialysis, these salts enter the concentrated water with a salt content of up to 7%. In addition, some of our products (1.3 propylene glycol) also enter the concentrated water. Is there any good way to recycle the 1.3 propylene glycol and organic salts?
With such a high salt content, RO should be hopeless. As for NF, I haven’t seen one that can intercept 1.3 propylene glycol yet. Let’s consider other methods!
Assuming that NF has no selectivity for propylene glycol, it is first diluted and then nanofiltrated, and the dilute solution is then electrodialyzed.
This is a plan, but the concentration of PDO in the concentration chamber is not high to begin with. Adding water to dilute the concentration will make it even lower. The energy consumption for recycling is definitely not low.
Is the salt content in the concentrated water obtained by electrodialysis basically the same as the concentration of the original treatment solution?
Such high salt can be evaporated, concentrated and crystallized.
Nowadays, electrodialysis technology has made great progress, especially after the localization of homogeneous membrane electrodialysis. Compared with imported membranes in terms of application and technology research and development, there is almost no difference, and they can communicate with each other!