How to utilize the wastewater from the secondary brine purification stage
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This post was last edited by sunjl1981 on 2013-1-7 00:00. In the process of secondary brine purification, the main source of wastewater is that generated during the regeneration of the resin column. Since this regeneration wastewater contains large amounts of heavy metal ions, the likelihood of reusing this water in the system is low. How do people make use of this wastewater? This post was last edited by gufeng on 2007-11-30 14:00 ] # ， ， &
I don’t think there’s much value in recycling this wastewater. To remove the metal ions from it, the cost involved is higher than the value of the water. What we have designed is to discharge the waste after acid-base neutralization.
**Policies are becoming increasingly strict, with higher and higher requirements. It’s fine if there is wastewater treatment facilities nearby a new factory, but otherwise zero emissions must be achieved; in such cases, it’s difficult to recycle this water. At the very least, a plan that can be approved by experts should be outlined in the environmental impact assessment report.
The cost of removing the metal ions from it is higher than the value of using the water itself. In our factory, acids and bases are neutralized before being discharged to the waste treatment station, from where they are then fed into the sewage network.
Our company just sends it back to the salt-chemical mixing tanks for use; the situation is pretty good
Please check the post: http://bbs.hcbbs.com/viewthread.php?tid=94395&page=1 - pid427105
What we have designed is to discharge the waste after acid-base neutralization. But I have seen a paper that discusses using regenerated hydrochloric acid and caustic soda for dechlorination, which saves hydrochloric acid and caustic soda used for dechlorination.
I contacted the person on the 5th floor, and she said that their company does indeed do things in that way. According to the analysis results, the situation isn’t as serious as imagined; in fact, no significant impact can be seen. :L
If a diaphragm process is available, the salt can be directly converted back using that method; but can salt production via the ion-exchange membrane process also use such water? If there are no problems, it means that all the heavy metals can be removed, and no accumulation will occur.
Our company also reprocesses recycled wastewater to convert it back into brine, but we only did this for a month without any problems occurring.
In my opinion, short-term use should be fine; generally, as mentioned above, acidic and alkaline wastewater is combined before being sent to the wastewater treatment plant. However, there is still a problem of heavy metal accumulation when using this system. In actual production, the levels of various substances in the brine water (using the HVM process with barium-based nitrate removal) are roughly as follows: calcium + magnesium: 500 ppb, aluminum: 20, iron: silicon: 259, barium: 100, strontium: 1000, nickel: nil； Parameters of secondary brine (ppb): Calcium + Magnesium: 5, Aluminum: 20, Iron: 10, Silicon: 115, Barium: 15, Strontium: nil, Nickel: nil. From these figures, it can be seen that in acidic and alkaline wastewater, it is primarily calcium, magnesium, and strontium that accumulate; silicon comes next, followed by barium. Other metals do not accumulate to any significant extent. There is no problem with calcium and magnesium; the main issue is the increased consumption of purification agents. Regarding strontium, it depends on the time required for the calcium removal process and the amount of sodium carbonate used. Silicon cannot be removed in the primary brine, while barium levels depend on the solubility product of barium sulfate and the concentration of sulfate ions. Once membrane-based nitrogen removal methods are implemented, there will be no problem with barium. Therefore, accumulation does have an impact on ion exchange membranes, but it has not been thoroughly studied as to how long it will take for this effect to become apparent. There are so many ion-exchange membrane cells using brine these days, let alone wastewater containing secondary salt water After all, the mystery surrounding the ion membrane has been unveiled. So it can be used, or it can be left unused. It depends on the decision-makers’ attitude!