The pH value issue of water purified by sewage stripping
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The major maintenance of the facility has been completed, and just a few days after operations resumed, the pH value of the purified water obtained after sewage stripping dropped below 7; several consecutive samples showed a pH value ranging from 5.8 to 6.8. The sulfide content in the purified water was less than 1, while the ammonia nitrogen level was below 150 ppm. Apart from the pH value, all other parameters were very similar to those recorded before the maintenance. The problem is that the cause of the decrease in pH value cannot be determined. The following possible factors may be the source of the problem: 1. The hydrogenation catalyst was replaced in the upstream water supply unit during maintenance. The hydrogenation effect improves. Will it affect the quality of wastewater? 2. The Cl ion level in the purified water is around 200 ppm; could it be that the aqueous solution is a strong acid with a weak base, resulting in an overall acidic pH? 3. Other acidic substances in the purified water were not detected (what might these acidic substances be? The upstream unit is a heavy oil hydrogenation unit. ）
This post was last edited by ylb913 on 2015-11-30 at 19:31. A chloride level of 200 ppm in the purified water is indeed very high; this should be the main reason. Our main approach is to inject alkali into the middle and lower sections of the wastewater stripping tower to raise the pH value and reduce ammonia nitrogen. There are two topics that I’m familiar with in HaiChuan: http://bbs.hcbbs.com/thread-1291623-1-1.html http://bbs.hcbbs.com/thread-1292692-1-1.html