Can the ammonia nitrogen level increase in refinery wastewater after oil and gas separation by flotation treatment? ? ?
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Can the ammonia nitrogen concentration increase after refinery wastewater is treated through an oil separation tank, two stages of oil separation, and two stages of flotation (using PAC and PAM as flocculants)? ? ? For example, the ammonia nitrogen level in the wastewater entering the treatment plant is 30 mg/l, but it rises to 60 mg/l in the wastewater exiting the flotation process. Thank you for your discussions! ! !
Let me share my personal opinion – could there be two reasons for this? 1. Organic amines undergo ammonification to turn into ammonia nitrogen! ! ! 2. The added PAM increased ammonia nitrogen levels.
This post was last edited by cdpulin on 2009-12-4 at 13:35. There is also a possibility that anaerobic hydrolysis of oils could increase ammonia levels earlier on. Hydrolysis of PAM is also possible. The molecular formula of PAM is (CH2CHCONH2)r; it contains nitrogen, so this is possible. However, the amount of PAM added is not large; it generally only serves a coagulation aid function, so there is little possibility of a significant increase in nitrogen levels.
Organic nitrogen is usually an unstable compound, such as urea; changing its fluid state or releasing water-soluble gases through flotation accelerates the hydrolysis of organic nitrogen. The dosage of PAM is usually very low, resulting in ammonia nitrogen levels that can be disregarded.
In my opinion, PAM can undergo hydrolysis to produce polyacrylic acid and ammonia nitrogen; however, this hydrolysis occurs more rapidly only at higher temperatures and in alkaline conditions. Moreover, the amount of PAM used as a flocculant is very low, so it shouldn’t have such a significant impact. Therefore, I believe it cannot be the effect of PAM. So it is likely the result of oxygen in the air oxidizing and hydrolyzing the organic amines during the air flotation process.