The relationship between ammonia nitrogen and total nitrogen in the wastewater treatment process
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I would like to ask the experienced colleagues: what is the relationship between ammonia nitrogen and total nitrogen in wastewater treatment, and what does each of them include? Why is the required dissolved oxygen level set at more than 2 mg/L? What is the relationship between the removal of ammonia nitrogen and dissolved oxygen levels? The removal of ammonia nitrogen is primarily a nitrification process, and nitrification requires oxygen. Can it be said that ammonia nitrogen removal mainly occurs during the aeration stage, with little relevance to the anaerobic stage?
What is the relationship between ammonia nitrogen and total nitrogen in wastewater treatment? Total nitrogen includes ammonia nitrogen, nitrate nitrogen, nitrite nitrogen, and organic nitrogen.
What is the relationship between the removal of ammonia nitrogen and dissolved oxygen levels? The removal of ammonia nitrogen is primarily a nitrification process, and nitrification requires oxygen. Can it be said that ammonia nitrogen removal mainly occurs during the aeration stage, with little relevance to the anaerobic stage? The removal of ammonia nitrogen occurs in two stages: one is the nitrogen required for the growth and reproduction of microorganisms, and this amount is relatively small; the normal ratio is BOD5/N = 100:5 ； Secondly, ammonia nitrogen is oxidized to nitrite by nitrobacteria, and then further oxidized to nitrate, thereby removing the ammonia nitrogen. The carbon sources required for the growth, reproduction, and metabolism of nitrifying bacteria are carbon dioxide and carbonate. The nitrification process requires a large amount of oxygen; 2 molecules of oxygen are needed to oxidize 1 molecule of ammonia nitrogen, which means that 4.57 kilograms of oxygen are required to oxidize 1 kilogram of ammonia nitrogen. Moreover, oxidizing 1 kilogram of ammonia nitrogen consumes 7.14 kilograms of alkalinity (calculated as calcium carbonate).
Ammonification occurs in both aerobic and anaerobic stages, which involves the conversion of organic nitrogen into ammonium nitrogen. In the aerobic stage, ammonium nitrogen is oxidized to nitrate nitrogen under the action of nitrifying bacteria, while in the anaerobic stage, nitrate nitrogen is reduced to nitrogen gas and nitric oxide under the action of denitrifying bacteria.