What is the reason why ammonia nitrogen exceeds the standard to make water yellow?

Why does ammonia nitrogen exceed the standard repeatedly?  Ammonia nitrogen wastewater mainly comes from the decomposition of nitrogen-containing organic matter in domestic sewage, coking in industrial wastewater, synthetic ammonia and farmland drainage wastewater.  The difficulties of wastewater ammonia nitrogen treatment are: ammonia nitrogen pollution sources, large emissions, and emissions of concentration change.

There are roughly three reasons for exceeding the standard of ammonia nitrogen, which are: 

1. The impact of pH value.  The pH values of ammonia-oxidizing bacteria and nitrite oxidizing bacteria have certain standards. Under normal circumstances, oxidizing bacteria are suitable for living in an environment close to alkaline. Under inappropriate pH, nitrifying bacteria and denitrifying bacteria in the oxidation ditch are limited, which will convert oxidizing bacteria into ammonia-like nitrogen, but will increase the content of ammonia nitrogen in the influent.  

2. The C/N ratio is too low.  For sewage plants/stations with low influent COD, due to lack of sufficient carbon sources to maintain bacterial cell synthesis, long-term lack of carbon sources will lead to cell self-resolution and release ammonia nitrogen, resulting in excess of effluent ammonia nitrogen, and even abnormal phenomenon that effluent ammonia nitrogen will be higher than inlet ammonia nitrogen. 

3. The influent concentration is too high, which exceeds the existing biochemical treatment capacity.  Because the influent concentration is too high to exceed the designed load, it is often necessary to control the amount of water and reduce the treatment load, which can quickly solve the problem of ammonia nitrogen exceeding the standard.  In the process of sewage treatment, the pH of the process can be controlled according to the situation of water in and out. For the case of too low C/N ratio, IDN-C series nutrient solution can be added to greatly improve the nitrification reaction rate and impact resistance. In view of the problem of ammonia nitrogen wastewater exceeding the standard, stable treatment can be achieved.