Treatment of landfill leachate exceeding the limit of total nitrogen

High total nitrogen content in sewage will cause eutrophication of water, resulting in algae blooms and red tides. When the total nitrogen content in water is greater than 0.3mg/L, the eutrophication standard is reached.  In addition, nitrate itself is harmless to people, but in the body will be reduced to nitrite, on the one hand, nitrite will react with hemoglobin to produce methemoglobin, affecting oxygen transmission capacity, especially for infants, easy to lead to methemoglobin disease (blue baby disease);  On the other hand, nitrite is too high, can produce nitrosamine with protein, belong to strong carcinogenic substance, great harm to health.

Causes of excessive total nitrogen in sewage;

1. The internal and external reflux of biological denitrification system is smaller than that of biological denitrification system alone.

2. Denitrification system sludge sedimentation rate is faster.

3. The DO of dissolved oxygen in the hypoxic area is too high.

4. Improper temperature control, when the temperature is lower than 15℃, denitrification rate will be significantly reduced, to 5℃, denitrification will tend to stop.

5 BOD5/TKN because denitrifying bacteria is in the process of decomposition of organic matter denitrification, so into the anoxic area of the sewage must have sufficient organic matter, to ensure the smooth progress of denitrification.

Solution to the total nitrogen overload:

1. The high total nitrogen is due to the short denitrification time, that is, the short hypoxia time, or the high DO control of hypoxia, which changes from hypoxia to aerobic; while the high ammonia nitrogen is caused by the failure to carry out denitrification in time after nitrification reaction, or the short denitrification time.

2, can detect whether the carbon and nitrogen ratio is within the control range.

3. In the activated sludge method, the concentration of MLSS meets the requirements and whether DO can meet the requirements.

4. Pay attention to the ORP of aerobic pool and anoxic pool.