The traditional biological denitrification technology in landfill leachate treatment includes two stages: nitrification and denitrification. Firstly, ammonia and helium are oxidized to nitrite or nitrate by aerobic nitrifying bacteria under aerobic condition, and then nitrite or nitrate is reduced to nitrogen by denitrifying bacteria under anoxic condition, so as to achieve the purpose of denitrification. The traditional biological nitrogen removal process adopts the combination of aerobic and anoxic processes, and the representative processes are a / O and SBR. Traditional nitrification and denitrification process plays a role in biological nitrogen removal, but there are still many problems.

Landfill leachate treatment

1. Nitrifying bacteria proliferate slowly, and it is difficult to maintain high biological concentration, resulting in long hydraulic retention time and low volume load, increasing investment and operating costs.

2. In the traditional denitrification process, denitrification needs a certain amount of organic carbon source, and a large part of COD in landfill leachate is removed in the process of nitrification, so additional carbon source is often added in denitrification, which increases the treatment cost.

3. The complete nitrification of ammonia nitrogen needs a lot of oxygen, and the power cost increases.

4. In order to neutralize the acidity produced in the nitrification process, it is necessary to add alkali to neutralize and increase the treatment cost.

5. In order to maintain high biological concentration and obtain good nitrogen removal effect, nitrification liquid and sludge must be recycled to increase power consumption and operation cost.

6. The operation control is complex.

Therefore, the study of new ideas, new technologies and appropriate control conditions of nitrogen removal in landfill leachate treatment process is one of the core issues in the study of effective removal of nitrogen pollutants in landfill leachate.