Basic principle of biological nitrogen removal

The basic principle of biological nitrogen removal is to use the metabolism of microorganisms and plants to convert nitrogen-containing compounds in wastewater into nitrogen, thus removing nitrogen from wastewater.

The process of biological denitrification is mainly divided into two stages: nitrification and denitrification of ammonia nitrogen. The nitrification process of ammonia nitrogen is completed by nitrifying bacteria, which can transform ammonia nitrogen in wastewater into nitrate. This process requires oxygen and suitable temperature, and nitrifying bacteria can survive in an aerobic environment.

Denitrification is accomplished by denitrifying bacteria, which can convert nitrate into nitrogen. This process requires anoxic conditions and suitable temperature, and denitrifying bacteria can survive in anoxic environment.

The principle of biological denitrification is based on the metabolism of microorganisms, and nitrogen in wastewater is converted into nitrogen through nitrification and denitrification of microorganisms, thus reducing the nitrogen content in wastewater. At the same time, biological denitrification can also transform nitrogen in wastewater into organic matter in plants through absorption and assimilation of plants, and further reduce the nitrogen content in wastewater.

Influencing factors of biological nitrogen removal;

1. Composition of wastewater: The composition of wastewater directly affects the effect of biological nitrogen removal. For example, the content of ammonia nitrogen in wastewater, organic nitrogen and other substances that may interfere with the process of biological nitrogen removal will affect the effect of biological nitrogen removal.

2. Concentration: The concentration of ammonia nitrogen and nitrate will affect the effect of biological nitrogen removal. Too high or too low concentration may affect the growth and metabolism of microorganisms, thus affecting the nitrogen removal effect.

3. Temperature: Temperature has a great influence on the biological nitrogen removal process. Low temperature will reduce the activity of microorganisms, while high temperature may lead to microbial death. Appropriate temperature range can promote the growth and metabolism of microorganisms and improve the nitrogen removal effect.

4.pH value: The influence of pH value on biological nitrogen removal is also very significant. Both nitrification and denitrification processes need to be carried out in a certain pH range. If the pH value is not within this range, it may affect the activity of microorganisms, thus affecting the nitrogen removal effect.

5. Dissolved oxygen: For the nitrification process, sufficient oxygen is essential. If the dissolved oxygen is insufficient, the activity of nitrifying bacteria will decrease, thus affecting the nitrification effect of ammonia nitrogen. For the denitrification process, anoxic conditions are necessary. If the dissolved oxygen is too high, the activity of denitrifying bacteria will be inhibited, thus affecting the denitrification effect of nitrate.