The ability to remove nitrogen after an impact on the feed water may be compromised, as the shock may cause an imbalance in the microbial community in the biological treatment system, particularly the activity of nitrifying and denitrifying bacteria. Nitrifying bacteria are sensitive to environmental changes, such as pH, temperature, dissolved oxygen (DO), and fluctuations in toxic substances that may inhibit their activity. Denitrifying bacteria are dependent on the presence of organic matter and nitrates, and any change in these conditions may affect the denitrification process.
In order to quickly restore the nitrogen removal capacity, the following measures can be taken:
1.Diagnosing the problem:
Analyze the influent water quality and determine the cause of the impact, such as the presence of toxic substances, abnormal pH value, temperature changes, etc.
Monitor the performance indicators of activated sludge, such as sludge sedimentation performance, respiration rate, ratio of volatile suspended solids (VSS) to total suspended solids (SS), etc.
2.Stable operating conditions:
Maintain the stable operation of the treatment system and avoid frequent adjustments and large changes.
Ensure an adequate supply of dissolved oxygen to support the nitrification process.
3.Microbial inoculation:
If nitrifying bacteria are severely inhibited, inoculation with healthy nitrifying sludge or the use of suspended biological carriers (e.g., biofilms) may be required to accelerate the recovery of the nitrification process.
In the case of denitrifying bacteria, their growth can be promoted by increasing the concentration of organic matter in the influent water.
4.Optimize nutrient balance:
Ensure the balance of nutrients such as nitrogen and phosphorus in the system to support the growth and metabolism of microorganisms.
5.Sludge Age Control (SRT):
Sludge age is controlled by adjusting the sludge return ratio and sludge discharge strategy to promote the growth of beneficial microorganisms.
6.Monitoring and Adjustment:
Closely monitor the quality of the incoming and outgoing water, especially the form of nitrogen (ammonia, nitrite, nitrate).
Adjust process parameters such as aeration volume, sludge concentration, reflux ratio, etc. based on the monitoring results.
7.Emergency Treatment:
For severe impacts, it may be necessary to temporarily reduce the amount of water ingress or apply bypass measures to reduce the pressure on the biological treatment system.
8.Precautionary measures:
Analyze the causes of shocks and develop preventive measures to reduce the occurrence of similar events in the future.
It takes time to regain the ability to remove nitrogen because it takes a period for microorganisms to grow and adapt to environmental changes. During recovery, some processing efficiency may need to be sacrificed to ensure the long-term stability of the system and improved denitrification.