In order to do a good job in sewage operation, I have summarized the emergency measures for these abnormal situations!

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1、 Insufficient water volume
When the water volume is insufficient, the process control is as follows:
1. The lifting pump room should try to keep the water pump flowing smoothly, but it is necessary to avoid low liquid level operation of the water pump.
2. When the water volume is below 50% of the designed water volume, the sewage treatment system operates in a single group (dual group system) or intermittently (single group system). Pay attention to monitoring the operating parameters of the biochemical system (DO, pH, MLSS, etc.) and adjust the process in a timely manner.
3. Control the reflux ratio between 50-100%.
4. Put half of the secondary sedimentation tank into operation.
2、 Water volume exceeds the design load
When the water volume exceeds the design load, the process control is as follows:
1. Increase the pump room's full load production, but do not exceed the coefficient of change of the design load.
2. The coarse and fine grids shall be continuously opened on site and the slag shall be removed in a timely manner.
In the initial stage of sudden increase in water volume, the aeration equipment of the sewage treatment system should be fully opened, and attention should be paid to monitoring the operating parameters of the biochemical system (DO, pH, MLSS, etc.), and adjusting the process in a timely manner.
4. Increase the sampling frequency of the supernatant from the biochemical tank, the effluent from the secondary sedimentation tank, and the total effluent.
5. All secondary sedimentation tanks are put into use.
As the biochemical system gradually stabilizes, DO increases, and the ammonia nitrogen in the system is low, it can be considered to reduce the number and frequency of aeration equipment opening.
3、 Sludge bulking
When sludge bulking occurs, the duty personnel should immediately report to the production supervisor, notify the laboratory to immediately collect water samples, measure BOD, COD, MLSS, DO, PH, SV of the water samples, and conduct biological microscopy. Then, based on the on-site situation, a preliminary analysis of the sludge should be conducted to determine which measures to take. The most prominent manifestation of sludge bulking is that the sludge settling performance index SVI is greater than 150%. If there are many carbohydrates in sewage, insufficient dissolved oxygen, lack of nutrients such as nitrogen and phosphorus, and high water temperature or low pH value, it is easy to cause sludge bulking. In addition, overloading, excessive sludge age, or low organic concentration gradients can also cause sludge bulking. Poor sludge discharge can cause the combined water-based sludge to swell.
The process adjustments for the causes of expansion are as follows:
1. Increase aeration rate due to hypoxia or high water temperature, or reduce water temperature to reduce load, or appropriately reduce MLSS value to reduce oxygen demand, etc;
2. If the sludge loading rate is too high, the MLSS value can be appropriately increased to adjust the load, and if necessary, the inlet water should be stopped for a period of "suffocation";
3. If nitrogen, phosphorus and other nutrients are lacking, nitrifying sludge or nitrogen, phosphorus and other components can be added;
4. If the pH value is too low, lime or other additives can be added to adjust the pH (6-8);
5. If a large amount of sludge is lost, 5-10mg/L of iron chloride can be added to promote coagulation, stimulate the growth of bacterial micelles, or bleaching powder or liquid chlorine (added at 0.3% -0.6% of dry sludge) can be added to inhibit filamentous growth, especially to control the expansion of combined water sludge. In addition, adding substances such as asbestos powder, diatomaceous earth, and clay also has a certain effect.
4、 Sludge disintegration
When the phenomenon of sludge disintegration occurs, the symptoms include: turbid treatment water quality, fine sludge flocculation, and deterioration of treatment effect.
The process should be adjusted as follows:
1. When conducting laboratory analysis on the inflow water quality and determining that toxic substances have been mixed into the sewage, it should be considered that this is the result of the mixing of new industrial wastewater. The inflow water quantity should be reduced and the aeration rate should be increased