What is the reason for the lack of sludge growth in aeration tanks

What is the reason for the lack of sludge growth in aeration tanks

Summary

In the process of sewage treatment, we often encounter the phenomenon that the activated sludge in the aeration tank does not grow or even decreases. What is the reason? And how to solve it?

What is the reason for the lack of sludge growth in aeration tanks
What is the reason for the lack of sludge growth in aeration tanks
What is the reason for the lack of sludge growth in aeration tanks
In the process of sewage treatment, we often encounter the phenomenon that the activated sludge in the aeration tank does not grow or even decreases. What is the reason? And how to solve it?
1 The main reason for excessive sludge loss is that sludge swelling causes the sludge settling performance to deteriorate. The suspended solids content in the effluent of the secondary sedimentation tank is large, and the sludge is lost too much, resulting in a gradual reduction in the sludge in the aeration tank. The specific countermeasure is to add a small amount of flocculant to the inlet or outlet of the aeration tank to improve the sludge settling performance.
2 Excessive aeration and oxygenation .Excessive aeration and oxygenation will cause the activated sludge to be overoxidized, resulting in the sludge's own consumption, and the total amount of sludge will not increase. The countermeasure is to reduce the number of fans in operation or reduce the speed of the aerator, reasonably adjust the aeration volume, and reduce the oxygen supply.

3 Low influent organic load Low influent load causes a relative shortage of organic matter required for the growth of activated sludge, so that the microorganisms in the activated sludge can only be in a maintenance state, and may even enter the self-oxidation stage to reduce the amount of activated sludge. The countermeasure is to try to increase the influent volume, or reduce the number of fans in operation, reduce the speed of the aerator, and reduce the residence time of the aeration tank.

4. Unbalanced nutrient content. Unbalanced nutrient content will deteriorate the coagulation performance of activated sludge microorganisms, poor sedimentation performance, and sludge loss in the secondary sedimentation tank, resulting in sludge reduction. The countermeasure is to replenish sufficient nitrogen, phosphorus and other nutrients in time.

5. Excessive discharge of residual sludge. Excessive discharge of residual activated sludge makes the sludge growth less than the discharge of residual sludge, and the sludge in the aeration tank gradually decreases. The countermeasure is to reduce the discharge of residual sludge.