Although SS isn’t regarded as the main indicator of water quality, once an abnormality occurs, it will inevitably be held accountable. On the other hand, this is a signal that the biochemical system is abnormal, so the operators have to give full attention.

01 Source of suspended matter

To figure out the problem of SS over-standard, we must understand its source firstly. The SS is main from the activated sludge. In most cases, the SS, in the influent water have been eliminated in pre-treatment stage. Only Activated sludge produces SS.

The problem of SS over-standard is on the activated sludge. There are two main links :

1,The aerobic tank.

2,The secondary sedimentation tank.

 02 Causes "Over-standard of SS"

A. Abnormal aerobic tank section

The reason for the "Over-standard of SS" at this stage is mainly due to the abnormal performance of the activated sludge. The main performance is deteriorated, such as the activity, the sedimentation performance. Common situations are:

1. Sludge poisoning

2.Sludge aging

3. Sludge expansion

4. Aerobic tank aeration is too strong

B. The second settling tank section is abnormal

In the case, the activated sludge in the aerobic tank is normal, the problem of the secondary settling tank may also cause the effluent SS to be abnormal. Common situations are:

1. Water load shock

2. Algae attachment

3. Scraper suction machine failure

4. The sludge stays in the second settling tank for too long

5. Denitrification occurs in the secondary settling tank

6. The selection of the process parameters of the second settling tank is incorrect.

But for the second reason - The second settling tank section is abnormal.

Using the MBR system could deal with it.