Diagnosis of the Impact of Insufficient DAF Performance on Lamella Clarifier

A medical equipment company in Jiangsu used our company's lamella inclined plate clarifier in the sewage treatment system upgrade and renovation project. During the commissioning and operation, we received feedback from the customer that there were flocs floating on the liquid surface of the lamella clarifier and small flocs in the effluent.

After arriving at the site, our technical staff learned that this process is a process in which the effluent after dissolved air flotation enters the lamella clarifier for sedimentation. There is a small amount of floating mud on the surface of the coagulation and flocculation tank of the sedimentation tank, and the effluent is mixed with trace particles.

After investigation and analysis, it was found that the DAF system of a manufacturer at the previous level had large bubbles and small amount of bubbles, resulting in low removal rate of suspended solids and a large amount of suspended solids in the effluent. Our technical staff took water samples from the flocculation tank using a beaker, after 30 minutes of natural sedimentation, there were still suspended solids floating on the surface.

Due to incomplete separation of suspended solids with low specific gravity, they begin to float up in the coagulation reaction tank of the lamella clarifier and are difficult to settle in the lamell clarifier.

The sewage treatment process is a process in which various equipment functions and cooperates with each other.

In this process, the removal efficiency of dissolved air flotation is poor, which will inevitably affect the treatment efficiency of the lamella clarifier. So to solve the floating mud problem in the lamella clarifier of this project, it is necessary to improve the dissolved air flotation in the previous stage, increase operational efficiency, and remove as much suspended solids as possible that are difficult to settle.

Finally, let me ask you a question. In sewage treatment processes, which process first settles before air flotation, and which process first air flotation before settling? Welcome everyone to leave a message for discussion.