Blog Article

This is a difficult question to answer in a universal way, because there are many technical factors that must be considered in order to provide a reliable recommendation.

Why many suppliers discourage it

Most companies that sell lamella modules do not recommend installing them in a secondary clarifier, as they can be prone to clogging and therefore require periodic cleaning.

There are many negative experiences in this regard. I have seen large wastewater treatment plants that need to clean lamella modules in secondary clarifiers almost every month, which leads to very high maintenance costs for the WWTP, in addition to how cumbersome the cleaning process can be.

So, can they be installed?

Yes, they can be installed. A lamella module performs a physical separation of suspended solids from water. If the particles have the right size and density, the settling process should not be negatively affected and the lamella module can operate correctly.

The real reason: bulking from the biological process

So why are they often discouraged? The main reason is not always the secondary clarifier itself, but the biological reactor. Under certain conditions, filamentous bacteria can develop, and these organisms can reach the secondary clarifier and cause bulking.

Bulking sludge tends to behave like a spongy mass, with a tendency to float or remain in suspension. In some cases it is not on the surface, but suspended at mid-depth within the secondary clarifier. If lamella modules have been installed, this spongy sludge can become trapped in the lamella zone, clogging it completely and preventing proper operation.

What to evaluate before deciding

• Type of water to be treated: influent characteristics and process conditions.
• Bulking risk: whether bulking occurs and how stable the biological process is.
• Floatables: presence and quantity.
• Suspended solids: type and concentration.
• Particle size and density: key data for a thorough assessment.

Although it may sound excessive, our latest research on lamella settling – developed using a full-scale pilot plant and CFD simulation models – supports the importance of these parameters.

I hope this article helps and provides additional clarity on the topic.

Would you like to assess whether lamella modules are suitable for your clarifier? Our team can review your case based on technical criteria.