Tennessee Wastewater Operator Practice Exam

Which foaming filamentous bacteria tends to cause problems during colder weather?

1. Nocardia

2. M. Parvicella

3. Thiothrix

4. Clostridium

The correct answer is: M. Parvicella

M. parvicella is known to be a foaming filamentous bacterium that often causes problems in wastewater treatment systems, particularly during colder weather. This bacterium thrives in colder temperatures and lower dissolved oxygen environments, which can lead to excessive foaming during the treatment process. M. parvicella forms long filaments that can contribute to scum formation and interfere with the proper operation of wastewater treatment systems. Understanding the behavior of M. parvicella is critical for operators because managing its growth can help mitigate operational challenges such as foaming and poor settling characteristics in secondary clarifiers. In contrast, other bacteria like Nocardia, Thiothrix, and Clostridium are less frequently associated with colder conditions and do not pose the same specific risks related to foaming in these environmental circumstances. These distinctions emphasize the particular role that M. parvicella plays in the context of wastewater treatment during colder months, which is crucial for effective system management.