Tennessee Wastewater Operator Practice Exam

Which of the following is a consequence of too many fines in a wastewater treatment system?

1. Increase in settlability

2. Decrease in chemical dosages

3. Filamentous growth

4. Pumice-like foam formation

The correct answer is: Pumice-like foam formation

In a wastewater treatment system, an excess of fine particles can significantly affect the physical and biological processes taking place. When there is an overabundance of fines, one notable consequence is the formation of pumice-like foam. This foam is often a result of the accumulation and entrapment of finer solids, which can lead to an improper separation in the treatment process. The presence of too many fines disrupts the normal settling characteristics of the sludge, leading to poor separation in the clarifier and creating conditions that promote foam formation. The physical properties of the fines, such as their low density, contribute to this phenomenon. Such foaming can negatively affect the efficiency of the treatment process by interfering with the hydraulic performance of the system and may require additional measures to manage. Therefore, recognizing the impact of excess fines is crucial in maintaining effective wastewater treatment operations, as proper settling and overall process stability are essential for achieving desired treatment outcomes.