Wastewater New York State Practice Exam

What characterizes the conventional activated sludge process?

1. Utilizes a living community of microorganisms

2. Operates without aeration

3. Relies solely on chemical treatment

4. Requires higher water temperatures

The correct answer is: Utilizes a living community of microorganisms

The conventional activated sludge process is characterized by its use of a living community of microorganisms, which play a critical role in the treatment of wastewater. In this process, microorganisms such as bacteria are employed to break down organic matter in the wastewater. This biological treatment occurs in an aeration tank, where the microorganisms are supplied with oxygen, allowing them to metabolize the organic pollutants. The effectiveness of this process relies on maintaining optimal conditions for these microorganisms, including the right levels of dissolved oxygen, temperature, and nutrient availability. The sludges formed as a result of these microbial activities are then settled out in a secondary clarifier, where treated water is separated from the biomass. The other options depict processes or characteristics that do not apply to the conventional activated sludge process. For example, this process inherently involves aeration, as oxygen is crucial for the aerobic microorganisms to thrive. It does not rely solely on chemical treatment, as biological treatment is its primary mechanism. While temperature can affect microbial activity, the conventional activated sludge process does not specifically require higher water temperatures compared to other processes.