Tennessee Wastewater Operator Practice Exam

What type of treatment is a pond system categorized as?

1. Suspended growth

2. Fixed film

3. Activated sludge

4. Trickling filter

The correct answer is: Suspended growth

A pond system is categorized as suspended growth treatment because it relies on microorganisms that are suspended in the water to break down organic matter present in the wastewater. In this treatment method, algae and bacteria float freely in the pond, utilizing sunlight and nutrients to proliferate. The suspended growth design allows for effective biological treatment as these microorganisms can easily come into contact with the pollutants in the water, facilitating the degradation process. This type of system is recognized for its simplicity and low operational costs, as natural processes within the pond can effectively treat wastewater. It often includes features like aeration to promote oxygen transfer, which is critical for the growth of aerobic bacteria necessary in the treatment process. In contrast, fixed film processes involve microorganisms attached to a fixed surface, such as in trickling filters, or in media where the microorganisms grow, rather than being suspended. Therefore, the classification of pond systems as suspended growth underscores their reliance on free-floating microbial communities to achieve effective wastewater treatment.