Tennessee Wastewater Operator Practice Exam

What is the most important function of algae in a facultative lagoon?

1. To provide nutrients for bacteria

2. To produce oxygen during the daytime

3. To absorb pollutants

4. To prevent mosquito breeding

The correct answer is: To produce oxygen during the daytime

In a facultative lagoon, the most important function of algae is to produce oxygen during the daytime. This production of oxygen occurs through the process of photosynthesis, where algae utilize sunlight to convert carbon dioxide and water into oxygen and glucose. The oxygen generated by the algae is crucial for the aerobic bacteria present in the lagoon, which require oxygen to efficiently break down organic matter. This symbiotic relationship supports the overall health and functioning of the lagoon ecosystem. As the algae produce oxygen, aerobic bacteria can thrive and effectively degrade waste, which helps maintain water quality and prevent the build-up of harmful substances. Additionally, this oxygen production is vital for maintaining a balanced environment, particularly in the context of wastewater treatment. While other options like providing nutrients for bacteria, absorbing pollutants, and preventing mosquito breeding are relevant functions, they are secondary to the critical role that oxygen production plays in the aerobic degradation process essential for effective wastewater treatment in a facultative lagoon.