Wastewater Treatment Operator Certification Practice Test

What happens when there is an increase in food in the influent to the aeration tank?

1. Less oxygen is required

2. More oxygen is required

3. Less organism activity takes place

4. Less oxidation occurs

The correct answer is: More oxygen is required

When there is an increase in food or organic material in the influent to the aeration tank, more oxygen is required to support the higher demand from microorganisms that break down the increased food supply through biological processes. This is primarily due to the fact that organic matter serves as food for bacteria and other microorganisms involved in the treatment process. As the concentration of organic material rises, microorganisms become more active in metabolizing this food. Their metabolic processes require oxygen, which is necessary for aerobic respiration. The oxygen is used to oxidize the organic compounds, resulting in the conversion of these compounds into carbon dioxide, water, and new cell biomass. The other options do not align with the biological principles at work in an aeration tank. The statement about less organism activity taking place contradicts the expected increase in microbial activity driven by the availability of more food. Likewise, claiming that less oxidation occurs dismisses the fundamental role of oxidation in breaking down organic materials in the presence of adequate oxygen. Therefore, the correct choice highlights the critical relationship between the increased food supply and the demand for oxygen to support the enhanced biological activity and metabolic processes.