Tennessee Wastewater Operator Practice Exam

What does the SOUR test specifically measure regarding microorganisms?

1. The health of microorganism colonies

2. How fast microorganisms consume oxygen

3. The total biomass in the sample

4. Microbial resistance to conditions

The correct answer is: How fast microorganisms consume oxygen

The SOUR test, or Specific Oxygen Uptake Rate test, specifically measures how fast microorganisms consume oxygen in a given sample. This rate of oxygen consumption is an important indicator of the biological activity of the microorganisms present, showcasing their metabolic rate. The test typically involves measuring the amount of oxygen consumed over a defined period of time under controlled conditions, which reflects the metabolic processes of aerobic microorganisms that are breaking down organic matter. A higher SOUR indicates more active microorganisms, which can be crucial for understanding the efficiency of biological treatment processes in wastewater management. In contrast, other options focus on different aspects of microbial assessment. For instance, measuring the health of microorganism colonies considers factors such as their growth and vitality, rather than their oxygen consumption rate. The total biomass in the sample would refer to the overall mass of microorganisms present, while microbial resistance pertains to their ability to withstand various environmental conditions. Each of these measures serves a different purpose than the SOUR test, which is specifically concerned with oxygen uptake and microbial metabolic activity.