Tennessee Wastewater Operator Practice Exam

What does turbidity primarily measure?

1. pH level

2. Light absorption

3. Light scatter

4. Temperature fluctuations

The correct answer is: Light scatter

Turbidity primarily measures the scatter of light as it passes through a liquid. When a beam of light is directed through a sample of water, suspended particles such as sediment, algae, and other microorganisms can cause the light to be scattered in different directions. This scattering effect is what turbidity quantifies; the more particles present in the water, the greater the scatter, resulting in a higher turbidity measurement. In the context of water quality, turbidity is an important indicator, as it can affect aquatic life, hinder photosynthesis in aquatic plants, and provide a general gauge of water cleanliness. While terms like light absorption and pH level relate to water quality, they do not specifically capture the concept of turbidity, which is distinctly tied to how particles within the water interact with light. Similar reasoning applies to temperature fluctuations, as they are unrelated to the measurement of light in the context of turbidity.