Tennessee Wastewater Operator Practice Exam

What is the purpose of adding seed to a BOD sample?

1. To increase oxygen levels

2. To introduce microorganisms for decomposition

3. To adjust the temperature

4. To stabilize the sample

The correct answer is: To introduce microorganisms for decomposition

Adding seed to a BOD sample serves the vital function of introducing microorganisms that are essential for the decomposition of organic matter present in the water sample. The microorganisms, or "seeds," help facilitate the biochemical reactions necessary to break down the organic substances, which is ultimately what BOD (Biochemical Oxygen Demand) measurements aim to assess. In a BOD test, the oxygen demand of a sample is measured over a specific period, typically five days. The activity of the introduced microorganisms is crucial for simulating the natural conditions of a wastewater environment, allowing for an accurate evaluation of the organic pollution level. While some might consider other options like stabilizing or adjusting conditions, the core purpose of adding seed is specifically to ensure that there is a sufficient population of bacteria to initiate this essential decomposition process effectively. Hence, the introduction of these microorganisms is central to obtaining valid and reliable BOD results.