Which test measures the amount of organic matter oxidizable in days at a given temperature?

• A. BOD
• B. pH Scale
• C. Hydrogen Sulfide
• D. BOD Test

Answer: (D)

This item is about a test that quantifies how much organic matter can be oxidized over a defined time at a standard temperature. The measure is biochemical oxygen demand, or BOD, which indicates the amount of oxygen microorganisms need to break down organic material in water. In practice, samples are incubated at a controlled temperature (commonly 20°C) for a fixed period (often five days), and the decrease in dissolved oxygen is measured. The oxygen consumed during that period is the BOD value, such as BOD5 when the time is five days. Therefore, the test used to quantify how much organic matter can be oxidized over days at a given temperature is the BOD Test. The other options don’t fit: the pH scale covers acidity/alkalinity, not oxidation of organics; hydrogen sulfide measures sulfide-related phenomena; and while BOD is the concept, the specific measurement method is the BOD Test.