What is the significance of measuring biochemical oxygen demand in water quality assessments?

• A. It indicates the amount of salt in the water
• B. It indicates the amount of available nutrients
• C. It indicates the level of biodegradation occurring
• D. It indicates the presence of heavy metals

Answer: (C)

Measuring biochemical oxygen demand (BOD) is significant in water quality assessments because it provides insights into the level of biodegradation occurring in a body of water. BOD is a measure of the amount of oxygen that microorganisms will consume while decomposing organic matter in water. A higher BOD indicates a higher level of organic pollution, as it suggests that more oxygen is being used up by these microorganisms. This is critical for determining the health of aquatic ecosystems, as excessive organic material can lead to oxygen depletion, which can harm or even kill aquatic life.

Monitoring BOD helps water quality managers understand the degree of pollution and the effectiveness of wastewater treatment processes. It allows them to assess whether a waterbody can support aquatic life and indicates how much organic matter is undergoing microbial decomposition, which is crucial for maintaining ecological balance.