Question

Biochemical Oxygen Demand (BOD) measures organic material present in water. A sample of water has a BOD value of less than 5 ppm. This indicates that:

• A. Water is rich in dissolved oxygen
• B. Water is poor in dissolved oxygen
• C. Water is highly polluted
• D. Water is not suitable for aquatic life

Answer 1

The correct option is A Water is rich in dissolved oxygen

Biochemical oxygen demand (BOD) is defined as the amount of dissolved oxygen required by aerobic biological organisms to break down organic material present in a given water sample at a certain temperature over a specific time period. If BOD value is less than 5 ppm, means water is considered to be pure and if BOD level reaches 17 ppm it is highly polluted.