Question

A river with a high BOD value is

• A. Highly clean
• B. Highly polluted
• C. Highly productive
• D. None of these

Answer 1

The correct option is B

Highly polluted

The correct option is B.

Explanation of the correct option:

1. Biological oxygen demand (BOD) is the measurement of dissolved oxygen (DO) that is utilized by aerobic microorganisms when organic matter is decomposed in water.
2. It is an important water quality parameter that is used to assess the discharged wastewater in the aquatic environment.
3. The higher the BOD value of the waterbody, the higher the amount of organic matter present in the water source.
4. A high BOD value indicated that high amounts of oxygen are required and implies low water quality.
5. Organic matter present in the water body results in high BOD values and the dissolved oxygen level is low and affects the aquatic animals.

Explanation of the incorrect options:

Option A:

1. A high BOD value indicates increased oxygen requirement and signifies low water quality.
2. Clean water has a very low BOD value.

Option C:

1. A high BOD value indicates increased oxygen requirement and signifies low water quality.

Final answer: A river with a high BOD value is highly polluted.