Question

The high value of BOD (Biochemical Oxygen Demand) indicates that:

• A. Consumption of organic matter in the water is higher by the microbes
• B. Water is pure
• C. Water is highly polluted
• D. Water is less polluted

Answer 1

The correct option is C Water is highly polluted

Biological Oxygen Demand (BOD) is one of the most common measures of pollutant organic material in water. BOD indicates the amount of organic matter present in water. Therefore, a low BOD is an indicator of good quality water, while a high BOD indicates polluted water. Dissolved oxygen (DO) is consumed by bacteria when large amounts of organic matter from sewage or other discharges are present in the water. DO is the actual amount of oxygen available in a dissolved form in the water. When the DO drops below a certain level, the life forms in that water are unable to continue at a normal rate.