Question:

Biochemical Oxygen Demand (BOD) value can be a measure of water pollution caused by organic matter. Which of the following statements is correct?

Clean water has BOD value higher than 10ppm

Aerobic bacteria decrease the BOD value

Polluted water has BOD value higher than 10ppm

Anaerobic bacteria increase the BOD value

Clean water has BOD value less than 5 ppm. Polluted water has BOD value higher than 10 ppm. The option (C) represents the correct statement.