12.13.    What do you mean by Biochemical Oxygen Demand (BOD)?

Answers (1)
M manish

Biochemical Oxygen Demand (BOD)
It is the amount of oxygen required by bacteria to decompose the organic matter present in a  certain volume of the sample of water. Clean water would have a BOD value less than 5 ppm and highly polluted water could have a BOD value of 17 ppm.