Ques. 1AIPMT 2001
What is B.O.D.?
- The total amount of O2 present in water
- The amount of O2 utilised by organisms in water
- The amount of O2 utilised by microorganisms for decomposition
- All of the above
Answer
(3) The amount of O2 utilised by microorganisms for decomposition
Solution
As per NCERT, BOD (Biochemical Oxygen Demand) refers to the amount of oxygen that would be consumed if all the organic matter in one litre of water were oxidised by bacteria (microorganisms).
⇒ It is a measure of the organic matter present in water; the greater the BOD, the more polluted the water.
∴ BOD is the amount of O2 utilised by microorganisms for decomposition.
Answer: (3)
Out of syllabus