Biochemical Oxygen Demand (BOD) in a river water

Biochemical Oxygen Demand (BOD) in a river water
  1. remains unchanged when algal bloom occurs
  2. has no relationship with concentration of oxygen in the water
  3. gives a measure of Salmonetla in the water
  4. increases when sewage gets mixed with river water

Solution

Biochemical Oxygen Demand (BOD) is the amount of oxygen used for biochemical oxidation by micro-organisms in a unit volume of water. Polluted water has high BOD. Thus, when sewage gets mixed with river water, BOD will increase.

Asked in: NEET 2009 (Screening)

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