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Environmental Issues — BIOLOGY STD 12 Science — Question

Maharashtra BoardEnglish MediumSTD 12 ScienceBIOLOGYEnvironmental Issues3 Marks
Question
Biological Oxygen Demand or BOD increases with increase in water pollution. In this reference, answer the questions that follow:
  1. At a particular segment of the river near a sugar factory, the BOD is much higher than the normal level. What is it indicative of?
  2. What will happen to the dissolved oxygen and living organisms in this part of the river?
✓

Answer

  1. It indicates that the sugar factory releases organic waste in the water body. To degrade the organic matter, microbes utilise the dissolved oxygen in the water, thereby, reducing the levels of dissolved oxygen and increasing the BOD.
  2. In this part of river, the dissolved oxygen will be depleted making it difficult for aquatic species to survive. It can result in death of fishes in severe cases.

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