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STD 12 - 8. microbes in human welfare — Biology STD 12 Science — Question

CBSE BoardEnglish MediumSTD 12 ScienceBiologySTD 12 - 8. microbes in human welfare1 Mark
MCQ
What would happen if oxygen availability to activated sludge flocs is reduced ?
  • A
    It will slow down the rate of degradation of organic matter
  • ✓
    The centre of flocs will become anoxic, which would cause death of bacteria and eventually breakage of flocs
  • C
    Flocs would increase in size as anaerobic bacteria would grow around flocs
  • D
    Protozoa would grow in large numbers
✓

Answer

Correct option: B.
The centre of flocs will become anoxic, which would cause death of bacteria and eventually breakage of flocs
b
In the secondary treatment of sewage, if oxygen availability to activated sludge flocs (masses of bacteria associated with fungal filaments to form mesh like structure) is reduced; the centre of flocs will becomes anoxic, which would cause death of bacteria and eventually breakage of flocs.

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