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Wastewater Story — Science STD 7 — Question

Gujarat BoardEnglish MediumSTD 7ScienceWastewater Story1 Mark
MCQ
Dried sludge is used as:
  • ✓
    Manure
  • B
    Source for biogas
  • C
    Fertilizers
  • D
    Both $A$ and $B$
✓

Answer

Correct option: A.
Manure

Activated sludge is formed as the suspended microbes settle at the bottom of the aerator tank.
This activated sludge is $97\%$ water and it is dried using sand drying beds or machines to obtain dried sludge.
Dried sludge is used as manure, returning organic matter and nutrients to the soil.

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