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Microbes in Human Welfare — BIOLOGY STD 12 Science — Question

Gujarat BoardEnglish MediumSTD 12 ScienceBIOLOGYMicrobes in Human Welfare3 Marks
Question
Describe how do 'flocs' and 'activated sludge' help in Sewage Treatment.
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Answer

Flocs- Aerobic microbes consume the major part of the organic matter in the effluent, significantly reduces BOD.
Activated sludge- Small part of activated sludge is used as inoculum and pumped back to aeration tank/pumped into anaerobic sludge digesters where microbes or bacteria grow anaerobically to produce CH4 or H2S or CO2 or biogas.

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