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ScienceCLASS 7CBSE

answered 27 Mar 2026

What is sludge? Explain how it is treated.

A.VERIFIED ANSWERfact-checked by tutors

Solution:

Solids like faeces settle at the bottom while treating sewage, and this material is called sludge. Sludge can be treated as follows:

Sludge is removed using a skimmer and then transferred to a tank where it is decomposed by anaerobic bacteria to produce biogas.

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