In a filtration, plant water is filtered using layers of (a) sand and clay. (b) clay and fine gravel. (c) sand and fine gravel. (d) sand, fine gravel and medium gravel.

A.VERIFIED ANSWERfact-checked by tutors

Soln:

The answer is (d) sand, fine gravel and medium gravel.

Explanation:

During wastewater treatment wastewater is allowed to enter a grit of sand, fine gravel and medium gravel. Here the speed of wastewater is slowed down to allow sand, fine gravel and medium gravel to settle down.

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