Question

When impurities are separated by the gravitation of settling particles, the operation is called _____

(a) Sedimentation with coagulant

(b) Plain sedimentation

(c) Secondary sedimentation

(d) Disinfection

I had been asked this question in quiz.

My question comes from Theory of Sedimentation in section Sedimentation of Environmental Engineering

Answer 1

Correct choice is (b) Plain sedimentation

For explanation: In plain sedimentation, impurities are separated from a suspending fluid by use of natural forces like gravitational forces.