Question

In which device, the primary mixing is followed by a secondary reaction zone resulting in formation of sludge blanket?

(a) Centrifugal pump

(b) Flocculator

(c) Tube settler

(d) Solid contact clarifier

I had been asked this question in an online interview.

My doubt stems from Flocculation and Clarification topic in section Sedimentation of Environmental Engineering

Answer 1

Correct answer is (d) Solid contact clarifier

To explain I would say: In Solid contact clarifier, sludge blanket is formed where straining action occurs to remove some of the finer particles. The thickness of the blanket is 1m.