Question

Which of the following order is correct regarding the specific gravity of the materials used in the mixed media filter?

(a) Anthracite coal < Sand > Garnet sand

(b) Anthracite coal > Sand > Garnet sand

(c) Anthracite coal = Sand = Garnet sand

(d) Anthracite coal < Sand < Garnet sand

This question was addressed to me by my college director while I was bunking the class.

I want to ask this question from Dual Media and Mixed Media Filter in portion Filtration of Environmental Engineering

Answer 1

The correct answer is (d) Anthracite coal < Sand < Garnet sand

The explanation: Anthracite coal has a specific gravity of 1.42, sand has a specific gravity of 2.65 and Garnet sand has a specific gravity of 4.2. So, coal has lower, sand has medium and Garnet sand has the highest specific gravity between them.