Question

What is the ratio in which coal, sand and garnet are present in the mixed media filter?

(a) 2 : 3 : 5

(b) 4 : 2 : 1

(c) 6 : 3 : 1

(d) 1 : 2 : 3

This question was addressed to me by my school principal while I was bunking the class.

This intriguing question comes from Dual Media and Mixed Media Filter in section Filtration of Environmental Engineering

Answer 1

Right answer is (c) 6 : 3 : 1

Easiest explanation: In mixed media filter, the coal is placed on top, sand in the middle and garnet at the bottom in the proportion of 60%, 30%, 10% respectively.