Question

The normal dose of chlorine during post chlorination is ___________

(a) 0.5-1ppm

(b) 0.1-0.2ppm

(c) 0.1-0.5ppm

(d) 1-2ppm

I had been asked this question during an internship interview.

My enquiry is from Forms of Chlorination in division Properties of Disinfection of Environmental Engineering

Answer 1

Correct option is (b) 0.1-0.2ppm

Easy explanation: The normal dose of chlorine during post chlorination is 0.1-0.2ppm. It is used for protection against contamination.