Question

The residual chlorine after 10 minutes contact is 0.2mg/l what is the dosage

Answer 1

The presence of chlorine residual in drinking water indicates that: 1) a sufficient amount of chlorine was added initially to the water to inactivate the bacteria and some viruses that cause diarrheal disease; and, 2) the water is protected from recontamination during storage.

Dosage definition, the administration of medicine in doses.

after 10 minutes contact is 0.2mg/l

dosage=0.2*10=2mg/l