What is Residual chlorine in chlorination of water should be: and explain in detail?
The minimum recommended concentration of free chlorine is 0.5 mg/L for one hour. The sum of the chlorine demand of the specific water plus the free residual chlorine of 0.5 mg/L constitutes the correct dose of chlorine to be applied. The chlorine has no effect on spores, protozoal cysts and helminthic ova, except in higher doses. Ref: Park's Textbook of Social and Preventive Medicine, 19th edition, Page 575.