Question

Please explain the science behind municipal water treatment including chlorination and alternatives to chlorination (UV radiation, etc).

Answer 1

The chlorination of water means treatment of water with hypochlorite (sodium hypochlorite , calcium chlorite or chlorine gas)

All the chlorine containing agents react with water to produce hypochlorous acid ( which can be called as available chlorine ) and this hypochlorous acid or hypochlorite has germ killing properties, it ruputre the wall of bacteria and causes its lysis.

Cl2 + H2O --> HOCl + HCl

NaOCl + H2O --> HOCl + NaOH

The other alternatives like UV radiation and chloramine are also used as disinfectant they cause killing of microbes and hence make water drinkable.