Disinfection:

The various physiochemical treatment processes such as sedimentation, coagulation and filtration etc. mainly aim at providing aesthetically acceptable water. Although, these processes assist in removal of bacterial or micro-organism to varying degree, but may not produce safe water. Disinfection is aimed at inactivation or destruction of disease producing micro-organism such as bacteria, virus etc., which are considered to be mainly responsible for water-borne disease.

Disinfection can be distinguished from sterilization process. Sterilization is employed to completely kill all micro-organism through various physical processes such as boiling water for long time, while in disinfection reduction of harmful micro-organism is done such that they become inactive to cause any infection or disease.