Factors Affecting Disinfection:

Following factors affect the disinfection process :

Contact Time between Disinfectant and Micro-organism

The destruction of micro-organism increases with the increase in contact time available between disinfectant and micro-organism. In practice, contact time is limited by the design of plant and normally is not less than 30 minutes.

Type of Micro-organism Present

Among various micro-organism present in water it has been found that pathogens are less resistant than coliform group. Virus appear to be more resistant than bacteria and cyst are extremely resistant, hence require longer period of contact as well as higher concentration of disinfectant.

Characteristic of Water

Various characteristic such as concentration of organic and suspended matter, presence of metallic and ammonia compounds, etc. in water reduces the rate of disinfection.

Concentration of Disinfectant

Higher the concentration of disinfectant, higher is the destruction of micro-organism.

Temperature of Water

Rates of chemical reactions are speeded up as the temperature of the reaction is increased. The higher the temperature, the more rapid is the destruction of organisms.