After calculating the chlorine demand from a sample of water, the calculated amount of chlorine is applied as
• Chlorine gas or
• Chloramine or
Chlorine gas is the first choice because it is economical and
• Quick in action
• Efficient and
• Easy to apply
Since chlorine gas is an irritant to the eyes and poisonous, a special equipment known as ‘chlorination equipment’ is required to apply chlorine gas to water supplies
In some water treatment plants, chloramine is used instead of chlorine gas
Chloramines are loose compounds of chlorine and ammonia
They produce lesser chlorinous tastes and give a more persistent type of residual chlorine
The greatest drawback of chloramines is that they have a slower action than chlorine
Perchloron or high test hypochlorite HTH is calcium compound which carries 60 -70% of available chlorine.
Solutions prepared from HTH are also used for water disinfection.
As discussed already, chlorine gas has replaced all other chlorine derivatives in the disinfection of urban water supplies
Membrane processes in water purification: http://www.ihatepsm.com/blog/membrane-processes-treatment-drinking-water
Super Chlorination and Break Point Chlorination: http://www.ihatepsm.com/blog/super-chlorination-and-break-point-chlorina...
Slow sand filter: http://www.ihatepsm.com/blog/slow-sand-filter-biological-filter
Rapid sand filter: http://www.ihatepsm.com/blog/rapid-sand-filter-mechanical-filter
Purification of water at a large scale: http://www.ihatepsm.com/blog/water-purification-large-scale-water-supply
Criteria for a Chemical to be Suitable as Water Disinfectant in Water Supplies: http://www.ihatepsm.com/blog/criteria-chemical-be-suitable-water-disinfe...
Water Supplies Disinfection with Chlorination: http://www.ihatepsm.com/blog/water-supplies-disinfection-chlorination
Principles of Chlorination: http://www.ihatepsm.com/blog/principles-chlorination
Methods of Chlorination in Water Supplies: http://www.ihatepsm.com/blog/methods-chlorination-water-supplies
Horrock's Apparatus: http://www.ihatepsm.com/blog/horrock%E2%80%99s-apparatus
Disinfection of well during emergency: http://www.ihatepsm.com/blog/disinfection-wells-during-emergency-%E2%80%...
Double Pot method: http://www.ihatepsm.com/blog/disinfection-wells-during-emergency-%E2%80%...
Disinfection of Wells: http://www.ihatepsm.com/blog/disinfection-wells
OT and OTA test: http://www.ihatepsm.com/blog/ot-and-ota-test
Domestic or Household Purification of Water: http://www.ihatepsm.com/blog/domestic-or-household-purification-water