Correct Answer - Option 2 : Super chlorination
Explanation:
Super Chlorination:
(i) When excess chlorine ( 5 to 15 mg/l ) is added during an epidemic such that it gives a residual of 1 to 2 mg/l beyond breakpoint is called super chlorination.
(ii) It is most commonly added at the end of filtration.
(iii) It is preferred when water contains cysts of histolytica (i.e. the organism which causes amoebic dysentery).
Breakpoint chlorination:
- Breakpoint chlorination is a term that gives us an idea of the extent of chlorine added to water.
- In fact, it represents that much dose of chlorination, beyond which any further additional chlorine will appear as free residual chlorine.
Post Chlorination:
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Post chlorination is the normal process of applying chlorine in the end, when all other treatments are completed but before the water reaches the distribution system. At this stage, chlorination is meant to kill pathogens and to provide a chlorine residual in the distribution system.
