[[Image:chlor pipe icon.png|right|100px80px]]
[[Image:chlorination in piped.jpg|thumb|right|200px|Floating bowl chlorinator can be placed in tanks or reservoirs. Photo: WHO.]]
[[Image:floating chlorinator.jpg|thumb|right|200px|A type of floating chlorinator. Photo: [http://www.thinkcbw.com/equipment.html Thinkcbw.com]]]
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Chlorination is a chemical method for disinfecting water. The chlorine inactivates pathogens in the water and provides a barrier against recontamination. It is normally applied at the last stage of a drinking-water treatment process.
'''Yield''': Generally, 350–1400 m3 of treated water per kg of a 70% chlorine compound.
===Suitable conditions===
'''Area of use''': Wherever drinking-water needs to be disinfected and chlorine is available.
===Construction, operations and maintenance===
The flow rate of the raw water must be checked and adjusted if necessary, and the chlorine tank must be refilled with a freshly-prepared solution once or twice a week. Operators must be careful to avoid contact with chlorine compounds or solutions, and use protective gloves and utensils to prepare the chlorine solutions. The gloves and utensils will need to be replaced occasionally. In some cases, the amount of chlorine added to the water, together with residual chlorine levels, are recorded in a logbook. Chlorinators must be adjusted and cleaned of chlorine salts regularly, and when the hoses become corroded by chlorine they must be replaced.
Despite these limitations, disinfecting drinking-water by chlorination is one of the most effective and least-expensive technologies available and should be encouraged.
===Costs===
'''Initial cost''': A chlorinator and hoses can cost as little as US$ 15, but there will be additional costs for the tank, for the concentrated chlorine solution, and for the construction costs of a protective shelter.
===Field experiences===
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===Acknowledgements===
* Brikke, François, and Bredero, Maarten. [http://www.washdoc.info/docsearch/title/117705 Linking technology choice with operation and maintenance in the context of community water supply and sanitation: A reference document for planners and project staff] or ([http://www.who.int/water_sanitation_health/hygiene/om/wsh9241562153/en/ alternative link]). World Health Organization and IRC Water and Sanitation Centre. Geneva, Switzerland 2003.
