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→Construction, operations and maintenance: metering pump
When added to water, NaDCC releases hydrochloric acid which reacts through oxidization with microorganisms and kills them.
# Excess chlorine that is not consumed or combined remains in the water. This portion is called free residual chlorine (FRC). The FRC helps prevent recontamination of the treated water.
===Suitable conditions ===
Unlimited amounts of water can be processed at a time, depending on the amount of active chlorine.
{{procontable | pro=
- Some NaDCC products claim that there is no bad odour or taste after use <br>
- Highly acceptable to users because of ease of use, chlorine taste and prestige <br>
| con=
- Distribution system of the products should be developed <br>
- Relatively high cost <br>
- Toxoplasma oocysts and cryptosporidium oocysts are highly resistant to chlorine disinfection <br>
- Most users cannot determine the dosing quantity themselves; proper use requires instructions from the manufacturer <br>
}}
{{Potential_Treatment_Capacity_table
}}
==Technical specification== ====Operation=Construction, operations and maintenance===[[Image:chlorine tablet WHO.jpg|thumb|right|200px|Domestic chlorination using a chlorine tablet. Photo: WHO.]]
Each product should have its own instructions for correct dosing. In general, the user adds the correct sized tablet for the amount of water to be treated, following the product instructions. Then they agitate the container, and wait for the amount of time instructed on the package, normally 30 minutes (“contact time”). The water is then disinfected and ready to be used.
Most users cannot determine the dosing quantity themselves; proper use requires simple instructions from the manufacturer. Users often use less than the recommended dose to save money.
Metering pumps as [[Dosatron]] can be used to perform proportional dosing
====Manufacturing====
NaDCC tablets cannot be produced locally, but they can be bought in bulk and packaged locally.
Materials and facilities required are simply the tablets and packaging materials. Workshop space is required for packaging the tablets.
Anyone can be trained for light packaging work.
NaDCC tablets do not contain hazardous chemicals, they are safe to handle and store. Manufacturer’s instructions should be followed.
====Treatment Efficiency====
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Products should be protected from exposure to temperature extremes or high humidity.
====Estimated Lifespan====
====Suppliers====
Hydrachem Ltd. manufactured Oasis [http://www.oasiswaterpurification.com/ Water Purification tablets] in the United Kingdom. Hydrachem are the largest suppliers to UNICEF.<ref name=unicef14>[[#unicef14|UNICEF Supply Report (2014)]]</ref> Medentech Ltd. manufactures Aquatabs for water disinfection, hospital surface infection control and general environmental disinfection. In Tanzania, PSI imported a single sized 20 litre-tablet that are packed locally in boxes of 36 10 tablet-strips. ===Costs=Cost==
{{Treatment_Cost
|CapCost=US$ 0
Note: Program, transportation and education costs are not included.
==Country experiences== ==Manuals, videos, and links== ==Movies==* [http://fieldresearch.msf.org/msf/bitstream/10144/618835/1/FRC+Op+Guidance+Briefing+Note+%28Nov+2016%29.pdf Operational Guidance Briefing Note: Evidence-based Free Residual Chlorine (FRC) Targets]==External Links==* [http://www.hydrachem.co.uk Hydrachem Ltd.]*[http://www.cawst.org CAWST (Centre for Affordable Water and Sanitation Technology)]
* [http://www.aquatabs.com Aquatabs]
* [http://www.medentech.com Medentech Ltd.]
==Footnotes=References===
<references/>
===Acknowledgements===
This article is based on a factsheet from [http://www.cawst.org/ Centre for Affordable Water and Sanitation Technology (CAWST)], which is gratefully acknowledged.
* Clasen, T. and P. Edmondson (2006). Sodium dichloroisocyanurate (NaDCC) tablets as an alternative to sodium hypochlorite for the routine treatment of drinking water at the household level. International Journal of Hygiene and Environmental Health Volume 209, Issue 2, pp. 173-181.
* Clasen, T., Saed, T., Boisson, S., Edmondson, P., and O. Shipin. (2007). Household Water Treatment Using Sodium Dichloroisocyanurate (NaDCC) Tablets: A Randomized, Controlled Trial to Assess Microbiological Effectiveness in Bangladesh. Am. J. Trop. Med. Hyg., 76(1), 2007, pp. 187–192.
* Lantagne, D.S., Blount, B. C., Cardinali, F., and R. Quick, R (2008). Disinfection by-product formation and mitigation strategies in point-of-use chlorination of turbid and non-turbid waters in western Kenya. Journal of Water and Health, 06.1, 2008.
* Molla, N., (2007). Practical Household Use of the Aquatabs Disinfectant for Drinking Water Treatment in the Low-Income Urban Communities of Dhaka, Bangladesh. Thesis, Asia Institute of Technology, School of Environment, Resources and Development.