Public Health - Always Working for a Safer and Healthier Washington
Washington State Department of Health Division of Environmental Health Office of Drinking Water
Chlorination
Muhammad Fahad Ansari 12IEEM14
Public Health - Always Working for a Safer and Healthier Washington
Washington State Department of Health Division of Environmental Health Office of Drinking Water
SUHAIL RAJPUT
12IEEM27
Definaton:Chlorination is the process of adding the element chlorine to water as a method of water purification to make it fit for human consumption as drinking water.
Public Health - Always Working for a Safer and Healthier Washington
Washington State Department of Health Division of Environmental Health Office of Drinking Water
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Our Shared Mission
To protect the health of the people
by ensuring safeand reliable
drinking water.
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Sources Chlorinated
50%Sources Not Chlorinated
50%
Sources Chlorinated (WA 2008)
Sources Chlorinated
Sources Not Chlorinated
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Supplied Chlorinated
Water82%
Supplied Unchlorinated
Water18%
Group A Residential Population Supplied Chlorinated Water
(WA 2008)
Supplied Chlorinated Water
Supplied Unchlorinated Water
Public Health - Always Working for a Safer and Healthier Washington
Washington State Department of Health Division of Environmental Health Office of Drinking Water
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Chlorination MechanicsHow well does chlorine work?
Bacteria: Penetrates cell wall and kills the organism
Viruses: Relatively effective inactivation
Giardia: Relatively ineffective inactivation
Public Health - Always Working for a Safer and Healthier Washington
Washington State Department of Health Division of Environmental Health Office of Drinking Water
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What Interferes With the Disinfection Process?
High pH Low water temperature Turbidity Insufficient mixing Presence of chlorine-demanding compounds, such
as iron or manganese
Public Health - Always Working for a Safer and Healthier Washington
Washington State Department of Health Division of Environmental Health Office of Drinking Water
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Chlorine treatment standards: “C x T”Chlorine treatment standards: “C x T”
T = time water is in contact with the chlorine
C = concentration of free chlorine (mg/l), measured after “T”
Need C x T = 6 for groundwater
0.3 mg/l for 20 min. same as 0.6 mg/l for 10 min.
Public Health - Always Working for a Safer and Healthier Washington
Washington State Department of Health Division of Environmental Health Office of Drinking Water
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Chlorine Chemistry
Total = Free chlorine + Combined chlorine
Free chlorine:hypochlorous acid + hypochlorite ion
Combined chlorine (chloramines):chlorine combined with ammonia or organic nitrogen (causes chlorine taste and odor)
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0
0.2
0.4
0.6
0.8
1
1.2
6.0 6.5 7.0 7.5 8.0 8.5 9.0
pH
Frac
tion
of F
ree
Chl
orin
e
HOCl (20oC)
OCl- (20oC)
Ionization of Chlorine in Water
Hypochlorous vs. Hypochlorite80% “strong stuff” at a pH of 7.0
20% “strong stuff” at a pH of 8.2
“Strong stuff”
Public Health - Always Working for a Safer and Healthier Washington
Washington State Department of Health Division of Environmental Health Office of Drinking Water
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Chlorine Demand and Chlorine Residual
Demand - Inherent properties of the water that consume chlorine
Residual - What’s left after the chlorine demand has been satisfied, remaining available to act against microorganisms
Public Health - Always Working for a Safer and Healthier Washington
Washington State Department of Health Division of Environmental Health Office of Drinking Water
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Sources of Chlorine in Drinking Water
Chlorine gas
Calcium hypochlorite (dry)
Sodium hypochlorite (liquid)
Public Health - Always Working for a Safer and Healthier Washington
Washington State Department of Health Division of Environmental Health Office of Drinking Water
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Gas chlorination
Public Health - Always Working for a Safer and Healthier Washington
Washington State Department of Health Division of Environmental Health Office of Drinking Water
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Calcium hypochlorite tablet erosion feed system
Public Health - Always Working for a Safer and Healthier Washington
Washington State Department of Health Division of Environmental Health Office of Drinking Water
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Sodium hypochlorite injection system
Solution TankFeed Pumps Injection lines
What Happens to Chlorine After it’s Added to Water?
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HOCl
OCl -
Public Health - Always Working for a Safer and Healthier Washington
Washington State Department of Health Division of Environmental Health Office of Drinking Water
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Methods and StandardsIndustry specifications
American Water Works Association (AWWA)
WA State Department of Transportation
Public Health - Always Working for a Safer and Healthier Washington
Washington State Department of Health Division of Environmental Health Office of Drinking Water
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