Disinfection
Most suitable Disinfection Method: Chlorination
What is chlorination?
Chlorination is the process of adding chlorine to drinking water to kill parasites, bacteria, and viruses. Different processes can be used to achieve safe levels of chlorine in drinking water. Using or drinking water with small amounts of chlorine does not cause harmful health effects and provides protection against waterborne disease outbreaks.
Advantages
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Chlorination is a cheaper source than UV or ozone.
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Effective against a wide range of pathogenic microorganisms.
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Dosing rates are controlled easily as they are flexible.
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The disinfection effect is persistent.
Limitations ​
Limitations in using chlorine gas in a household context might include the distribution, procurement/manufacturing, dosing of chlorine, and accurate handling. The health hazards caused by chlorine are not only confined to its volatile nature. A great concern might be the byproducts and incompletely oxidized compounds present in chlorinated water that increase its toxicity.
Regulation
Chlorine levels up to 4 milligrams per liter are considered safe in drinking water external icon. At this level, harmful health effects are unlikely to occur.
Cost Analysis
Chlorine based-products had a low total cost of up to $0.13 per 1,000 gallons, which favors the use of chlorination when large water volumes require treatment.
Other Disinfection Methods:
Ozonation
What is Ozonation?
Ozone is an allotropic formula of oxygen in which three molecules are combined to produce a new molecule. It quickly decomposes to generate highly reactive free radicals.
Ozone is produced from ambient air or pure oxygen. Oxygen is converted to ozone in an electrical field. The ozone is then fed to the contact tank so that ozone is dissolved by water to proceed disinfection process.
Advantages
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Ozone possesses strong oxidizing power.
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Short reaction time is needed.
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No change in color and taste occurs.
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Requires no chemicals
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Oxygen is provided to water after disinfection
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Destroys and removes algae
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Oxidizes iron and manganese
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Reacts with and removes all organic matter.
Limitations ​
Onsite generation is necessary as ozone is unstable at atmospheric pressure. It is toxic in high concentrations. The three modules of an ozone plant are ozone destructor, ozone contact chamber, and generator. In contact chamber, ozone is added to water. The amount of ozone that are stripped out into the air must be strictly limited. Three main processes affect the release of ozone after introducing ozone into water: decomposition, reaction with water impurities, and stripping into the atmosphere.
Ultraviolet Light (UV)
​Ultraviolet light (UV)
The UV light causes disinfection by changing the biological components of microorganisms specifically breaking the chemical bonds in DNA, RNA, and proteins.
The light source is mounted so that water can pass through a flow chamber so that UV rays can be both admitted and absorbed into the stream.
​Advantages
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It limits the regrowth potential within the distribution system so no increase in biodegradable
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There are no concerns with respect to interactions with pipe material.
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Can achieve the same log inactivation of Giardia and Cryptosporidium, less in cost either than chlorine dioxide and ozone techniques.
​Limitations
It does not work against reinfection in water. Turbid, cloudy, or water containing a large number of bacteria can be used to shield bacteria.
Chemical composition is a basic problem as the water containing large amount of minerals might cause the coating on the lamp sleeve, thus reducing the effectiveness of the treatment.
Gravimetric is used over ion chromatography to test the sulfate concentration in Alberta's groundwater, sulfate concentration in Alberta's groundwater ranges from 0.3 to 1010 mg/l with an average value of 93.8 mg/l. The source for sulfate is typically through the dissolution of gypsum minerals, atmospheric deposition, and soil fertilizers for farming.