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WATER TREATMENT METHODS
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Removes chemical contaminants?
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Removes biological contaminants (microorganisms)?
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Disinfection by boiling water
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Some volatile chemicals ONLY. NO nonvolatile chemicals
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Kills bacteria, parasites, and viruses
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Chemical disinfection (chlorine, iodine)
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NO
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Kills bacteria, viruses, but NOT all parasites, e.g., not Giardia and cryptosporidium
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Activated carbon filters (granular carbon and carbon block filters)
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Especially effective against organic chemicals such as pesticides, industrial chemicals. Will remove chlorine, radon, bad tastes & smells, but not dissolved minerals. Carbon block
filters are more effective than granular carbon.
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NO.
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Filters for microorganisms
(ceramic and iodine-resin filters)
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NO
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Ceramic filters can eliminate bacteria, parasites, and some viruses, since viruses often attach to bacteria. Addition of an iodine-resin medium can inactivate viruses
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Mineral/metal filters
(alumina and redox filters)
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Alumina filter removes dissolved minerals, metals (e.g., lead), but does not remove organic chemicals or chlorine.
Redox filter removes dissolved minerals, chlorine.
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Alumina filter does NOT remove microorganisms. Redox filters can reduce but NOT eliminate bacteria in water; should not be used for disinfection by itself.
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Reverse osmosis
(membrane filters)
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Will remove most organic chemicals, toxic minerals, but not chlorine, radon.
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Only partially removes bacteria, parasites; should NOT be used by itself for disinfection.
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Distillation
(water or air cooled distillers)
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Removes all chemical contaminants except volatile organics
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Removes all microorganisms
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Ultraviolet disinfection
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NO
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Removes all microorganisms except cysts (e.g., giardia)
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