WATER TREATMENT METHODS

Removes chemical contaminants?

Removes biological contaminants (microorganisms)?

Disinfection by boiling water

Some volatile chemicals ONLY. NO nonvolatile chemicals

Kills bacteria, parasites, and viruses

Chemical disinfection (chlorine, iodine)

NO

Kills bacteria, viruses, but NOT all parasites, e.g., not Giardia and cryptosporidium

Activated carbon filters (granular carbon and carbon block filters)

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.

NO.

Filters for microorganisms
(ceramic and iodine-resin filters)

NO

Ceramic filters can eliminate bacteria, parasites, and some viruses, since viruses often attach to bacteria. Addition of an iodine-resin medium can inactivate viruses

Mineral/metal filters

(alumina and redox filters)

Alumina filter removes dissolved minerals, metals (e.g., lead), but does not remove organic chemicals or chlorine.

Redox filter removes dissolved minerals, chlorine.

Alumina filter does NOT remove microorganisms. Redox filters can reduce but NOT eliminate bacteria in water; should not be used for disinfection by itself.

Reverse osmosis

(membrane filters)

Will remove most organic chemicals, toxic minerals, but not chlorine, radon.

Only partially removes bacteria, parasites; should NOT be used by itself for disinfection.

Distillation

(water or air cooled distillers)

Removes all chemical contaminants except volatile organics

Removes all microorganisms

Ultraviolet disinfection

NO

Removes all microorganisms except cysts (e.g., giardia)