Water purification
Water purification is the process of removing undesirable chemicals, biological contaminants, suspended solids and gases from contaminated water.[1]
Contaminants
Aside from sediment, contaminants typically found in non-purified water are[2]:
- Protozoa
- Cryptosporidium
- Giardia lamblia
- Bacteria
- E. coli
- Salmonella
- Campylobacter
- Shigella
- (many others)
- Viruses
- Hepatitis A
- Enterovirus
- Norovirus
- Rotavirus
- (many others)
Cryptosporidium
Potential health effects from ingestion of water contaminated with Cryptosporidium are:
- Gastrointestinal illness (for example, diarrhea, vomiting, cramps).
Sources of Cryptosporidium in drinking water are:
- Human and animal fecal waste.
Methods that may remove some or all of Cryptosporidium from water are:
- Boiling (rolling boil for 1 minute) - very high effectiveness;
- Filtration - high effectiveness, when using an absolute less than or equal to 1 micron filter (NSF Standard 53 or 58 rated "cyst reduction / removal" filter);
Methods that are not effective in removing Cryptosporidium:
- Disinfection with iodine or chlorine is not effective in killing Cryptosporidium;
- Disinfection with chlorine dioxide has a low to moderate effectiveness in killing Cryptosporidium;
Combination filtration and disinfection has a very high effectiveness in removing and killing Cryptosporidium when used with chlorine dioxide and an absolute less than or equal to 1 micron filter (NSF Standard 53 or 58 rated "cyst reduction / removal" filter).
Giardia lamblia
Also known as Giardia intestinalis.
Potential health effects from ingestion of water contaminated with Giardia are:
- Gastrointestinal illness (for example, diarrhea, vomiting, cramps).
Sources of Giardia in drinking water are:
- Human and animal fecal waste.
Methods that may remove some or all of Giardia from drinking water are:
- Boiling (Rolling boil for 1 minute) 0 very high effectiveness;
- Filtration- high effectiveness in removing Giardia when using an absolute less than or equal to 1 micron filter (NSF Standard 53 or 58 rated "cyst reduction / removal" filter);
- Disinfection with chlorine dioxide - high effectiveness;
Methods that are not effective in removing Giardia: Disinfection with iodine or chlorine has a low to moderate effectiveness in killing Giardia;
Combination filtration and disinfection has a very high effectiveness in removing and killing Giardia when used with chlorine dioxide and an absolute less than or equal to 1 micron filter (NSF Standard 53 or 58 rated "cyst reduction / removal" filter).
