Water purification

Water purification is the process of removing undesirable chemicals, biological contaminants, suspended solids and gases from contaminated water.

Contaminants

Aside from sediment, contaminants typically found in non-purified water are:

• 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:

1. Gastrointestinal illness (for example, diarrhea, vomiting, cramps).

Sources of Cryptosporidium in drinking water are:

1. Human and animal fecal waste.

Methods that may remove some or all of Cryptosporidium from water are:

1. Boiling (rolling boil for 1 minute) - very high effectiveness;
2. 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 killing Cryptosporidium:

1. Disinfection with iodine or chlorine is not effective in killing Cryptosporidium;
2. 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).