Chlorination does not remove nitrates or other chemicals, but may oxidize organics and some minerals such as iron. Chemical metering devices must be maintained carefully. Using a carbon filter after chlorination will remove any excess chlorine and chlorinated chemicals that form. Other Methods Other methods of disinfecting water include boiling, pasteurizing, treating with ultraviolet light, and treating with ozone. These methods are usually less practical than chlorination or not readily available.
Disinfection reduces the concentration of organisms to safe levels.
Devices to kill or remove bacteria or viruses are termed purifiers. Chlorination, distillation, or boiling for 15 minutes are the usual methods used to purify water for household use. Disinfection by ozonation or ultraviolet light methods are replacing chlorination in some water treatment plants, but are not yet readily available for home use. Some filtration units with silver-coated activated charcoal blocks are being sold for removal or killing of bacteria. Before purchasing such a unit, evaluate it carefully and check for sufficient test data and certification to assure its effectiveness.