Purifiers and Filters - How do they differ?
There is some confusion in the water industry about the meanings and differences between water purifiers and water filters. Many industries use the two terms interchangeably to describe the same process, i.e. filtration. A technical definition of pure water would refer to water containing only hydrogen and oxygen molecules. Such "pure" water does not occur naturally in the world. All water contains some impurities, or elements of different chemical compounds than merely hydrogen and water (Binnie et al, 2002). As water passes through streams and rivers, it carries mineral sediments with it. Ground water, the source for most municipal water systems, contains remnants of pesticides, herbicides, and industrial waste. Water generally carries several bacteria and viruses, as well.
The accepted definition of "pure" water for most water industries
is water that is free of bacterial components. The definition
does not include chemical contaminants. The EPA,
also, has defined pure water as water free from all types of
bacteria and viruses. A water purification system, then, would
remove all bacterial components from water without attending
to undesirable chemicals and minerals.
Such a system is significantly different from a water filtration system. A water filtration system is designed to remove unwanted chemicals and minerals, but it is not recommended for the removal of bacteria and viruses. Practically every municipal water system in the world implements water chlorination for this purpose. Water that reaches a homes plumbing system will already have been disinfected through chlorination. Water filters then remove the chlorine and chlorine resistant parasites like cryptosporidium and giardia.