Now-a-days there is a wide range of water purifiers available for the purpose of purifying tap water for drinking. The cheapest of these consists of a carbon filter that is attached inside a pitcher or mounted directly to the tap. At first, water is passed through charcoal that traps all the dust particles and debris of metals like lead. In older days, some pipes were made up of lead which resulted in the leakage of small amounts of lead into the tap water, but these days all homes are upgraded to copper or plastic pipes according to the building regulations.
In many water purifiers charcoal filters are used to remove most heavy metals, chlorine and dust floating particles from the water. But they does not work for bacteria and other some small invisible particles. So, in such situations water is more contaminated with life threatening organisms.
Reverse osmosis is the recent research technique used for eliminating out objects, which are as tiny as contaminated organisms. Here water is forced to pass through a semi-permeable membrane that is most capable of removing the finest particles from the water. It is the most efficient filtering technique which removes virus and bacteria as well as dissolved metals that pass easily through a charcoal filter. This method is also used to remove the salt from seawater, making it safe for drinking purpose. So, before buying a water purifier, know about the different types of purifiers that works in making water safe for drinking.