The water available for drinking nowadays is not really safe for drinking crude and needs to be purified. Various pollutants like industrial waste and environmental degradation products have made the available water unhealthy for drinking. For this purpose, water filters and water purifiers are used. Both have the same mechanism, except that the purifiers are able to treat the water by killing the microorganisms, which a normal filter cannot do.
Types of Water Purifiers
The various types of water purifiers used are –
Active carbon Water filter
Many soluble gases get mixed with drinking water through industrial wastes like carbon monoxide, ammonia, nitrogen and even some pesticides. Activated carbon filters are coated with a layer of activated silver that helps in killing bacteria. Such filters are used to remove all such gases along with dead algae. The carbon blocks are porous and block all such impurities.
Biosand Water filter
It is a kind of filter which has layers of sand and gravel of varying diameters. The largest particles being at the bottom and smallest being at the top. The sand filters remove the dirt and gross impurities and kill the pathogens (disease causing organisms) as well.
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The top 2 cm layer of sand is known as biolayer as it has microbial growth, which helps in killing the pathogens and making the water pathogen-free. However, it cannot remove the soluble gases from the water.
Reverse osmosis filters (RO)
It offers the purification of water in multiple stages by combination of active carbon and particle filter. The water is first made to pass through the particle filter which has many small-sized pores, which prevent the passage of microorganisms and minerals. The impurities are then removed through an outlet pipe. This system is recommended in areas which have hard water supply.
Ultra violet (UV) Filters
This type of purifier uses the simple technique of killing microorganisms with exposure to UV light. Exposure to the UV light results in de-naturation of proteins and DNA of the microbes and pathogens. But it does not remove any dirt, chemicals or suspended particles from the water.
These are hollow cylindrical filters made up of ceramic, which have materials like saw dust, coffee or rice husks, which have small pores to prevent the flow of bacteria and chlorine. It is known to restrict up to 99% of the bacteria E. coli.
Ion Exchange Resin Filters
Such filters contain a layer of resin in them, which attach the minerals to themselves and prevent their passage, thereby converting hard water into soft water.