Pure water consists of two parts of Hydrogen and one part of oxygen. Pure water is colourless and tasteless. Pure water does not exist in nature. It always contains impurities in solution or suspension.
Filters are closed cylindrical vessel either vertical or horizontal (mostly vertical) containing the filter media over a collector system. Water flows from top downwards percolating through the media and is drawn off through the collector system at the bottom.
Filter which uses only sand is called sand filter. Filter which use two media (normally sand and anthracite) is called dual media filter.
The Pressure Sand filter will effectively remove up to 30 – 50 micron of the suspended solids to less then 5 ppm. The filter will have to be washed with raw water for 20 to 30 minutes daily. To filter the partials below 30 – 50 micron cartridge filter is used
Activated carbon, also called activated charcoal, or activated coal, is a form of carbon processed to have small, low-volume pores that increase the surface area available for adsorption or chemical reactions.
Activated Carbon is an effective method for adsorbing organics and removal of chlorine. Activated carbon can be used either as powdered activated carbon or as granular activated carbon. In demineralization plant, activated carbon is normally used in Granular form.
It normally precedes the Ion exchange unit. Activated carbon is used for removal of organics and dechlorination to protect the ion exchange resin from fouling and oxidation.
Template Assisted Crystallization (TAC). Atomic level Templates on the surface of small specially treated polymer spheres transform dissolved CaCO3 to a crystalline form. The crystals are relatively insoluble, effectively isolating the CaCO3 from the water chemistry and anything the water contacts.