Water filtration is a process in which water passes through one or multiple filters to remove odor, taste, color, organic material and suspended solids. The type of filters used in this process depends on the application. For example, Media filters are used to remove suspended solids and large particles from the water, while Activated Carbon filters are used to remove chlorine residual, odor, organic material and improve the taste of the water.
Chlorine does not appear to be bad other than the undesirable taste and odor. Chlorine is actually used as a disinfection chemical to kill bacteria in the water. Disinfection by-products however, have been considered carcinogens. If you feel like you water contains chlorine in it, it is best to install either Carbon block cartridges at the point of use (POU) or a big activated carbon filter on the point of entry (POE) of the house.
Carbon used in filtration processes is made by grinding various carbon sources like coconut shells, peat and bituminous coal. The material is heated up to 1000ºC in the absence of oxygen, then its subjected to steam at a temperature of 1600 ºC to activate the carbon. The steam fills the carbon grains with cracks and pores, allowing for chemicals.
Activated carbon removes contaminants by either adsorption, whereby contaminants are attracted to the surface of the carbon like if it were magnetic; or by acting as a catalyst to speed up chemical reformation and reactions of some contaminants.
Activated carbon is used to remove chlorine and organic chemicals such as pesticides, chloroform, gasoline, solvents, etc.
The list below highlights the chemicals that could be removed by carbon.
(Acetaldehyde, Acetone, Alcohols, Amy Acetate, Amy Alcohol, Antifreeze, Benzene, Bleach, Butyl Alcohol, Butyl Acetate, Calcium Hypochlorite, Chloral, Chloramine, Chloroform, Chlorine, Chlorobenzene, Chlorophenol, Chlorophyll, Citric Acid, Cresol, Defoilants, Diesel Fuel, Dyes, Ethyl Acrylate, Ethyl Alcohols, Ethyl Acetate, Ethyl Amine, Ethyl Ether, Gasoline, Glcols, Herbicides, Hydrogen Peroxide, Hypochlorous Acid, Insecticides, Iodine, Isopropyl Acetate, Isopropyl Alcohol, Ketones, Lactic Acids, Mercaptans, Methyl Acetate Methyl Alcohol, Methyl Bromide, Methyl Chloride, Methyl Ethyl Ketone, Naphtha, Nitrobenzene, Nitrotoluene, Odors (General), Oil-Dissolved, Organic Acids, Organic Esters, Organic Salts, Oxalic Acid, Oxygen, Ozone, PCB's, Pesticides, Phenol, Plastic Tastes, Potassium Permanganate, Propioic Acid, Propyl Acetate, Propyl Alcohol, Propyl Chloride, Radon, Rubber Hose Taste, Sodium Hypochlorite, Solvents, Sulphonated Oils, Tannins, Tar Emulsion, Tartaric Acid, Taste, THM's, Toluene, Toluidine, Trichlorethylene, Turpentine, Xanthophyll, Xylene)

Water flows through a filter vessel designed to remove particles. The vessel is filled with sand and gravel, or in our case, crushed glass. Filtration entraps suspended solids and particles from the water for less turbidity and improved quality. The filters are regularly backwashed for media cleaning.
Sand has been the ultimate filtration media used for the past years. Over the years, development of filtration using recycled glass has set a new standard.
While sand will filter to roughly 30 microns, glass media has been shown to vary between 5 and 10 microns depending on the manufacturer. Glass media has a negative charge on the surface, which helps in attracting fine particles for efficient filtration. Although glass media is slightly more expensive than sand is, but it can last between 10 and 15 years before needing to be replaced (sand may last between 5 and 8 years), some experts even say that it could be cleaned with chlorine or acid and topped of with a new layer to achieve top performance again.
Water disinfection can be in multiple ways, one of which is the use of an ultraviolet light. UV light provides quick inactivation of microorganisms. When bacteria and microbial organisms are exposed to UV light, they become incapable of reproducing and infecting.
UV has been proven to inactivate a large number of pathogenic bacteria, viruses and protozoa. It holds a key advantage over chlorine disinfection, as some pathogens, mainly protozoa, are chlorine resistant, and also UV doesn’t have by-product formation like chlorine does.
deciding whether you should install a UV system or not depends on the application of the treated water. For domestic usage, usually chlorination would be sufficient. However, if water is being used for drinking and cooking, then UV disinfection is highly recommended.