What is Chlorine?
Chlorine is a naturally occurring element; symbol Cl. It's a very dangerous toxin that has many uses, from disinfecting to bleaching. In small quantities, liquid and gas forms can be poisonous. In its gas form, chlorine is a pale green color and has a smelly odor and makes your breathing labored. In its solid form, it's more of a yellow green color. It is abundant in nature in its chloride ion form found in many of the salts that are in the earth.
Uses in Drinking-Water Treatment
Chlorine products are oxidizing agents used for disinfection of water supplies, Chlorination can also reduce color, tastes and odors in water and oxidize metallic substances for removing during filtration.
Liquefied chlorine gas, sodium hypochlorite and calcium hypochlorite are the chlorine products commonly used in treatment of drinking-water supplies for this purpose.
Methods of Dosing
Chlorine gas is normally fed directly into water, via an injector and automatic shutdown regulator.
Sodium hypochlorite is dosed from a corrosion resistant tank via a non-metallic pipe and corrosion resistant dosing pump.
Calcium hypochlorite (in powder, granular or tablet form) must be dissolved in water and dosed as a settled, clear solution.
Why not use chlorine?
Many people object to the taste and smell of chlorinated water. But more importantly, chlorine reacts with certain compounds that may be present in the water supply, resulting in by-products that have been linked to cancer (such as trihalomethanes, or THM's). UV light does not product harmful chemicals in drinking water. It's safe, effective and environmentally friendly.