Here we have a brief discussion of water purification technology. There are many methods of water purification now being used and improvements are being made all of the time.
Let’s start with distillation, as it is the oldest of the methods of water purification, used for thousands of years. Heat is used to boil a liquid to the point of vaporization. The vapors are transferred through a tube (typically made of copper) into another vessel, where it cools and returns to the liquid state. Left behind in the first pot are minerals and contaminants. Not all can be removed in this fashion. It all depends on the boiling point of the infiltrate.
Another of the many methods of water purification involves the use of carbon filters. The liquid passes by a carbon block, or through carbon crystals, which trap contaminants such as the chemical chlorine. This is not new water purification technology. The idea has been around since World War I, when masks containing activated carbon were used to prevent exposure to chlorine gas, an early chemical weapons.
The water purification technology used by your local treatment facility may be old or new, advanced or low tech, but most of them make use of a reverse osmosis step. Pressurized liquids are forced through an assortment of porous membranes, which remove minerals, metals and many visible contaminants.
Unfortunately, this is one of the methods of water purification that does not remove chemicals, so it must be followed by a carbon step. Bacteria would not be removed either, so it must be followed by a disinfecting step. In other words, it does not, by any means, provide complete safety.
Electo-deionization is a relatively new addition to water purification technology. This is one of the methods of water purification technology that works well because it can trap tiny synthetic particles and chemicals. Pre-filtration is necessary to remove large particulates, however.
Ultra violet radiation is one of the very cost effective methods of water purification. Low pressure mercury lamps which produce around 254MM of UV light sanitize or disinfect, killing germs and bacteria, without the introduction of additional chemicals. Of course, it is not a complete water purification technology, many additional phases are required. It is being used in some areas of the world as an alternative to chemical disinfection. The only problem is that it is used at the source or treatment facility. During transportation from the facility to the home, bacteria, germs and other biological organisms could again contaminate the water.
There are many other methods of water purification. Public utilities have an assortment to choose from. They may use wire mesh to remove large debris, sand or clay to filter tiny impurities or additional steps that target specific public health threats.
What you should take away from all of this is that numerous steps are required to insure that tap water is safe to drink. A good point of use or “home” filter completes the process. Water purification technology has advanced to the point that we can count on complete safety. We just have to take advantage of available technologies.