Water treatment is a procedure that aims to alter the natural behaviour and chemical composition of water supplies to become safe for human use and consumption. Water purification technology has changed much in the past 50 years as people discover more threats and contaminants in the systems. New devices now incorporate state-of-the-art mechanisms for safer and pure water.
Filtration is the most common water purification technology that can control several types and amounts of contaminants in drinking water. It is defined as separating substances or particles through a filter matrix by random adsorption or entrapment. Desired matter is allowed to pass through one or more filters while unwanted contaminants and materials are retained on the opposite side.
Filtration is categorized into 5 types according to the type of material or substance that can be retained by the process. Particle filtration involves anything from a coarse sand filter having a pore size greater than 1,000 microns to a cartridge filter having a pore size of 1 micron or more. Human hair has a diameter of about 100 microns while the naked eye can only view particles having a diameter of about 30 microns.
Microfiltration or sub-micron filtration involves filter devices having a pore size anywhere from just below 1 micron up to 0.05 micron. Bacteria can effectively be removed from water since these have a diameter of about 0.2 to 30 microns. Beer is cold sterilized in the same way. Ultrafiltration involves a molecular sieve or membrane filter that removes molecules from water having a diameter greater than 0.003 micron. Particles that can be removed include viruses, pyrogens, R-Nase, D-Nase and endotoxins.
Nanofiltration reduces the gap between reverse osmosis and ultrafiltration having a pore size of 0.001 to 0.01 micron. It is not commonly used in water purification technology. Reverse osmosis is included in the filtration methods of water purification using membrane filters with a pore size below 0.001 micron. The process can separate individual ions from solutions.
Other Methods of Water Purification
There are 4 more methods aside from filtration namely adsorption by activated carbon, ultraviolet radiation, distillation and deionization. Adsorption by activated carbon involves attracting impurities like chlorine and organic compounds to activated carbon filters. The impurities cling and are retained allowing clean water to pass through. Ultraviolet radiation involves the use of UV radiation at different wavelengths at known concentrations to sterilize the present microorganisms or reduce the amount of organic carbon compounds into less harmful materials.
Distillation is the oldest water purification technology that renders laboratory grade purified water. It involves heating water to boiling temperature then condensing and collecting the vapor. Only pure water vaporizes in theory but some contaminants having a boiling point close to 100 degrees Celsius can also vaporize and be included in purified water. Deionization or ion exchange involves letting water pass through resin beds having an affinity for ionized salts that are dissolved. Cationic and anionic resins when combined in a single container perform so many positive and negative ion exchanges resulting to pure water.
Some of these technologies can already be used in the home via manufactured devices. It is better if you understand and know the present contaminants in your water source to find the right product that eliminates it while preserving the natural beneficial minerals for optimum health and wellness.