Distillation...A Process for Purifing WaterThe process of distillation has been known and used for millennia. Its use has primarily been employed as a method of producing alcoholic beverages like whisky orvodka, but the process also works as a technique of water purification.  The
process utilizes heat to vaporize water. The
object is to separate pure water molecules from contaminants
with a higher boiling point than water. Water is first heated until it reaches its boiling point and starts to evaporate. The temperature is then kept at a constant to ensures continued water evaporization and stops drinking water contaminants with a higher boiling point from evaporating. Next, the evaporated water is captured and guided through a system of tubes to another container. Finally, the steam cools and condenses back into its original liquid form. Contaminants having a higher boiling point than water remain in the original container. Contaminants Removed From Water by Distilling It Distillation can remove nearly all impurities from water. Compounds removed include:
Removing the organic compounds in water by distilling it can vary depending on chemical properties of the contaminant. They do not remove chlorine, chlorine byproducts, pesticides, volatile solvents, VOCs such as enzene and toluene with boiling points close to or below that of water will vaporize along with the water as it is boiled in the distiller. These compounds will not be completely removed unless another process is used either prior to the water entering the distiller or before condensation. No one piece of treatment equipment manages all contaminants. All treatment methods have limitations and often situations require a combination of treatment processes to effectively treat the water. Pros and Cons: Distillation, similarly to reverse osmosis, will provide mineral-free water to be used in laboratories, for printing purposes, or medical facilities were mineral-free water is needed. It is often used as the preferred water purification method in developing nations, or areas where the risk of waterborne disease is high, due to its unique capabilities to remove bacteria and viruses from drinking water. There are has several qualities that make it undesirable for the purification of municipally treated water. Most synthetic chemicals, including pesticides, herbicides, and chlorine have a lower boiling point than the boiling point of water. Synthetic chemicals are the major contaminants remaining after municipal treatment and distillation does not remove these harmful chemicals. Also it provides mineral-free water that can be quite dangerous to the body’s system when ingested, due to its acidity. Acidic drinking water strips bones and teeth of valuable and essential mineral constituents. A good collidal mineral supplement should be added to any water used for drinking. Lastly, it is an incredibly long and wasteful process. Typically, 80% of the water is discarded with the contaminants, producing only one gallon of purified water for every five gallons treated.  |