The process of distillation has been known and used for millennia. Although it has primarily been employed as a method of producing alcoholic beverages like whisky and vodka, distillation also works as a technique of water purification. In the 1970s, distillation was a popular method of home water purification, but its use is now largely confined to science laboratories or printing industries.
The distillation process utilizes a heat source to vaporize water. The object of distillation is to separate pure water molecules from contaminants with a higher boiling point than water. In the distillation process, water is first heated until it reaches its boiling point and begins to evaporate. The temperature is then kept at a constant. The stable temperature ensures continued water vaporization, but prohibits 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, removed from the heat source, the steam condenses back into its original liquid form. Contaminants having a higher boiling point than water remain in the original container. This process removes most minerals, most bacteria and viruses, and any chemicals that have a higher boiling point than water from drinking water. For this reason, distillation is sometimes valued as a method of obtaining pure drinking water.
Pros and Cons:
Distillation, similarly to reverse osmosis, provides mineral-free water to be used in science laboratories or for printing purposes, as both functions require mineral-free water. It removes heavy metal materials like lead, arsenic, and mercury from water and hardening agents like calcium and phosphorous. Distillation 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.
Distillation has several qualities that make it undesirable for the purification of municipally treated water, especially when compared to the decontamination capacities of water filters. Although distillation processes remove mineral and bacterial drinking water contaminants, they do not remove chlorine, chlorine byproducts, or VOCs. These chemicals, which have a lower boiling point than water, are the major contaminants of municipally treated water. Most dangerous metals and bacteria are removed from water prior to its arrival at a home’s plumbing system. Thus, a distillation system, targeted at the removal of these contaminants, is unnecessary and irrelevant for most people.
Distillation, like reverse osmosis, 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.
Furthermore, distillation is an incredibly wasteful process. Typically, 80% of the water is discarded with the contaminants, leaving only one gallon of purified water for every five gallons treated.