Distilled Water

Distillation is one of mankind's earliest forms of water treatment, and it is still a popular treatment solution throughout the world today. In ancient times, the Greeks used this process on their ships to convert sea water into drinking water. In far-eastern cultures, water was distilled for use in "Ranbiki" tea ceremonies. Today, distilled water is still used to convert sea water to drinking water on ships and in arid parts of the world, and to treat water in other areas that is fouled by natural and unnatural contaminants. Distillation is perhaps the one water treatment technology that most completely reduces the widest range of drinking water contaminants.

Not only is distillation one of the most effective forms of treatment, but it is also one of the easiest to understand: untreated water is converted into water vapor, which is then condensed back into liquid form. Most of the contaminants are left behind in the boiling chamber, with the condensed water being virtually contaminant-free. Anyone who has accidentally let a pot of water boil completely out on the stove is familiar with this process, and familiar with the crust of contaminants typically left behind after the water is gone.

In nature, this basic process is responsible for the hydrologic cycle. The sun causes water to evaporate from surface sources such as lakes, oceans, and streams. The water vapor eventually comes in contact with cooler air, where it re-condenses to form dew or rain. This process can be imitated artificially, and more rapidly than in nature, using alternative sources of heating and cooling.

Early distillation equipment was very simple in design: a pot of undrinkable water (or water unfit for a ceremonial, commercial, or medical purpose) would be heated over an open flame until it boiled, forming steam. The steam would then condense on a cool surface suspended above the pot. The condensed water droplets would then run off into a storage container for future use. Alternatively, sponges could be suspended above the pot to collect the treated water. While such systems were relatively inefficient, it tended to be quite adequate for the limited water treatment needs of the time.

The efficiency of the distillation process began to see improvements as distillation was adapted to commercially refine many different liquids such as alcohol, perfume, petroleum, and various solvents. Finally, population demands have strained water resources in the 20th century to the point where efficiently treating otherwise undrinkable sources of water for human consumption is increasingly important.

Distillation is an effective process for producing highly treated drinking water. Distillation can significantly reduce levels of sediment, metals, and biological contaminants, which are unable to travel out of the boiling chamber with the steam. When combined with effective activated carbon filtration, contaminants like VOC's and radon can also be controlled. It is recommended that only units designed and tested for health-contaminant reduction be used for such purposes. These units, when combined with activated carbon filtration, can be used to effectively treat such contaminants as:

• Arsenic
• Asbestos
• Atracine (Herbicide/pesticides)
• Benzene
• Fluoride
• Lead
• Mercury
• Nitrate
• Trichloroethylene (TCE)
• Trihalomethanes
• Radium
• Radon
• Biological contaminants ( bacteria, viruses, and water-borne cysts like Cryptosporidium)

A distillation system with activated carbon filtration can also be quite effective for treating aesthetic drinking water contaminants like chlorine or iron bacteria, which lead to unpleasant tastes, odors, or colors.