With no other equipment, nearly pure water, free of minerals such as sodium and nitrate, can be produced from a properly designed and operated distillation unit. It would be a good alternative for removing nitrate, fluoride, selenium and some other pollutants. However, distilled water has a very flat taste because of its lack of minerals. Many people do not care for this taste. The principle for operation of a still is simple.
Water is heated to boiling in an enclosed container.
As the water evaporates, the impurities are left behind in the boiling chamber. The steam is conducted to a cooled area in the still where it condenses back to a liquid. In operation, distillation is not so precise. Minute amounts of mineral, dissolved gases and some organic contaminants typically are carried with the steam into the treated water. Well-designed stills use a variety of methods to overcome these problems.