Page "Water purification" Paragraph 68

# Distillation involves boiling the water to produce water vapour.

The vapour contacts a cool surface where it condenses as a liquid.

Because the solutes are not normally vaporised, they remain in the boiling solution.

Even distillation does not completely purify water, because of contaminants with similar boiling points and droplets of unvapourised liquid carried with the steam.

However, 99. 9 % pure water can be obtained by distillation.