Purified Water

Industrial, biological, and pharmaceutical applications require high purity of water in their processes. Although purification can be done by different process, distillation and deionization remain the most popular. Both involve removal of mineral ions like sodium, iron, calcium, copper, bromide, and chloride, although the processes are different.

Deionization, also known as demineralization, uses ion exchange resins that bind and filter mineral salts from water. This process prevents scale buildup because majority of impurities removed are dissolved salts. Deionization however does not remove uncharged organic molecules, viruses, or bacteria unless when trapped in the resin by chance.

On the other hand, distillation involves boiling the water and subsequently condensing the steam. Water is demineralized but microorganisms are eliminated as well. Distilled water has an electrical conductivity of not more than 10 µS/cm and total dissolved solids of more than 10mg/liter.

Applications:

• Laboratory experiments
• Top up lead-acid batteries for cars and trucks.
• Automotive cooling systems
• Carwash and house cleaner
• Fresh water and marine aquariums
• Water-fog fire-extinguishing systems for sensitive environments
• Cosmetic component
• Drug ingredient
• High voltage dielectric for pulsed power applications

References:

http://en.wikipedia.org/wiki/Double_distilled_water

http://www.ehow.com/about_5420891_deionized-vs-distilled-water.html