There are different types of water and each type is used in a specific way. Most homes use plain water that has undergone a considerable level of purification. However, this is not used by many companies because plain water still contains some impurities only removed through a more thorough process of demineralization. Indeed, plain water contains some metallic minerals and carbonates and chlorides. The only way to remove these is through deionization.
Water that has undergone ultra-filtration and deionization is what most chemical companies and laboratories need. But the applications can be very extensive.
1. Chemical analyses – Chemical analysts and scientists cannot use just any kind of water when observing chemical reactions taking place under controlled conditions. For instance, determining solute concentrations always commands accuracy in measurement. The same thing is needed during measurements of chemical contents of substances. For instance, identification of the composition of a mixture could mean diluting it in pure water. Ordinary water has minerals and ions that may alter the precision of the result. This is why DI water is used in chemical labs.
2. Microbiology/Tissue culture/Specimen preparations – Biological laboratories are concerned about sanitation and all equipment and apparatuses should be in their pristine, spot-free condition upon usage. Moreover, the medium should be free from bacteria and viruses and other chemically altering agents. Thus, water used in any biological experiments must be clean, ion-free, and microbe-free. This type of water is only achieved through ultra-purification that involves deionization/demineralization.
3. Rinsing of laboratory instruments – Whether laboratory instruments are used in hospitals, medical facilities, or science labs, they should be rinsed in DI water because ordinary water leaves stains on the surfaces of these objects. Ion deposits on beakers and flasks, for instance, could lead to ugly stains later on. Such stains could affect the chemical nature of whatever is placed in the laboratory apparatus. Hence, any glassware, such as pipette, burette, graduated cylinder, test tube, flasks, and beakers, should be washed or rinsed in pure water. In hospitals, the sterilization of instruments is done through autoclaving, which use DI pure water to avoid stain deposition on surfaces of instruments and on the inner walls of the autoclave machine.
4. Carwash/Glass window cleaning – People do not realize that even something as typical as washing cars and window panes make use of demineralized water. Just as mentioned earlier, ordinary water leaves a mess of spots upon drying, and this is not a good scene, as it destroys the aesthetics of windows and doors made of glass. Cars would look dull with all those stains left by tap water. This is why carwash shops use DI water during the final rinsing.
5. Pharmaceuticals and cosmetics – Imagine if the water used in medicine syrups or perfumes is ordinary tap water. Now, that is outrageous. Pharmaceutical and cosmetic companies cannot sacrifice the value of their products with the use of ordinary tap water. In most cases, water that is not pure enough could affect the chemical composition or chemical mixture of the drug or cosmetic preparation. Ions present in plain water could affect the chemistry of a product by reacting with other ingredients.
6. Vehicle batteries – Could you actually believe that even car batteries should use pure water. They actually call it battery or vehicle water which is an extremely pure water very similar to DI water. Wet cells rely on ionic integrity and tap water could only ruin the ionic/electrolyte balance inside the cells. This could affect battery life span. Hence, manufacturers recommend that only pure/DI or distilled water must be added to car batteries.
The known application of DI water is extensive. Though it may be impractical to use it at home, considering its cost, it is basically an important feature in a wide array of industries.