Water ionizer
A ‘water ionizer' is a device that decomposes water by electrolysis to produce an alkaline or acidic solution. In order for this to happen, the water supplied to the device must contain a dissolved metallic salt of some kind, since pure water does not conduct electricity and its ionic content and pH cannot be altered. Some well waters may have sufficient salt content to allow electrolysis; otherwise, the water can be rendered conductive by adding some ordinary table salt (sodium chloride, NaCl.)
Electrolysis of a dilute sodium chloride solution liberates hydrogen gas and hydroxide ions at the cathode, producing an alkaline solution that consists essentially of sodium hydroxide NaOH which can be drawn off as “alkaline water”. At the anode, chloride ions are oxidized to elemental chlorine. If some of this chlorine is allowed to combine with some of the hydroxide ions produced at the cathode, it disproportionates into hypochlorous acid HOCl, a weak acid and an oxidizing agent. Some ionizer devices allow the user to draw off this solution for use as a disinfecting agent. In many cases the two streams can be combined to form a mixture consisting of both HOCl and sodium hypochlorite (equivalent to diluted ordinary laundry bleach), depending on the pH desired.
These devices were originally developed in Japan and are now being widely promoted to the North American alternative health market, primarily as a means of generating “alkaline water” which is claimed to help balance body pH by compensating for the preponderance of acidic foods in most diets. It must be noted that no reference to this need can be found in any standard textbook on nutritional biochemistry or physiology. Some vendors claim that “ionized water” has useful antioxidant properties (despite the fact that hypochlorous acid and hypochlorite ions are oxidizing agents), or that the resulting water is “clustered” into smaller aggregates, thereby promoting improved “cellular hydration”. At the time of this writing (2007), there is no clinical evidence in the reputable scientific literature that would support any of these claims.
See also
External links
- http://www.chem1.com/CQ/ionbunk.html A chemist's view of "ionized" and alkaline water