Electrolysed water

Creation

The electrolysis occurs in a vessel with separation of the cathodic and anodic solutions.

At the cathode, hydrogen gas and hydroxide ions are produced, leading to an alkaline solution that consists essentially of sodium hydroxide.

At the anode, chloride ions can be oxidized to elemental chlorine, which is present in acidic solution and can be corrosive to metals. If the solution near the anode is acidic then it will contain elemental chlorine.

The key to delivering a powerful sanitizing agent is to form hypochlorous acid without elemental chlorine. This occurs at around neutral pH . Hypochlorous is a weak acid and an oxidizing agent. This "acidic electrolyzed water" can be raised in pH by mixing in the desired amount of hydroxide ion solution from the cathode compartment, yielding a solution of Hypochlorous acid (HOCl) and sodium hydroxide (NaOH). A solution at pH 7.3 will contain equal concentrations of hypochlorous acid and hypochlorite ion; reducing the pH will shift the balance toward the hypochlorous acid. At a pH between 5.5 and 6.0 approximately 90% of the ions are in the form of hypochlorous acid.

Proposed use as a disinfectant

Both sodium hydroxide and hypochlorous acid can be disinfecting agents; The key to effective sanitation is to have a high proportion of hypochlorous acid present, this happens between acidic and neutral pH conditions.

Under some controlled circumstances, EOW can kill bacteria and inactivate viruses.

The disinfectant claims of EOW are based on a formulation containing a mixed oxidant with a corrosive pH of 2.53.

EPA registration

Although the field of electro-chemical activation (ECA) technology has existed for more than 40 years, companies producing such solutions have only recently approached the U.S. Environmental Protection Agency (EPA) seeking registration. Recently, a number of companies that manufacture electrolytic devices have sought and received EPA registration as a disinfectant.

Drawbacks and Risks

Electrolyzed alkaline water loses its potency quickly and cannot be stored for long. Electrolysis machines can be, but are not necessarily. expensive to purchase and operate. The electrolysis process needs to be monitored and measured to obtain the correct potency.

Hypochlorous acid, hypochlorite ions, and free chlorine can all react with benign contaminants in tap water to create undesired and harmful byproducts. See Disinfection by-products for more information.

References

References

1. (2009). "Inherently Safer Water Purification". Chemical & Engineering News.
2. Huang, Yu-Ru. (April 2008). ["Application of electrolyzed water in the food industry"](http://ntur.lib.ntu.edu.tw/bitstream/246246/190091/1/12.pdf }}<!--). Food Control.
3. [doi: 10.13031/2013.19980]
4. (2001). "New Disinfection and Sterilization Methods". Emerging Infectious Diseases.