Basic principles of the
ECA water production
The basic principle behind the electrochemical activation of water is electrolysis. Electrolysis is a process where chemical substances are transformed into oxidized and reduced forms by applying voltage and current.
Some of the oxidized substances, mainly hypochlorous acid formed from chloride contained in the water, are in a so-called meta stable state and try to get back to their original form by oxidizing other, for example organic, substances. Thus, the water coming from the anode side has oxidizing and disinfecting properties. This coincides with an increase of the redox potential (ORP) in the water, which can serve as a measuring parameter for the disinfection potential.
In 1972 the World Health Organization (WHO) recognized in its Standards for Drinking Water that, at an ORP level of 650 mV, water is disinfected and viral inactivation is almost instantaneous. Thus we can call electrolyzed water “activated water”, which is able to inactivate germs and viruses.
Membrane cell electrolysis
In a normal electrolysis cell, the products of the anode reaction and cathode reaction are not separated. This can lead to both sides reacting with each other effectively losing the electrolysis effect.
In order to avoid that, in 1835 John Frederic Daniell developed the Membrane Cell Electrolysis, where anode products (also called anolytes) and cathode products (also called catholytes) could be separated.
The membrane cell electrolysis of common salt (NaCl) was developed 1885 by Breuer. It was mainly designed to produce chlorine gas and caustic soda as chemical base materials. The first industrial production started in Frankfurt 1890.
The production of chemical base components is the main application of common salt electrolysis. The so called amalgam process replaced membrane cell electrolysis.
Membrane cell electrolysis and disinfection
By 1822 the pharmacist Antoine Germain Labarraque had discovered that chlorine dissolved in water has a strong disinfecting effect. Later it was found out that the active agent for this effect was hypochlorous acid, which is formed out of chlorine or hypochlorite in the neutral pH area.
In the scope of the space travel programs since 1970, Russian scientists had the idea to develop reactors that could disinfect water with just the addition of a small amount of salt. This was so successful that they developed ECA water plants for other application fields, starting with the drinking water disinfection in the healthcare sector.
The term ECA water was originally formed in Russia. Nevertheless, Japan and the USA were also developing similar systems and materials.
Membrane cell electrolysis in the European Union
After the end of the Soviet Union in 1990, some of the Russian Scientists involved in the ECA plant development founded their own companies and started to commercialize the technology.
This brought the application of ECA water to Western Europe and the EU. As the obvious advantages of the technology (less dangerous than alternatives, cheaper, robust to run, efficient, …) became better known, companies started to market and to establish ECA water plants. The shareholders of the ECA Consortium are part of this progress.
Chemistry of the common salt electrolysis
The first reaction step at the anode side, which is the interesting step because the disinfectant is formed here, is the chloride oxidation to chlorine.
2 CI- > CI2 + 2e-
When the anode is surrounded by a neutral or alkaline aqueous medium, the formed chlorine disproportions immediately into hypochlorous acid and chloride,
CI2 + 2 H2O > HOCI + CI + H3O+ (4.5 < pH < 11)
or into hypochlorite and chloride.
CI2 + 2 Na + 2OH > OCI + CI + 2Na + H2O (pH > 11)
The disproportioning of the chlorine is an acidic reaction (it produces acid or consumes caustic). That happens in neutral or alkaline environment immediately.
If the reaction is performed in acidic environment, a balance is formed which also includes the existence of molecular solved chlorine. Hydrochlorous acid (HCl + H2O = Cl– + H3O+ ) also exists.
CI2 + 2 H2O > < HOCI + CI + H3O+ (pH< 4.5)
Electrolysis of water or a weak brine solution in a cell without membrane
The electrolysis product is highly dependent on the concentration of the added solution.
(The resulting pH shift towards caustic depends on the salt concentration in the added solution).
A variety of materials can be used for the electrodes (anode and cathode). This is where market participants differ. So for further details, please ask the Consortium shareholder company you have contact with.
Common scheme of a common salt membrane cell electrolysis
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