water treatment by means of oxigen

[Henderik]

Hi,
Somebody is offering to sell to me a new technique of water treatment. This technique is based on the activation of oxigen in poolwater by means of diamond electrodes (not real diamonds but industrial produced diamonds which contrary to real ones are conducting). Contrary to the classical "salt desinfection" the medium used is oxigen. For those of you who speak either German or Italian you can visit the website w ww DOT bio[space]fer men ta DOT c om

On paper the system sound good, but unfortunately I will be the guinea pig.

If somebody has any experience with such a system, I would be gratefull for his comments.

Thxs

[PoolDoc]

Please note poster's location (Austria); do not post replies appropriate only to N. America.

Hi Henderik;

I don't know anything about that particular system, but I can tell you two rules that I've learned the hard way -- by bad experiences -- and seen others do the same:

1. Being a guinea pig for a manufacturer's new product rarely works out as well as you hope, and is often a disaster. When I was young and naive, "New and Improved" sounded good, and "Revolutionary new technology" sounded great. Now that I'm old and experienced, "New and improved" translates, in my mind, to "Our marketing department has found a new way to sell less for more", and "Revolutionary new technology" translates to "We have no idea if this will work in the field, but we'd like YOU to pay to test it for us."

2. After 25+ years in the pool industry, I have seen many, many products that promised to do something good to the pool water by adding "oxygen". Without exception, all of the products were failures, and most were frauds. The only term I've seen more consistently associated with fraud (other than "oxygen") is "magnets".
Stay far, far away from ANY pool product that is going to add "oxygen" to your water or use "magnets".

Ozone -- O3 instead of O2 -- is a different case.

However, I did look at the link you provide, and I didn't see anything that looked like an "oxygen generator" using "diamond electrodes". Can you identify the exact page link, for the product you are speaking about?

[Henderik]

HaHa!
thanks. The website is ww w DOT bio fer[space]men ta DOT com
Unfortunately it is in german or italian.
regards

[PoolDoc]

I found the site; I just couldn't find the page that described the system you wrote about.

[chem geek]

Even after translation, I too could not find anything about diamond electrodes and oxygen generation on the site you linked. However, there is such a thing as boron-doped diamond electrodes (see this list (http://scholar.google.com/scholar?q=boron-doped+diamond&hl=en&as_sdt=0&as_vis=1&oi=scholart) of papers on the topic) that through electrolysis mostly produce oxygen gas, but also produce a relatively high concentration of hydroxyl radicals that are indeed very powerful oxidizers, stronger than ozone and very short-lived. The Oxineo® product from Adamant Technologies (http://www.adamantec.com/en/products/systems/oxineor) is an example, but this technology is expensive so is typically only used in water treatment and in some commercial/public pools. A similar system might also be used in the Ace® Salt Water Sanitizing System (http://www.hotspring.com/hot-tub-accessories/hot-tub-water-care/ace-salt-water-sanitizing-system) for spas though that is not as clear (they do not refer to boron-doping of their diamond electrodes). Because the system is electrolysis, one also gets other sanitizers such as chlorine or bromine depending on the salt levels of chloride and bromide, respectively. The hydroxyl radicals can combine to form hydrogen peroxide (which would react with chlorine to reduce it) and can form MPS if there are sulfates in the water and can form some ozone as well.

The most important thing to understand with these "active oxygen" systems, even when legitimate as with boron-doped diamond (BDD) electrodes or with ozonators, is that they do not leave a substantial residual of disinfectant in the water. So you still need to use a bulk-water disinfectant such as chlorine in order to kill pathogens that stay stuck to pool surfaces and never make it through the circulation system and also to kill pathogens to prevent person-to-person transmission of disease (especially in commercial/public pools where one sick person can infect dozens or hundreds of others). Since chlorine is also a decent oxidizer and since residential pools typically have low bather-load (so low oxidizer demand), there is little need for such supplemental oxidation systems. This is especially true in outdoor residential pools where sunlight breaks down chlorine to produce ... wait for it ... hydroxyl radicals (HOCl + hν --> OH• + Cl•)! Indoor pools not exposed to sunlight can often require supplemental oxidation or a UV system to control chloramines.

So while not bogus, a boron-doped diamond electrode system would be an expensive add-on with relatively small incremental value in an outdoor residential pool. In a high bather-load commercial/public pool or with some indoor residential pools and possibly residential spas, it is more useful, though still expensive. If you want automated production of chlorine, then get a saltwater chlorine generator.

[PoolDoc]

Thanks for the interesting and useful post, Richard.

Unfortunately, it turns out Henderik is apparently a shill for the company, and is trying to improve their Internet ranking. Found the SEO traffic trying to verify this post in my logs tonight!

Otherwise, this all goes down as yet ANOTHER case supporting the general rule that, "If they are trying to sell "oxygen" for your pool, they are trying to rip you off!