How do you mix ozone into water?

Frequently Asked Question 19
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Question:

I would like to know how to mix Ozone into water - I need the easiest and best way. Thank you.

Answer:

=== There are number of different ways how to mix ozone (gas) into water (liquid). The difference between these different mixing processes is mainly reflected in :

the simplicity -> cost
effectiveness

In general, the most simple mixing processes tend to be the cheapest.

Please, keep in your mind that following list represents only a quick "crosscut" of the field which deals with mixing of gasses to liquids:

Diffusing ozone via air stone or any other porous material (aquariums)
Using a special design chamber filled with ozone gas where water is cascading over multiple layers of fill with high surface:volume ratio - imitating waterfall with stones.
using injector (ventury) - a special design "T" in witch water rushing trough the straight part of the "T" creates a suction in the 3rd port trough ozone is introduced. Mixing process utilizing injector is far more effective then A & B, however additional pump is usually used to deliver the energy for water flow and pressure needed for correct operation of injector. Needless to say, injectors are produced from different materials in different sizes. The smallest I have seen was 1/2" with orifice 1/16", the largest one was over 4".....

In order to further increase effectiveness of mixing process delivered by injectors many installations call for additional installation of:

in-line mixers which further break (mix) ozone bubbles already introduced to water. These in-line mixers are produced in a huge variety and it would be very difficult to describe most of them.
in-line "ozone mixing chambers" which in most cases have multiple chambers. Total volume of these chambers is usually calculated from a water flow, ozone mixing and desired time exposure. To my knowledge, vast majority of "ozone mixing chambers" also act as off-gas chambers. In other words, un-dissolved ozone is separated in the ozone mixing chamber from water and released for further use or its destruction (in ozone destructor) trough some form of off-gasing valve.

I would like to also point out one more aspect of water ozonation which is closely related to materials used to construct the ozone generator and ozonation system.

With the technological progress namely in the development and the production of new materials the family of so called ozone resistant materials is slowly, but steadily growing.

Before I will list ozone resistant materials I know about, we should try to understand what is the real meaning of the term "ozone resistant".

From my practical experience with ozone I can honestly say that most people active in ozone field would provide you with different definition of this term. Most definitions will be rather confusing and there is almost 100% guarantee that what ever definition I will present you with, this definition will be challenged as soon as I will make this answer public.

As far as I see it, the problem with the definition of what is and what is not ozone resistant should be seen in the context of the application for which particular materials are used for.

Following is a very simple overview of different applications and the estimated range of concentrations of ozone gas used for these applications:

Application
Description Estimated ozone
ppm Concentration µg/ml
[gamma] Range % - Volume

Air Treatment 0 - 0.1 N/A N/A

Water Treatment residential
& light commercial 0 - 28,000 0 - 40 < 2% (*)

Ozone Therapies 0 - 63,000 0 - 90 < 5%

Water Treatment commercial 0 - 210,000 0 - 300 <15%

Special Applications 0 - ??? 0 - ??? 0 - ???

(*) to my knowledge there are very sophisticated systems in operation which reach ozone concentrations as high as 25%, however vast majority of applications (including commercial applications) operate in ozone concentration range 0 - 2%

As you can see the differences between applications are huge and huge will be also the differences in requirements for the ozone resistance of materials used to construct ozone generator, tubing connections, mixing chambers for water treatment on so on.

In order to reach some reasonable conclusion I started to divide ozone resistant materials into three groups:

Materials with fair resistivity to ozone which can be used for applications dealing with concentrations as high as 40gamma - Stainless steel, Neoprene, EPDM, Karlez,
Materials with good resistivity to ozone in concentrations up to 90 gamma - silicone, LDPE, Viton^® , Kynar (also known as PVDF)
Materials with theoretically unlimited resistivity to any ozone concentration - Teflon, glass

=== I hope this helps...

=== The OzoneLab™ Team

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