Photocatalytic Oxidation; PCO, Hydroxyl Radicals, Reactive Oxygen
o3ozone.com carries both corona discharge and UV ultraviolet ozone generators.
Some companies are selling UV units with
which do not produce large quantities of ozone - using Photocatalytic
Oxidation "PCO" air purification in place of an ozone treatment.
Some companies are also selling UV units with ozone producing bulbs but are
highlighting "PCO tecnology" therefore hiding the actual ozone amount produced
to make it harder to compare products and for marketing.
It is claimed that Hydroxyl Radicals or Reactive Oxygen Species (ROS)
will travel throughout a building like ozone, however, the life span of these
While Hydroxyl Radicals or ROS are real and more reactive than ozone, because their life span is similar to
an ion, (and ROS is produced as an ION and measured on particles), which is only
a few seconds, they do not have the ability to travel throughout a room or kill
germs on surfaces. It is true that Hydroxyl Radicals kill germs similar to
ozone's ability and are even more reactive than ozone, but because of their
extremely short life span, will not travel throughout a room or building killing
germs on surfaces.
Hydroxyl Radicals are best used in air purifiers which move a lot of air through
the machine with UV Sterilizer tubes surrounded with Titanium Dioxide coating on
plates or surfaces inside the air purifier to increase the Hydroxyl Radical
production already present. Our UV ozone generators produce and abundance
of PCO Hydroxyl Radicals (Hydro Peroxides, Passive Negative Ions, Super Oxide
Ions, Hydroxides) though are mostly useless for shock treating for mold or
bacteria on surfaces because of their reactiveness (very short life
span....seconds). On the other hand, ozone has a half life span of a full
30 minutes, meaning if we put an amount of ozone into a room under normal room
temperatures, in 30 minutes the amount of ozone is cut in half. This means
that ozone will have a minimum of an hour to build up concentration and also
gives it adequate time to travel throughout the treatment area shock treating
and fully decontaminating surfaces effectively.
UV tubes and tio2 (titanium dioxide) are used to create
UV Photocatalytic Oxidation; or Photocatalytic Oxidation "PCO"
which produces Hydroxyl Radicals and or Hydro Peroxides, Passive Negative Ions, Super Oxide Ions,
Hydroxides, Reactive Oxygen Species (ROS) see:
(usually referred to in the body as a medical term where), and Ozonide Ions. (some of the terms used to describe this process are
redundant, taken out of context, or have been re-worded
to make it sound
Hydroxyl Radicals or ROS / ions are claimed to work better than ozone, but these
ions last only a few seconds - because they are so reactive. While Hydroxyl
Radicals are suited for certain applications, where the application is in very close
proximity - or in the machine producing of the Hydroxyl Radicals or ROS, Hydroxyl Radicals will
not be suited for
shock treatments or germ killing action in a room or building. They are really
only for air purifying in a small area or a filter system where air exchange will be
relied upon. The air passing through the unit or in very close proximity will be
treated. Because of the short life of Hydroxyl Radicals , these machines are not
shock treating or removing odors permanently except for the air passing through the machine.
In a 20'x25' sized room, Photocatalytic Oxidation, or, PCO can be effective air
purification if the purifier has a large airflow and enough UV tubes (two 8-12"
UV Sterilizer tubes recommended in a purifier @ 220 CFM) with the Tio2 coating
in the light chamber. Still, this is not recommended for someone with
asthma or other lung conditions. University of Colorado at Boulder
Catalysis Research on Photocatalytic Oxidation states:
"PCO is well suited for modular systems and is effective on a small scale. These
reactions take place on a semiconductor catalyst (usually TiO2) with near-UV
light (<380 nm). Photocatalytic oxidation is a low-energy way to reduce low
concentrations of pollutants in air"
|Some companies have taken the analogies or
applications vs. Hydroxyl radical applications out of context, much in the
same way some politicians often do (for their own benefit)
or widespread complete germ and mold killing action, high ozone levels must be achieved.
These systems, using the Hydroxyl Radical process, (or other trademarked processes using
Hydroxyl Radicals ), will not produce sufficient gases for
shock treatment results alone. The only part of this process that will "travel through the
house" is the ozone production, which is a very small amount in a UV
sterilizer air purifier.
If you are looking into a PCO machine for mold
or surface decontamination, you probably wont find ozone output specifications
(as some of these are using ozone producing tubes combining PCO technology as it
will be the ozone that travels to surfaces to do the decontamination/
Ozone monitors are thrown off by the presence of these ions making it more
difficult to get a valid reading.
"Reactive oxygen species
Reactive oxygen species or ROSs are species such as superoxide,
hydrogen peroxide, and
hydroxyl radical and are associated with cell damage. ROSs form as a
natural byproduct of the normal metabolism of
oxygen and have important roles in cell signaling."
Note that UV ozone generators are
not simply UV sterilizers, but high output UV ozone generators.
There is a big difference in the
two types of UV bulbs used - often they are confused.
The bulbs included in our
UV ultraviolet ozone
generators produce high levels of ozone
for Shock treatments.
With these ozone producing bulbs, ozone air purification of a room can usually be
obtained in a just few minutes of use. Longer treatment times will result in high
levels of ozone for
use - these high levels are for germ and mold killing treatments and should be done
while no one is in the room.
also offers UV sterilizer bulbs that are interchangeable with the UV ozone
producing bulbs of our UV Ultraviolet Ozone Generators for those wanting small room
occupied air purification without high output ozone production.
UV ozone generation is superior to corona
discharge ozone generation for any ozone air delivery use including shock
treatments because of stable
high outputs and reduced cleaning/ maintenance.
UV Ozone Generators:
UV PRO 550
UV PRO 1100 Ozone Generator
UV PRO 2800
UV PRO 4000
UV PRO 6800 Ozone Generator