Ozone
is generated naturally by short-wave solar
ultraviolet radiation, and appears in our upper
atmosphere (ozonosphere) in the form of a
gas. Ozone also may be produced naturally by passing
an electrical discharge - such as lightning -
through oxygen molecules. Lightning is a
perfect example of making an abundance of O3 to
purify the earth's atmosphere Nature's way. Most of
us have noticed the clean, fresh smell in the
outdoor air after a thunderstorm, or the way
clothing smells after it's been dried outside on a
clothesline in the sun.
Oxygen
Molecules
Oxygen, as we know,
has two atoms. High voltage, as from lightning,
breaks these two atoms apart. Quickly, these atoms
hop back together in threes {O3}. Confused, these
atoms do not like this arrangement and
want desperately to dissolve this uncomfortable
trio. So as this O3 molecule floats in the air, when
one of the atoms spots a contaminant molecule to
attach itself to, it breaks away from the other two
atoms. To its surprise, this attachment is actually
an attack on the contaminant and creates a
microscopic explosion. Both the contaminant and the
atom are destroyed. This leaves the other two atoms behind as pure oxygen {O2} without the
presence of the contaminant. The explosion
changes the contaminant into carbon dioxide and
hydrogen, which we can breathe.
Should the O3
molecule not find a contaminant in its environment,
it will attack itself to change its
configuration of O3 back to O2 (normal
oxygen) in 20 to 30 minutes at room temperature and
normal humidity.
Ozone is highly
reactive, so it interacts with most
contaminates and allergens it encounters.
The "lightning
method" of ozone production has been duplicated
commercially by many manufacturers of ozonating air
purifiers and is known as corona discharge.
In this method, 5,000 to 10,000 volts of electricity
is used to split the O2 atoms to produce ozone.
However, in addition to safety concerns and high
operating costs, air purifiers utilizing the corona
discharge method are plagued by unpredictable levels
of ozone production - ozone "blasts" -
and also produce undesirable and unhealthful
byproducts such as nitric oxides. These oxides
actually irritate the respiratory system - not
what you want in an air purifier. So in spite of
claims that these units give you a
"thunderstorm in a box," they have clear
drawbacks.
Short-wave
solar ultraviolet radiation -
ultraviolet
light - is another method used by many air purifier
manufacturers. When ultraviolet light rays collide
with a contaminant such as carbon monoxide (CO) and
nitrogen oxides (NO2 and N2O) in the presence of
oxygen (O2), ozone is produced.
Ozone reacts with
and oxidizes pollutants it encounters, rendering
them harmless, while also removing odors. O3
loses one of its oxygen molecules in this oxidation
process, causing it to revert back to oxygen,
leaving behind pure, fresh air. Ozone can be effective
against chemical sources, bacteria, mold, odors,
etc. Once a pollutant is oxidized by ozone,
it is no longer toxic, allergenic, or odor causing.
As a result, even if an oxidized contaminant remains
in the air and is inhaled, it has no negative
effect. Microorganisms (such as mold spores or
bacteria) that have been exposed to ozone are no
longer able to reproduce, which causes their numbers
to quickly diminish.
Most
ozone air purifiers
use the corona discharge method for creating
ozone, which is not as reliable and
consistent. As a result, there is more of a
likelihood that such a unit will need repair work,
and that it will produce excessive ozone levels,
unlike the Biozone air cleaning system.
How
Else Does Ozone Purify?
Ozone
is also biocidal - which means it kills
harmful biological and bacterial contaminants. This
biocidal action results from its reaction with the
double bonds of fatty acids in bacterial cell walls,
membranes and the protein capsid of viruses. In
bacteria, the oxidation results in a change in cell
permeability and leakage of cell contents into
solution. Ozone attacks these cell walls, breaking
down membranes and ultrastructural components of the
organism. In more simple terms, the unstable
electrons of ozone blast holes through the
membranes. This occurs by cell lysing or rupturing
the cell wall of viruses, bacteria, yeast, and
abnormal tissue cells, thereby destroying them by
inactivation of the microorganism's enzymes. In
viruses, alteration of the protein capsid prevents
the virus from being taken up by susceptible cells.
Ozone
displays an "all or nothing" effort in
terms of destroying bacteria.
It is such a strong germicide that only a few
micrograms per liter are required to demonstrate
germicidal action. Factors like humidity,
temperature, pH, ozone concentration levels, type of
organism and time, determine the kill rate for
pathogens. The action of ozone gas in water is
instantaneous. After oxidation, ozone returns to its
original form of oxygen, with out leaving any toxic
by-products or residues.
Ozone
oxidizes natural organic compounds like acetic and
oxalic acids, as well as synthetic substances like
nitro- and chloro-benzic compounds, detergents,
herbicides and composite pesticides. Ozone oxidizes
inorganics such as iron, manganese, heavy metals,
cyanide, sulfides, and nitrates in water.
Ozone retards the ripening of fruits and vegetables
by destroying ethylene gas and bad odors, which are
produced by aging and decay.
Ozone
is more cost-effective than ethylene filters, which
are costly and have to be replaced each month.
Filters only act on the air that happens to pass
through them, and ionization machines put a negative
charge on air particles in the air which causes them
to gravitate to room surfaces. Unlike ozone,
filters, ionizers and sprays do not eliminate the
cause of odors. Once the cause has been
eliminated, the odor does not come back unless the
source that caused the odor is reintroduced.
