What is ozone?
Ozone is a molecule that consists of three oxygen atoms (O3),with
a delta negative and a delta positive electric charge. The ozone molecule is
very unstable and has a short half-life. Therefore, it will decay after some
time into its original form: oxygen (O2, according reaction
presented below) 2O3 3O2
In essence ozone is nothing more than oxygen (O2), with an
extra oxygen atom, formed by an electric high charge an extra oxygen atom.
In nature ozone is produced by some chemical reactions. The most familiar
example is of course the ozone layer, where ozone is produced from the sun's
ultra-violet (UV) rays. But ozone is also produced at thunderstorms and
waterfalls. The extreme high voltages attended with thunderstorms produce
ozone from oxygen. The special fresh, clean, spring rain smell is a result
from nature-produced ozone. Ozone derives from the Greek word ozein, which
means to smell. Ozone is only produced under extreme circumstances. This can
also be created by ozone generators. Ozone generators produce ozone with
extreme high voltages or with UV-light.
How does ozone work?
Ozone operates according the principle of oxidation. When the static loaded
ozone molecule (O3) contacts with something oxidation able, the
charge of the ozone molecule will directly flow over. This is because ozone
is very instable and likes to turn back in its original form (O2).
Ozone can oxidize with all kinds of materials, but also Odour and
microorganisms like viruses, moulds and bacteria. The extra oxygen atom
releases from the ozone molecule and binds with the other material.
Eventually remains only the pure and stable oxygen molecule.
How is ozone produced?
Ozone can be produced artificially according the same principle as it
occurs in nature, which means by UV light (ozone layer) or via
corona-discharge (high voltages, thunderstorm). In both methods the
connection between the oxygen molecules is broken up. Consequently oxygen
radicals are produced, which connect with the oxygen molecule to O3
(ozone). For the production of ozone, corona discharge is used more because
of the greater advantages of this method. Advantages are the lower costs for
ozone production (more cost-efficient) and the greater durability of the
system. For the feed inlet ambient air can be used as well as pure oxygen.
For pure oxygen, oxygen generators can be used to concentrate oxygen out of
air. When pure oxygen is used a higher concentration of ozone can be
produced.
Is Ozone harmful?
At higher concentrations ozone is harmful for human health after
inhalation. Several agencies, such as the occupational safety and health
agency (OSHA) have proposed MAC-values for ozone. The MAC-value is the
Maximum Acceptable Concentration a human is allowed to be exposed to for a
certain time and certain agent. For ozone the MAC-values is 0.06 PPM for 8
hours a day, 5 days a week (PPM = Parts Per Million). For a maximum of 15
minutes a MAC-value of 0.3 PPM is applied. The concentrations mentioned
above are much higher than the odour threshold at which ozone can be
smelled, so critical concentrations will be noticed quickly.
What are the effects when people are exposed to high ozone
concentrations?
When people are exposed to high ozone concentrations the symptoms can vary
from dryness in the mouth and throat, coughing, headache and chest
restriction. Nearby the lethal limits, more acute problems will follow. When
larger ozone generators are applied, ozone destructors can be used for the
destruction of residual ozone.
Is ozone a new technology?
Ozone has been around as long as oxygen, sunshine and lightning. It was
discovered and isolated in 1840 by C. F. Schonbeinwho noticed a unique odour
during electrical sparking and electrolysis experiments. He realized that
the odour was the same one he observed after a lightning flash. In 1886 de
Meritens of France conducted the first experiments using this unique gas as
a disinfectant. He proved that even minute amounts of ozonised air would
sterilize polluted water. A few years later in 1891, the German scientist
Frolich reported the bactericidal properties of ozone from pilot plant tests
conducted at a drinking water treatment plant in Martinkenfeld, Germany. In
1893, the first drinking water treatment plant to employ ozone was built in
Oudshoorn in the Netherlands. In 1906, the first large-scale water treatment
facility built specifically to use ozone as a disinfectant was completed. By
1977, there were 1039 ozone drinking water treatment plants in Europe. Today
there are more than 2000 water treatment plants worldwide using ozone. Ozone
has been used in swimming pools and spas in France, Germany, Netherlands,
and other European countries since the early 1950's and in the United States
since about 1975.
