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What is
OZONE?
A study on the generation of anion
and ozone by air cleanerWritten by Jang Soon Lim, professor
at the Dept. of Mechanical Engineering, Inha University
The word "Ozone" was originated from a Greek "Ozein"("Smell").
Ozone was discovered by a German "Van Marum" in 1785
about 200 years ago. Its sterilizing effect was discovered
by a French "De Meritenus" in 1886.
Ozone always exists in the air in a small quantity (0.01
to 0.03ppm), and is not any particular matter.Ozone
is readily generated by electric discharge (lightening)
in the air as well as by the photochemical reaction
of ultraviolet with nitrous oxide, methane and hydrocarbon.
Most of ozone naturally generated exists in the atmosphere
20 to 50km above sea level.
The existence of ozone layer has been well known to
us. The recent destruction of this ozone layer has hung
over men as a serious issue. Ozone absorbs ultraviolet
from sun's ray in the stratosphere. So only the visible
ray reaches the ground. However, abusing of Freon gas
and automobile exhaust gas has destructed the ozone
layer to create ozone hole. Ultraviolet reaches the
ground through this ozone hole to cause serious damage.
Ozone is also generated by dry oxygen or radio discharge
in the air. In addition to this, ozone is generated
as accompanied with oxygen when yellow phosphor is slowly
oxidized in the air or when oxygen compounds such as
permanganic acid potassium and dichromic acid potassium
are discomposed to thick sulfuric acid, when water is
discomposed to fluorine and when water is decomposed
in a high current density. Ozone is also generated when
oxygen is heated, when sulfuric acid is decomposed by
electrolysis, or when ultraviolet, X-ray or cathode
ray passes the air.
So high mountain, seashore and forest are abundant in
ozone in the air, So we feel fresh on high mountain,
seashore and forest. However, large quantity of ozone
may offer unpleasant feeling due to its unique smell.
Ozone is considered to be contained in the high atmospheric
layer called "Ozone layer".
Ozone reduces to oxygen. Therefore, it is used in theater,
school and hospital to purify air. Since ozone has a
sterilizing effect, it is used for sterilization of
drinking water, bleaching and restructuring of organic
compound. However, inhalation of thick ozone for an
extended period of time may inflict damage to respiratory
organ. Since ozone dissolves 9 times more than oxygen
does, 45 volume of ozone is dissolved in 100 of water.
Therefore, it is possible to get dissolved oxygen in
a large quantity.
The density of ozone is 0.05ppm in nature, and seasonally
varies.
It is 0.02ppm and 0.07ppm in winter and summer, respectively.
Ozone is naturally generated by electric discharge for
oxygen in the air. Atomic oxygen combines with oxygen
molecule in this reaction.
Since the density of ozone increases by radiant solar
energy, ozone layer exists outside the earth atmosphere.
Ozone has the highest reactivity among molecular oxygen,
and is a powerful oxidizer next to fluorine,
fluoric oxygen and atomic oxygen. Ozone generates pleasant
smell when its density is 2ppm or slightly less. If
the density exceeds this level, it generates stimulative
smell.
Ozone is used to sterilize water and air. It is also
used industrially to remove wax and oil stain and to
compose organic substance. Ozone is generated by discharge
of oxygen.
When ozone is blown into flame and used in the air,
it decompose heavy metals with strong sterilizing and
oxidizing power, kills infectious bacteria in several
minutes then reduces to dissolved oxygen in water.
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Effect
OZONE on human body?
Ozone promptly gives off one
of three oxygen atoms to other matters. Ozone blocks and
absorbs ultraviolet in the stratosphere due to this property.
This absorption ratio is approximately 99%. The harmful
effect that ozone have against human body in the atmosphere
is attributable to this high reactivity. It unconditionally
combines any organic substance on skin to create material
that is harmful or even fatal to human body.
This reactivity has not been understood fully. For example,
it attacks cells of lung to deteriorate function of respiratory
organ. What is more dangerous, it may hurt gene in the
cellular nucleus to cause DNA mutation and to develop
cancer.
Soft tissue such as cornea of the eye is prone to the
attack of ozone.
Ozone is highly toxic. If one is exposed to ozone at 1ppm
8 hours a day, it causes bronchitis, fibrosis in the tissue
of lung and bronchiolitis. If one is exposed to ozone
at 1.25ppm an hour, his/her breathing function deteriorates.
If the concentration of ozone rises, it develops pulmonaryedema
and bleeding and causes trouble in the gas exchange via
the alveolar membrane. The allowed maximum ozone concentration
is 0.1ppm for workers who work 8 hours a day. |
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| Toxicity
of ozone |
| Ozone(ppm) |
Effect on human body |
| 0.01-0.03 |
Smells only |
| 0.1 |
Generates odor stimulative to nose
or throat |
| 0.2 ~ 0.5 |
Eye sight deteriorates after 3 to
6 hour exposure |
| 0.5 |
Evidently stimulates airway and respiratory
organ |
| 1~2 |
Causes headache and phlegm. This
symptom becomes chronic |
| if exposed repeatedly |
| 5~10 |
Causes rapid pulse and pulmonaryedema |
| 15~20 |
Small animal may die within 2 hours |
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| Environmental
safety level of ozone(atmosphere) |
Country |
Korea |
Japan |
USA |
Organization |
Ministry of |
Ministry of Japan
Industrial |
OSHA |
Environment Korea |
OSHA(Occupational
Safety |
(Occupational
Safety |
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Environment Sanitary
Academy |
Health Association) |
|
Health Association) |
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TLV |
0.06(8hour average) |
0.06(8hour average)
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0.1(8hour average) |
0.1(1hour average) |
0.12(1hour average) |
0.3(15-30분) |
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| Environmental
safety level of ozone(atmosphere) |
 |
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Effect
OZONE on human body?
Ozone has strong oxidizing power to oxidize lots of organic
and inorganic compounds. In particular,
it rapidly decomposes nuclei of aromatic compound at ambient
temperature as well as organic olefin.
Ozone is used for bleaching, deodorization, decolorization,
restructuring of organic compound and synthesis of chemicals.
Ozone is an excellent sterilizer and deodorizer of potable
water and air, and largely used in water
purification plants in Korea. If chlorine is added excessively,
a byproduct that is called chloroform (one of trihalomethane)
and known as cancerogenic material generates. However,
ozone does not produce such a harmful byproduct. And ozone
is known to be a powerful oxidizer next to fluorine.
Industrial use of ozone
Application
Potable water treatment Wastewater treatment
Cooling tower Aquarium, fish farm
Swimming pool and pleasure park Natural water dispenser
Drinking beverage factory Material test(Aging of rubber,
color test)
(Bear and juice) Deodorization and odor control
Fresh food storage Health care
Semiconductor production
(CVD, wet processing)
Source of ozone
Source
Electron beam welding Plastic film surface treatment
Duplicator, laser printer Automobile exhaust gas combined
with sun's ray |
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