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CASCADIAN®
Professional Water
Treatment Products |
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O3
Water Systems, Inc.
17700 147th St SE
Suite F
Monroe, WA 98272
USA
Phone:
360-794-9511
Fax: 360-794-0856
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What
is Ozone?
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Ozone is Created Naturally
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Ozone is a naturally occurring gas
created
by the force of corona discharge during lightning storms or by UV light from the Sun.
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Definition of Ozone:
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Ozone (O3) is an allotrope of oxygen (O2). It is 1.5 times
as dense as oxygen and 12.5 times more soluble in water and leaves no residuals or
byproducts except oxygen and a minimal amount of carbon dioxide and water. It can be
manufactured from dry air or from oxygen by passing these gases through an electric field
of high potential sufficient to generate a "corona" discharge between the
electrodes. Ultraviolet light and shorter wavelength radiation also causes oxygen to
undergo conversion to ozone, which may be used for industrial wastewaters (Belew 1969).
Ozone is a more potent germicide than hypochlorite acid by factors of 10 to 100 fold and
disinfect 3125 times faster than chlorine (Nobel 1980). Ozone is highly unstable and
must be generated on site. The measure of an oxidizer and its ability to oxidize organic
and inorganic material is its oxidation potential (measured in volts of electrical
energy). Ozones oxidation potential (-2.07V) is greater than that of hypochlorite
acid (-1.49V) or chlorine (-1.36V), The latter agents being widely used in water treatment
practice.
Oxidation potential indicates the degree of chemical transformation to be expected when
using various oxidants. It gauges the ease with which a substance loses electrons and is
converted to a higher state of oxidation (EPA 1990). Theoretically the substance with the
lower oxidation potential will be oxidized by the substance with the higher oxidation
potential. A substance can only be oxidized by an oxidizer with a higher potential (EPA
1978). The oxidation potentials of common oxidants and disinfectants associated with water
and wastewater treatment are all of a lower oxidation potential than ozone. There is only
one element with a higher oxidation potential than ozone and that is fluorine.
Organic compounds treated with a powerful oxidant as ozone will not always be converted
totally to carbon dioxide and water, especially under abnormal industrial wastewater
conditions.
Therefore, no other commonly employed and less powerful water treatment oxidant (i.e.
chlorine, bromine, chlorine dioxide, etc.), all of which have lower oxidation potentials
than ozone, will oxidize an organic material completely to carbon dioxide and water if
ozone will not.
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Is Ozone Safe?
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Ozone is very
safe - in over 100
years of use, there has never been a fatal accident. While chlorine forms thousands of
extremely toxic by-products, ozone forms virtually none. These and other properties make
OZONE an IDEAL PURIFICATION and DISINFECTING agent. Ozone is generated electrically and
therefore adds no chemicals into the treated water.
Check out the EPA
Guidelines
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About Ozone and What Ozone Can be Used For
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The universal disinfectant
Disinfection by 3-atomic oxygen called OZONE takes place by
rupture of the cell wall - a more efficient method than Chlorine that depends upon
diffusion into the cell protoplasm and inactivation of the enzymes. Ozone level of 0.4 ppm
for 4 minutes has been shown to kill any bacteria, virus, mold and fungus.
When the effectiveness of Ozone as a disinfectant was measured, up to a
certain dosage there was little or no disinfection. At higher levels the sanitizing effect
increased greatly. For complete disinfection there has to be a surplus of residual
Ozone in the solution to assure that every living microorganism has been contacted.
In the area of viruses there is yet to be discovered an
antibiotic that is truly effective. There are indications that DNA viruses such as Herpes
are implicated in human cancers, since they organize the genetic material of the host cell
to produce new viruses. Ozone will inactivate viruses on contact even at very low residual
concentrations. In case of polio only 0.012 ppm removes all viruses in less than 10
seconds.
Mold and mildew are easily controlled by Ozone in air and
in water. Giardia and Cryptosporidium cysts are susceptible to Ozone but not
effected by normal levels of Chlorine. Mold and mildew are easily controlled by Ozone in air and
in water. Giardia and Cryptosporidium cysts are susceptible to Ozone but not
effected by normal levels of Chlorine. |
TASTE & ODOR CONTROL
Most tastes and odors in water supplies come from naturally occurring or
manmade organic material contamination. Bacterial decomposition of humic material imparts
taste to surface water, also the action of algae and actinomycetes give rise to
objectionable tastes. Chlorination of humic material leads to chlorophenols that are far
stronger odor and taste antigonists than the original phenol and the Chlorine. Most of
these odors are removed by treatment with Ozone. Even some sulfur compounds such as
hydrogen sulfide, mercaptans or organic sulfides can be oxidized to Sulfates with Ozone. |
REMOVAL OF HEAVY METALS
Ozone oxidizes the transition metals to their higher oxidation state in
which they usually form less soluble oxides, easy to separate by filtration. e.g. iron is
usually in the ferrous state when it is dissolved in water. With ozone it yields ferric
iron, further oxidized in water to Ferric Hydroxide that is very insoluble and
precipitates out for filtration.
Other metals: Arsenic (in presence of Iron), Cadmium, Chromium, Cobalt,
Copper, Lead, Manganese, Nickel, Zinc - can be treated in a similar way. At Ozone levels
above 4 ppm however, Manganese will form soluble permanganate, showing up as a pink color. |
COLOR REMOVAL
Surface waters are generally colored by natural organic materials such
as humic, fulvic and tannic acids. These compounds result from the decay of vegetative
materials and are generally related to condensation products of phenol like compounds;
they have conjugated carbon/carbon double bonds. When the series of double bonds extend
upwards of twenty, the color absorption shows up in the visible spectrum. Ozone is
attracted to break organic double bonds. As more of these double bonds are eliminated, the
color disappears. Surface water can usually be decolorized when treated with 2 to 4 ppm of
Ozone. |
OZONE vs. CHLORINE
In comparing disinfection efficiency, Ozone is effective 25 x more than
Hypochlorous acid (HOCI), 2,500 x more than Hypochlorite (OCI) and 5,000 x more than
Chloramine (NH2CL). This is measured by comparison of CT constants - the
Concentration & Time needed to kill 99.9% of all microorganisms. Chlorine reacts with
organic materials to form Chlorine containing organics such as Chloroform, Carbon
Tetrachloride, Chloromethane and others, generally known as Trihalomethanes (THMs).
Ozone reacts with Organics to break them down into simpler compounds.
These (e.g. Oxalic Acid) do not readily break down all the way to Carbon Dioxide with just
Ozone, but if subjected to bacterial degradation on activated charcoal, they will be
removed. This water can be later treated with a low level of Chlorine say 0.2 - 0.3 ppm to
maintain sanitation in the distribution system. This way no THMs will be formed. The THMs
have been implicated as carcinogens in the development of Kidney, Bladder and Colon
Cancer. The regulatory authorities are again decreasing the levels of THMs that can be in
Community water systems. At the present time the limit is 0.05 ppm. Based on the
scientific research, the level will be most likely soon lowered to 0.01 ppm.
Ozone does not react significantly with THMs as they are more resistant
to oxidation - it takes a very long time to achieve full oxidation. Some THMs are removed
as a result of physical sparging by the aeration action of the ozone/air mixture. |
ALGAE REMOVAL
Ozonation of a water contaminated with Algae oxidizes
and floats the Algae to the top of the reservoir. The ozone will also oxidize the
metabolic by-products of the Algae and remove the undesirable odor and taste. |
IMPROVED COAGULATION & TURBIDITY REMOVAL
Oxidation of dissolved organic materials by Ozone results in polar and
charged molecules that can react with Polyvalent Aluminum or Calcium to form precipitates.
Treatment of a surface water with up to 0.5 ppm of Ozone results in a decrease in
turbidity, improved settleability and a reduction in the number of particles. Referred to
as pre-ozonation this treatment destabilizes the colloid with a resultant reduction
of the amount of coagulant needed to produce a clear filtrate. |
OZONE REACTIONS TO ORGANICS
Ozone reacts rapidly with most simple aromatic compounds and unsaturated
aliphatics, such as Vinyl Chloride, 1,1-dichloroethylene, trichloroethylene,
p-dichlorobenzene, Benzene, etc. But it reacts slowly with complex aromatics and saturated
aliphatics. Ozone will degrade many organic compounds, such as sugars, phenols, alcohols,
and as it degrades these materials it returns to Oxygen.
Coupling Ozone with Hydrogen Peroxide will cause the formation of
very active Hydroxyl ions which cause a nucleophilic attack on organic compounds. This can
cause displacement of Halogens and other functional groups such as Amines and Sulfides. Coupling Ozone with Hydrogen Peroxide will cause the formation of
very active Hydroxyl ions which cause a nucleophilic attack on organic compounds. This can
cause displacement of Halogens and other functional groups such as Amines and Sulfides. |
OZONE
SOLUBILITY
The solubility of Ozone depends on the temperature of
water and concentration of Ozone in the gas phase.
Table 1: mg/l (ppm) dissolved ozone |
| {O3}gas |
5°C |
10°C |
15°C |
20°C |
| 1.5% |
11.09 |
9.75 |
8.40 |
6.43 |
| 2% |
14.79 |
13.00 |
11.19 |
8.57 |
| 3% |
22.18 |
19.50 |
16.79 |
12.86 |
| If oxidizable
chemicals are present in the water, even more Ozone will dissolve to satisfy the demand.
One limiting factor is the efficient of the mass transfer device used. In case of a pump
and Bubble Diffuser, the water column should be at least 16ft. high. Higher concentrations
of Ozone in water cause more vigorous oxidation of even resistant organic compounds. |
AIR TREATMENT
Ozone reacts rapidly with most odors, oxidizing them to less harmful
elements or all the way to harmless Carbon Dioxide.
More and more of our furnishings and floor coverings are made from
synthetic materials. Under the stagnant air conditions which prevail because of the lack
of ventilation, decomposition products and solvents leach out of these synthetic materials
and fill the indoor space. Much has been said about the "sick building syndrome"
and this usually refers to institutional building. But they have basically the same
problems as the private home. When odors are inhaled, they increase the demand for oxygen
in the human body thus depleting the body of oxygen.
Ozone in natural settings is around 0.02 ppm, but it can be as high as
0.10 ppm. At this level it is capable of keeping pathogens in check and yet at this level
ozone is not harmful to higher life forms such as fish, birds, animals or man. Ozone is
not causing harm to the nature. Only a prolonged exposure to very unnatural high levels of
ozone may lead to discomfort, later headache and coughing, telling you to leave the space
and seek better air. |
ECONOMIES
Ozone is effective against a large variety of water
treatment problems. In general, the more problems in the water to be treated with ozone,
the less an ozonation system costs when compared to other more conventional treatment
methods. When one is comparing the cost of an ozonation system to other treatment systems
there are some key factors to consider; here are a few:
- There is
no need to purchase, ship or store chemical oxidants or disinfectants
- There is
no labor for handling.
- Many
health and safety concerns are reduced or eliminated.
- Because
ozone reacts so much more quickly there is opportunity for substantial savings in space
requirements for the treatment system.
- Because
ozone treatment design is flexible, one of the variety of installations can be adapted to
any fit any design circumstance.
- It is
likely that much of your existing treatment facilities are adaptable to an ozone based
treatment system.
- The pay
back of your investment can be surprisingly short.
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