1. UNDERSTANDING OZONE
When most people think of ozone, they picture the layer high in the earth's outer atmosphere
that protects us from the sun's ultraviolet rays, but this bluish gas, which sometimes can be
detected as a fresh smell after a thunderstorm, is actually a valuable tool with a variety of down-
to-earth uses.
Ozone gas (O3) is a naturally occurring tri-atomic form of oxygen (O2) that is formed as sunlight
passes through the atmosphere or when streaks through the air. It can be generated artificially
by passing high voltage electricity through oxygenated air (corona discharge), causing oxygen
to break apart and recombine in the tri-atomic form.
Because oxygen naturally seeks its normal state, ozone is an unstable, highly reactive form of
the gas. As an oxidizer, it is 51 times as powerful than chlorine, the oxidizer most commonly
used by most food processors, and 3,000 times faster at killing bacteria and other microbes.
Ozone is effective as a disinfectant at relatively low concentrations and does not leave toxic by-
products similar to those related to chlorination.
For more than a century, ozone has been used in Europe for purifying drinking water and is
currently used in the United States for purifying bottled water and decontaminating cooling
towers. The cities of Los Angeles, Dallas, and Las Vegas all currently use ozone to purify their
water supply.
Ozone's reactive nature takes two different chemical pathways, direct and indirect. In the direct
pathway, ozone reacts with unsaturated bonds and causes them to split, especially under acidic
conditions. The indirect pathway requires initiators that break down the ozone even more
rapidly.
Compared to chlorine, ozone offers several advantages for food and beverage processors or
anyone who wants to sanitize materials or surfaces. Chlorine has traditionally been the sanitizer
of choice in the food processing industry, but experts share a growing concern about the
dangerous byproducts such as trihalomethanes or dioxins produced when chlorine reacts with
organic matter in the water. These substances are known carcinogens and are regulated in
drinking water by the U.S. Environmental Protection Agency.
Ozone, on the other hand, is simply oxygen in an unstable and highly reactive form. It naturally
tends to seek its normal state, exhibiting a short half-life as it reverts to oxygen fairly rapidly.
When it reacts with organic matter, it does not form any toxic byproducts and the water in which
it was delivered can be filtered and reused. Because it is so highly reactive, ozone is effective at
controlling or removing biofilms that sometimes form on processing equipment. It can also be
used to reduce biological oxygen demand (BOD), chemical oxygen demand (COD), and
turbidity or other residues in water.
2. While chlorinated wash systems require transport and storage of potentially hazardous toxic
chemicals, ozone is unique in that it is generated onsite from oxygen and can be produced on
demand with no storage required. When the generator is turned off, there are no dangerous
substances on the premises. While the oxidation reduction potential (ORP) of ozone is affected
by the amount of organic matter or chemicals in the water, its ORP is not as sensitive to
changes in pH as that of chlorine.
Ozone also has a variety of uses in food and beverage processing plants. Water containing low
concentrations of ozone gas can be sprayed onto processing equipment, walls or floors to both
remove and kill bacteria or other organic matter that may be present. Because it has such a
short half-life, ozone does not build up on surfaces the way detergents can if not removed by
proper rinsing.
Ozone can also be injected or dissolved in process waters of all kinds to provide chilling,
fluming, rinsing or washing of food products such as meat, poultry, seafood, fruits or vegetables.
Processors who chill fruits or vegetables after harvest using water held at approximately 34
degrees Fahrenheit can ozonate the water to prevent contamination of the product. Cooling
fruits and vegetables helps slow product respiration, and preserving freshness and quality.
Studies of fruits and vegetables indicate that removing field heat as soon as possible after
harvest is a critical factor in extending product shelf life. As a side benefit, ozone with filtration
can remove particulates, chemicals and organics from water, settling them out by flocculation.
Because it is so effective at removing suspended or dissolved substances, ozone can help
conserve process water by making it possible to filter and recycle the stream.
Ozone is also an effective sanitizer for air and has been used successfully to decontaminate the
atmosphere in storage rooms, containers and other areas. Airborne contaminants are a concern
in some food facilities or clean rooms. Gaseous ozone reacts with unwanted odors or
contaminants in ambient air just as aqueous ozone decontaminates process water. The degree
to which it is effective at destroying contaminants in the atmosphere or on exposed surfaces in
a room depends on the concentration of ozone that can be safely used in the area.
On June 23, 2001, the U.S. Food and Drug Administration officially granted GRAS (Generally
Recognized As Safe) status to ozone for use in food contact applications. While there was
already interest among food processors in the use of ozone for killing microorganisms and
sanitizing equipment, the FDA approval opened up the opportunity for food processors to begin
putting this exciting technology to use in their plants. Today, meat, poultry and seafood and
produce plants are using ozonation as a food safety measure.
For many years now, food and beverage processors in the United States, Mexico, Canada,
Latin America, Europe, Africa, and Asia have installed working ozone wash systems and the
results indicate that bacterial plate counts are lower with ozone as compared to chlorinated
systems.
3. Fresh food when washed with ozone exhibit a longer shelf life than similar products processed
using chlorine.
Aquentium has theorized that ozone reacts with the enzymes released from damaged lettuce
cells when this vegetable is sliced or shredded. Because the enzymes seem to be deactivated,
natural browning is delayed, not only enhancing shelf life but also preserving color and flavor of
the product. Vegetable and fruit tissues are not injured during contact with ozone water.
Ozone is also proving to be compatible with other disinfectants.
In light of continued outbreaks of food-borne illness and more recent food security concerns in
the United States and internationally, as well as questions about the relative safety of chlorine,
ozone is certainly the desirable solution for enhancing not only the safety but also the quality of
the world food supply.
WHY OZONE?
The potential utility of ozone in the FOOD & BEVERAGE industry depends on the fact that as
an oxidizing agent, it is 1.5 times stronger than chlorine and is effective over a much wider
spectrum of microorganisms than chlorine and other disinfectants.
Ozone kills bacteria such as Escherichia coli, Listeria, and other food pathogens much faster
than traditionally used disinfectants, such as chlorine, and is free of chemical residues. Ozone
is a high-energy molecule. Its half life in water at room temperature is only 20 minutes, and it
decomposes into simple oxygen with no safety concerns about consumption of residual ozone
in the treated food product. It can also be used for recycling water.
For decades, it has been known that ozone is an effective disinfectant and sanitizer for the
treatment of food product. It is commonly used in Europe for treatment of public water systems
and food processing. It is being used in the U.S. for bottled water and many food and other
beverage processing applications.
The benefits of ozone applications in the food industry have been confirmed. Thus, ozone can
successfully replace traditional sanitizing agents to control food pathogens.
Additionally, when Fresh food is washed first by ozonated water, then the wash water can be
recaptured and treated by a combination of ozonation and filtration. The treated wash water is
free of bacteria, color, and suspended solids and can be recycled to reduce water usage.
Unlike conventional chlorine-based washing systems, wastewater discharged by an ozonation
process is free of chemical residues, a growing concern related to the environment and
groundwater pollution. Ozone can also destroy pesticides and chemical residues, such as
chlorinated by-products.
4. Gaseous ozone is a strong sanitation and fumigation agent and can be used to sanitize foods in
the storage room and during shipping to prevent bacteria, mold, and yeast on the food surface
and to control insects. It can eliminate undesirable flavor produced by bacteria and chemically
remove ethylene gas to slow down the ripening process, thus allowing extended distribution.
In light of continued outbreaks of food-borne illness and more recent food security concerns in
the United States and internationally, as well as questions about the relative safety of chlorine,
ozone is certainly a desirable solution for enhancing not only the safety but also the quality of
the world food supply.
Common Organisms that are Oxidized by Ozone
BACTERIA
Achromobacter butyri NCI-9404
Aeromonas harveyi NC-2
Aeromonas salmonicida NC-1102
Bacillus anthracis
Bacillus cereus
B. coagulans
Bacillus globigii
Bacillus licheniformis
Bacillus megatherium sp.
Bacillus paratyphosus
B. prodigiosus
Bacillus subtilis
B. stearothermophilus
Clostridium botulinum
C. sporogenes
Clostridium tetoni
Cryptosporidium
Coliphage
Corynebacterium diphthriae
Eberthella typhosa
Endamoeba histolica
Escherichia coli
Escherichia coli
Flavorbacterium SP A-3
Leptospira canicola
Listeria
Micrococcus candidus
Micrococcus caseolyticus KM-15
Micrococcus spharaeroides
Mycobacterium leprae
Mycobacterium tuberculosis
Neisseria catarrhalis
Phytomonas tumefaciens
Proteus vulgaris
Pseudomonas aeruginosa
Pseudomonas
FUNGUS & MOLD SPORES
Aspergillus candidus
Aspergillus flavus (yellowish-green)
Aspergillus glaucus (bluish-green)
Aspergillus niger (black)
Aspergillus terreus, saitoi & oryzac
Botrytis allii
Colletotrichum lagenarium
Fusarium oxysporum
Grotrichum
Mucor recomosus A & B (white-gray)
Mucor piriformis
Oospora lactis (white)
Penicillium cyclopium
P. chrysogenum & citrinum
Penicillium digitatum (olive)
Penicillium glaucum
Penicillium expansum (olive)
Penicillium egyptiacum
Penicillium roqueforti (green)
Rhizopus nigricans (black)
Rhizopus stolonifer
PROTOZOA
Paramecium
Nematode eggs
Chlorella vulgaris (Algae)
All Pathogenic and Non-pathogenic forms of Protozoa
FUNGAL PATHONGENS
Alternaria solani
Botrytis cinerea
Fusarium oxysporum
Monilinia fruiticola
6. Ozone Water Purification
Ozone water purification is the most effective FDA approved water purification method for
eradicating toxins that are found in water. Ozone, also known as O3, is a highly powerful
oxidant that inactivates pesticides, fungus, organic materials, contaminates and viruses
much more potently than chlorine. Ozone water purification accounts for the majority of
purified water in the world; it’s currently the most popular water purification method used.
The Advantages of Ozone Water Purification
Ozone is an excellent disinfectant with the superior ability to kill viruses and biological
contaminants found in water. It is also a very powerful oxidant that can oxidize metals in
water such as manganese, iron and sulfur into insoluble particles, aiding in their filtration
and removal from water. Oxidization by ozone in water purification also aids in removing
taste and odor problems from water much more efficiently than chlorine, and ozone itself
doesn’t produce any odor or taste. Due to the fact that ozone consists of oxygen, it reverts
back to pure oxygen and disappears without a trace after it’s been used. Not only does
ozone remove microorganisms from water, it also halts the accumulation of deposits in
your pipes and water system which greatly improves the quality of your water. Another very
important benefit of water purification using ozone is that no chemicals are added to the
water. Ozone is a naturally occurring substance and when utilized for water purification
purposes it immediately degrades back to oxygen leaving no trace.
How Does Ozone Water Purification Kill Bacteria and Germs
Ozone is composed of three Oxygen atoms. One of the atoms is connected to the others
weakly and will transfer itself to other substances such as viruses and bacteria, causing
them to oxidize by binding itself onto them.
What is Ozone Water Purification?
It is the process of using ozone to purify, that is removing the harmful micro organisms that
can make you sick, from our drinking water. This process has been used in drinking water
plants since 1906 where the first industrial ozonation plant was built in Nice, France and is
more widely used in Europe and Asia than the United States.
7. Have you ever smelled the clean, fresh scent in the air just after a sudden summer
thunderstorm? ...... That's the ozone!
In this case, you smell ozone, which has been creating from lighting bolts during the
electrical storm. Ozone is also created by the sun’s ultra violet rays reacting with the Earth's
upper atmosphere which creates our protective ozone layer.
At the instant that ozone is created, the oxygen (O2) molecules in the air are broken apart,
by either the suns UV rays or by intense electrical discharge (lightening) and then
recombined with an extra oxygen atom (O3).
Ozone is a very reactive and unstable gas with a short half-life before it reverts back to
oxygen. Ozone is the most powerful and rapid acting oxidizer man can produce, and will
oxidize all bacteria, mold and yeast spores, organic material and viruses given sufficient
exposure. It is said to be:
50 times more powerful than chlorine and
3000 times faster at killing bacteria and other microbes
Does not leave any by-products such as, with chlorine which create trihalomethanes
(THM's).
8. How are Germs and Bacteria killed during Ozone Water Purification?
Ozone is made up of three oxygen atoms (O3)
a "free radical" of oxygen. It will readily give up one atom of oxygen providing a powerful
oxidising agent which is toxic to most waterborne organisms such as bacteria, mold and
yeast spores, viruses or harmful protozoa that form cysts.
This single Oxygen atoms binds with these substance causing them to oxidize (think iron
tuning into Iron Oxide - Rust). The byproduct of this oxidation a single Oxygen atom.
The advantages of using Ozone Water Purification include:
Ozone is primarily a disinfectant that effectively kills biological contaminants.
Ozone also oxidizes and precipitates iron, sulfur, and manganese so they can
be filtered out.
Ozone will oxidize and break down many organic chemicals including many
that cause odor and taste problems.
Ozonation produces no taste or odor in the water.
Ozone is made of oxygen and reverts to pure oxygen and it vanishes without a trace
once it has been used.
The disadvantages of using Ozone Water Purification include:
The process of creating ozone in the home requires electricity. Loss of power means
no purification.
Ozone is ineffective at removing dissolved minerals and salts.
9. How Does an Ozone Water Purification System Work?
Ozone is created with what is called an Ozone Generator. It creates O3 in much the same
way as the sun does. AN ELECTRICAL CHARGE converts the oxygen in the air into ozone.
This ozone is then sent through a line into a diffuser, which creates ozone-saturated
bubbles. Water is drawn in to mix with the bubbles, and then fed into the water purification
tank.
The weak Oxygen molecule in the Ozone attaches to other organic molecules in the water
and oxidizies them. This is the oxidation process that was discussed earlier.
It is important to note that the effectiveness of the process is dependent, on good mixing of
ozone with the water, and ozone does not dissolve particularly well, so a well designed
system that exposes all the water to the ozone is important. The Aquentium patented
technology achieves that great result of purified water.
The ozone water purification system is one of the most advanced water treatment processes
in the water industry. Water purified by ozone is now free of protozoa, fungi, germs and
bacteria and is safe for human consumption. Ozone water purification accounts for more
than ninety percent of the world’s purified water and most bottled waters are treated by
ozone.
Aquentium - Ozone Systems - Benefits for Water Treatment:- Disinfection at rates much faster than
Chlorine (E-Coli killed at low Ozone dosages).- Inactivation of viruses.- Removal of Iron and Manganese.-
Control of Tastes and Odors.- Can be used for some pesticide removal in water depending on severity-
Oxidation of Organics and Inorganics- Improves taste, appearance, quality and acceptability of drinking
water.
Systems Are Now Available for Municipal, Well-Water and Domestic Use
Ozonation - What is it?
Ozone is one of the most powerful water treatment compounds available to systems managers today. It
is a technology that has been in continual commercial use for over 100 years and has distinct properties
that allow disinfection of even heavily compromised water streams.
With the 1996 reauthorization of the Safe Drinking Water Act, Ozone was named as among Abest
available technology@ (BAT) for small system compliance to National Primary Drinking water
Regulations as overseen by the US Environmental Protection Agency.
10. DISINFECTION TREATMENT TECHNOLOGIES LISTED IN THE U.S. ENVIRONMENT PROTECTION
AGENCY=S SURFACE WATER TREATMENT RULE (SWTR)
Ozone - Ozone is a powerful oxidant with high disinfectant capacity. A study found that within a pH
range of 6 to 10, at 3 to 10 C, and with ozone residuals between 0.3 to 2.0 mg/L, bacteriophage MS-2
(a surrogate test organism) and Hepatitis A virus were completely inactivated. Inactivations ranged
from >3.9-log to >6-log, and occurred within very short contact periods (i.e., 5 seconds). A 1992
research report describes treatment studies conducted on MS-2, poliovirus, and Giardia cysts. It found
that MS-2 in natural waters are very sensitive to ozone in comparison to poliovirus type 3. In addition,
Giardia muris and enteric viruses may be inactivated by ozone (as the primary disinfectant) with 5
minutes contact time and ozone residuals of 0.5 to 0.6 mg/L to 3-log and 4-log removals, respectively.
The report concludes that design of ozone as a primary treatment should be based on simple criteria
including ozone residual, competing ozone demands, and a minimum contact time to meet the required
cyst and viral inactivation requirements, in combination with USEPA guidance recommendations. Viral
inactivation CT values for ozone were published in the original USEPA guidance manual for the SWTR.
The EPA has reviewed survey data submitted by the International Ozone Association and found that
ozonation has been applied at many drinking water treatment facilities in the U.S. with capacities
greater than 100,000 gal/day and some smaller facilities, for disinfection as well as for other water
treatment objectives. Applications at the smallest water system size category (i.e., systems serving
<500) are not plentiful. However, ozonation technology for even the smallest public water system
applications is available by Aquentium, and is found to be currently in use in relevant systems. Ozone
treatment, therefore, is a listed technology for all categories of public water systems.
Ozone Small Potable Water Systems
Ozone, the strongest oxidant and disinfectant in commercial use has been employed in over 3,000
large scale municipal plants world-wide. In August 1997, and again in August 1998, the U.S. EPA
identified ozone as a Small System Compliance Technology for existing National Primary Drinking
Water Regulations related to revisions in the 1996 Safe Drinking Water Act. Survey data developed
to support the inclusion of ozone as a "Compliance Technology" identified that over half of the
more than 260 U.S. municipal ozone installations known to be operating in early 1998 are in
systems treating less than 1 MGD (e.g., plants that serve less than 10,000 persons). An additional
363 community, non-community and single family ozone installations using ultraviolet generation
and filtration process also were identified.
Ozone Treatment of Potable Water
Ozonation has been in continuous use in Nice, France since 1906, to ensure disinfection of
mountain stream water. Because ozone is both the strongest oxidant and strongest disinfectant
available for potable water treatment, this unique material can be utilized for a number of specific
water treatment applications, including disinfection, taste and odor control, color removal, iron and
manganese oxidation, H2S removal, nitrite and cyanide destruction, oxidation of many organics
11. (e.g., phenols, some pesticides, some detergents), algae destruction and removal, and as a
coagulant aid.
Even though ozone is the strongest chemical disinfectant available for water treatment, there are
some refractory organics that it will not oxidize, or will oxidize too slowly to be of practical
significance. In such cases, ozone can be combined with UV radiation and/or hydrogen peroxide to
produce the hydroxyl free radical, HO*, which is an even stronger oxidant than is molecular Ozone,
O3. Deliberate production of the hydroxyl free radical starting with ozone has been termed "Ozone
Advanced Oxidation". Some groundwaters that are contaminated with chlorinated organic solvents
and some refractory hydrocarbons are being treated successfully by ozone advanced oxidation
techniques.
Properties and Generation of Ozone
At ambient temperatures, ozone is an unstable gas, partially soluble in water (generally more
soluble than oxygen). Due to its instability (it quickly reverts to oxygen), ozone cannot be produced
at a central manufacturing site, bottled, shipped and stored prior to use. It must be generated and
applied on-site, as it is required. This means the installation of an ozone production plant at its
point of use B which for small systems can be inside or outside of an individual home.
Ozone is generated for commercial uses either by corona discharge or by ultraviolet radiation. By
the UV technique, rather low concentrations of ozone (below 0.1 wt %) are generated, whereas by
corona discharge, ozone concentrations in the range of 1 - 4.5 wt % are produced when dry air is
fed to the ozone generator. When concentrated oxygen is used as the feed gas, gas phase ozone
concentrations of up to 14 to 18% (by wt) can be produced on commercial scale. Since ozone is only
partially soluble in water, once it has been generated it now must be contacted with water to be
treated in such a manner as to maximize the transfer of ozone from the gas phase into water. For
this purpose, many types of ozone contactors have been developed; all of which are effective for
their designed water treatment purposes. However, as higher concentration ozone gas is employed,
contacting system design becomes more critical due to the lower gas to liquid ratios. Also, the use
of oxygen as the feed gas can result in oxygen super saturation of the treated water causing both
operational problems in following treatment processes and aesthetic in the distribution system.
Ozone contacting system options include atmospheric tall tower or pressurized gas to liquid mass
transfer processes. Fine bubble diffusers, static mixers or venturi injectors can be used to mix the
gas with the water to be treated in either full flow or sidestream configurations. In many small
systems, small in-line injectors and pressurized reaction vessels replace the huge concrete, 20-ft
deep bubble diffuser tanks which are cost-effective in large scale systems.
Once dissolved in water, ozone now is available to act upon water contaminants to accomplish its
intended purposes of disinfection and/or oxidation. At low pH levels (3-6, for example) the ozone is
present primarily in its molecular form (O3). However, as the pH rises, the decomposition of ozone
12. to produce the hydroxyl free radical (HO*) becomes increasingly rapid. At pH 7 about 50% of the
ozone transferred into water produces HO*. At pH > 10, the conversion of molecular O3 to HO* is
virtually instantaneous.
Engineering Aspects of Ozonation Systems
Because ozone is such a powerful oxidant/disinfectant, the trick to applying it to solve water
treatment problems is to do so in a manner that is effective for water treatment, yet at the same
time ensuring the safety of people in the vicinity. Ozone safety issues are handled quite easily by
use of proper ambient ozone monitoring, tank venting and ozone destruction. In the case of
systems driven solely by a pumping/injector system, Ozone may be produced under vacuum, which
ensures no leakage of Ozone into the operating environment.
The five basic components of an Ozone system include
1. Gas Preparation - either drying gasto a suitable dewpoint or using oxygen concentrators.
2. A suitable electrical power supply.
3. A properly sized Ozone Generator(s)
4. An Ozone contacting system.
5. Ozone off-gasdestruction or suitable venting system.For corona discharge ozone generation, it is
critical to feed the generator a clean and dry oxygen- containing gas. Moisture in the feed gas
causes two operating problems.
First, the amount of ozone produced by application of a given electrical energy level is lowered as
relative humidity rises. Consequently, it is usually cost-effective to dry the air to a recommended
dew point of minus 65'C (-65'C = -76'F) or lower. Second, when ozone is generated using air in the
presence of moisture, the small amount of nitrogen oxides react with the moisture to produce nitric
acid. Moist gas condensation at the cooling/heat transfer surfaces produces the corrosive
compound which can soon cause corrosion problems in the ozone generation equipment, with
concomitant increases in equipment maintenance requirements. Because of the high oxidative
qualities of gas-phase ozone and the chance of moisture from a failing feed gas unit, small system
managers should take extra care to make certain that all components in the ozone generator, ozone
supply line, ozone gas to liquid mass transfer equipment and the contact vessel are ozone-
compatible.
For large scale ozonation systems, the equipment for cleaning and drying feed gases can become
quite complex. For example, effective air drying can involve the multiple treatment steps of air
filtration, compression, cooling, desiccation, and final filtration prior to passage into an operating
corona discharge ozone generator.
13. For small community systems, several commercial-grade air dryers and small oxygen generators are
available, but these must be matched carefully to the specifications of the ozone generator.
The need for efficient ozone contacting has been discussed earlier, and the final necessity is a unit
for destruction of excess ozone always present in contactor off-gases when generated by corona
discharge. Absent an effective ozone off-gas destruct unit, this excess ozone would be present for
people in the vicinity to breathe, which is not recommended due to its strong oxidizing nature.
Additionally, ozone is heavier than ambient air, can settle in the vicinity, and can attack oxidizable
materials. Destruction of contactor off-gas ozone is readily accomplished thermally (370'C),
catalytically, thermal-catalytically, or (only for small air-fed systems containing very low ozone
concentrations) by passage through granular activated carbon. Care should be exercised in selecting
an ozone destruct method whenever very high concentrations of ozone will be encountered.
To the five-component system outlined above can be added instrumentation and controls for
ensuring the effective and safe operation of the total system. And now the concern for applying
ozone to small water treatment systems becomes one of how to miniaturize the tried and true large
scale units to be effective and affordable systems for treating water in small systems. Aside from
simply making each of the five components smaller in physical size, there are some additional
techniques for corner-cutting without sacrificing quality in terms of production of ozone at
desirable gas-phase concentrations. For electrical power, the home or business wall plug providing
110-V or 220-V single phase power replaces 3-phase supplies at 230, 460 or 575- V required at large
installations.
For air drying, desiccation or oxygen concentration is appropriate as the sole feed gas approach on
small scale, replacing the multiple-treatments required at larger installations. For contacting, small
in-line injectors replace the huge concrete, 20-ft deep bubble diffusers, which are cost-effective on
large scale. In many small applications with extended storage capacity for prolonged ozone
addition, UV generation of ozone can be practical for oxidation of iron and manganese, whereas UV
generation at large water treatment plants is prohibitively higher in cost than corona discharge.
Oxygen concentrators often replace air desiccation units to feed oxygen-enriched air to the ozone
generators, thus producing higher gas phase ozone concentrations and increased output (g/h) per
unit size on small scale, thus avoiding the need for on-site oxygen production and/or storage
facilities
14. Disinfection with Gaseous Ozonation
The agricultural industry producing edible horticultural crops is very much concerned with
the shelf life of their products. Despite thorough washing and rinsing, one can simply not
completely prevent a decay process and possible infection by human pathogens.
The consumer has demanded produce being of fresh quality and a high safety standard. The
challenge of preserving taste, odor, and extending shelf life significantly, can be met with
gaseous ozonation ( mixing ambient air with ozone gas ). Applying gaseous ozonation today
in a post-harvest environment is accepted by the regulatory agencies. Under the statute of
GRAS (generally recognized as safe), the EPA has allowed ozone as a disinfectant.
While packaged during transport and product in storage, the primary objective with
ozonation is sanitization and extension of shelf life. Since in all of these operations humans
would come in contact with the ozonation process, a controlled and safe environment is
essential.
When using ozone as an anti-microbiological agent, the process of mixing ozone gas with air
and at the same time increasing the relative humidity to a preferred value of above 85
percent, we could also refer to this process as fumigation.
To our advantage are the physical characteristics of ozone having a half-life in the gaseous
phase extending more than 3 days at a temperature around 40o
F. Even when packaged in
large bins and in plastic containers, eventually ozone gas will find its way to the surface of
fresh and dried fruits and vegetables. This will occur through forced ventilation but also
through natural osmosis.
Most benefits of applied ozonation in cold storage rooms have been achieved in the
substantial reduction of fungus spore production, elimination of bacterial pathogens, such as
salmonella, e-coli, and shigella, decreased development of ethylene through oxidation, and
significant reduction of listeria monocytogenes.
APPROVALS
15. INDUSTRY USES -
HOTELS
RESTAURANTS
SCHOOLS
HEALTHCARE
FOOD PROCESSING
BEVERAGE PROCESSING
COMMERCIAL BUILDINGS
CONTACT:
Mark Taggatz, CEO
Tel: 1-951-244-8208
www.aquentium.com
Vice-Presidents
Africa – Mr. George Atkins
Asia –Mr. Robert Hungate
Canada – Mr. Stewart Simpson
Europe – Mr. Otto Parson
South America – Mr. Antonio Portilla
