What is ozone?

Ozone itself is a form of oxygen, O3, produced when ultraviolet light or an electric spark passes through air or oxygen.

 

 Benefits of Ozone in water treatment

OZONE oxidizes and decomposes organic and inorganic contaminants at a higher rate that other reagents. Normally one or more orders of magnitude faster than Chlorine, the most commonly used reagent.

 

OZONE has faster sterilization and disinfection rate over 3000 times that of Chlorine in water and it is far safer. That is why OZONE has been used in the Paris water system since 1903 and is currently used by Los Angeles, (1984) and San Diego, (1986).Los Angeles has the world’s largest ozone generating system. (LA Aqueduct)

Sterilization and disinfection rates are independent of NH3 and are not affected by pH as is Chlorine. Microorganisms that are normally resistant to Chlorine, requiring hours of contact time, are killed in seconds by ozone.

 

There are no bacteria or viruses which are resistant to OZONE, as it act as an OXIDANT of PROTOPLASM. That is why trace residual OZONE is accepted as a standard of reference for full disinfection of water. (Ref. Bottled Water)

 

Other than microorganisms, OZONE decomposes organic and inorganic contaminants in water into harmless compounds that can be easily separated or transformed by settling, filtering, etc.

 

OZONE reacts favorably with material and compounds with which Chlorine does not react or reacts in an unfavorable manner so as to leave undesirable by-products.

 

Substances imparting color, smell or taste.

 

Iron and Manganese.

 

Cyanides, Phenols, etc.

 

OZONE is the most “Environmentally Friendly” oxidant and even, at least partially, decomposes Chlorinated compounds. (PCBs, Chlorinated solvents, etc.)

 

Effects on human beings

• In low concentrations, (Less than 0.05 Parts Per Million), OZONE has a sweet pleasant odor. It is responsible for the familiar odor of a thunder storm due to the OZONE created by lightning. (High voltage electrical discharge)
• Natural ground-level concentrations are typically 0.03 PPM.
• O.S.H.A. 24 hour exposure limit, 0.05 PPM, (Parts Per Million)
• O.S.H.A. 8 hour exposure limit, 0.1 PPM
• O.S.H.A. Short-term exposure limit, 0.3 PPM
• Effective as a disinfectant and sterilizing agent at levels of 35% to 50% of that specified by O.S.H.A. for 24 hour exposure levels.

Prolonged exposure to high levels, (^ 100 PPM), produces headache and perhaps nausea.

Home applications and uses

• Odor control/removal.
• Pets.
• Sick Room and/or body odors.
• Tobacco smoke
• Food preparation and cooking, (Onions, garlic, fish).
• Mold and/or Mildew in carpets and moist areas.
• Removal of Formaldehyde, (from carpets, furniture, draperies, processed wood, etc.).
• Pools, “Jacuzzis” and Spas, elimination of dangerous and toxic chlorine.
• A/C duct work sanitation and maintenance (kills mold and/or mildew in ductwork).
• Extraordinarily effective in combating allergens.

Emergency first aid procedure is to remove victim from areas of high concentration, whereupon the symptoms will disappear.

Industrially, ozone is used to:

• Disinfect laundry in hospitals, food factories, care homes etc.
• Disinfect water in place of chlorine
• Deodorize air and objects, such as after a fire. This process is extensively used in fabric restoration
• Kill bacteria on food or on contact surfaces
• Sanitize swimming pools and spas
• Kill insects in stored grain
• Scrub yeast and mold spores from the air in food processing plants;
• Wash fresh fruits and vegetables to kill yeast, mold and bacteria;
• Chemically attack contaminants in water (iron, arsenic, hydrogen sulfide, nitrites, and complex organics lumped together as “colour”);
• Provide an aid to flocculation (agglomeration of molecules, which aids in filtration, where the iron and arsenic are removed);
• Manufacture chemical compounds via chemical synthesis
• Clean and bleach fabrics (the former use is utilized in fabric restoration; the latter use is patented);
• Assist in processing plastics to allow adhesion of inks;
• Age rubber samples to determine the useful life of a batch of rubber;
• Eradicate water borne parasites such as Giardia lamblia and Cryptosporidium in surface water treatment plants.

Physical and chemical characteristics

• Made from three atoms of OXYGEN, Chemical symbol, O3.
• Colorless in gaseous form, appears blue in “Thick Layers” (Blue Sky).
• Dark blue or almost black in liquid form.
• Solid crystalline form is violet to blue in color.
• Melting point ~ 80 K.
• Boiling point ~ 161 K.
• Has a very unique “Electric” odor that can be detected as low as 0.012 PPM.
• Highly unstable and not possible to store, all users generate it on-site, as needed.

Formation

Natural

• Lightning.
• Solar radiation. (Ultraviolet wavelengths A, B, & C)
• Photochemical Smog in large cities.

Man-made

• Corona discharge. (Usually in air or oxygen atmospheres)
• High voltage gas discharge tubes. (Germicidal UV lamps)

Solubility

• Soluble in water.
• Affected by temperature, pressure and contaminant levels.

Optical Properties

Ozone has a peak absorption in the UV Spectrum at 255.3 NM, which puts its most effective band in the UV “C” spectrum. Without this particular property, no life could exist on the earth’s surface.

Basic Applications

OZONE is highly unstable and will easily give up one atom of oxygen to combine, with, (Oxidize), almost anything.

• Naturally occurring OZONE and the OZONE formed from auto exhaust causes the premature aging and cracking of tires and wiper blades.

OZONE is the second most powerful oxidant after FL, (Fluorine), and the by-products are harmless as opposed to some chlorine by-products as:

• Trihalomethanes.
• Chloramines, (Chloroform, etc).

OZONE is used extensively for processes requiring oxidation and disinfection

• Drinking water treatment; purification, odor, taste, color, container sterilization.
• Waste water treatment; disinfection, sterilization, BOD & COD reduction.
• Cooling towers; scale removal, microbe control, corrosion control.
• A/C Air Handlers; Odor control, mold/mildew elimination/control.
• Aquaculture, fish and shrimp farming; ammonia removal, bacteria control.
• Pools, spas, water parks, water displays; replacement of Chlorine.
• Bottling plants; container sterilization.
• Canning plants; container sterilization.
• Breweries; removal of taste/odor and microbe control in process water.
• Metal plating and finishing processes for waste water reclamation.
• Bleach and detergent reduction in wash processes. (35% to 75% Typical)
• Transportation and/or storage of fresh fruit and produce.
• Fire damage restoration; smoke odor and mold/mildew removal.
• Casinos and bars; elimination of tobacco smoke and stale wine & beer odor.
• Rental car and truck agencies; removal of tobacco, pet, and body odor.
• Hotels; elimination of tobacco smoke and stale room odors.

Common processes generating Ozone as a by-product

• Sunlight.
• Lightning.
• Photocopiers.
• Laser-Jet printers, scanners and copiers.
• Surface treatment of plastic film.
• Automobile exhaust + sunlight.
• Fluorescent lighting.
• Electric arc welding.
• Electric-arc, “PLASMA-JET” metal cutting.
• Any high voltage process that generates a “Corona discharge”.
• “Tanning” beds

11.   MARINE APPLICATIONS

• Fresh water purification.
• Ballast water sterilization.
• Mold and mildew that cause a boat’s “Musky” odor.
• Tobacco smoke.
• Black and gray water holding tank and vent odor control.
• Bait and live well odor elimination.
• Control of bilge water odor.
• Extend fresh fruit and vegetable storage life in refrigerators and coolers.
• Prevent odor and taste cross-contamination of foods in refrigerators and coolers.
• A/C air handlers and duct work mold and mildew and indoor air quality control.
• Diesel fuel odor elimination.
• Food preparation and cooking odors.
• Elimination of pet odors.
• Destruction of substances that cause allergic reactions.

12.   OZONE GENERATION METHODS

1.      Electric (Corona) Discharge.

1.1.   Basic Equation.

1.1.1.      a. 3 O2 <——-> 2 O3 <——-> 3 O2

1.2.   Theoretical Power Required.

1.2.1.      285 K JOULES to generate 2 MOLES (96 Gram) of O3

1.2.2.      Equal to 0.9 Wh per Gram.

1.3.   Actual Power Requirements.

1.3.1.      15 to 20 Wh per gram O3

1.3.2.      7 to 10 kWh per pound of O3

2.      UV Radiation.

2.1.   UV Radiation of Oxygen or other gases containing oxygen will produce OZONE

2.2.   Process is photochemical dissociation of oxygen.

2.3.   Typical concentrations achievable via UV radiation are below 1 gram OZONE per cubic meter of process gas. (Approx. equal to 500 PPM).

3.      OZONE generation is limited by the inherent power demands from any given piece of equipment; therefore, design limits impose the maximum amount of OZONE that can be produced from any single, specified source.

4.      There has never been one single fatality that resulted from the generation and application of OZONE, since it was first isolated in 1840 in Germany.

13.   UNITS OF MEASUREMENT FOR OZONE

• Mass of OZONE / Volume of gas, expressed as ” g O3 / m3 ” AIR or OXYGEN.
• Mass of OZONE / Mass of gas, expressed as ” % Weight ” {Large masses only}.
• Volume of OZONE / Volume of gas, expressed in “PPM”, {Parts Per Million}.
• Volume of OZONE / Mass of gas {Not Used}.
• Mass of OZONE / Volume of water, ” g / m3 “, {Or PPM}.

14.   CONCENTRATION CONVERSION TABLE

• Physical Properties, Standard conditions P = 1013.25 MB, T = 273.3 K
  1. Density of OZONE , 2.14 Kg / m3
  2. Density of oxygen, 1.43 Kg / m3
  3. Density of air, 1.29 Kg / m3
  4. Density of water, 1000 Kg / m3
• USEFUL CONVERSION FACTORS.
  1. 1000 liters = 1 m3 = 264 US gallons
  2. 1 g / m3 = 1 mg / L
• OZONE CONCENTRATION IN WATER.
  1. 1 g O3 / m3 H2O = 1 PPM O3 in water (By weight)
• OZONE CONCENTRATION IN AIR BY VOLUME.
  1. 1 g O3 / m3 AIR = 467 PPM O3 in air (By volume)
  2. 1 PPM O3 in AIR by volume = 2.14 mg O3 / m3 AIR
• OZONE CONCENTRATION IN AIR BY WEIGHT.
  1. 100 g O3 / m3 AIR = 7.8% O3 in AIR (By weight)
  2. 1% O3 in AIR by weight = 12.8 g O3 / m3 AIR
• OZONE CONCENTRATION IN OXYGEN BY WEIGHT.
  1. 100 g O3 / m3 O2 = 6.99% O3 in OXYGEN (By weight)
  2. 1% O3 in OXYGEN {By weight} = 14.3 g O3 / m3 O2