Why Ozone - O3 Greentech

Ozone (O3) is an allotrope of Oxygen (O2). Because of the extra Oxygen atom, Ozone is 1.5 times denser and 12.5 times more soluble than Oxygen.

What’s more remarkable about Ozone is that, when dissolved in water, it doesn’t leave any residue except Oxygen and a little bit of Carbon Di Oxide (CO2) and water (H2O). Both of these by-products are environment-friendly and merge in the atmosphere easily. It was discovered during laboratory experiments conducted during the mid-1800s. The word ozone is derived from the Greek word ozein, which means to smell. This comes from the pungent odor that allows it to be detected even in small amounts.

Chemical Properties – Ozone vs Oxygen

Property	Ozone	Oxygen
Molecular Formula	O3	O2
Molecular Weight	48	32
Colour	Light Blue	Colourless
Odour	- Freshly Washed Clothes - Ink of Photocopy Machines - Air in the Lightning Storm	Odorless
Solubility in Water (at 0o C)	0.64	0.049
Density (grams per liter)	2.144	1.429
Electrochemical Potential (V)	2.07	1.23

How Ozone is Formulated?

Ozone is created using the following process:

1. An oxygen molecule (O2) is split using a source of energy in the form of:
   • Ultraviolet light
   • Corona discharge of electricity through an oxygen stream
2. The bonds of Oxygen (O2) are broken and the free oxygen atoms now bind together to form Ozone.
3. However, because Ozone is a fairly unstable molecule, it breaks down easily when introduced to any chemicals to return to its form as an Oxygen molecule.

To be able to generate Ozone on a large scale, the commercial ozone generators employ the corona discharge principle:

1. Ozone Generation: Properly dried air or pure oxygen passes through the gap between a high-voltage electrode and ground electrode separated by a dielectric material. This produces enough electric discharge to form ozone
2. Cooling process: The residual energy is converted into heat that, if not removed immediately, may cause decomposition of Ozone back to oxygen. Therefore it is important to have a proper cooling system for the ozone generator.
3. Transferring ozone to water: Many ozone generators consist of a side-stream venturi injection system to mix the ozone in a fluid stream. This method is considered to be more effective than the bubble diffuser

Why Ozone?

So far, the disinfection of water and air has been carried out using strong chemicals, mainly chlorine. For these chemicals, stronger purification requires stronger chemicals. Such free use of strong chemicals can not only prove hazardous to living health, but also to the environment in general.
Recent research has proven that Ozone is much more effective in providing disinfection than Chlorine, without it being hazardous to health or producing harmful by-products. This claim is not unproven, here are the details of the same:

Property	Chlorine	Ozone
Toxicity	Extremely toxic and poisonous at any concentration level	Toxic only at a concentration of 100 ppt (which is rarely used)
Preparation	Stored in high pressure containers on-premise. Extremely hazardous.	Generated on premise, with no requirement to storage and transportation
Effect on organic matter	Produces chloramines when in contact with organic fluids resulting carcinogenic substances and eye irritation	Reacts with organic substances to produce harmless by-products such as water, carbon dioxide and oxygen.
Cost-effectiveness	Constantly increasing prices due to market demand.	Less expensive due to less requirement for any application and growing popularity
pH control	Essential pH control to maintain value between 7.0 and 7.4	No requirement for pH control, but accompanying chemicals may require pH control
Effect on E. Coli	Destroys E.Coliin 15,000 seconds at a concentration of 1 mg/l	Destroys E. Coli, cysts, and spores within 5 seconds (300 to 600 times more effective than chlorine)
Other useful functions	No useful functions	- Excellent deodorizing agent for many substances like Hydrogen Sulphide (H2S), Ammonia, Smoke, Cooking smells and so on - Effective against decomposition of organic waste, mildew and fungus - Eliminates “locker room” odors in dressing room

Oxidation-Reduction Potential (ORP)

There have been enough instances leading to the realisation that it is difficult to measure the concentration of ozone in water on a commercial level. This applies specifically to evaluation of seawater or water consisting of high level of ionic and organic content. Therefore, it is important to have a standard unit of measurement for this purpose.

Oxidation-Reduction Potential (ORP) – or Redox Potential – is a measure of the cleanliness of water and its ability to break down contaminants. It lies between -2000 and +2000 and is measured in milliVolts (mV). Because ozone is an oxidizer, its ORP value will only be positive.

ORP sensors work by measuring dissolved oxygen. More the contaminants in the water, lesser the ability of the water to disinfect itself, lower the ORP.

More the ability of the water to destroy microbial contaminants, higher the ORP level.