Ozone Water Treatment System

Ozone Treatment of Water

The discovery and benefits of ozone dates back well over 100 years. Recent developments in technology have allowed a new generation of applications and products, using ozone, to emerge.

What is ozone?

Ozone is a very active form of oxygen. It is formed when oxygen is exposed to a high-energy field causing some oxygen molecules (O2) to break down to oxygen atoms (O). The oxygen atoms (O) then react with the oxygen molecules (O2) to form ozone (O3). Notice that this is a reversible reaction meaning that ozone can decompose back to oxygen.

Is ozone found in nature?

Yes, ozone is formed by lightning.
In nature, ozone is produced by the action of lightning on the oxygen found in the air. The formation of ozone leads to the fresh smell that you find outside after a lightning storm. One type of ozone generator, known as the corona discharge type, mimics this natural process in its ozone generating cells.

Yes, ozone is found in the Earth's stratosphere.
Also, the ozone layer found in the upper stratosphere protects the earth's surface from harmful UV rays. UV rays cleave oxygen molecules into oxygen atoms which recombine to form ozone. UV rays also excite ozone molecules causing them to breakdown to oxygen to begin the cycle again. In this way, the energy of the UV rays is absorbed by the "ozone layer" protecting the Earth's surface from their harmful effects. UV-type ozone generators mimic this natural process.

1. What can ozone be used for?

The very reactive nature of ozone makes it the ideal oxidant for air and water treatment. Ozone will:

• destroy bacteria and viruses
• precipitate heavy metals (example iron and manganese) allowing them to be filtered
• eliminate color from water (for example, like the yellowish colour caused by tannin)
• remove rotten egg smell from water (caused by hydrogen sulfide)
• oxidise organic compounds to form compounds that can be easily flocculated and filtered or to form water (H2O) and carbon dioxide (CO2).
• eliminate bad odor from air

Applications include pool & spa treatment , home drinking water treatment, irrigation water treatment, smoke odour elimination from air, seafood storage… the list goes on and on.

The collage below shows but a few areas where ozone has been used successfully to improve water and air quality and to improve industrial processes.
Water Treatment by Ozone

Applications

• Ozone Disinfection For Pool Water
• Ozone Treatment For Cooling Towers

Techniques for Dissolving Ozone in Water
Ozone can be dissolved in the water using the following techniques:

Diffusion Method
This is a simple method diffuser is used for bubbling ozone through the water. The diffuser is connected to the output of the ozone generator.

Online Venturi Injection System
This method is more efficient as compared to the diffuser. In this method the Venturi injector is placed on the main supply line. Just after the Venturi static mixer is installed for the better results. The differential pressure across the Venturi should be atleast 1.0-1.5 kg/c.m for efficient working of the Venturi. For better mixing and absorption the differential pressure must be kept higher.

Recirculation Method
This method uses recirculation pump, Venturi injector, static mixer, tank diffuser and single pass or multiple pass ozonation tank. In order to provide a counter current flow of ozone and water, the water enters the ozonation tank from the top. The use of separate loop ensures the better mixing of water and ozone.

Pressure Booster Injection System
This is a latest innovation that increases the dissolution efficiency. The pressure differential is created between the inlet and the outlet of the Ventury injector for the ozone injection. The system consist of by pass branch header line with a booster pump, Ventury injector, static mixer, booster pump etc.

Ozonation System
A typical ozonation system consist of following components:

Ozone Generator

Ozone generator is an engineering product that produces ozone molecules for disinfecting water. These generators produces ozone molecules from various methods like corona discharge tube, ultraviolet light and cold plasma.
Bubble Diffuser
Ozone contactors with bubble diffusers are used for dissolving ozone into water. These diffuser creates bubbles that transfer the ozone into the liquid phase. The advantage of this bubble diffuser contactors is that, without any additional energy input they can use the pressure of the ozone generator to drive the gas through the diffusers. There is a series of deep multi chamber basin in which the diffusers are located.

Side Stream Injection
This system is splits main flow into a side stream in which the Ozone is injected and then the side stream is mixed into the main flow. The whole system comprises of booster pump, a venturi and nozzles that helps in the introduction of the side stream back into the main flow.

Other
the other components of ozonation system are feed gas system, feed gas system ozone reaction system, ozone controller and concentration monitor, vent ozone destructor and control system.

Advantages Of ozone treatment
Ozone act as the strongest and most effective agent for disinfecting water. The advantages of using ozone in water treatment are:

For powerful germicides like faecal bacteria they act as strong germicides.

By breaking organic constituents, it reduces turbidity of water.

Whole process can be controlled easily. The process is easily controlled.

In the process no chemical is added to the water.

All the inorganic, organic and microbiological problems can be eliminated by ozonztion

It very effective against coliform bacteria and destroys them much faster than chlorine or bromine.

PH can be neutralized by them very easily.

Helps in the destruction of fungus, mold and yeast spores.

All heavy metals are precipitated by them easily

It is capable of conditioning the water naturally without the addition of any chemicals. Water conditioning is achieve by removing excess iron, manganese, and sulfur.

Water color an odor is effectively removed by ozone generator.

There is no scale build up on pipes and water heaters thereby reducing the instances of stains on showers, sinks, bathtubs and toilets.

There is no residue left by it as its byproduct is pure oxygen.

Strongest oxidizer and disinfectant commercially available

Decomposes into harmless oxygen

Ozone reacts with a large variety of organic compounds

Generated and used at point of use

Kills bacteria over 3,000 times faster than chlorine

The applications of ozone span a variety of topics and industries.

Used as a replacement for chlorine and bromine in swimming pools, Ozone is a very effective disinfection agent which even prevents the formation of chlorine and bromine byproducts. For soil remediation, Ozone has been used to clean up sites containing a variety of soil contaminants, including oil and fuel.

Following is information about a few of the applications of ozone and ozone generators:



Ozone can be used in aquaculture water treatment as follows:

• Removal of fine and colloidal solids
• Removal of dissolved organic compounds
• Removal of Nitrite
• Disinfection

A fast-acting and effective treatment technology, Ozone is now used in a variety of water treatment applications and provides multiple benefits to the beverage market. Ozone is one of the strongest commercially available oxidizers, making it popular as a primary disinfectant of water bottling plants.

The use of ozone in cooling towers has some great advantages, including the fact that Ozone is produced on-site and requires no storage of dangerous chemicals. A major problem in cooling tower water treatment is Legionella (legionnaires disease). In the prevention and control of Legionella causing microbes, ozone has taken an eminent roll. The specific characteristics of the Ozone disinfectant make sure it gets the job done where others fail.

Use Ozone to disinfect stored food for unprecedented pathogen destruction. Recent food contamination reports in the media have highlighted the need for more effective methods of food safety. Mainly, the guilty parties have been Escherichia coli, Salmonella enteriditis, Listeria monocytogenes and other pathogens found in fruits, meats, shell fish and other foods consumed by the public. The use of Ozone in food processing has been recently approved by the U.S Food and Drug Administration...

Thanks to intensive development work on more efficient ozone generation, ozone has become a popular choice for a wide and steadily expanding range of industrial applications. The rapid growth of interest in ozone as an oxidant is due to its high oxidative potential and the selectivity of the processes that occur. Virtually no residual materials are produced.

Producing water of high chemical purity is not the challenge it once was, however it is often still difficult to maintain low levels of microbial contamination in these same nutrient waters. Only one alternative method for sanitization of stored and distributed pure water and ultra pure water has proven substantially equal to heat sanitization and that is the use of ozone, when properly applied.

Treating water to make it suitable to drink is much like waste water treatment. For example, Nitrate in drinking water can cause cyanosis, a reduction of the oxygen carrying capacity of the blood. Ozone is a strong oxidizing agent which oxidizes and kills organic substances, pesticides and pathogenic organisms such as viruses and bacteria, so that they can be filtered out in the subsequent steps.

Recently, Ozone has been used to clean up sites containing variety of soil contaminants. The reason for using ozone is to target those compounds that are not biodegradable or the ones which are biodegradable over a long period of time. Many hydrocarbon compounds will biodegrade if they are dissolved, although these contaminants are not readily biodegraded by microorganisms if they are are on soil particles. Ozone can help...

Ozone is used effectively in the processing of water laden with concentrations of industrial byproducts. Pesticides, organics, BOD and COD are all treated thoroughly and effectively through ozone oxidation.

Because it’s highly reactive and unstable, ozone does not persist—any ozone not instantly consumed by contact oxidation of organics quickly reverts to oxygen. This makes ozone perfect as a final, no-rinse sanitizer. With no persistence, ozone requires no special disposal system.

Comparison of Various Disinfection Technologies