Ozonation process is carried out in the ozone generator using an electric discharge or by ultraviolet radiation as in UV-type ozone generators. Apart from this, ozone can also be created through electrolytic and chemical reactions. Generally speaking, in an ozonation system dry and clean air is passed through a high voltage electric discharge.
Water Treatment by Ozone
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 Ventury Injection System
This method is more efficient as compared to the diffuser. In this method the Ventury injector is placed on the main supply line. Just after the Ventury static mixer is installed for the better results. The differential pressure across the Ventury should be atleast 1.0-1.5 kg/c.m for efficient working of the Ventury. For better mixing and absorption the differential pressure must be kept higher.
Recirculation Method
This method uses recirculation pump, Ventury 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.
