Difference Between Chlorination and Ozonation

The key difference between chlorination and ozonation is that chlorination is the disinfection of drinking water with chlorine, whereas ozonation is the disinfection of drinking water with ozone.

Chlorination and ozonation are processes that are useful for the disinfection of drinking water. These processes can remove contaminants from water by reacting with them to convert the dissolved contaminants into undissolved contaminants.

CONTENTS

1. Overview and Key Difference
2. What is Chlorination
3. What is Ozonation
4. Side by Side Comparison – Chlorination vs Ozonation in Tabular Form
5. Summary

What is Chlorination?

Chlorination is the process of adding chlorine or compounds containing chlorine to water for disinfection purposes. This method is useful in killing bacteria and other microorganisms in tap water. It is because chlorine is highly toxic to them. Moreover, chlorination is very important in preventing water-borne diseases such as cholera and typhoid.

Chlorine is a highly efficient disinfectant. We can add it to public water supplies to kill disease-causing pathogens that commonly grow in water supply reservoirs. Chlorine is manufactured from salt via electrolysis. It usually occurs as a gas at room temperature, but we can liquefy it. Therefore, the liquefied form can be used in the disinfection process.

Figure 01: Determination of Chlorine Level in the Water

Chlorine is a strong oxidant. Thus, it kills bacteria via oxidation of organic molecules in microorganisms. Here, chlorine and hydrolysis product of chlorine, Hypochlorous acid, are charged chemical species which can easily penetrate into the negatively charged surface of pathogens. These compounds can disintegrate the cell wall lipid components and can react with intracellular enzymes. It makes the pathogen non-functional. Then the microorganisms die or they lose their ability to undergo multiplication.

What is Ozonation?

Ozonation is a disinfection process we can use to purify drinking water via the addition of ozone. Ozone can be used to treat drinking water to remove effluents and to degrade organic and inorganic pollutants in wastewater. However, ozone is an unstable gas. It quickly transforms into oxygen. Therefore, there is no residual disinfection effect that takes place during ozonation. That means; there are no residual byproducts formed.

Figure 2: Ozone Generators

A typical ozonation system contains an ozone generator and a reactor in which the ozone can be bubbled into the water to be treated. Ozone is a powerful oxidizing agent. It directly attacks the surface of microorganisms and destroys the cell walls. Here, the microorganisms lose their cytoplasm and are no longer reactive.

What is the Difference Between Chlorination and Ozonation?

Chlorination and ozonation are two types of drinking water purification processes. The key difference between chlorination and ozonation is that chlorination is the process of disinfecting drinking water with chlorine, whereas ozonation is the process of disinfecting drinking water with ozone. Moreover, chlorination involves the oxidation of organic molecules in pathogens, while ozonation involves ozone directly attacking the surface of microorganisms.

Below tabulation summarizes the difference between chlorination and ozonation.

Summary – Chlorination vs Ozonation

Chlorination and Ozonation are two types of drinking water purification processes. The key difference between chlorination and Ozonation is that chlorination is the process of disinfecting drinking water with chlorine whereas Ozonation is the process of disinfecting drinking water with ozone.