Ozone Applications in Water Treatment and Disinfection

When we talk about “ozone”, we generally have in mind the ozone layer that covers the Earth’s atmosphere and protects its surface from ultraviolet rays. But ozone is also a component long mastered by men, that has proven useful in numerous applications. Although controversial, ozone has been used in different industries over time, and has in recent years gained market for domestic use. Let us take a look at different ways ozone is used in for water treatment and disinfection.

Ozone is an inorganic molecule also referred to as activated oxygen because it is composed of three atoms of oxygen bound together. It is generated by stimulating a flow of oxygen from ambient air, with high energy amounts and causing the atoms of oxygen to split and reorganize into new molecules, oxygen free radicals and O3 (ozone). More than a 100 industries daily use ozone in countless applications. From water treatment to manufacturing processes, equipment maintenance, odor treatment, and preservation of food and raw materials.

Disinfecting Properties

Usually in the form of a gas, it is largely used as a disinfecting agent because of its strong oxidation abilities. When it comes in contact with bacteria, ozone breaks through the cell membrane and neutralizes the bacteria’s essential components (RNA, DNA, enzymes and proteins) leading to its destruction. Not only is ozone a disinfection agent, it is also categorized as a sporicidal agent (kills spores), an algaecide (kills and prevents the growth of algae) and a virucide (destroys or inactivates viruses).

Water Treatment

Ozone is often used in water treatment as a disinfectant. One of its main advantage is that it does not leave residues or byproducts after its application. In normal water, the half-life of ozone is from 10 to 20 minutes while in wastewater, ozone disappears after 9 seconds because it reacts to the particles and debris present in the wastewater. The use of ozone for disinfecting water reduces the need for chemical involvement and spending cost. Ozone is used to treat drinking water, industrial wastewater, it is also used for treatment of cooling towers, for ground water remediation and even in the hydraulic fracturing (fracking) industry among other things. Ozone is also effective to remove colors and bad odors from ground water and wastewater.

Food and Beverage Industry

The second prominent use of ozone is found in the food and beverage industry. Ozone eliminates germs and bacteria the moment it comes in contact with them. Since it can be produced on site, it is a good alternative to other disinfection and sterilization methods. The particularity of ozone is that its application is non residual and does not affect the taste or smell of food such as dairy products. And its oxidation is applied on fruits and vegetable to prolong their life and reduce food production waste. In addition to treating water and food, ozone is utilized to sanitize and sterilize food plants surfaces and equipment.

Oxidation of metal

When they are not oxidized, metals such as iron are quick to pass through mechanical filtration and end their course in water sources. Once there, it is a difficult process to remove them from these waters. So to avoid this situation, oxidation before filtration is necessary for such metal. But the use of traditional oxidizers such as permanganate are costly, residual and have to be closely monitored while with ozone, the oxidation time is quicker at a low dosing. Not only is ozone as effective but it is also less costly.

In the recent years, ozone has proven to be an efficient alternative to numerous commonly used chemicals in water treatment. Used as a disinfectant or oxidizer, it is a very practical element that is making its way into domestic use through portable ozone generator devices. But is water treatment the only domain of application for ozone? To answer this question do not forget to check out our future article part 2, ozone application in air treatment.