In the 1980s, there is a sharp increase in the sales of bottled water and beverage in the world. Since then, consumers have become more health-conscious. So, bottled water and beverage manufacturers are beginning to think about how to ensure the safety of the liquids in the bottles. One of the main challenges they face is how to provide a bacteria-free product that can extend its shelf life. After studying and comparing several disinfection methods, ozone has become the best solution for bottled water manufacturers for its strong ability to disinfect water and its ability to remove undesirable odors from water. Bottled water ozone treatment has been adopted by many water and beverage manufacturers such as Coca Cola and Nestle.
Ozone’s Excellent Performance
As an isotope of oxygen, ozone is a strong oxidant and a very effective disinfectant. Their strength in oxidation, compared with ordinary oxygen molecules, lies in the triangular arrangement of three oxygen atoms in an ozone molecule. This unstable structure allows ozone molecules to seek out and react with electrons from other molecules. In the process of reacting with other molecules, the structure of ozone molecules will be broken down and reduced to oxygen molecules, while the molecules of other materials will also be oxidized.
Ozone is applied in water treatment for its strong oxidizing properties. Ozone can oxidize both organic and inorganic matter, with its oxidizing capacity 52% higher than chlorine. Ozone can remove unwanted tastes, smells and colors from water. It is also capable of removing microorganisms such as cryptosporidium, which cannot be treated by chlorination. Ozone can also be used to oxidize and remove elements such as iron and manganese from water. After the process, ozone molecules will break down into regular oxygen molecules in about 20 minutes. So, there will be no concern about leaving any by-product of the disinfection reaction in the water. Thus, compared with other disinfectants, ozone disinfection is a benign process.
Ozone for Bottled Water
In the bottled water production industry, ozone is commonly used to disinfect products in three ways. They are inline atmospheric contacting, batch processing, and inline pressure contacting.
In the inline atmospheric contacting method, product water will first be pumped from a storage tank and injected into an atmospheric stainless steel contact tank. Ozone is then injected into the water via Venturi ejectors or diffusion stones. In the contact tank, the contact time between water and ozone needs to be controlled to ensure effective treatment. Also, an ozone detector is required to ensure adequate ozone levels.
In the batch processing method, storage tanks will first be treated with ozone until the desired level is reached. There are two common oxidation methods for storage tanks: circulation method and bubbling method. The circulation method uses an ozone generator, a circulating pump and a Venturi ejector to produce and introduce ozone into the water stream. The bubbling method uses an ozone generator and an air pump. Ozone is injected into the water by diffusion stones. This method is suitable for small-scale bottled water production.
Inline pressure contacting can be achieved in two ways. The first way is to pump water from a storage tank to the pressurized contact tank through a Venturi ejector. This way requires a return line from the filling machine to the storage tank. The second way requires two water pumps. One works as the primary, and the other as the secondary. The primary pump is responsible for drawing the product water from the storage tank and pushing it through the contact tank and into the filler. The secondary pump is used to increase the pressure of the water through the Venturi ejector and to inject the appropriate amount of ozone into the water. The two streams of water will merge in the pressurized tank. The inline pressure contacting method is suitable for medium scale bottled water production.
As the demand for clean and safe drinking water increases, bottled water producers will have to work hard to find clean water sources and more efficient bottled water treatment methods. Ozone treatment will be the best sterilization solution in the bottled water production industry. Ozone can ensure that the water to be bottled can be efficiently treated before it is ready for sale, and also ensure the good taste in the water for its shelf life. Ozone technology has been a mature solution and has been serving us in the water treatment industry for many years. In the future, ozone will continue to provide an efficient, safe and cost-effective sterilization solution for bottled water and beverage and many other industries.