Ozone treatment in bottling plants has had a pivotal role since 1970's when the bottling industry was introduced. The challenges faced in the bottling industry were in production, sterile handling and storage due to the contamination with explosive growth in microorganisms. This had a significant impact on taste, odor, and health problems due to lack of disinfection in bottled water. In 1982 Food and Drug Administration (FDA) classified ozone as safe in disinfection applications and Good Manufacturing Practice (GMP) while residual ozone concentration in bottled water can be up to 0.4 ppm. Thereafter many state health organizations has approved ozone as a key component in the bottled water industry, for example (WHO). Recent changes in legislature and industry guidelines have increased the need of ozone in breweries. Ozone is safe to use in water bottling plants while leaving no residual or taste in bottled water according to International Bottle Water Association (IBWA) guidelines.
Ozone is a tri-atomic form of oxygen which is very unstable. Due to this unstable nature, it reduces to oxygen within a very short span of 60 mints. in air and 20 mints. in water. This reduction reaction releases one atom of oxygen which acts as a very powerful oxidising agent and, as a result, a very powerful disinfectant. Because of this nature of ozone, it has proven to be an extremely powerful disinfectant and oxidising agent. It destroys all the air borne and water borne, microorganisms including bacteria, virus, mold, fungi, spores, etc.
As a result of this, ozone has become a mandatory treatment requirement for packaged drinking water treatment. Today it is unthinkable to put up a packaged drinking water plant without the use of ozone. Ozone is used at the end of the treatment line, just before packaging the water. Ozone destroys all the water borne pathogens and also helps reducing some of the organics present in the water. Besides purifying the water, it is essential to maintain some amount of residual ozone in water before packaging. This helps in sterilising the bottle or the jar in which the water is being packaged. Since the half life of ozone in water is 20 mints., there is hardly any residual ozone in water and hence the water is free of any toxicity which is associated with other disinfectants which are present in the water while the water is being consumed. Hence the water is absolutely safe to drink. This makes ozone the most sought after disinfectant for packaged drinkingwater.
The normal ozone plant for the packaged drinking water consists of an ozonator of required capacity depending upon the hourly flow rate of water being treated for packaging, followed by an ozone contact tank. The ozone contact tank is designed to give sufficient time for carrying out the disinfection reaction. The ozone contact tank consists of a recirculation pump in the output of which is connected a venturi injector followed by a static mixer. The venturi injector creates the necessary negative pressure due to the high pressure recirculation pump, and sucks in the ozone in to the water. Static mixer dissolves ozone in to water. The water with dissolved ozone goes in to the tank whose size is designed to give sufficient contact time before it flows out of the tank. The water coming out of the contact tank completely disinfected and is ready for packaging thereafter. The tank, its piping, recirculation pump, venturi injector, static mixer and all the other wetted parts are made from stainless steel 316 grade to withstand the ozone.
In bottled water treatment process, ozone plays a major role as a powerful disinfectant. Nowadays it is hard to imagine a water bottling plant without ozonation process. Ozone improves the quality, consistency, and shelf life period of water. Ozone disinfects not only bottled water, but also disinfects bottles, bottle sealing caps and bottling equipment. Ozone treatment process is environmentally friendly. Ozone has become the best choice of technology among water bottles due to its ability to remove unwanted taste and odor.