V. Baratharaj
April 5, 2016

Packaged water Industry uses ozone during bottling of the product. BIS has made this compulsory before bottling approvals are given. Manufactures that do not have ozone in the production line are made to integrate ozone when they approach the BIS for annual renewals.

What has made ozone compulsory in bottled/packaged water Industry? While normal production process takes care of initial bacterial contamination, there are issues at a later stage during bottling. Also ozone provides other benefi ts while it provides a residual disinfectant level during bottling.

The raw water undergoes initial chlorination, filtration (sand and carbon), RO and cartridge filtration and UV process before it is sent for bottling. The initial process takes care of contamination, and chlorine residual before bottling. The process water meant for bottling does not contain any residual disinfectant to take care of contamination due to pet formed bottles, bottle caps, bottling area and also contamination from the workers in the bottling area. Often it is found that contamination takes place at this level and bacterial growth is observed days after the products are sent to the market. QC samples may pass the test but products in the market could be contaminated and there is no insurance against this.

Ozone provides this insurance. Manufacturers who use ozone before bottling will ensure that their product will be bacteria free for months after it leaves the factory. Ozone provides this residual disinfectant and takes care of accidental contamination through pet bottles, bottle caps, fi lling machines and from workers. What are the other benefits of ozone in packaged water? The action of ozone in water can be classifi ed into 4 stages. Benefi ts obtained in ozone treatment will depend on the location of ozone in the treatment process. Ozone can be used in pre-treatment, before filtration and final disinfection. In case an ORP is installed in the process, the ORP level can be taken as an indication of different stages (as compiled from different studies conducted by researchers).

Stage 1: At ORP level 450 mV approximately

• Bio-fouling control
• Oxidation of Inorganic substances like Iron, Manganese, Sulphites, Nitrites, Arsenic, Cyanide

Stage 2: At ORP level 600 mV approximately

• Disinfection of bacteria
• Viral inactivation
• Removal of color, taste and odor

Stage 3: At ORP level 750 mV approximately

• Oxidation of organics, including bacterial toxins
• Turbidity control
• Micro-fl occulation
• THM control

Stage 4: At ORP level above 750 mV

• Ozone residual 0.1 to 0.3 ppm

This does not mean that you cannot achieve a Redox level of above 750 mV if ozone is not used. The Redox level is the oxidation reduction potential of the water and a high level can also be obtained if suffi cient oxidation takes place during the treatment process but knowing the actions of chlorine and UV is most likely that these high levels are difficult to achieve with the kind of chlorine/UV dose used during treatment and the design of the contact time for chlorination.

Using high levels of chlorine during pretreatment will enhance the dangers of formation of THMs in water. THMs are toxic and carcinogenic in the long run. Many large packaged water companies have now incorporated ozone even at the pretreatment stages and have stopped using chlorine to avoid this formation of THMs.

The ozone should be introduced in the water and mixed well if even the slightest benefi ts are to be obtained. Mear introducing the ozone through a hose into the large storage tank, a practice adopted by numerous manufacturers is as good as not having ozone. Ozone should be introduced through a venturi with a well designed pump and sufficient contact tank.


V. Baratharaj V. Baratharaj is Head, Ozone Technologies & Systems India Pvt Ltd. He can be reached at otsilozone@gmail.com, and +91 44 4211 8266.

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