An effective ozone water treatment process needs to have a good ozone contact system. This system must efficiently transfer the ozone gas into the water and then provide a sufficient contact time for ozone to react with the micro organisms and chemicals in the water. The mixing of ozone with water ozone is usually done with an ejector or venturi. These systems can achieve transfer efficiencies of 85-95%. The system should allow enough time for the ozone to act on the constituents of the water to insure proper disinfection and removal of unwanted chemicals. The amount of ozone required is determined by the ozone demand of the water. Any constituent that can be oxidized by ozone will consume ozone must be satisfied while leaving an excess residual.

The excess residual will insure that all pathogens have been inactivated if sufficient contact time has been provided. Typically, testing is needed to define the ozone demand of specific water. Besides the specific constituents of the water, other factors impact ozone demand. These include: pH, temperature, filler design, operating procedures, etc. Process control for ozonation will focus on the proper dosage of ozone into the water to achieve the necessary residual without adding excess ozone to the water. A typical configuration will involve a contact tank with a recirculation loop. Ozone is injected into the recirculation loop and the tank provides the proper contact time for the reaction of the ozone with the water. The system will have a level control and vent. The vent will allow excess ozone gas released from the water to pass into an ozone destroyer (decomposer). The decomposer prevents excess ozone from entering the atmosphere of the bottling plant.