Ozone sterilization

Guinvarc h, P. Three years of ozone sterilization of water in Paris. Adv. Chem. Set. 21 416-429, 1957. 

The present ozone sterilization installation at Sissach, the only one of its kind, was preceded by a pilot plant test. For over half a year the results of ozone and sulfur dioxide sterilizations were compared. For rapidity of sterilization and the vigor of its bactericidal action, ozone was in every way equal to sulfur dioxide, even with ozone dosages only one hundredth as great. The operating cost with ozone proved to be only about one twentieth the cost with sulfur dioxide. Figure 1 is a schematic outline of the plant-scale process, whose application has been completely satisfactory from the start some 2% years ago. 

During experiments which preceded the adoption of the new ozone process, the results of sterilization with sulfur dioxide were compared with the results of ozone sterilization (with preliminary evacuation). Table I is based on data from a report... 

Although excellent results are obtained by ozone sterilization in 13 to 15 seconds, it is recommended that the sterilization cycle be maintained if possible at no less than 18 seconds. 

Figure 3. Ozone sterilization installation at Sissach, Switzerland...

The experimental data were examined to determine whether any correlation exists between variations in the experimental procedures and the efficiency of the ozone sterilization system. It can be concluded that there was no definite correlation among the flow rate of the gas stream, per cent concentration of ozone in the gas stream, and... 

Three Years of Ozone Sterilization of Water in Paris... 

In Switzerland. The very fine ozone sterilization plant built at Berne includes a novel air-drying installation designed by the Carba Co., Berne. 

In some cases, reverse osmosis is applied, and this removes almost all the particulates and organic materials, as well as microorganisms and endotoxins. Electrodeionization, which combines ion exchange membranes and resins, removes the last traces of dissolved ions from water under influence of a direct electric current. The last stage of the purification is ozone sterilization of water to inactivate residual microorganisms, as ozone is an efficient disinfectant (UV at 254 nm wavelength is then used to break up the spent ozone). The PW generated is then circulated to each point where it is used (point of use POU). 

Pharmaceutical Industry. In the pharmaceutical industry, sterility of deionized water systems is maintained by using an ozone residual. The ozone residual concentration is maintained at >0.3 ppm ppm in the water recirculation loop. Prior to product compounding, the ozone residual is removed by contact with uvirradiaton for <1 s. Ozone also is used to oxidize pyrogens from distilled water destined for intravenous solutions. 

Chlorine Dioxide. Like ozone, chlorine dioxide [10049-04-4] is a powerflil oxidant. It is usually generated as used. It has been used for disinfecting drinking water and bleaching paper pulp. Its effectiveness in killing microorganisms is well documented (305,306), and it has received recent study as a gas to sterilize medical devices. It requites 50% rh or higher to be effective. Bacterial cells had a D-value of 2.6 min and spores of 24 min (307). 

Besides the disinfeetion of sewage effluent, ozone is used for sterilizing industrial containers sueh as plastic bottles, where heat treatment is inappropriate. Breweries... 

Ozone can also be used as an oxidizing agent, but because of its instability, it must be generated on-site. It is a powerful oxidant for some organic materials, but others are oxidized only slowly or not at all. Ozone is only suitable for low concentrations of oxidizable materials. A common use is for the sterilization of water. 

Sterilization. In some processes, such as food and beverage and pharmaceutical processes, water might need to be sterilized before it is reused or recycled. Chemical oxidation (e.g. ozonation) can be used. Ultraviolet light is an alternative for lightly contaminated water. Alternatively, a combination of chemical oxidation and UV light can be... 

Adverse oxidation of membrane occurs at higher concentrations of oxidizers such as chlorine, ozone and hydrogen peroxide. The chemicals are important for slime control, and rather high concentrations of the chemicals are dosed for sterilization of RO feed system, especially in cases of ultrapure water system, and of waste water treatment system. The evaluation of membrane durability against oxidizing chemicals informs us the proper procedures for RO maintenance. 

Ozone is the fourth strongest oxidant known to man and is more effective at sterilizing water than chlorine. Ozone s reaction with NO is a natural phenomenon that takes place in the upper atmosphere that depletes the ozone layer and creates acid... 

Lead dichloride occurs in nature as the mineral cotunnite. The compound is used in making many basic chlorides, such as Pattison s lead white. Turner s Patent Yellow, and Verona Yellow, used as pigments. Also, it is used as a flux for galvanizing steel as a flame retardant in nylon wire coatings as a cathode for seawater batteries to remove H2S and ozone from effluent gases as a sterilization indicator as a polymerization catalyst for alpha-olefins and as a co-catalyst in manufacturing acrylonitrile. 

Ozone has many industrial applications. It is a sterilizing and deodorizing agent. It is used for disinfection of filtered drinking water and to purify waste-waters. It also is used in water treatment plants for removal of metal impurities by oxidizing them into insoluble compounds. This removes undesired taste, odor, and color from the water. Ozone also is used for odor control. 

Since no added substances are allowed, if chloride and ozone are applied in the preparation of purified water, the following should be ensured tests for total organic carbon and conductivity apply to purified water produced on site for use in manufacturing. Purified water packaged in bulk for commercial use elsewhere shall meet requirements of all tests under sterile purified water, except labeling and sterility, per USP XXIV. 

Nevertheless, ozone is beneficial in at least three ways. It is an excellent disinfectant and is used increasingly to sterilize municipal water supplies (Section 14.7). It can also be used as a powerful oxidant in the chemical process industries. Finally, O3 is an important constituent of the ozone layer in the stratosphere. The ozone layer absorbs short-wavelength ultra-... 

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