PUBLISHED CITATIONS OF OZONE DISINFECTION FOR YOUR REFERENCE:
1.) Appl Microbiol Biotechnol. 1998 Jun;49(6):766-9.
Inactivation of bacteriophage lambda, Escherichia coli, and Candida albicans by ozone.
Komanapalli IR, Lau BH.
Department of Microbiology and Molecular Genetics, School of Medicine, Loma Linda University, Loma Linda, CA 92350, USA.
The effects of ozone (O3) on three types of microbes were studied. Test suspensions were exposed to 600 ppm O3 at room temperature. Control experiments were performed under identical conditions using oxygen gas. Bacteriophage lambda was completely inactivated at 10 min while Escherichia coli and Candida albicans were only inactivated by factors of 10(5) and 10(4) respectively at 40 min. Exposure of a mixed microbial suspension to O3 for 5 min resulted in 100% killing of bacteriophages while the viability of E. coli remained unchanged. Various body fluids containing phages were exposed to O3. Compared to buffered solution, the decrease in phage titers was significantly slower in whole blood, plasma, and albumin. Both E. coli and C. albicans had increased production of thiobarbituric-acid-reactive substances with increased O3 exposure. 3H-labelled amino acids were incorporated into E. coli. O3 treatment resulted in a loss of radioactivity, indicating leakage of cytoplasmic contents. The data indicate that microbes are inactivated by O3 at different rates, possibly related to differential membrane permeability. The milieu in which microbes are present determines the effectiveness and outcome of O3 treatment.
2.) Microbiol Res. 1994 Nov;149(4):351-70.
Ozone disinfection dynamics of enteric viruses provide evidence that infectious titer reduction is triggered by alterations to viral colloidal properties.
Vanden Bossche G, Wustmann U, Krietemeyer S.
Institut fur Umwelt- und Tierhygiene sowie Tiermedizin (460), Universitat Hohenheim, Stuttgart, Germany.
The inactivation dynamics of three enteric virus species (polio-, rota- and parvovirus) were analysed in different aqueous suspensions by using O3 under continuous flow conditions. A mathematical model for the reaction rate of infectious titer reduction was proposed, based on the thermodynamic principles of phase behaviour of colloids suspended in aqueous environments. Up to a certain threshold dosage of residual ozone (RO), and depending on the type of test virus and the ionic or organic load in the stock suspension, the logarithm of the reaction rate constant of viral inactivation rate was observed to vary in a rather sigmoidal manner with log RO concentration. Data from photon correlation spectroscopy, electron microscopy and tensiometric analysis suggested that below the threshold RO, the pattern of virus inactivation dynamics reflects the varying potential of different-sized viral particles (VPs) to adsorb to the cellular monolayer. There is strong evidence that oxidant-induced surface activity of organic matter causes redistribution of VP infectivity. This hypothesis was statistically corroborated inasmuch as experimental inactivation data proved to be satisfactorily fitted by a logistic equation. It was concluded that viral infection, and thus viral inactivation, is a complex process which is governed largely by the classical laws of colloidal behaviour. The latter is suggested to appreciably determine the capability of inoculated VPs to infect host cultures. This notion may especially be cause for concern when regulatory requirements for virus disinfection are being based on titration results from in vitro testing procedures.
3) Sci Total Environ. 1981 Apr;18:245-61.
Advantages and disadvantages of chemical oxidation and disinfection by ozone and chlorine dioxide.
Fiessinger F, Richard Y, Montiel A, Musquere P.
Ozone and chlorine dioxide present definite advantages and disadvantages over chlorination. Chlorination, particularly for the removal of ammonia and the maintenance of a disinfectant residual in the distribution system has decisive advantages and will be difficult to replace. Ozone and chlorine dioxide seem to produce fewer carcinogenic by-products but the risk for acute toxicity, especially from the chlorites which follow chlorine dioxide, is higher than with chlorine. Chlorine dioxide and more particularly ozone should be considered as useful complements to chlorination, but no strong oxidative treatment should be applied before most of the organic matter has been removed.
4) AIHA J (Fairfax, Va). 2003 Mar-Apr;64(2):222-7.
Demonstration of a hermetic airborne ozone disinfection system: studies on E. coli.
Kowalski WJ, Bahnfleth WP, Striebig BA, Whittam TS.
Department of Architectural Engineering, The Pennsylvania State University, PA, USA.
An enclosed flow-through system using airborne ozone for disinfection and which removes the ozone with a catalytic converter was tested with a strain of Escherichia coli. Petri dishes containing the microorganisms were inserted in a chamber and exposed for 10-480 min to ozone concentrations between 4 and 20 ppm. Death rates in excess of 99.99% were achieved. Survival data is fitted to a two-stage curve with a shoulder based on the multihit target model. Ozone was removed from the exhaust air to nondetectable levels using a metal oxide based catalyst. The possibility of using ozone as an airborne disinfectant for internal building surfaces and catalytically removing the ozone on exhaust is demonstrated to be feasible. A model for the decay of Bacillus cereus under ozone exposure is proposed as an example for predicting the sterilization of buildings contaminated with anthrax. The potential for disinfecting airstreams and removing ozone to create breathable air is also implied by the results of this experiment.
5) J Appl Microbiol. 2002;93(1):144-8.
Interaction of ozone and negative air ions to control micro-organisms.
Fan L, Song J, Hildebrand PD, Forney CF.
Agriculture and Agri-Food Canada, Atlantic Food and Horticulture Research Centre, Kentville, Nova Scotia, Canada.
AIMS: The aims of this study were to investigate the effect of ozone and/or negative air ions (NAI) on the viability of bacteria. METHODS AND RESULTS: Dilute cell suspensions of Pseudomonas fluorescens, Erwinia carotovora pv. carotovora and Escherichia coli were inoculated onto agar and subsequently exposed to ozone and/or NAI. Ozone concentration was maintained at 100 +/- 5 nl l-1 and NAI at 106 ml-1. When exposed to a combination of ozone and NAI, viability among all three bacterial species decreased more rapidly when they were inoculated onto potato dextrose agar (PDA) than onto nutrient agar (NA). A subsequent test examined the effect of ozone and NAI alone or in combination on the bacteria inoculated onto PDA only. Treatment with NAI alone had no killing effect on any of the bacterial species. However, a strong interaction between ozone and NAI was observed. Pseudomonas fluorescens was most susceptible to the combined treatment. Cell viability was reduced to 0.7% after 6 h, while 76% of the cells remained viable when exposed to ozone alone. Viability of Erwinia carotovora pv. carotovora was reduced to 4% after 6 h in the combined treatment compared with 69% when exposed to ozone alone. Escherichia coli was relatively more resistant to the combined treatment; viability was reduced to 40% after 11 h compared with 70% in the ozone alone treatment. CONCLUSIONS: A strong synergism between ozone and NAI on bacterial cell death was found, but the degree of this effect varied depending on bacterial species. SIGNIFICANCE AND IMPACT OF THE STUDY: The synergism of ozone with NAI may provide an effective method of reducing food-borne disease and decay of fresh produce.
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