Development of a Practical Method for Using Ozone Gas as a Virus Decontaminating Agent

Our objective was to develop a practical method of utilizing the known anti-viral properties of ozone in a mobile apparatus that could be used to decontaminate rooms in health care facilities, hotels and other buildings. Maximum anti-viral efficacy required a short period of high humidity (>90% relative humidity) after the attainment of peak ozone gas concentration (20–25 ppm). All 12 viruses tested, on different hard and porous surfaces, and in the presence of biological fluids, could be inactivated by at least 3 log_10, in the laboratory and in simulated field trials. The ozone was subsequently removed by a built-in catalytic converter.     

Microbiological Environmental Monitoring After the Use of Air Purifier Ozone Generator

The work aimed to evaluate the indoor microbiological air quality after using the purifier ozone generator (Brizzamar®), by counting the total viable microorganisms. The plates containing the culture media were exposed on pre-defined locations for 10 min at the times 0 h (without purifier), 1, 2 and 3 h (with purifier). The results showed significant decreases in the microorganisms after using the purifier, reaching a reduction up to 80% of the fungi and bacteria in the environment after two hours. The amount of ozone in the atmosphere was kept at 0,01 ppm, which is considered non-toxic to human exposure. The purifier significantly improved the air quality in indoors.     

Recent Developments in Food and Agricultural uses of Ozone as an Antimicrobial Agent-Food Packaging Film Sterilizing Machine using Ozone

Recent food putrefaction with new strains of microorganisms, such as Lactic acid bacteria and disinfectant-resistant strains of gram-negative bacteria, mold, yeast have increased interest in exploring different disinfection techniques for food sanitation. In Japan, food processing companies consider Lactic acid bacteria and gram-negative bacteria, mold, yeast, to be of greatest concern because of the severity and number of food putrefaction they cause. We supplied a laboratory machine that sterilizes for food packaging film and preformed cups using ozonated water and ozone gas. UV-ray sterilizing can be used for support. Ozone should be useful in reducing the degree of microbial contamination caused by inadequate disinfection against new resistant strains. There is growing tendency to use ozone in food industry as an effective means of disinfection without any additives. Many types application equipment have been developed. Based on the properties of ozone as a strong germicidal agent, conversion of factories to use ozone for sterilization of food packaging film is being implemented.     

The Ozone Laundry Handbook: A Comprehensive Guide for the Proper Application of Ozone in the Commercial Laundry Industry

Applications of ozone in commercial laundry systems began in the late 1980s–early 1990s. Early installations showed promise for ozone to save considerable energy over conventional (thermal) systems. However, inconsistent performances of ozone equipment of that period coupled with a lack of in-depth understanding of how ozone was performing hindered commercial acceptance of ozone. With continued study and testing, these early misunderstandings about ozone have been overcome, and today many thousands of commercial laundry systems are using ozone successfully in many parts of the world. For example, more than 2,000 ozone laundry systems are operating in commercial laundry systems in the USA and another 2,000 commercial ozone laundry systems in the United Kingdom alone! Based on proven performance data obtained from many of these successful applications of ozone in commercial laundry systems, the authors have developed an Ozone Laundry Handbook, intended to be a summation of current knowledge and a guide to the laundry owner/operator considering the use of ozone. The Handbook contains 10 chapters, including discussions of the economic, environmental and microbiological benefits of ozone in commercial laundries, a discussion of ozone technologies as they apply to laundry systems, a comparison of traditional vs ozone laundry formulations, methods of applying ozone for laundering, operator training and ozone safety, a discussion on facts and fallacies about ozone for laundering, and finally a chapter on the future of ozone for laundering. The Handbook also contains a Glossary of Ozone Terms, Indices, and an Index.     

Research Note: Measurement of Ozone via an Indirect Gas Chromatography Method

Gas chromatography was used to measure the ozone concentration in oxygen produced by an ozone generator. In this indirect method, the ozone reacts with the coating of the capillary column and produces carbon dioxide, which is then detected. The primary methods of calibration for this technique were based on a wet-chemistry process and absorption of ultraviolet light. This finding also is important if the primary reason for using gas chromatography is detection of carbon dioxide, as artificially high readings of carbon dioxide would be measured in the presence of ozone. The method was tested for ozone concentrations of 3–70?mg/L but the method should also be applicable to higher concentrations.     

Effects of Ozone Gas Exposure on Toxigenic Fungi Species from Fusarium,Aspergillus, and Penicillium Genera

The antifungal properties of ozone (O₃) gas exposure towards toxigenic fungi were evaluated in laboratory-scale treatments trials. O₃ gas was utilized at a concentration of 60 μmol/mol at different times of exposure, which efficiently inhibited the fungi colonies growth, especially F. graminearum and P. citrinum. At the concentration applied, O₃ gas exposure was able to inhibit conidia germination, caused hyphae morphological alterations that led to hyphae death and ROS production of all fungi tested. O₃ action can be related to cell metabolism alterations, leading to apoptosis and oxidative stress, showing to be effective on controlling toxigenic fungal development which is one of the main problems regarding food contamination.     

Reaction Kinetics of Ozone Gas in Green Gram (Vigna radiate)

This study was carried out to evaluate the reaction kinetics of ozone gas in different height (5 and 10 cm), moisture content (10.6 and 13.4% (d.b.)) and gas flow rate (2 and 4 L/min). The decomposition kinetics obtained was first-order model. As far as the half-life of ozone is considered, the highest value obtained was equivalent to 8.72 min for grains ozonated at 5 cm height, 10.6% (d.b.) moisture content and 2 L/min gas flow rate. In the process of ozone reaction rate in green gram grains, height (p < 0.01) and moisture content (p < 0.01) were found to be the key factor for the effectiveness of ozone fumigation.     

Ozone Applications in the Post-Harvest of Papaya (Carica papaya L.): An Alternative to Amistar Fungicide

The objective of this article was to evaluate ozone applications in the post-harvest of papaya (Carica papaya L) as an alternative to Amistar fungicide, taking into account the effect on the control of fungal pathogens growth, shelf-life, seed germination percentage and soluble solids content. Ozone doses were applied in vitro to strains of seven fungi species, which cause rot of papaya. Papayas cv. Maradol-red were harvested and treated with gaseous ozone (500 mg m^?3), ozone-containing water (1 mg L^?1) and a solution of Amistar fungicide (0.1 ml L^?1). They were stored for 10 days. Washing with ozone-containing water was found to be the most favorable alternative. The ozone use showed a delay in fruit ripening. The effect on seed germination percentage and soluble solids content was not significant. A methodology for ozone use in the post-harvest phase was proposed.     

Equilibrium,Thermodynamic, and Kinetic Studies on Trichoderma viride Biomass as Biosorbent for the Removal of Cu(II) from Water

Equilibrium, thermodynamic, and kinetic studies on the biosorption of Cu(II) using biomass, Trichoderma viride were carried out. The biosorbent was characterized by Fourier transform infrared spectroscopy and Scanning Electron Microscopy. The Langmuir and Freundlich isotherm models were applied to describe the biosorption process. The influence of pH, the biomass dosage, the contact time, the initial metal ion concentration, and the temperature of the solution on the biosorption was studied. The maximum Cu(II) biosorption was attained at pH 5. The equilibrium data were better fit by the Langmuir isotherm model than by the Freundlich isotherm. The maximum biosorption capacity of T. viride biomass was found to be 19.6 mg/g for Cu(II). The kinetic studies indicated that the biosorption of Cu(II) followed the pseudo-second-order model. The calculated thermodynamic parameters, Gibbs-free energy (ΔG^o), enthalpy (ΔH^o), and entropy (ΔS^o) showed that the biosorption of Cu(II) onto T. viride biomass was spontaneous and endothermic. It can be concluded that the T. viride biomass has the potential as an effective and low-cost biosorbent for Cu(II) removal from aqueous solutions.     

Verification of Ozone Clusters (O6 & O9)

The use of silica gel for the storing of ozone was investigated. The ozone gas that was discharged from the silica gel was found to be different from normal ozone which is generated by the ozone generator that makes ozone with electric discharge. Ozone clusters could be synthesized by this method, which detaches ozone from silica get without requiring any additional energy. These ozone clusters didn't decompose at room temperature and atmospheric pressure over a half-day. We confirmed that the cluster was heavier than a heavy standard gas, the presence of clusters with an analysis using GC/MS, and the existence of ozone clusters by the bonding energy using a computer simulation by MOPAC.     

The Use of para-Chlorobenzoic Acid (pCBA) as an Ozone/Hydroxyl Radical Probe Compound

Since OH^· radicals cannot be measured directly during an ozonation process, para-chlorobenzoic acid (pCBA) has been used recently as an OH^· radical probe compound during ozonation based on its very slow direct reaction with ozone and fast reaction with OH^· radicals. However, in experiments of this study it was shown that pCBA accelerated ozone decay. Furthermore, the formation of hydrogen peroxide was observed during this process. The formed H₂O₂ increases the decomposition of aqueous ozone and leads to enhanced formation of OH^· radicals. The chain reaction therefore changes to HO₂ ^? ion initiated decay of ozone instead of hydroxide ion, OH^?. Thus, an error in applying pCBA as a probe compound in low scavenger containing waters is likely to occur if the scavenging rate of pCBA makes up more than 5% of the total scavenging rate.     

The Use of Gaseous Ozone as a Cleaning Agent on Stainless Steel Surfaces Fouled with Bovine Protein

Facilitation of cleaning of stainless steel particles fouled with heat-treated bovine serum albumin (BSA) was studied using gaseous ozone generated from a pure oxygen-fed ozonizer at concentrations of 0.1 to 0.5% (v/v). Ozone pretreatment markedly accelerated the rate of BSA desorption during subsequent caustic alkali cleaning. The effect of ozone pretreatment depended on the concentration of ozone and it was attributed to partial decomposition of BSA molecules into some fragments. It was also found that the surface charge property of stainless steel particles was modified by ozone oxidation, resulting in the improvement of the cleanability of stainless steel surfaces.     

The Influence of Ozone on Tumor Tissue in Comparison with Healthy Tissue (in vitro)

In comparison with healthy tissue, freshly operated carcinomatous ovarial tissue was treated in vitro with ozone in a suitable medium using air as the reference. In an analogous test arrangement and for reference purposes, the cytostatics Adriblastin (= Doxorubicin, an adriamycin) and Holoxan (= Ifosfamide, a cyclophosphamide) were included for the tumor tissue. After preparation of the tissue samples, the following substances were examined: 2,3-DPG, NAD (Nadide, DPN), Lecithin, Lysolecithin plus different enzymes and metabolites both in the mitochondrial fraction as well as, in the supernatant layer, the following: LDH, α-HBDH, Aldolase, ICDH, F-6-PK, cytochrome oxidase, Na, K, Ca and peroxidic metabolites.     

Analysis of Ozone in Aqueous Solutions Using A Modified Iodometric Technique with as (III)

A modified iodometric procedure using an absorbing solution of 2% NBKI with a known amount of As(III) is described for 10 ml aqueous samples. Ozone contents from 0.5 to 65 mg O3/I were determined. High ozone concentrations can also be measured for generator calibration. This method gives results which are not significantly different than a boric acid method but are for a modified standard methods procedure. Volatility of iodine has been completely eliminated. Stabilized samples do not make the time between sampling and final titration critical.     

Destruction of Helminth (Ascaris suum) Eggs by Ozone

Based on the properties of ozone as a strong germicidal agent, the inactivation kinetics or disintegration of Ascaris suum eggs in water were studied. Ozone was applied in synthetic samples, the concentration of dissolved ozone in the liquid phase was typically between 3.5 to 4.7mg/L, pH 5, 9. The value of 90% inactivation (t₉₀) obtained was at 1 h, the remaining 10% being inactivated in 2 h. A linear correlation between the logarithm of bacterial or yeast concentration (N) and contact time was found, being the linear significant correlation coefficient (r of 0.95). That 2-log inactivation occurred at a CT value near 4.7mg/min/L. The best reduction percentage was of 99.00 in 120min. It therefore could be demonstrated that ozone indeed induces effects on the helminth eggs.     

Oxidation of Methyl tert-Butyl Ether (MTBE) and Ethyl tert-Butyl Ether (ETBE) by Ozone and Combined Ozone/Hydrogen Peroxide

The aim of this work was to study the reaction of ozone and combined ozone/hydrogen peroxide on oxygenated additives such as methyl tert-butyl ether (MTBE) and ethyl tert-butyl ether (ETBE) in dilute aqueous solution using controlled experimental conditions. Experiments conducted in a semi-continuous reactor with MTBE and ETBE in combination (initial concentration: 2 mmol/L of each) showed that ETBE was better eliminated than MTBE with both ozone and combined O₃/H₂O₂. Batch experiments led to the determination of the ratio of the kinetic constants for the reaction of OH°-radical with MTBE and ETBE [k_OH°/ETBE/k_OH°/MTBE = 1.7). Tert-butyl formate and tert-butyl acetate were identified as the ozonation byproducts of MTBE and ETBE, respectively, while tert-butyl alcohol was found to be produced during the ozonation of both compounds.     

Evaluation of Variations in Ground-Level Ozone (O3) Concentrations

This article presents the results of measuring the concentrations of ground-level ozone (O₃) in ambient air and meteorological parameters (atmospheric pressure, temperature, wind speed, and relative humidity during the year 2008. The measurements were performed at measuring station located near Campo Grande, away from local sources of O₃. Fourier analysis, Principal Component Analysis (PCA) and Multiple Linear Regression (MLR) were used as tools for mathematical analysis of the indicated occurrence. The results of Fourier analysis indicate that not only the daily cycles but also the weekly and monthly cycles are visible in all periods as well as the 12-h cycles. The statistical analysis of the obtained data, based on PCA have shown that approximately 60% of the variance in the measured values can be described with two factors. The attempt of O₃ distribution modeling, using MLRA, resulted in a linear model whose coefficient of determination was equal to R² = 0.98. The results of the study indicate that all these methods are useful for understanding the impact of meteorological parameters on variations of ozone concentration over time.     

Degradation of Cellulose Models During an Ozone Treatment. Ozonation of Glucose and Cellobiose With Oxygen or Nitrogen as Carrier Gas at Different pH

Many parameters can influence the kinetics of cellulose models ozonation. In this work the effect of pH and oxygen as gas carrier on the evolution of the reaction was studied. The involvement of free radical species seemed to be unimportant in high ozone concentration available in water, even at high pH with regard to the reaction rate and by-product formation. Conversely, in basic pH conditions better reaction selectivity with formation in a higher yield of gluconic acid and cellobionic acid was found during the glucose and the cellobiose ozonation. The participation of the solvent and the partial ionization of the hydroxyl group at the Cl position explain this enhanced selectivity. Furthermore, the formation of compounds with a low molecular weight has been proved to be due to a hydrotrioxide fragmentation mechanism involving oxygen.     

An AM1 Study of Decomposition of Ozone on a Cu(110) Surface

The decomposition of ozone on a Cu(l10) surface has been studied using AM1 method. O₃ probably adsorbs on Cu(l10) to decompose into a molecular oxygen and an adsorbed atomic oxygen species, an adsorbed atomic oxygen reacts with O₃ to form an O₄ ^-intermediate, and O₄ ^- decomposes into two oxygen molecules. Intermediates, O₃ ^-, O₄ ^- and O₂ ^- are presumably involved in this process. Adsorbed atomic oxygen species are concluded to be stable on a Cu(l10) surface and to have low reactivity to O₃, which agrees with the experimental results in literature.