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The paper describes the protection circuit designed as a technological improvement in OZONEY SL, Ozone Generator Equipment designed by engineers at National Center for Scientific Research. This ozone generator is utilized on treatment of water from 450l/h. Ambient air is used to produce ozone gas by means of high voltage. The new design was necessary because of the difficulties produced by absence of water supply for treatment. Some failures affect the equipment if it does not have water to treat. In this case some equipment installed in different organizations has been damaged, because the equipment has been designed to work automatically according to the consumption. To solve this problem a new block of Control and Protection was incorporated to protect the equipment. This paper describes the new control and protection circuit, the block diagrams and how to connect to the original equipment. [ABSTRACT FROM AUTHOR]

Ozone efficiency in the water treatment systems is widely published in national and international papers. The criteria design of the treatment plants have changed over the years with increasing knowledge about the mechanism through which ozone reacts with chemical and microbiological pollutants. It recognizes the existence of a relationship between morphological and physiological characteristics of microorganisms and their resistance to ozone. However, there are few studies reported about the mechanisms by which ozone inactivates microorganisms in aqueous media. The aim of this study was to evaluate the effect of ozone on cytoplasmic membrane and enzymes related to oxidative balance on two microorganisms: Escherichia coli ATCC 25922 and Salmonella enterica var. Thyphimurium ATCC 12 048. From a kinetic study was determined, the variation of the efflux of potassium, changes in SH groups and the action exerted by ozone on the enzymes catalase and superoxide dismutase. The results showed an involvement of SH groups present, mainly, in protein and the potassium efflux outside microbial cells, demonstrating that these compound are among the first targets of ozone on microorganisms. An increased activity of the catalase enzyme and a decreased activity of superoxide dismutase enzyme were observed. The decrease in the relationship between these two enzymes suggests that the antioxidant systems of microorganisms are not able to counteract the damage caused by ozone. [ABSTRACT FROM AUTHOR]

Ozone efficiency in the water treatment systems is widely published in national and international papers. The criteria design of the treatment plants have changed over the years with increasing knowledge about the mechanism through which ozone reacts with chemical and microbiological pollutants. It recognizes the existence of a relationship between morphological and physiological characteristics of microorganisms and their resistance to ozone. However, there are few studies reported about the mechanisms by which ozone inactivates microorganisms in aqueous media. The aim of this study was to evaluate the effect of ozone on cytoplasmic membrane and enzymes related to oxidative balance on two microorganisms: Escherichia coli ATCC 25922 and Salmonella enterica var. Thyphimurium ATCC 12 048. From a kinetic study was determined, the variation of the efflux of potassium, changes in SH groups and the action exerted by ozone on the enzymes catalase and superoxide dismutase. The results showed an involvement of SH groups present, mainly, in protein and the potassium efflux outside microbial cells, demonstrating that these compound are among the first targets of ozone on microorganisms. An increased activity of the catalase enzyme and a decreased activity of superoxide dismutase enzyme were observed. The decrease in the relationship between these two enzymes suggests that the antioxidant systems of microorganisms are not able to counteract the damage caused by ozone. [ABSTRACT FROM AUTHOR]

The objectives of the paper consisted of the evaluation of the economic impact and the water microbiological quality, by applying ozone disinfection. This technology has been installed in water bottled industry, as well as in facilities for the breeding of pathogenic germ-free animals located in the National Center of Laboratory Animal Production and in the Genetic and Biotechnology Engineering Center facilities, where the laboratory animals remain during different drugs evaluation. A procedure to estimate the applied ozone dose and the dissolved ozone concentration at the contact column exit was used. The use of a single contact stage in the practice was valid. The ozone applied in the water treatment as in the bottling of water, as in production units of laboratory animals has a high economic and technical feasibility as compared to other treatments. Ozone guarantees efficient water disinfection. An appropriate treatment for the elimination of microbiological contamination for Pseudomonas aeruginosa in water bottled industry was not found. However, the water ozonization during the bottling process and sanitizing the plant lines, with a high dissolved ozone concentration, provides an adequate disinfection. The conventional thermal water treatment used for the consumption of laboratory animals is difficult and very expensive, being the annual production cost of the ozone treatment around seven times cheaper. [ABSTRACT FROM AUTHOR]

This paper presents the ozonization evaluation of a secondary effluent. Parameters of reactor design as the value of the initial demand and the kinetic constant of consumption of ozone were determined. The obtained values were 1,6 mg/L and 0,192 min-1 respectively. As well as, ozone effluent disinfection was evaluated to determine the most appropriate operation conditions, to guarantee a sure disinfection and to diminish the environmental impact. The ozonization effect on the quality effluent parameters was evaluated. They were chemistry oxygen demand, the absorbance value to 254 nm, conductivity, pH, biochemical oxygen demand and total suspended solids total. The ozone disinfection was very effective for the inactivation of total and fecal coliforms with a Ct of 5 mg.min/L. On the other hand, the secondary effluent was inoculated with a concentration of 3,4 x 10² UFC/mL of Pseudomonas aeruginosa, to simulate a potential contamination. This pathogen microorganism is frequent in this wastewater and it is resistant to the chloration. The results indicated that a dose of 7 mg/L during 5 minutes is enough. The ozone reduces the environmental impact as disinfection stage, since the high chlorine doses generate residual concentrations higher than 3 mg/L. Which is not desirable and it constitutes an ecological risk for the population health, that is supplied of the water receiver body. A design of the contact system was proposed. The chlorination tank can be used as ozonization reactor with a minimum of modifications. The investment costs can be reduced. This diminishes the investment cost for construction cost reduction. A bubble reactor with double baffles is proposed. It is composed by two mixing chambers. The countercurrent contact among the phases is guaranteed. In the third chamber ozone is not injected. The double baffles are recommended to avoid the short circuit effect. [ABSTRACT FROM AUTHOR]

The hydrocarbons are a significant component in urban air because of combustion, solvent and fuel evaporation and tank leakage and most of aromatic compounds are considered as toxic air contaminants (e.g. benzene) or potential toxic air contaminants (e.g. toluene, xylenes). The no-methane hydrocarbons are considered as precursors for ozone production at the ground level when the sunlight and nitrogen oxides are present. This ozone is usually considered as "bad ozone" which can seriously damage our environment and human health. In fact, no-methane hydrocarbons and aromatic hydrocarbons participate in the formation of urban and suburban photochemical smog with their concentrations influencing greatly the total ozone in different percentage. In this paper, we report the results obtained during ten-years of measurements. The air quality determinations were conducted by automatic analyzers and Differential Optical Absorption Spectrometry investigating traditional atmospheric pollutants like ozone, nitrogen dioxide, nitrous acid, carbon monoxide, formaldehyde, benzene and toluene at the ISPESL Pilot Station located in downtown Rome. The trends of benzene, toluene, CO, NO and IPA are decreased, expecially because of introduction of both the green fuel and the autovehicular catalytic pot. Even if the pollutant levels are decreasing, the sources are still the same and, in particular, the emission from the incomplete combustion of LPG is the most important source of pollution in Rome. [ABSTRACT FROM AUTHOR]

Prior studies have proven that proton Nuclear Magnetic Resonance technique can be used to follow up ozone reaction with unsaturated fatty acids. In this paper, ozonation of sunflower oil at a different applied ozone dosage was carried out and peroxide index and aldehydes contents were determined. The reaction products were identified using Proton Nuclear Magnetic Resonance Spectroscopy (¹H NMR). The principal signal intensities values were used for following the reaction course between ozone and sunflower oil. The reaction was following up to peroxide index values of 1 202 mmol-equiv/kg . The intensities of olefinic proton signals decreased with the gradual increase in ozone concentration but without disappearing completely. The Criegee ozonides obtained at 107.1 mg/g of ozone doses were approximately 7.4 folds higher than that at the beginning of reaction. The aldehyde protons were observed as a weak intensity signal in all the spectra. The signals belonging to olefinic protons from hydroperoxides appeared weak with the increase in ozone doses. Signals from other oxygenized groups were assigned. It was concluded that the higher applied ozone doses the higher the ozonation reaction advance corresponding with a higher oxygenized compounds formation. [ABSTRACT FROM AUTHOR]