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Printing inks optimization for ozone dosimeter
Petříčková, Zuzana ; Krystyník,, Pavel (referee) ; Veselý, Michal (advisor)
In the study various methods to measure concentration of ozone were investigated. Emphasis was placed on opto-chemical sensors, which change their colour when exposed to augmented dose of the substance. Numerous solutions have been prepared by changing ratios of substances and were used to make ozone dosimeter. The goal was to produce highly sensitive composition which would change colour noticeably when exposed to ozone, with good mechanical properties when dried up. When the solution with required properties had been discovered, it is suitably for silk-screen printing was tested.
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Generation of ozone by photochemical processes in O2 and admixtures
Tomečková, Klára ; Blahová, Lucie (referee) ; Mazánková, Věra (advisor)
Ozone is a toxic gas with the fatal impact to living organisms at high concentrations. Therefore, this gas is useful in sterilization in many cases. The subject of this work is the generation of ozone using various methods and determination of its concentration. Then the generated ozone can be used in ozone therapy. The theoretical part deals with properties and use of ozone. In addition, information gathering connected to ozone was performed. It was about methods of ozone generation and subsequently about the diagnostics determine of ozone concentration. In the experimental part the ozone generation and determination of its concentration was performed using spectrophotometric method and iodometric titration. The ozone concentration in the air was also measured over the long term using the Schönbein method.
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Determination of the ozone concentration generated by dielectric barrier discharge.
Manduchová, Ivana ; Töröková, Lucie (referee) ; Mazánková, Věra (advisor)
The bachelor´s thesis is focused on the study of determination of the ozone concentration generated by dielectric barrier discharge from high-purity oxygen gas of 99,999 9 %, at changes in different experimental conditions, using absorption spectrometry. The emphasis was put also equally on the comparison of two representatives of the basic methods determining the concentration of ozone. In the theoretical part are described characteristic properties of ozone and fields of utilization, methods of ozone generation, experimental methods of determining the concentration of generated ozone and microbicidal effects of ozone. In the experimental part was investigated the generation of ozone created by interaction of oxygen with oxygen adsorbed on the walls of ozonizer depending on variation of experimental conditions. Multiple series of experiments were conducted, where the changing variable of experimental conditions was the change of voltage on power supply, the flow change of oxygen and the change of reaction time period. Besides of these, there has been also examined the applicability of determining the concentration of ozone using iodometric titration in comparison with the method of UV absorption at conditions used in the experiment. Ozone was generated by assembly of two identical cylindrical ozonizers made from stainless steel functioning on principle of dielectric barrier discharge using dielectric from alumina.
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Study of Inkjet Inks Degradative Processes
Samcová, Kateřina ; Čeppan, Michal (referee) ; Veselý, Michal (advisor)
This diploma thesis follows the degradation of inkjet print by ultraviolet radiation and ozone effect for different types of papers. Colour test charts for the evaluation of accelerated ageing effect of ultraviolet light and gas fading were designed. These test charts were printed by dye-based inks on selected receiving media and exposed to ozone-enriched environment, UV radiation and their combination. The colorimetric values L* a* b* were calculated from spectral data of all patches of the test charts. The ozone effect on the prints was evaluated in the terms of total colour difference and dye concentration. The degradation of dye caused by ozone was observed also in a long-term period, after the contact of sample with ozone was terminated. Results of printed samples accelerated ageing by UV radiation and those that were influenced by the ozone effect were evaluated in the same way. It was found out that UV radiation and ozone treatment have a different effect on the degradation of dyes. The degradation rate is also strongly influenced by the receiving layer composition of papers used for inkjet printing. Also the catalytic effect of dyes was evaluated.
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Conceptual design of a specific industrial process
Beneš, Daniel ; Babička Fialová, Dominika (referee) ; Jegla, Zdeněk (advisor)
This bachelor thesis deals with the conceptual design of the specific industrial process for the thermal destruction of residual ozone using the Pinch Technology method. In the theoretical part of the thesis, the issue of production, use and destruction of ozone is summarized. The theoretical foundations of the Pinch Technology method for conceptual process design are also introduced. The practical part of the thesis deals with the conceptual design of a specific process for the thermal destruction of residual ozone, based on specified industrial data, with a technical-economically optimal heat exchange size, including a subsequent decision on a suitable heat exchanger for this process.
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Printed ozone dosimeter
Védlová, Petra ; Čeppan, Michal (referee) ; Veselý, Michal (advisor)
This diploma thesis deals with ozone measurement methods, especially focusing on opto-chemical methods, when the color change of the sample is examined. Moreover it deals with dyes that are sensitive to ozone and their degradation kinetics. In the experimental part kinetics of dyes Orange I, Orange II and Indigo carmine is examined, These dyes are prepared in the form of ink of different composition. These inks are applied to diverse substrate materials by the material printing method, further by using a Baker film aplicator and in the end by the screen printing method. The properties of the samples are evaluated as well as factors affecting their degradation.
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Assessment of the drinking water treatment plant effectiveness via ecotoxicological tests and screening analyses
Nývltová, Barbora ; Mravcová, Ludmila (referee) ; Zlámalová Gargošová, Helena (advisor)
The quality of raw water is deteriorating with the continuous increase in environmental pollution. Raw water is being modified to drinking water by technological processes, and it is therefore necessary to put increased demands on the efficiency of these technological processes and their possible innovation. Due to the fact that raw water is contaminated with different types of pollutants, it is necessary to continuously control the drinking water supplied to the public distribution network in order to ensure its quality. Drinking water treatment is still unable to treat the raw water perfectly, its pollution is only reduced to acceptable standards. For this reason, it is indispensable that the quality of drinking water is being checked regularly and at the same time the efficiency of individual technological processes of drinking water treatment is assessed. This includes screening analysis or eventually ecotoxicological tests. The thesis focuses on the efficiency of technological processes of drinking water treatment. Within the experimental part, samples of raw water and samples of water after each separation stage have been collected at the drinking water treatment plant in the Czech Republic. These samples have been subjected to ecotoxicological tests and screening analysis. Based on the ecotoxicological tests carried out on Thamnocephalus platyurus, Lemna minor and Vibrio fischeri, we can assume the emergence of harmful chlorinated by-products, resulting to nearly 100% mortality in T. platyurus. The results of the screening analysis carried out indicate, after the extraction of specimens by the SPE method using HPLC/MS, that the most effective method for the removal of hormonal substances is ozonization.
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Influence of surface electrodes on the ozone generation in the dielectric barrier discharge.
Mierna, Jana ; Dzik, Petr (referee) ; Mazánková, Věra (advisor)
The bachelor´s thesis is focused on the study of influence of adsorbed gases on the electrode surface on ozone generation in dielectric barrier discharge. The theoretical part describes some basic properties and applications of ozone, methods of its generation, determination and interaction with the solid surfaces. In the experimental part was studied formation of ozone by the recombination of molecules and atoms of oxygen on the wall of electrodes and also its destruction caused by the reaction with particles present in closed ozoniser without discharge. Ozone was generated in cylindrical configuration system of electrodes made of staniless steel and alumina ceramics as dielectric material. Several series of experiments were measured by using various operating gases (oxygen; oxygen and argon; oxygen and nitrogen). It was also examined the decrease of generated ozone concentration in long-term operation by using pure oxygen of 99,999 90 % as a feeding gas. The resulting ozone concentration for given reaction time of individual measurements was determined by the method of absorption spectrometry.
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Organic dye decomposition by AOP´s methods
Olexová, Barbora ; Dzik, Petr (referee) ; Kozáková, Zdenka (advisor)
This diploma thesis is focused on the study of the influence of advanced oxidation processes on degradation of organic dyes. The field of AOP – very effective physically-chemical methods of wastewater treatment – includes application of strong oxidation agents, UV and ionizing radiation and electrical discharges. For this thesis, two of these methods were chosen – the application of oxidation agent (ozone) and UV radiation. Along with electrolysis, which is mentioned rather marginally in this thesis (it is the subject of the previous thesis), these phenomena are products of electrical discharge in water, where they participate in the processes of degradation in a different way. For all measurement series, two direct azo dyes were chosen as model substances – C.I. Direct Blue 106 and C.I. Direct Red 79. The ozonizer, in which either oxygen or synthetic or technical air were loaded as carrier gases, was used for degradation of dyes by ozone. The generated ozone was loaded into the bubbling vessel with dye solution of different initial concentration (10–130 mg.dm-3), which was followed by other bubbling vessel with KI solution for the next analytical determination of the amount of generated ozone. The other parameters changed were the gas flow (1–2 dm3.min-1), ozonizer output (minimal and maximal), type of dye, pH value of the solution (neutral or acid) and additional electrolyte (NaCl, Na2SO4 or any). The reactor for the study of the influence of UV radiation on degradation of dyes was an UV sterilizer into which the equivalent volume of dye solution was added. The possibilities of experimental settings were limited and only the type of dye, an additional electrolyte and pH value of the dye solution were adjusted (as in the case of ozone). Several series of samples were measured with various input conditions which more or less influenced the degradation of investigated dyes in this experiment. It was found that for both used methods the Direct Blue 106 dye was more degradable (with significantly better results for ozone than for UV radiation). The degradation of Direct Red 79 dye proceeded only by ozone treatment, in the case of the application of UV radiation no degradation occurred. By investigation of the influence of initial concentration of dye on its degradation, it was confirmed that with the initial concentration enhancement the final concentration rises as well, whereas in low concentrations (10–50 mg.dm-3) the initial concentration has no effect. The addition of an electrolyte had an accelerating effect on dye degradation in both methods (NaCl and also Na2SO4 showed similar results though the degradation proceeded in different ways). The addition of HCl accelerated the degradation only in the case of UV radiation; during the application of ozone the pH level of the system did not have any influence on the degradation. Oxygen and synthetic air had the strongest effect on ozone degradation (comparable results); in the case of technical air the final dye concentration was higher up to 30 %. The gas flow of 1.5 dm3.min-1 was stated as optimal with the ozonizer output 30 W (maximal). At minimal power the ozonizer produced very low amount of ozone.
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Test cell for ozone degradation of tires
Píza, Tomáš ; Veselý, Oldřich (referee) ; Brandejs, Jan (advisor)
This diploma thesis is occupy by assesment optimum method straining of tyres and then constructional concept of test cell for ozone degradation of rubber tyres with sizes from 13” to 15”. The final aim of this diploma thesis is construction of test cell which is based on choice of optimum method straining of tyres. The next output of this diploma thesis is concept of unit for ozone degaradation of tyres.
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