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Plasma activated water prepared by electrical discharge in liquids
Možíšová, Aneta ; Krčma, František (referee) ; Kozáková, Zdenka (advisor)
The aim of the diploma thesis is generation of active particles in plasma activated water (PAW) using a low-temperature plasma discharge. In this work I focus on the determination of hydrogen peroxide, nitrites and nitrates as active particles. The practical part is focused on a specific case of use of a plasma discharge in selected electrolytes dissolved in an aqueous solution. Here, three phosphates, differing in the number of acidic hydrogens, were selected for each experiment, and sodium chloride and tap water were compared for comparison. Phosphates were selected for their stable pH during plasma discharge in solution to monitor the effect of pH. The experiments were focused on investigating the stability of active particles in PAW, under which conditions is the highest production rate of these particles and what effect the pH value has on the result. It was found that hydrogen peroxide is generated the most in an alkaline environment but shows better stability in neutral. The concentration of generated nitrites is not high, but it shows stability, regardless of the polarity of the main electrode used for PAW generation. Nitrites were generated the most in alkaline environment and nitrates in acidic environment. One of the conclusions is that nitrates are not a very stable particle in PAW. Thanks to the activation and oxidation properties of plasma activated water, this method can be used in medicine or agriculture
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Study of plasma activated water properties
Maďarová, Štefánia ; Trunec, David (referee) ; Mazánková, Věra (advisor)
ABSTRAKT The goal of the diploma thesis was to carry out professional research focused on the formation of chemically active particles in plasma and their identification. The experiment was performed for the preparation of plasma activated water (PAW), using a hydrodynamic cavitation plasma jet device (HCPJ). The main goal of the experimental part of the thesis was the analysis and determination of the concentration of active particles generated during the experiment. The active particles I dealt with in my work were nitrates, nitrites and hydrogen peroxide. Samples of commercial (Danube) water, treated distilled water, treated tap water and treated Mixbed water were analysed. In addition to the production of reactive particles, their temporal stability was also studied. The samples were stored at room temperature. As the samples aged, the concentration values of the active particles changed due to mutual interactions between the particles, when nitrites were oxidized to nitrates. Physical properties of PAW, pH value and conductivity were monitored in the work. After PAW preparation, the conductivity increases due to the increase in the concentration of active particles created during the dissociation and ionization of water molecules by plasma treatment. The particles present in the air contribute to the increase in conductivity, they dissociate and ionize the plasma, which diffuse into the liquid. A drop in pH is the cause of an increase in the concentration of hydrogen ions and the formation of nitric acids. It was found that PAW does not retain its activated effects for too long, with aging the concentration of active particles decreased. The theoretical part is focused on plasma-activated water, its preparation, produced particles and their stability. The work also describes the use and application of PAW in agriculture, biomedicine and other industries. Various types of plasma discharge preparation are described. I also deal with the preparation of Mixbed water from Danube water. In the diploma thesis, we analyzed the plasma discharge using optical emission spectroscopy (OES). The measurement by OES was in the range of wavelengths from 200 to 1100 nm. The measurement by OES was in the range of wavelengths from 200 to 1100 nm. In the overview spectrum using tap water measured in the visible region, H-alpha, H-beta, H-gamma can be seen.
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Plasma activated water prepared by electrical discharge in liquids
Možíšová, Aneta ; Krčma, František (referee) ; Kozáková, Zdenka (advisor)
The aim of the diploma thesis is generation of active particles in plasma activated water (PAW) using a low-temperature plasma discharge. In this work I focus on the determination of hydrogen peroxide, nitrites and nitrates as active particles. The practical part is focused on a specific case of use of a plasma discharge in selected electrolytes dissolved in an aqueous solution. Here, three phosphates, differing in the number of acidic hydrogens, were selected for each experiment, and sodium chloride and tap water were compared for comparison. Phosphates were selected for their stable pH during plasma discharge in solution to monitor the effect of pH. The experiments were focused on investigating the stability of active particles in PAW, under which conditions is the highest production rate of these particles and what effect the pH value has on the result. It was found that hydrogen peroxide is generated the most in an alkaline environment but shows better stability in neutral. The concentration of generated nitrites is not high, but it shows stability, regardless of the polarity of the main electrode used for PAW generation. Nitrites were generated the most in alkaline environment and nitrates in acidic environment. One of the conclusions is that nitrates are not a very stable particle in PAW. Thanks to the activation and oxidation properties of plasma activated water, this method can be used in medicine or agriculture
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