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Preparation and characterization of plasma activated water
Lemonová, Hana ; Klímová, Edita (referee) ; Krčma, František (advisor)
This bachelor thesis deals with suitable methods for plasma activated water preparation. The plasma activated water is a new way of the indirect plasma application for the treatment of biological materials like food or even for the direct application for therapeutic purposes. The theoretical part is focused on getting acquainted with plasma activated water and methods for its preparation, using various plasma systems. The detailed description of the plasma-liquid systems used during this thesis is given later. The selected physical chemical properties, namely conductivity, pH value and stability of hydrogen peroxide are presented in the results part. An important aspect of this work was to find suitable storage conditions for plasma activated water.
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Assessment of the ecotoxic effect of plasma-activated solutions
Belisová, Mária ; Šimečková,, Jana (referee) ; Zlámalová Gargošová, Helena (advisor)
This master‘s thesis deals with ecotoxicity assessment of plasma-activated solutions. Various plasma-activated solutions were prepared in the experiments. In the vast majority of tests, it was plasma-activated tap water – PAW. Depending on the test organism, dilution water was further processed, namely dilution water for Thamnocephalus platyurus and Daphnia magna. In this master‘s thesis the ecotoxicological effects were assessed through aquatic ecotoxicity tests with an aquatic plant Lemna minor, on a crustaceans T. platyurus and D. magna and on agricultural crops Lactuca sativa and Allium cepa L. . Crustaceans are fresh-water organisms on which the water contamination can be quickly and quite easily assessed. These plasma-activated solutions were also tested for acute ecotoxicity of soil organisms by ecotoxicological contact tests with Eisenia fetida, springtails Folsomia candida and seeds of L. sativa. Tests on T. platyurus and D. magna were performed in time intervals and a change in mortality was observed depending on PAW concentration. If the test results allowed, the LC50, IC50, A and NR escapism values were calculated. When the measured and calculated values did not allow such a calculation, the overall effect of PAW on organisms was assessed and a significant difference was calculated for the L.sativa root growth inhibition test. The final results showed that PAW has an ecotoxic effect on aquatic organisms, while it has rather beneficial effects on terrestrial organisms.
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Study of plasma activated water influence on soil microorganisms
Lungová, Tereza ; Šimečková,, Jana (referee) ; Krčma, František (advisor)
The bachelor thesis deals with the effects of plasma activated water on microorganisms found in the brown earth sample. The theoretical part is divided into two parts. The first part focuses on the analysis of soil and microorganisms living in it. The second part deals with the general properties of plasma and the formation of plasma-activated water. In the experimental part of this work, plasma-activated water was applied to the leachate of soil microorganisms and also directly to a selected soil sample in various concentrations. Subsequently the effect on the viability of soil microorganisms and the composition of soil microorganisms was observed. Based on the results from the practical part, it was found that plasma-activated water has no significant positive or negative effect on soil microorganisms. For this reason, it will be necessary to focus on specific types of microorganisms in further research.
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Vliv aplikace plazmatem aktivované vody na půdní strukturu
Jedlička, Jan
Progress can not be stopped even in agriculture, new techniques and technologies are applied and also interconnected with new specializations. In addition, alternative sources for fertilizers and plant protection products are being researched. Recently, the possibility of using plasma-activated water (PAW) in crop production as a source of nitrogen, along with fungicidal and bactericidal effects have been pointed out. For the time being, however, there is no verified effect on soil properties. This work aimed to verify the effect of PAW application on the soil structure, or water resistance of soil aggregates. The values of two types of PAW (PAW-AC, PAW-DBD) were assessed against the control (distilled water). The container experiment was administered in the form of gradual watering of the soil in flower pots and gradual termination in 5 terms (1st term 525 ml, 2nd term 825 ml, 3rd term 1125 ml, 4th term 1425 ml, 5th term 1725 ml). Soil samples were taken from the flowerpots in 3 layers (Top, Center, Bottom) to verify the potential accumulation of fluid efficiency in some parts of the container. From the comparison of two variants of plasma-activated water (PAW-AC and PAW-DBD) with the control (distilled water), it can be seen that neither variant of PAW violates the stability of soil aggregates and therefore the soil structure. Based on the pilot experiment, it would be possible to state that the application of PAW does not worsen the condition of the soil structure and could become part of agricultural management without affecting this property. However, further experiments with other soil types are needed.
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Influence of plasma activated water on seed germination and quality of corn
Kovařík, Martin ; Zlámalová Gargošová, Helena (referee) ; Kozáková, Zdenka (advisor)
The bachelor's thesis deals with the effect of plasma-activated water on corn germination. After water comes into contact with plasma, the water changes its chemical composition and thus, it acquires new properties that can be used in agriculture. The theoretical part is divided into two basic parts. At the beginning of the first part, plasma is briefly characterized, and then this part deals with plasma-activated water, its formation, physical and chemical properties, and at the end of this part, its use. The second part of the theoretical part is devoted to the germination of plants, external influences affecting germination and statistical evaluation of germination. At the end of the theoretical part, this thesis deals with the ecotoxicity of plants. The content of the experimental part was the preparation of PAW, its subsequent application to corn seeds and the study of its effect on germination and plant quality. PAW was created from distilled or tap water using three different plasma systems and the effect of each PAW on the seeds was compared with that of each control sample. The obtained results indicate a positive effect of PAW on seed germination, but the final hypothesis would require more extensive experiments in different environments, especially in soil.
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Influence of plasma and plasma activated water on fungi Aspergillus niger
Žitný, Michal ; Čechová, Ludmila (referee) ; Kozáková, Zdenka (advisor)
The thesis deals with the issue of decontamination of Aspergillus niger mold using plasma, plasma-activated water and their combination. The theoretical part concerns the effects on the general properties of plasma, its generation, effects on microorganisms known so far and its use in industry with a special focus on medicine. It also focuses on the generation and characterization of plasma-activated water, its effects on bacteria, yeasts and fungi and its use. It also deals with the description of fungi, their occurrence and their sterilization. Part of the theory was aimed directly at the fungus Aspergillus niger. Its cultivation and its industrial uses, such as its use for the cultivation of citric acid, were described here. The experimental part deals with the characterization of plasma-activated water generated using a torch jet. The influence of the supplied power on the formation of particles in plasma-activated water was monitored. The decontamination effect of the plasma, generated by the torch jet, alone and in combination with plasma-activated water generated by alternating and direct current is monitored. The characterization of plasma activated water was performed with 20 ml of distilled water at a carrier gas rate of 2 l/min and a power of a microwave source of 9 and 12 W. The decontamination effect of plasma and its combination with plasma-activated water was observed by inoculating 100 l of a ten-fold and a hundred-fold diluted treated mold culture on Petri dishes with malt agar. The evaluation of the effect was carried out by counting the grown fungal colonies and subsequent comparison with control samples. All measured and obtained data were processed in the results. Plasma activated water generated by the torch jet has been found to contain higher concentrations of nitrogenous substances and lower concentrations of hydrogen peroxide, with the generated nitrate concentrations being higher at lower output than at higher output. DC-generated plasma activated water containing low concentrations of nitrogenous species and a very high concentration of hydrogen peroxide compared to PAW generated by a torch jet. Furthermore, plasma-activated water generated using a high frequency source contains minimal concentrations of nitrogenous substances and slightly elevated concentration of hydrogen peroxide in regard to torch jet PAW. The highest decontamination effect of all the methods used was the combination of plasma and plasma activated water, prepared by a plasma nozzle using direct voltage, when the plasma was applied first. On the contrary, the least effective method was the application of plasma and plasma activated water, generated by high frequency voltage. Limiting oxygen access had almost no effect on direct plasma treatment, but other methods were significantly affected by it. The greatest difference in decontamination effect was observed for the combination of plasma and plasma activated water, generated by high frequency current, where the difference was up to 30 %, but all methods had a significant decontamination effect compared to the control.
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Study of decontamination effects of plasma and plasma activated water
Kovaříková, Kateřina ; Krouská, Jitka (referee) ; Kozáková, Zdenka (advisor)
The theoretical part of this Diploma’s thesis describes the use of plasma in decontamination processes. The experimental part of the thesis focuses on the preparation and characterization of model samples of organic dyes by appropriate analytical methods. The model samples were treated by direct exposure to plasma or plasma activated water. For both treatments, two different plasma sources were used - a dielectric barrier discharge in an ozonizer with subsequent bubbling of its gaseous products into the solution, and a microwave plasma jet applied to the liquid surface. The aim of the work was to evaluate the decontamination rate of the samples and to compare the performance of the different systems.
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Study of plasma activated water application on the total soil microbial biomass content
Poláková, Marianna ; Zlámalová Gargošová, Helena (referee) ; Krčma, František (advisor)
The aim of the diploma thesis was to choose the optimal method for evaluating the content of total microbial biomass in the soil, using plasma-activated water as irrigation, based on literature research. For this purpose, the fumigation-extraction method was chosen, which was evaluated using TOC/TN. The work further focused on the characterization of the physicalchemical properties of plasma-activated water and soil. The rate of decomposition of organic matter in the soil was monitored using the tea bag method, where green and roiboos tea are used to study the rate of decomposition. The content of total water-extractable polyphenolic substances was also determined in green tea. Based on cultivation tests, the presence of soil microorganisms was determined. From the measured data, it was found that the plasmaactivated water does not have a negative effect on the pH of the soil. However, probably as a result of its application, the values of the total microbial biomass in plasma-activated water samples for 10 minutes decreased to the value of (8063±1900) mgkg-1 for TOC and (98±74) mgkg-1 for TN compared to the distilled infusion water, where TOC values were (18068±4186) mgkg-1 and TN (123±10) mgkg-1. .
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Study of plasma activated water application on the soil enzyme activity
Lungová, Tereza ; Enev, Vojtěch (referee) ; Krčma, František (advisor)
The aim of this thesis was the characterization of plasma activated water (PAW) prepared by dielectric barrier discharge under atmospheric pressure and the evaluation of its effect on soil enzymatic activity in a black soil sample, which contains chemically active substances so-called long life species. For this purpose, the pot experiment was chosen based on literature research. Dehydrogenase (DHA) enzyme activity was investigated to determine total soil microbial activity in soil samples watered with plasma activated water with different activation times. Dehydrogenase belongs to the group of oxidoreductases and its activity is a suitable indicator of active biological activity in the soil. In this work, the values of dehydrogenase activity were determined for PAW with 2 minute treatment 2,3 g/gh, for PAW with 5 minutes treatment 2,7 g/gh and for PAW treated with plasma discharge for 10 minutes 3,5 g/gh. In the comparative sample, which was watered with distilled water, the value of dehydrogenase activity was determined to be 2,5 g/gh. Based on the overall analysis, it was found that there is no negative influence on the enzymatic activity in the soil despite the wide range of confirmation of the antimicrobial effects of PAW.
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Study on the influence of plasma activated water on seed germination
Vozár, Tomáš ; Zlámalová Gargošová, Helena (referee) ; Kozáková, Zdenka (advisor)
This bachelor thesis deals with study on the influence of plasma activated water on wheat seed germination. After interaction with the plasma, the water changes its composition and obtain new properties that are useful in agriculture. The theoretical part is divided into two parts. The first part of the theory is dealing with basic knowledge about plasma, its properties, and possibilities of plasma generation in laboratory conditions. In the second part, the work deals with plasma activated water – PAW. The preparation of plasma activated water is described in details as well as its physical-chemical properties and composition with respect to the PAW possible applications. The aim of the experimental part of this work was to prepare plasma activated water in three different plasma systems and apply it on wheat seeds. These three ways of activation used direct and indirect interaction of plasma with water surface. After the seeds were germinated, the influence of plasma activated water on seed germination and quality of crops was observed and compared to control samples. The influence of different ways of water activation was also evaluated. Results show positive effects of plasma activated water on the seed germination and it also increased the quality of crops. Next steps in this research should be the transfer of this experiment from the laboratory scale on the Petri dish to the pot experiments in soil.
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