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Optimization of laboratory denitrification test
Novotná, Klára ; Pániková, Kristína (referee) ; Malá, Jitka (advisor)
Leaching from agricultural fields not only releases high concentrations of nitrates into surface and groundwater, but also, for example, pesticides. The aim of this bachelor thesis is to optimize the input nitrate concentration of a laboratory denitrification test. This test will allow the study of the influence of different pesticides on the denitrification process and also the monitoring of their fate during this process. The theoretical part of the thesis describes the nitrogen cycle and its forms, the denitrification process and the factors that influence its progress are discussed in detail. In the practical part, a 28-day laboratory denitrification test was performed. Analytical methods used are described in the thesis as well as the process and the results of the laboratory experiment. Based on chemical oxygen demand profile, N-NOx concentration profile and denitrification rate, an input nitrate concentration of 15 mg.l-1 was recommended.
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Determination of nitrate in root vegetables
Fiala, Petr ; Štursa, Václav (referee) ; Diviš, Pavel (advisor)
The Bachelor thesis deals with the study of nitrates occuring in different species of root vegetables. The aim is to compare the amount of nitrates in common type of vegetables to bio vegetables. The theoretical part of the Bachelor thesis is devoted to root vegetable in general and also to nitrates and their influence to human health and nature. Fertilizers and organic agriculture are also mentioned. The last chapter focuses on the analytical method. The measurrement is carried out by the ion chromatography and the outcome of nitrate concentrations in both types of vegetables is compared and discussed. The results point out higher concentration of nitrates in bio-quality vegetables.
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Characterization of plasma activated water for biomedical applications
Šindelková, Kateřina ; Dzik, Petr (referee) ; Kozáková, Zdenka (advisor)
The aim of this master thesis is to characterize plasma activated water (PAW) prepared in various plasma systems using direct and indirect interaction of plasma with liquid or its surface. Plasma was generated by electric discharges at atmospheric pressure. The prepared plasma-activated water was studied with respect to its use in biomedical applications. The theoretical part deals with plasma activated water. It contains a description of the PAW preparation, its characterization in terms of produced particles or its physico-chemical properties. Also, methods for antimicrobial activity estimation or colorimetric determination of produced particles are described in this section. In the experimental part of this work, the types of discharges that were used for the PAW preparation and their comparison are presented. Two types of liquids were selected for the activation, namely distilled and tap water. Subsequently, concentrations of selected reactive particles in PAW (hydrogen peroxide, nitrates and nitrites) produced in three different plasma systems were determined. Besides the comparison of reactive particles production in various systems, their time stability was studied as well. Over time after the PAW preparation, the values of active particles concentrations have changed due to mutual interactions between the particles. Mainly, nitrites were oxidized to nitrates or vice versa depending on the PAW type and other conditions. Part of the work was also monitoring selected physical properties of PAW, namely pH value and specific conductivity. It has been found that PAW does not retain its activated properties for too long, depending on the type of preparation and methods of storage. Therefore, one of the important goals of this work was to determine and compare suitable storage conditions for PAW with respect to its potential biomedical applications.
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Nitrate removal from agricultural runoff
Schrimpelová, Kateřina ; Šálek,, JAN (referee) ; Drtil,, Miloslav (referee) ; Malá, Jitka (advisor)
The increasing concentration of nitrates in surface water and groundwater is becoming a global problem. The dissertation thesis is focused on the denitrifying bioreactors with organic fill material designed for the reduction of nitrate input from agricultural areas in the Czech Republic. A set of laboratory experiments was performed – static leaching tests and column tests, including chemical analyses of outflow water and ecotoxicological bioassays. Seven materials common in the Czech Republic, various process parameters, types and lengths of bioreactor shutdown in dry periods and the use of outflow water for irrigation were tested. The thesis deals with both denitrification efficiency and ways of reducing negative effects. An evaluation of the overall effect bioreactors is included along with a prediction regarding leaching over the following years.
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Comparison of plasma activated water quality prepared by different plasma systems
Staškovanová, Denisa ; Krčma, František (referee) ; Kozáková, Zdenka (advisor)
This diploma thesis deals with generation of reactive species (hydrogen peroxide, nitrates, nitrites) using various plasma systems in distilled and tap water. Prepared plasma activated water differs in the way the plasma is applied, namely plasma above the water surface, plasma inside water or bubbling of plasma gaseous products into water. The main goal is to determine the amount of species produced in different plasma systems and compare them with each other. The effect of ozonizer experimental conditions on the generated amount of reactive species is also monitored.
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Diagnostics of active particles generated by the interaction of plasma microwave discharge with liquids
Kovaříková, Kateřina ; Töröková, Lucie (referee) ; Kozáková, Zdenka (advisor)
The first part of this Bachelor’s thesis describes problems of electric discharges in gas and on a surface of water solutions. It focuses on the generation of the active particles that are generated during the discharge and their subsequent analysis by appropriate analytical methods. The second part focuses on identification of the active particles that are generated during the microwave discharge in gas phase and during the interaction with water solution surface. The aim is to determine the influence of experimental conditions on the information of the active particles, specifically the nitrates and nitrite ions.
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Humic substances - colloidal transport system of plant nutrients
Hudlíková, Iva ; Pospíšilová, Ľubica (referee) ; Klučáková, Martina (advisor)
The thesis deals with humic substances as major components of soil organic carbon during nutrients transport to plants root system. Literature research is focused on humic substances, adsorbing complex and transport of soil substances to plants. The experimental part of the work concentrates on interaction of humic acid with nitrates. A part of the work was humic acid characterization, and determination of titratable acidity and acidity COOH values.
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Návrh managementu jímacího území vodního zdroje Nová Ves u Pohořelic
Ohryzek, Dominik
The quality of the water in source Nová Ves near Pohořelice was degraded by an above-limit nitrate concentration, which caused complications with use of the water for drinking purposes. The causes of this pollution have not been fully confirmed, one of the possible factors is increased mineralisation of humus substances in the soil (Leugner et al. 2021) after deforestation of spruce and pine stands. These died gradually during the drought and bark beetle calamity in 2015 and the following years. The presented thesis propose management principles of site with respect to the water management needs of the resource owner. There were proposed phytoremediation techniques using tree species grown in a coppice manner. Management is also focused on the care of remaining vegetation in the area, where close to nature species composition prevails.
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