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Sledování vybraných parametrů čistírenského kalu
Hirschová, Linda
This thesis deals with the evaluation and characterization of sludge parameters relevant to the drying process and subsequent energy recovery. The main parameters monitored are the dry matter of the sludge, the loss on ignition, the calorific value of the primary, thickened and dewatered sludge. Marginally, the paper also deals with the evaluation of pH, conductivity and oxidation-reduction potential. In particular, the characteristic of dewatered sludge entering the drying process is central. The dry matter of the dewatered sludge ranged from 13.5 to 25.7 %. The measured values of the calorific calorific value of the dewatered sludge ranged from 10.2 to 17.9 MJ∙kg-1, an assessment observed a dependency between the loss on ignition and the calorific value of the sludge. The impact of thickening (gravitational, mechanical) and stabilization (aerobic, anaerobic) sludge technology is taken into account in the evaluation. Part of the thesis deals with statistical evaluation of the effects of seasonality on monitored parameters.
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Measurement of Stream Flow Rate Using Salt Dilution Method
Burdych, Marek ; Ondovčin, Tomáš (advisor) ; Slavík, Martin (referee)
Tracer dilution method for measuring flow rate in surface streams is the main topic of the bachelor's thesis. The first part contains a summary of the most important flow measuring techniques for surface streams, including current meter, float method, FlowTracker, ADCP, volumetric method, and computing techniques based on channel cross-section data. Large part is dedicated to tracer dilution method. The findings of field measurements of flow made on the Lo- děnice River using the salt dilution approach are detailed in the second section. Five conductometers were used to measure the water conductivity at three di- fferent sites. Conductometry was performed simultaneously in two different distances from injection site. Throughout the experiment, a sixth conductome- ter recorded the background conductivity value as a standard. The predicted flow values are compared to those acquired from nearby hyd- rometric station of the Czech Hydrometeorological Institute (CHMI) and from observations made using Flowtracker. Diferences in measured flow rate were interpreted as tracer losses. These losses were estimated. Keywords: hydrology, surface water, water stream, tracer dilution, conducti- vity, tracer
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Diatoms as bioindicators for tracking freshwater salinization.
Severa, František ; Kopalová, Kateřina (advisor) ; Dobiáš, Jakub (referee)
The focus of this thesis is on the relationship of diatom (Bacilariophyta) communities to conductivity, and the utilization of this relationship for the monitoring of freshwater salinization. Salinization of freshwaters as a consequence of anthropogenic influences is emerging as a threat to many freshwater habitats due to increasing anthropogenic sources of salts (like use of de-icing salts on roads), wastewaters, and fertilizers. The problem is intensifying because salts are further concentrated through increased evaporation as a consequence to climatic changes. Salinization of ecosystems has a direct impact on the physiological processes of present organisms, and because the ability to adapt to this stress differs between organisms, results in the reorganization of communities. In this way, salinization can indirectly threaten ecosystem services that benefit mankind. Furthermore, salinization is a direct threat in terms of its influence on drinking water and crop irrigation. These forces also act on diatoms, which have long been used as bioindicators, and exhibit strong community links with conductivity. Like for other organisms, this tight relationship is caused by differences in adaptation mechanisms between species, which includes osmolytes, extracellular polymeric substances and adaptation of...
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Quantification of the Influence of Biochar on Soil Respiration
Losová, Anežka ; Mravcová, Ludmila (referee) ; Kalina, Michal (advisor)
This master‘s thesis is focused on the investigation of methods for evaluating the effect of biochar and NPK fertilizer on the activity of soil microorganisms by measuring soil respiration. The theoretical part describes the characteristics of soil, the properties of biochar and its production process. Furthermore, the literature research was focused on the definition and optimization of the various methodologies that can be used to measure soil respiration. The experimental part describes selected physicochemical characteristics of soil and biochar (pH, conductivity, water retention capacity). Thermogravimetric analysis and elemental analysis were used for measuring of the amount of organic and inorganic content and the composition of organic elements (C, H, O and N) in the soil and biochar samples. From the literature research, a dynamic incubation system was chosen for monitoring of the influence of biochar application on the microbial activity of soil microorganisms through the measurement of soil respiration. The produced carbon dioxide was sorbed into sodium hydroxide solution during the incubation and the released amount was determined by titration and conductometric method. The measured results of both methods correlated with each other, and both of these methods are suitable for determining the rate of soil respiration. Experimental data showed that biochar had positive effects on the rate of carbon dioxide production by soil respiration. The combined application of biochar and NPK fertilizer did not significantly increase the efficiency of biochar. In summary, biochar as a soil conditioner in agriculture has great potential to act and to support the level of soil respiration.
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Kontrola kvality vod Bílého potoka
Brychtová, Jana
This work is focused on monitoring the water quality of the White Creek and basic information characterizing the selected site. Samples were collected from October 2012 to September 2013 monthly to capture the changes in the seasons. I measured the conductivity and pH of samples taken from three locations using the multimeter. Two measured sections were chosen in the natural park of the White Creek Valley third grader segment is outside the Valley of the White Creek near the source of the White Creek. Measurements should prove fluctuations pH and conductivity in the case of larger tributary waters from rainfall or melting snow. The paper further describes the natural park of the White Valley Creek with regard to protected species occurring plants and animals. There are also described methods, principles and importance of pH and conductivity. The work is made of the laws governing water quality and flow distribution. In conclusion is emphasized influence of pH on aquatic life and the importance of measuring these indicators. The aim of the work was the monitoring of selected sections of the stream flow White Creek using selected methods (pH, conductometry).
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Provozní diagnostika bioplynových stanic
Dokulilová, Tereza
Tato diplomová práce stručně popisuje proces anaerobní fermentace, rozdělení bioplynových stanic a vybrané parametry, které byly sledovány v praktické části. V praktické části byly při laboratorním testování anaerobní fermentace v Celorepublikové referenční laboratoři bioplynových transformací na Mendelově univerzitě v Brně sledovány následující parametry: složení a množství vznikajícího bioplynu, konduktivita, oxidačně redukční potenciál, pH, obsah sušiny, celkového organického uhlíku, celkový obsah dusíku v sušině a poměr C:N ve zpracovávaném materiálu. Výsledky analyzovaných parametrů byly vyhodnoceny, interpretovány a na jejich podkladě byly navrženy možnosti jejich použití pro screeningovou diagnostiku provozních stavů bioplynových stanic.
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Dielectric Properties of Vegetable Oils for Electrical Engineering
Spohner, Milan ; Mejzlík,, Miroslav (referee) ; Mentlík, Václav (referee) ; Liedermann, Karel (advisor)
The dissertation thesis deals with the analysis of prospective environmentally compatible electrical insulating fluids for electrical engineering in relation to their chemical structure. The thesis starts with the overview of the current state of the art and of the latest trends in the use of synthetic and biodegradable natural oils. In the experimental part were studied these oils: mineral oils, rapeseed oil, sunflower oils, soybean oil, methyl oleate, peanut oil, MCT oil, castor oil and other. Dielectric properties were measured using LRC meter Agilent 4980A including dielectric liquid test fixture Agilent 16452A and also by the Novocontrol Alpha-A analyzer. Electrical properties are presented in the frequency range 10 mHz – 1 MHz range in the temperature interval 253 K to 363 K. The work goes on with the study of the suitability of individual oils for lower temperature, including the impact of the chemical structure and formulation on electrical properties.
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Diagnostics of Diaphragm Discharge in Water Solutions and its Application for the Nanomaterials Surface Treatment
Dřímalková, Lucie ; Brablec, Antonín (referee) ; Janda,, Mário (referee) ; Krčma, František (advisor)
The exact mechanism of the discharge in liquids ignition is not sufficiently known up to now. Although during the last years was achieved the great progress and overloading which some of them are written in this theoretical part of thesis. This thesis is divided into two experimental parts. When the first part deals with diagnostics of diaphragm discharge in electrolyte solutions and the second part is focused on its use for uncoiling (higher homogenization) of carbon nanotubes in solutions. In experiment 1, three different sized (4 l, 100 ml, 50 ml) diaphragm discharge configurations were used to diagnose diaphragm discharge in electrolyte solutions. Diagnostics is done through current and voltage waveforms with the addition of synchronized ICCD camera images that have been connected to a four-channel oscilloscope. The V-A characteristic can be described by three events occurring in the electrolyte solution with a gradual increase in voltage. Slowly increasing of the voltage in the solution leads first to electrolysis. The next phase is the formation of microbubbles or bubbles, which is characteristic of the curve by a slight decrease in the increase of the current passing between electrodes. The sudden increase in the current flow is characteristic of the last phase, namely the discharge phase. The distance of the electrodes from the diaphragm does not significantly affect the V-A characteristic. The higher diameter of the pin hole, therefore, has a higher voltage, but this does not affect the origin of bubble generation or breakdown. The higher thickness of diaphragm, the higher voltage is needed to the beginning of the bubbles generation, and consequently the discharge breakdown. Comparison of the voltage of the start generation of the bubbles and breakdown for PET diaphragms and diaphragms from the ceramic there was no mark able difference. One of the most important parameters is the conductivity of the electrolyte solution. The lower voltage is needed for the start generation of the bubbles at the higher solution conductivity, and also the discharge generation is observed at a lower breakdown voltage. The second experimental part is focused on the study of the diaphragm discharge effect on carbon nanotubes. A specially designed U-shaped reactor is used to modify carbon nanoparticles. Tap water and aqueous solutions of organic compounds are used as the electrolytic solutions. The discharge is generated by a non-pulsed DC high source with a voltage in the range of 0-2.8 kV supplied to platinum electrodes located in the electrolyte solution. The experimental results have shown that the diaphragm discharge has positive effects on the disintegration of clusters and agglomerates of carbon nanotubes. The primary effect on disintegration is probably the shock waves generated by the discharge. It turned out that it depends on the electrode configuration, where the treatment in anode space has far greater effects than the treatment in cathode half of the reactor. Effects of carbon nanotubes disintegration in solution are long-lasting and the treatment effect is not loosed after several months. There were detected no significant changes in the structure of plasma-treated nanotubes by Infra-red spectroscopy.
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Measurement of selected physical properties of the waste water from biogas plant
Ondruška, Vojtěch ; Zejda, Vojtěch (referee) ; Vondra, Marek (advisor)
The aim of this Bachelor’s thesis is the experimental measurement of physical and chemical properties of the wastewater from biogas plants. Thesis concisely describes wastewater and its origin. The main part is dedicated to the design of experiments and to the detailed description of the measurement of selected properties with the available laboratory methods. Measured data are evaluated and compared to literature. The results of this thesis can be employed to further develop the equipment for thickening wastewater from biogas plants or to other scientific activity in the field of waste management in agriculture.
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Use of conductivity meter LTC to characterize the flow of groundwater in well: Use of artificial well and field monitoring
Rodovská, Žaneta ; Bruthans, Jiří (advisor) ; Procházka, Martin (referee)
My Master thesis is focused on a tracer dilution technique in the well using automatic conductivity logging probes LTC Levelogger (Solinst co. Canada). The main aim of my thesis was to test the application conductivity meters LTC to track the movement of fluids in wells. Different set up were used moving probes with unmodified sensor slit, moving probes with modified sensor slit, probes measuring at fixed points, combined moving and fixed points probes and results were compared. 15 wells in quaternary and 11 wells in Bohemian Cretaceous Basin were measured, some of them repeatedly. The comparison of results indicate that the highest apparent flow velocity have probes with unmodified sensor slit. On the other hand fixed point probes indicate flow velocity, which is 40 - 50% lower at the same wells. The combination of the stable positioned probe LTC and the moving probe LTC has about 40% higher flow velocity than the rate of steady probe LTC placed in the well. The results also indicate that extremely slow velocity values (below approximately 0.02 m/day) can be measured only with LTC probes at fixed points. Modified probe slit was tested in the laboratory in plexi-glass tube using fluorescein and NaCl tracers. Unfortunately the modified geometry of measuring slit does not show distinctively better...
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