National Repository of Grey Literature 74 records found  beginprevious21 - 30nextend  jump to record: Search took 0.01 seconds. 
Influence of groundwater on hydrologic drought in the Lužnice River floodplain
Korejs, Tomáš ; Šobr, Miroslav (advisor) ; Janský, Bohumír (referee)
The object of this thesis is to evaluate influence of groundwater on the period of hydrological drought in the Lužnice river floodplain, focusing on interaction between surface water and groudwater. Floodplain of the Lužnice is unique fluvial ecosystem characterized it's diversity and natural value. Especially upper stream of Lužnice represents river floodplain river and creater good conditions for water retention. Main first part of this thesis is focused on work with literature about issue interaction between surface water and groundwater in the river floodplain with examples from Czech republic and the world, including the characteristics the groundwater Work with literature is also focused at characterizing the types of drought, it's cause and consequences. The second part evaluates the basic characteristics of runoff and hydrological drought on the Lužnice. This analysis is based on statistical evaluation of longtime data series from Pilař and Bechyně stations. Both profiles are compared to identify correlations.
Anomalous occurences of arsenic in natural waters in the Czech Republic
Rodovská, Zuzana ; Drahota, Petr (advisor) ; Redlich, Aleš (referee)
This bachelor thesis reviews the data on the distribution of arsenic in surface and underground natural waters of the Czech Republic. In addition the thesis focuses on the occurrence of anomalous arsenic concentrations and tries to detect sources of arsenic contamination. Results of the thesis suggest high quality of the surface and groundwater in the Czech Republic with respect to arsenic. Its anomalous concentrations in the natural waters in Czech Republic have been rarely documented only in areas with strong anthropogenic impact and in areas affected by historical mining operations. Keywords: Arsenic, toxicity, contamination, surface water, groundwater, Czech Republic
Comparison of effectiveness of three applications of zero-valent iron nanoparticles for remediation of groundwater polluted by chlorinated ethenes
Vacková, Nikola ; Stejskal, Vojtěch (advisor) ; Oswald, Sascha (referee)
This master's thesis is focused on remediation of groundwater polluted by chlorinated ethenes with a use of nanoiron particles. Three injections of different types of nanoiron were carried out in the contaminated area of Spolchemie a.s. company in Ústí nad Labem. The main aim of the thesis was to compare effectiveness of those three applications. The remediation of groundwater was done by direct- push injection of suspension of nanoscale zero-valent iron. After that a monitoring of groundwater level and physicochemical parameters was performed. Samples of groundwater were collected during the monitoring and were analysed for contaminants and products of dechlorination. It was discovered that NANOFER STAR nanoiron had the strongest influence on reductive dechlorination. This was reflected by concentration decrease of TCE by 84 %, VC by 60 % and total concentration of CHC by 39 % in the period three months after the injection and the increase of degradation products of chlorinated ethenes. Injections of conservative tracers potassium bromide and lithium chloride served as a criterion for differentiation between the process of dechlorination and simple dilution effect. The effectiveness of NZVI-C3 nanoiron and NANOFER STAR with CMC nanoiron were notably lower than the bare NANOFER STAR nanoiron. In...
Bacterial role in silicate mineral alteration in near-neutral pH conditions
Duchoslav, Vojtěch ; Falteisek, Lukáš (advisor) ; Seydlová, Gabriela (referee)
It is well established that bacteria are able to catalyze dissolution of silicate minerals. Bacteria may dissolve silicates for two different purposes. They may use certain elements that can undergo redox transitions as substrates for their energetic metabolism or they can leach nutrients, that are otherwise unaccessible in their habitat. The main mechanisms of bacterially mediated silicate leaching are acidic or basic catalysis and surface complexation. The main nutrients extracted are K, Mg, P and Fe. The only element significantly exploited as substrate for dissimilative energetic metabolism is iron. In order to leach iron as a nutrient, even extremely strong complexants (i.e. siderophores) may be employed. However, only moderate complexing agents can serve to obtain iron as terminal electron acceptor. The second possibility is to reduce iron directly in the crystal grid by means of the conductive nanofibres. The oxidative dissolution of silicates by chemoautotrophs is rare, in contrast to that of sulfides. Bacterial dissolution of silicates leaves morphological and geochemical signatures, but it is still problematic to recognize and interpret them. Although it is well-known that bacteria can dissolve most of the rock-forming minerals in diverse environments we are unable to quantify their contribution...
Tidal phenomena in groundwater hydraulics
Ondovčin, Tomáš ; Mls, Jiří (advisor) ; Šembera, Jan (referee) ; Novotný, Oldřich (referee)
Manifestations of the tidal force have been known to humanity since an- tiquity. The oldest extant remarks on the origin of the tidal force are in the Natural History of Pliny the Elder. He also left us remarks on periodic changes of water-level in wells. This phenomenon does not necessarily have to be connected to the proximity of seas. As such, it is a subject of research since the end of 19th century. Exploring the mechanisms with which the tidal force affects the groundwater level requires combining the findings of geology and hydrogeology but also the knowledge of hydraulics and geomechanics of porous media and certain understanding of astronomy. This thesis contribu- tes to the knowledge of the mechanism of tidal oscillations in groundwater measured in a borehole near Teplice nad Metují in Police Basin. It utilizes models based on the knowledge of geological and hydrogeological structure of the surroundings of the borehole. It investigates the relation between the physical properties of porous media and the amplitude and phase of the tidal oscillations and presents solutions of the models.
Groundwater protection legislation
Rybka, Jakub ; Sobotka, Michal (advisor) ; Franková, Martina (referee)
Groundwater Protection Legislation The theme of this thesis is the issue of legislation of protection of groundwater in the context of Czech and European legislation. At the outset, this work deals with the historical development of the legislation concerning the protection of waters in the Czech Republic and the legal nature of water to which they relate and adjustment of their property. The main emphasis of this work is put on administrative-legal, conceptual and economic tools for protecting groundwater and deals also with the Water Framework Directive, which is the main regulation of the European Union in this area. Also presented are the main changes proposed by the amendment to the Water Act. This study thus provides an overview of current legislation on protection of groundwater, its evaluation and is concluded with author's forecast for world development in this area in the 21st century.
Office Building
Tručka, Jiří ; Mizerová,, Lenka Smolková (referee) ; Smolka, Radim (advisor)
This master's thesis deals with project documentation of an office building with commercial premises, cafe, and canteen. The building is located in Žďár nad Sázavou, on plot 2197. The access road is from the north side. The building has 6 floors above ground and 2 underground floors. The building is designed as monolithic reinforced concrete frame with shear core. Basement consists of monolithic reinforced concrete walls. Whole building is based on reinforced concrete slab, which is supported by a system of piles. The external wall is designed from clay blocks. The facade is ventilated.
The Behaviour of Atrazine under Denitrification Conditions
Pániková, Kristína
Atrazine is one of the most persistent pesticides. This substance negatively affects the environment and the human body. It is a frequent contaminant of groundwater, in which ideal conditions for the denitrification process prevail. Using a methodology of long-term testing, atrazine was investigated under denitrification conditions, as well as its transformation behaviour and effect on the denitrification process itself. After 28 days, adsorption on poplar shavings was observed as the dominant process, 30.6%. A biotic loss of 9.8% was found, and, at a concentration of 0.1 mg/l, atrazine did not significantly affect the denitrification process. Stimulation reached the value of 6.9%.
Comparison of effectiveness of three applications of zero-valent iron nanoparticles for remediation of groundwater polluted by chlorinated ethenes
Vacková, Nikola
This master's thesis is focused on remediation of groundwater polluted by chlorinated ethenes with a use of nanoiron particles. Three injections of different types of nanoiron were carried out in the contaminated area of Spolchemie a.s. company in Ústí nad Labem. The main aim of the thesis was to compare effectiveness of those three applications. The remediation of groundwater was done by direct- push injection of suspension of nanoscale zero-valent iron. After that a monitoring of groundwater level and physicochemical parameters was performed. Samples of groundwater were collected during the monitoring and were analysed for contaminants and products of dechlorination. It was discovered that NANOFER STAR nanoiron had the strongest influence on reductive dechlorination. This was reflected by concentration decrease of TCE by 84 %, VC by 60 % and total concentration of CHC by 39 % in the period three months after the injection and the increase of degradation products of chlorinated ethenes. Injections of conservative tracers potassium bromide and lithium chloride served as a criterion for differentiation between the process of dechlorination and simple dilution effect. The effectiveness of NZVI-C3 nanoiron and NANOFER STAR with CMC nanoiron were notably lower than the bare NANOFER STAR nanoiron. In...
Long-term groundwater regime in multilayered water-bearing systems on the example of uranium mining impact on groundwater conditions of the Bohemian Cretaceous Basin, Czech Republic
Lipanský, Tomáš
Lipanský T. (2016): Dlouhodobý režim proudění podzemních vod v hlubokých pánevních kolektorech, na příkladu ovlivnění hydrogeologických poměrů české křídové pánve hornickou činností v okolí Stráže pod Ralskem. Doktorská disertační práce. - Univerzita Karlova v Praze Abstract: This thesis sumerises the development of groundwater regime in a multilayered water-bearing system of the Bohemian Cretaceous Basin in maximal proposed extent of area where the groundwater regime had been affected by mining of radioactive materials near Strář pod Ralskem. The aim of the work was to describe the groundwater regime on the basis of measured monitoring data and map interpolations. The former Uranium mining from Cenomanian sandstone sediments represents the largest human impact on the natural groundwater flow of a multilayered water-bearing system within both the Bohemian Cretaceous Basin and the Czech Republic. Newly created graphs and maps of piezometric surfaces bring an insight into the dynamics of the Bohemian Cretaceous Basin water-bearing system and give an idea of long- term groundwater heads and flow directions development in the studied area. This was achieved despite the fact that this study does not present a hydraulic model, but an interpolation of monitoring data. Maps and grids of piezometric surfaces can be...

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