National Repository of Grey Literature 136 records found  beginprevious116 - 125nextend  jump to record: Search took 0.01 seconds. 
Zinc in environment and methods of remediation
Landová, Ludmila ; Michálková, Zuzana (advisor) ; Dvořáková Březinová, Tereza (referee)
Zinc and other heavy metals cause negative effects on both the environment and human health. Depending on the concentration of zinc in the ecosystem, it can produce unwanted effects in the environment and on the human. Due to pollution, vegetation may not be able to grow on the contaminated soils, which can further result in strong soil erosion. For these reasons, remediation of soils contaminated with risk elements is necessary to minimize their impact on ecosystems. This bachelor thesis describes properties, utilization, stability and behavior of zinc and other risk elements in the environment, including the removal from contaminated soils using remediation methods. The experimental part aims at the influence of AMO and Sm-AMO on stability of zinc and risk elements in contaminated soil together with the adsorption kinetics of zinc onto these two materials. The results detected high efficiency of Sm-AMO on sorption of zinc and lead in the test kintetics of adsorption. For most heavy metals having a similar effect, when Sm-AMO is as efficient as AMO, any cases, it has a higher efficiency.
Sorption heat pump
Veselý, Josef ; Štelcl, Otakar (referee) ; Pospíšil, Jiří (advisor)
This thesis deals with the issue of sorption heat pumps. The theoretical part is devoted to a detailed description of the function of adsorption and absorption heat pumps. For a better understanding of the adsorption cycle is computed theoretical thermal cycle and the heating factor of zeolite adsorption heat pump are computed. The practical part is focused on the design absorption heat pump that works in conjunction with a natural gas boiler. The pump is designed for cooling flue gas condensing boiler and the possible use of thermal energy from other low-temperature source. The thesis contains a thermal calculations, engineering design and structural design of the heat pump.
Study of utilization of waste material from the food industry for the removal of metals from waste waters
Křikala, Jakub ; Obruča, Stanislav (referee) ; Diviš, Pavel (advisor)
In this bachelor thesis is discussed the potential use of the marc from the wine production for the removal of metals from wastewaters. Marc containing stems, peels and seeds without any prior chemical treatment were homogenized and rinsed with distilled water to remove soluble impurities. IR spectrometry was used for characterization of the major functional groups responsible for the adsorption of metal ions. The experimental part of this work consisted of the assessment of the optional pH value for adsorption of copper and the maximum adsorption capacity of the used material in column and batch method. The results show that the optional pH values for adsorption of copper were in the range pH 3 – 4. Maximum adsorption capacity were calculated form adsorption isotherms by applying the Langmuir model and found to be 0,260 4 mg/g Cu at a column method and 1,246 2 mg/g Cu after 30 minutes the batch adsorption method. Further, it was experimentally demonstrated that the adsorption of copper in addition to the pH depends also on the initial copper concentration in the solution, contact time and other parameters whose optimization would achieve greater adsorption capacity of the referred material. The results indicate that the marc from the wine production have good potential form removing metals from wastewaters by adsorption.
The Study of Aditives and Admixture Influence on High-Performance Concrete Properties
Šiler, Pavel ; Bílek, Vlastimil (referee) ; Brandštetr, Jiří (referee) ; Havlica, Jaromír (advisor)
The aim of this work was to develop the method for the determination of the superperplasticizers (SP) content in the water solution. The method developed was then applied to study the SP adsorption on the individual components used for high-performance concrete and the influence of the temperature and pH values over this adsorption. Furthermore the influence of the water to binder ratio, SP, finely grounded granulated blast furnace slag, fly ash, silica fume, finely ground silica sand and bauxite on the hydration process was studied by means of isoperibolic, isothermal and solution calorimetry. The compressive and flexural strength of most samples used in calorimetric experiments was also determined.
Cleaning of biogas by the PSA (pressure swing adsorption)
Navrátil, Petr ; Houdková, Lucie (referee) ; Leštinský, Pavel (advisor)
The topic of this master thesis is upgrading of biogas. As a mixture of gases produced during anaerobic digestion, contains methane which is highly energy valuable gas. But also other substances that we want to remove. We will present the motivation for upgrading biogas and the possibility of separation, generally the pressure swing adsorption method. The key parameter of this technique is the choice of a suitable adsorbent. This is possible based on the knowledge of adsorption processes, therefore, is also described below. The objective of this thesis is to determine the parameters of the pressure swing adsorption metod. To do this it is necessary to determine the adsorption capacity of the adsorbent, measure breakthrough curves of carbon dioxide and methane, and determine the pressure drop of solid bed, etc. As a result we can finally make a balance and evaluate the applicability in practice.
Utilization of biogas in gas distribution system
Frühbauer, Zdeněk ; Niesner, Jakub (referee) ; Dvořák, Radek (advisor)
The thesis deals with the technologies upgrading the biogas to the quality of the natural gas for the following use in the gas distribution system. The main concern of the thesis is the pressure swing adsorption (PSA), which is nowadays one of the most exploited technologies. For a certain flow and composition of the biogas, completely new PSA technology was designed. Technological schema was created and the main technological devices (adsorbers) were drawn up together with the design documentation for this new technology. The important part of the thesis is also the model of the whole PSA technology in the ChemCAD programme and the evaluation of the operating and investment costs.
Interactions of humic hydrogels with cupric ions
Lang, David ; Gregorová, Eva (referee) ; Klučáková, Martina (advisor)
This diploma thesis deals with humic acid gels and their ability to bind metallic ions on their surface. In the thesis, there was studied the adsorption of copper ions on the provided gels. The gels were prepared by dissolving the humic acid in sodium hydroxide or sodium tripolyphosphate and then precipitated with hydrochloric acid or metal chlorides. Adsorption was studied at different concentrations of the copper (II) chloride and measured on UV-VIS spectrophotometer. It was proved from measuring that gels made from sodium tripolyphosphate are adsorbing less copper ions than the ones prepared by sodium hydroxide. Also, the copper ions are bound with smaller force on gels prepared with polyphosphate. Gels precipitated with magnesium chloride adsorb much more than gels precipitated with acid, thus in the case of gels sequestered metal ions extracted higher.
Sorption ability of humic acids
Pokorná, Markéta ; Havelcová, Martina (referee) ; Klučáková, Martina (advisor)
The Diploma thesis deals with humic acids and their ability to adsorb metal ions on their surface. Humic acids are aromatic polycyclic compounds which contain carboxylic and fenolic functional groups on their sidechains. Thanks to these functional groups humic acids can form complexes with metal ions of different stability and assist the partial immobilization of pollutants in the nature. In this thesis, the sorption of Pb2+ and Zn2+ ions on humic acids was studied by relatively new electroanalytic method called galvanostatic stripping chronopotentiometry. Experimental data were described by Freundlich and Langmuir isotherms. The results show that the amount of examined metal ions increases with their increasing concentration. Furthermore it was determined that Pb2+ ions are adsorbed better on humic acids than Zn2+ ions. Both metals are adsorbed better from solution containing only one metal ion than in presence of four metals at the same time (Cd, Cu, Zn and Pb) where the sorption of these metals is not influenced by the presence of other metals.
Adsorption of natural organic matter (NOM) on granular activated carbon in the treatment of drinking water
Le Duc, Duy ; Mega, Jaroslav (referee) ; Dolejš, Petr (advisor)
In the first part of this thesis the methodic of lab trial was studied, which will be useful for studying adsorption of natural organic matter by activated carbon. As an optimal method of testing adsorption characters jar testing was chosen. Again as an indicator of organic contamination, it was decided to use permanganate chemical oxygen demand (in Czech CHSKMn) will be used. In the second part of this thesis the adsorption characters of eight types of granular activated carbon were studied. Those granular activated carbon came from two world produces, from company NORIT five type of granular activated carbon were tested: NORIT GAC 1020, NORIT PK 1-3, NORIT GAC 1240, NORIT ROW 0.8 SUPRA a TOD NORIT ROX 0.8 and from company Chemviron Carbon three types of granular activated carbon were tested: F100 FE11120A, F400 FE11210A a TL830 FE2028B. Batch kinetic tests of natural organic matter adsorption were conducted with all types of granular activated carbon at first. For description of sorption not only the batch kinetic tests and duration needed for setting equilibrium were observed, but also the process decreasing of concentration of natural organic matters to the value of equilibrium concentration known as adsorption equilibrium was followed.
PCP sorption of lignite
Šnédarová, Gabriela ; Taraba, Boleslav (referee) ; Pekař, Miloslav (advisor)
Within the framework of this diploma thesis, the sorptive capability of a lignite as a natural adsorbent was applied on an aqueous solution of pentachlorophenol. The aqueous solution of this substance, which is very dangerous for the environment, was prepared in various concentration ranges according to reached solubility. The solubility is noticed in different literatures variously and then is not applicable. That is why it was necessary to find out the ”real“ solubility. The aqueous solution of pentachlorophenol of given concentration was subsequently put to adsorption with exactly defined quantity of the lignite and as a result the adsorptive isotherms were obtained. These isotherms represent the adsorption capability in dependence on the adsorption duration, quantity of used lignite and concentration of pentachlorophenol solution. By the adsorption with duration longer than one hour, the quantity of adsorbed PCP does not increase markedly.

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