|
|
Leachability of Ba and Cr from alkali-activated matrices
Cába, Vladislav ; Hajzler, Jan (referee) ; Koplík, Jan (advisor)
The aim of this work is to determine the usability of alkaline activated matrices made from ashes to inhibition of barium and chrome. Ashes – fly ashes and ashes from fluidized bed combustion – were compared with cement used for inhibition. By using inductively coupled plasma atomic emmission spectrometer were determined concentrations of barium and chrome in leachates based on norm ČSN EN – 12457-4. In addition, images were taken on the scanning electron microscope and crystallographic spectra from X-ray crystalography were obtained to determine structure. The results show that ashes from fluidized bed combustion are suitable for inhibition of both barium and chrome, whereas fly ashes can not sustain these elements with such success.
|
|
|
Creation of database of heterogenous systems FT – IR spectra
Hajzler, Jan ; Ptáček, Petr (referee) ; Opravil, Tomáš (advisor)
The aim of this thesis was to create a FT – IR database of heterogenous inorganic samples. The contents of the theoretical part include an introduction to infrared radiation and display the theoretical basis for measurement in a concise form. The experimental part consists of two areas. The first area focuses on the measurement of IR spectra of chosen samples. The measured samples are mostly based on silicon dioxide. The second area of the experimental part studies the influence of the selected method of measurement on the results of the measurement. The experiment examines two methods of measurement of the IR spectra, one being carried out with the use of KBr tablets and the other using the ATR accesory. Both of these methods were measured in the middle infrared and far infrared region.
|
|
|
Impact of soil samples treatment and used measurement methods on heavy metals concentrations.
Kejík, Marek ; Marko, Michal (referee) ; Hajzler, Jan (advisor)
This bachelor thesis aims to explore the possibilities of treatment of soil samples and compare the suitability of selected analytical methods of analysis for determining the concentration of heavy metals. 7 reference certified materials of various soil types and one soil sample from the recreational area located in Brno were selected. Each soil sample was subjected to three different treatments. It is a method of melting into a solution, decomposition in aqua regia and aqueous extract. All thus treated samples were subsequently subjected to analytical methods for determining the concentration, specifically the ICP-OES and GF-AAS methods were used. To assess the suitability of selected methods of treatment of soil samples and analytical methods of determination, the 4 most risky elements were selected, namely arsenic, cadmium, copper and lead. The measured concentrations were compared with reference values of soil samples. Finally, the suitability of combinations of different sample preparation procedures and selected methods of analytical determination of the content of determined elements from soil samples was assessed.
|
|
|
Possibilities of elimination of residual ammonia content from technological water in power plants
Hajzler, Jan ; Bartoníčková, Eva (referee) ; Opravil, Tomáš (advisor)
This master thesis aims to study the possibilities of eliminating, or separation of ammonium shares from technological water of plants, where is introduced a secondary method of flue gas denitrification (SCR, SNCR). The need for elimination of ammonium shares arose after introduction of emission cap, which have been tightened since January 2015. The denitrification technologies were installed on devices that did not comply with the new limits. The theoretical part of the thesis deals with the description of combustion processes, as a fluid, and high temperature combustion of solid fuels, mechanisms of emissions and their reduction options. At the conclusion of the theoretical part is discussed the contents of the ammoniacal nitrogen in waters used in electricity and heating facilities to transport, or from which are separated by solid products of some processes such as desulphurization. There are also discussed some options for removal of ammonium salts from technological waters. Experimental part deals with finding appropriate method of determination of ammoniacal nitrogen, and the possibilities of its elimination by conversion to insoluble compound. Last but not least, the work deals with the evaluation of the sustainability of the proposed solutions. And as well as the real possibilities of their application in practice.
|
|
|
Influencing the hydration of high-performance composites using zinc ions
Všetečka, Tomáš ; Hajzler, Jan (referee) ; Novotný, Radoslav (advisor)
The bachelor thesis is focused on the influence of hydration of high-performance cementitious composites, more specifically reactive powder composites. Zinc ions were supplied by the compounds of zinc oxide and zinc sulphate heptahydrate. Zinc ions were added by weight content to cement at concentrations of 0.2; 0.5 and 1.0 wt. %. The development of properties depending on the content of zinc ions and the type of compound used was monitored in this work. The measured values were compared with reference values that did not contain zinc ions. The highest compressive strengths were obtained with a sample containing 1.0% Zn in the form of zinc oxide. However, this sample is associated with a longer setting time due to the retarding effect of zinc ions on hydration. The retardation effect was monitored using isothermal calorimetry. For samples containing zinc ions, a negative effect on the brass layer of steel fibers, which was used as reinforcement, was observed. Due to the addition of zinc ions, dezincification and subsequent removal of brass from the surface of the fibers took place. Therefore, these specimens had lower tensile strengths. A positive effect on the differential ballistic protection efficiency factor was observed for a sample containing 1% Zn in the form of zinc oxide.
|
|
|
Influencing the hydration of high-performance composites using zinc ions
Všetečka, Tomáš ; Hajzler, Jan (referee) ; Novotný, Radoslav (advisor)
The bachelor thesis is focused on the influence of hydration of high-performance cementitious composites, more specifically reactive powder composites. Zinc ions were supplied by the compounds of zinc oxide and zinc sulphate heptahydrate. Zinc ions were added by weight content to cement at concentrations of 0.2; 0.5 and 1.0 wt. %. The development of properties depending on the content of zinc ions and the type of compound used was monitored in this work. The measured values were compared with reference values that did not contain zinc ions. The highest compressive strengths were obtained with a sample containing 1.0% Zn in the form of zinc oxide. However, this sample is associated with a longer setting time due to the retarding effect of zinc ions on hydration. The retardation effect was monitored using isothermal calorimetry. For samples containing zinc ions, a negative effect on the brass layer of steel fibers, which was used as reinforcement, was observed. Due to the addition of zinc ions, dezincification and subsequent removal of brass from the surface of the fibers took place. Therefore, these specimens had lower tensile strengths. A positive effect on the differential ballistic protection efficiency factor was observed for a sample containing 1% Zn in the form of zinc oxide.
|
|
|
Impact of soil samples treatment and used measurement methods on heavy metals concentrations.
Kejík, Marek ; Marko, Michal (referee) ; Hajzler, Jan (advisor)
This bachelor thesis aims to explore the possibilities of treatment of soil samples and compare the suitability of selected analytical methods of analysis for determining the concentration of heavy metals. 7 reference certified materials of various soil types and one soil sample from the recreational area located in Brno were selected. Each soil sample was subjected to three different treatments. It is a method of melting into a solution, decomposition in aqua regia and aqueous extract. All thus treated samples were subsequently subjected to analytical methods for determining the concentration, specifically the ICP-OES and GF-AAS methods were used. To assess the suitability of selected methods of treatment of soil samples and analytical methods of determination, the 4 most risky elements were selected, namely arsenic, cadmium, copper and lead. The measured concentrations were compared with reference values of soil samples. Finally, the suitability of combinations of different sample preparation procedures and selected methods of analytical determination of the content of determined elements from soil samples was assessed.
|
|
|
Leachability of Ba and Cr from alkali-activated matrices
Cába, Vladislav ; Hajzler, Jan (referee) ; Koplík, Jan (advisor)
The aim of this work is to determine the usability of alkaline activated matrices made from ashes to inhibition of barium and chrome. Ashes – fly ashes and ashes from fluidized bed combustion – were compared with cement used for inhibition. By using inductively coupled plasma atomic emmission spectrometer were determined concentrations of barium and chrome in leachates based on norm ČSN EN – 12457-4. In addition, images were taken on the scanning electron microscope and crystallographic spectra from X-ray crystalography were obtained to determine structure. The results show that ashes from fluidized bed combustion are suitable for inhibition of both barium and chrome, whereas fly ashes can not sustain these elements with such success.
|
|
|
Possibilities of elimination of residual ammonia content from technological water in power plants
Hajzler, Jan ; Bartoníčková, Eva (referee) ; Opravil, Tomáš (advisor)
This master thesis aims to study the possibilities of eliminating, or separation of ammonium shares from technological water of plants, where is introduced a secondary method of flue gas denitrification (SCR, SNCR). The need for elimination of ammonium shares arose after introduction of emission cap, which have been tightened since January 2015. The denitrification technologies were installed on devices that did not comply with the new limits. The theoretical part of the thesis deals with the description of combustion processes, as a fluid, and high temperature combustion of solid fuels, mechanisms of emissions and their reduction options. At the conclusion of the theoretical part is discussed the contents of the ammoniacal nitrogen in waters used in electricity and heating facilities to transport, or from which are separated by solid products of some processes such as desulphurization. There are also discussed some options for removal of ammonium salts from technological waters. Experimental part deals with finding appropriate method of determination of ammoniacal nitrogen, and the possibilities of its elimination by conversion to insoluble compound. Last but not least, the work deals with the evaluation of the sustainability of the proposed solutions. And as well as the real possibilities of their application in practice.
|
|
|
Creation of database of heterogenous systems FT – IR spectra
Hajzler, Jan ; Ptáček, Petr (referee) ; Opravil, Tomáš (advisor)
The aim of this thesis was to create a FT – IR database of heterogenous inorganic samples. The contents of the theoretical part include an introduction to infrared radiation and display the theoretical basis for measurement in a concise form. The experimental part consists of two areas. The first area focuses on the measurement of IR spectra of chosen samples. The measured samples are mostly based on silicon dioxide. The second area of the experimental part studies the influence of the selected method of measurement on the results of the measurement. The experiment examines two methods of measurement of the IR spectra, one being carried out with the use of KBr tablets and the other using the ATR accesory. Both of these methods were measured in the middle infrared and far infrared region.
|
guest ::
