National Repository of Grey Literature 151 records found  1 - 10nextend  jump to record: Search took 0.01 seconds. 
Study of the content of risk elements in power plant ash
Vlčková, Renáta ; Doležalová Weissmannová, Helena (referee) ; Komendová, Renata (advisor)
This thesis deals with the study of the content of the risk elements Hg, Cr, Pb and Cd in samples provided by the Thermal Power Plant. Samples of lignite, biomass, fly ash and bottom ash were collected monthly over a period of one year. In addition to this set of samples, river water and fly ash pond water were sampled monthly. A total of 72 samples were analysed by atomic absorption spectrometry (AMA 254 and ETAAS). The concentrations of the elements of concern in the lignite and biomass samples decrease in the order Cr > Pb > Hg > Cd and in the fly ash and bottom ash samples decrease in the order Cr > Pb > Cd > Hg. Overall, it was assessed that the concentrations of the risk elements after co-firing of lignite and biomass were mainly transferred to fly ash and less to bottom ash. It was found that the combustion of higher amounts of biomass decreased the Hg, Cr and Pb contents in both fly ash and bottom ash. The water samples according to the determined parameters were classified as unpolluted water.
Assessment of the state of the environment with regard to the content of risk elements in fish bodies
Jonášová, Simona ; Zlámalová Gargošová, Helena (referee) ; Komendová, Renata (advisor)
The diploma thesis deals with the study of the content of potentially toxic elements in fish bodies in the Jihlava River. The biological samples were first transferred into solutions by microwave digestion. Afterwards, the potentially toxic elements Cd, Cr, Cu, Hg, Ni, Pb, Zn in muscle, heart, liver, genital organs, gills and intestine were determined by AAS. A total of 20 fish samples were analysed. In european chub and common bream, the concentrations of elements decreased in the order Zn > Cu > Ni > Cr > Hg > Pb > Cd. In rainbow trout, common nase, common carp, european perch and common roach, element concentrations decreased in the order Zn > Cu > Ni > Cr > Hg > Cd > Pb. In northern pike the following decreasing trend was found: Zn > Cu > Hg > Ni > Cr > Cd > Pb. The assessment of the condition of the watercourse was made according to the individuals that were assumed to have been present in the Jihlava River for more than 1 year. According to these fish species, the contamination of the aquatic environment with elements Cr, Cu, Hg and Ni was demonstrated. All fish samples except sample 8 (perch) were assessed as suitable for consumption.
Study of the content of risk elements in river sediments of the Váh River
Držíková, Klára ; Zlámalová Gargošová, Helena (referee) ; Komendová, Renata (advisor)
This bachelor thesis deals with the analysis of selected heavy metals in the river sediment of the Váh River. The elements were selected based on their relatively frequent occurrence and adverse effects on humans, fauna, and flora. Also due to their ability of good accumulation and persistence in sediments. The selected elements have a chalcophile character, which plays a significant role in the occurrence of the elements at the sampling sites. The analysis of the collected sediment samples was carried out using atomic absorption spectroscopy. The highest concentration of zinc (386.58 mg/kg), followed by copper (57.67 mg/kg), lead (42.24 mg/kg), and the lowest concentration of mercury (0.332 mg/kg) was measured in the sediments. Sediments are used in agriculture and forestry to improve soil properties. Their application to soils is regulated by Slovak legislation, which sets limit values for risk elements in the concerned sediment and soil. These established limits were not exceeded in any of the sediment samples.
Determination of mercury in selected fish species and in fish products
Kroupová, Kateřina ; Ing.Tomáš Gregor, Ph.D. (referee) ; Diviš, Pavel (advisor)
Theoretical part of the master thesis deals with the occurrence of different mercury species in the environment and describes analytical methods used for determination of mercury in biological samples. In practical part of the master thesis mercury concentration in 14 samples of selected fish and fish product was determined using single purpose absorption spectrometer AMA 254. Measured results were statistically processed and consulted with EU legislative norm.
Testing of modified Iontosorb resins for its use in diffusive gradient in thin films technique
Szkandera, Roman ; Řezáčová, Veronika (referee) ; Diviš, Pavel (advisor)
6-mercaptopurine was joined by diazotation and copulation reactions on Iontosorb AV. Presence of thiol groups in modified resin was showed by infrared spectrometry. Amount of thiol groups was determined by iodometric titration. Resin gel was preparated from modified resin and agarose and both of them were tested for mercury determination by DGT technique.
Development of Diffusive Gradients in Thin Films Technique for Determination of Mercury in Aquatic Systems
Szkandera, Roman ; Chýlková, Jaromíra (referee) ; Čelechovská, Olga (referee) ; Řehůřková, Irena (referee) ; Dočekalová, Hana (advisor)
The theoretical part of this doctoral thesis deals with determination of mercury and its species in aquatic systems. Special attention is paid to the use in situ sampling technique diffusive gradients in thin films technique (DGT) and its development. Current resin gels used for determination of mercury by DGT technique Duolite GT-73, Chelex-100 and Spheron-Thiol are described. Moreover, new types of resin gels including Iontosorb AV modified by imidazole or 6-mercaptopurine and commercially available titanium dioxide. Preparations of resin gels and their basic tests in model solution according to DGT Research are described. Mercury accumulation in relation to time and basic recovery test were tested and capacity of resins was determined. All tested resins meet the requirements of basic DGT Research tests and relative standard deviations of mercury in recovery tests were lower than 10 %. The sorption capacity of resins varied from 1,5 to 6 µmol.l-1 and decreased in following order: Duolite GT-73 > ISAV-IM > Chelex-100 > Spheron-Thiol > TiO2 > ISAV-MP. Mercury sorption on resins was investigated under conditions similar to those in natural waters. It was found that the ionic strength commonly occurring in natural waters does not affect the determination of mercury. The presence of chlorides significantly affects the determination of mercury using DGT with titanium dioxide and therefore this sorbent can not be recommended for the determination of mercury in sea waters. The accumulated amount of mercury, depending on the pH shows that all the sorbents can be used in natural waters with pH in the range form 4 to 8. Mercury sorption is most affected by the presence of humic acids, especially at ion-exchange resins containing other than thiol functional groups. The exception is titanium dioxide for which physical sorption of humic acid metal complexes is typical. Cadmium and copper in model solutions in the molar balance of the excess mostly influenced the sorption of mercury on Chelex-100 and Spheron-Thiol resins. After laboratory tests, the DGT units with studied sorbents were used for the determination of mercury in natural waters of South Moravia (Svratka, Jihlava and Svitava river). Mercury concentration determined using DGT units containing Duolite GT-73 resin was comparable to the total dissolved concentration of mercury in river water provided by direct determination using AAS technique. Order of magnitude smaller concentrations than the total dissolved mercury concentration were found using DGT containing Spheron-Thiol and ISAV-MP resins. These sorbents are probably able to capture only mercury present in the form of labile complexes. This can be used for speciation analysis if more DGT units with different resins are deployed together. Subtracting the measured DGT Spheron-Thiol or ISAV-MP concentrations from the DGT Duolite GT-73 concentration, information about the amount of mercury present in the form of stabile complexes can be obtained. The amount of mercury determined after application of DGT units containing ISAV-IM, Chelex 100 or TiO2 can probably represent the mercury fraction bound in even weaker complexes than fraction determined by Spheron-Thiol and ISAV-MP DGT.
Analysis of alkyl-derivatives of mercury at biotic matrixes.
Tuhovčáková, Lenka ; Vávrová, Milada (referee) ; Doležalová Weissmannová, Helena (advisor)
At diploma thesis will be used for determination of alkyl - derivatives of mercury especially gass chromatography. At diploma thesis will be developed metod for it´s identification, quantification, standard operating procedure and validation of the method of determination of alkyl - derivatives of mercury in animal tissues. There will be evaluated level of contamination by the polutants.
Diagnostic of nitrogen post-discharge by optical emission spectroscopy
Kabeláčová, Kateřina ; Slavíček,, Pavel (referee) ; Mazánková, Věra (advisor)
The aim of this thesis is diagnose post-discharge nitrogen plasma with optical emission spectroscopy. There is long interest of investigated of nitrogen post-discharge plasma and study how to use it in theory as well as in practice. All results were measured with method of optical emission spectroscopy of post-discharge plasma. Discharge was generated by direct-current voltage generator with flowing regime. In this thesis was used for different series of experiments. First experiment was performed with adding water vapour into argon plasma. Measuring was processed at constant current 140 mA, voltage 1.5 V and pressure 1 000 Pa. It was changed flow rate and for each individual flow rate was measured in range 1–25 cm from end of active discharge. Second experiment was with adding nitrogen into argon plasma. Measuring was processed at constant current 140 mA, voltage 1.5 V and pressure 1 000 Pa. We were changing flow rate of nitrogen (0,2 sccm, 0,4 sccm and 0,8 sccm). For each individual flow rate was same experiment with changing distance from active discharge. Third experiment was about adding mercury vapour into nitrogen post-discharge. Measuring was processed at constant current 120 mA, voltage 3.5 V and pressure 1 000 Pa. Measuring was performed with two configuration: with diaphragm and without it. Last experiment was about adding air into argon plasma. Measuring was processed at constant current 140 mA, voltage 1.0 V and pressure 1 000 Pa. Temperature of outer face of tube was measured by thermocouple and infrared thermometer, was measured for last two experiments (argon – air and nitrogen). During experiments with pure nitrogen was visible phenomenon called pink afterglow which is manifested by noticeable increase pink coloration. Optical emission spectrums post-discharge was take at various range of wavelength. At argon with water vapour was 280–600 nm and at adding nitrogen into argon was at range 320–500 nm. At added mercury vapour into nitrogen was 320–600 nm. For experiment argon – air was wavelength range 320–600 nm. From results of experiments were designed dependencies of calculated intensity from measured spectra on distance from active discharge. Also were constructed dependencies of measured temperature on distance from active discharge.
Heavy metal contamination of selected Brno city localities
Šebková, Michaela ; Sommer, Lumír (referee) ; Dočekalová, Hana (advisor)
The aim of this work is to study the soil and plant contamination by heavy metals (lead, cadmium and mercury) in five selected places of Brno city. The sampling place Opuštěná represents the heavily polluted locality with high traffic density situated in the city centre. Sampling places Vídeňská and Podstránská belong to medium polluted localities, that are situated close to frequented roads. Relatively clean localities are represented by Musorgského and Šrámkova places, which are situated in peripheral city district with smaller traffic density. Soil and plants were sampled at two time periods (November 2008 and January 2009). Average amounts of mercury, cadmium and lead in collected soil samples are lower then limits of the Directive number 13/1994 of the Code of Ministry of the Environment. The content of heavy metals in soils corresponds to the sampling place. The highest value of metals content was found in the soil sampled at Opuštěná site. The content of lead and mercury in leaves of common dandelion was higher than the content in roots. In the case of cadmium the situation was opposite, the highest content was measured in underground part of the plant. It was found, that the content of heavy metals in leafy and underground part showed only small difference between sampling places. Nevertheless, the locality Opuštěná is found again as the highest contaminated place. Values of pH of collected soil samples were ranged in neutral area between 7 and 7,5.
The presence of pollutants in matrices of bioindicators
Vlček, Ladislav ; Vávrová, Milada (referee) ; Doležalová Weissmannová, Helena (advisor)
This master‘s thesis concerns with occurrence of heavy metals in the environment, mainly in the matrices of bioindicators. Special attention is given to occurrence of mercury in the environment and its quantification in bioindicators. Mercury and its compounds are today considered as one of the most significant contaminants in the environment. Some sorts of mushrooms cumulate sizable amounts of mercury in their fruiting body and therefore we can use them to consider loading of different areas. Eight areas in Vizovice and its surroundings were chosen for these purposes and during the years 2006 – 2008 harvested 50 samples from 19 sorts of mushrooms from there. The concentrations of Hg were determined in all samples by single-purpose absorption spectrometer AMA 254. Comparison of the mercury content between individual sorts of mushrooms in the same area as well as comparison of loading of areas was performed and also bioaccumulation ability of individual sorts of mushrooms was determined.

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