|
| |
|
|
Assessment of soils and sediments contamination by heavy metals in the region Jihlava river
Marek, Milan ; Adamec, Vladimír (referee) ; Doležalová Weissmannová, Helena (advisor)
This diploma thesis deals with a potential contamination of hazardous metals of soil and sediments. The metals cadmium, copper, lead and mercury were chosen, their specification, limited concentration and methods of determination are also described in thesis. City Jihlava and its surroundings were chosen for evaluating pollution of the soil and sediments in this area. In collected samples of the soil and sediments presence of copper, cadmium, lead and mercury were detected via atomic absorption spectrometry (F-AAS, ET-AAS, AMA 254). The metal pollution of soils and sediments by hazardous elements in Jihlava River and in Jihlava region was evaluated.
|
|
|
Mercury in waste water
Paříková, Lucie ; Čelechovská, Olga (referee) ; Dočekalová, Hana (advisor)
In the time period from November to April of the academic year 2007/2008 presence of mercury and its forms was monitored in the waste waters of Faculty of Chemistry, VUT in Brno. The level of mercury was determined as total mercury with help of the atomic absorption spectrometry method and in available forms by diffusive gradient in thin film technique.
|
|
|
Determination of heavy metals in waste energetic materials with using sequential extraction
Kořínková, Alena ; Sommer, Lumír (referee) ; Doležalová Weissmannová, Helena (advisor)
Tato diplomová práce pojednává o stanovení vybraných kovů v energetických odpadech, jako je úletový popílek, škvára, struska, ložový popel, produkt odsíření apod., které pocházejí ze čtyř moravských tepláren. Extrakce kovů z energetických materiálů byla provedena Tessierovou extrakcí. Za tímto účelem byla použita extrakční činidla chlorid hořečnatý (MgCl2), octan sodný (CH3COONa), hydroxylamin hydrochlorid v kyselině octové (NH2OH.HCl v CH3COOH), peroxid vodíku v kyselině dusičné (H2O2 v HNO3) a kyselina fluorovodíková (HF). Extrakce probíhala při teplotách 25°C a 40°C. Ve všech frakcích byly stanoveny olovo, měď a kadmium s využitím atomové absorpční spektrometrie (F AAS, ET AAS) a rtuť metodou AMA 254.
|
|
|
Monitoring of mercury and methylmercury content in fish meat and evaluation of risks associated with the consumption of this meat
Křížová, Lucie ; Pořízka, Jaromír (referee) ; Diviš, Pavel (advisor)
Mercury and its compounds are one of the most toxic global pollutants in the environment. It occurs in all segments of the environment, and it attains the food chain ang human body by people consuming fish. The theoretical part of this thesis examines the characteristics of mercury, its occurrence, the roots of its pollution, and the toxicity of various forms of mercury. Consequently, the thesis delineates analytical methodologies applied to determine the overall level of mercury and chemical forms of mercury. The practical part focuses on monitoring the level of mercury and methylmercury in 12 extracts of fish meat. The analyzer AMA 254 has been used to determine the level of mercury and methylmercury in these extracts. Based on the level that resulted from the measurements, the thesis concludes a risk that correlates with consuming this type of meat.
|
|
|
Contamination of soil and sediment by hazardous metals
Pidima, Tomáš ; Komendová, Renata (referee) ; Doležalová Weissmannová, Helena (advisor)
This bachelor thesis deals with soil and sediments from the environmental perspective. For selected heavy metals – cadmium, lead and mercury are given information about their occurrence, characteristics and potential sources of environmental contamination. It is also mentioned legislation dealing with the topic. The limit concentrations in soil and sediments, determination methodology and principles of the most commonly used instrumental analytical methods for these elements are described.
|
|
|
Spectrophotometric determination of Chromium(III) with organic reagents
Nevrlá, Jana ; Komendová, Renata (referee) ; Sommer, Lumír (advisor)
The theoretical part of this master’s thesis is mainly focused on the physical and chemical properties of chromium, its toxicity and possibility of entering of various forms of chromium into the environment. There are also described the most common analytical methods for determination of chromium in water, including ways of modification and preconcentration water samples. The aim of experimental part is the optimalization and assessing the conditions spectrophotometric determination of Cr(III) by selected organic reagents (chromazurol S, eriochromcyanine R, 4-(2-thiazolylazo)resorcinol) and their comparison with the determination of total chromium, as Cr(III), using atomic absorption spectrometry with electrothermic atomization. The analytical procedure for spectrophotometric determination of chromium with chromazurol S, which was found to be most suitable and ET-AAS, were applied to real water samples.
|
|
|
Determination of platinum in Brno's agglomeration
Dvořák, Rostislav ; Řezáčová, Veronika (referee) ; Komendová, Renata (advisor)
This thesis is focused on the determination of platinum in samples of road dust and soil by atomic absorption spectrometry. The theoretical part describes the basic physical and chemical properties of platinum, platinum function in automotive converters and its behavior in the environment. In the experimental section summarizes the methods used to decompositions samples, concentration of the analyte and the main results of the measurements.
|
|
|
Generation of volatile zinc chelates from aqueous matrix
Kračmarová, Aneta ; Nováková, Eliška (advisor) ; Červený, Václav (referee)
The topic of this work was optimization of the conditions for the generation of volatile zinc chelates. The aim was to develop an alternative method for generating volatile Zn speciates to its reduction by sodium tetrahydridoborate. Detection was carried out by atomic absorption spectrometry. Optimization of the conditions of the chelation reaction itself included the selection of a suitable chelating agent and appropriate modifiers, pH adjustment, suitable reagent and carrier gas flow rates, and appropriate apparatus arrangement. The following method characteristics were obtained under optimal conditions: LOD 1.55 mg L-1 , LOQ 5.17 mg L-1 and sensitivity 0.245 s L mg-1 . The repeatability was 13,7 %. The addition of modifiers was then tested to increase the efficiency of generation of volatile zinc chelates. Potential modifiers included transition metals, organic solvents, heterocyclic organic compounds, compounds from the carbamate group and surfactants. The heterocyclic 1,10-phenanthroline and the carbamate NaPDC were included in the optimal conditions because without them it was not possible to distinguish the signal from noise. Acetonitrile proved to be the most effective modifier, increasing the efficiency to 1547 %. With the addition of acetonitrile, the LOD decreased to 0.191 mg L-1 , the...
|
|
|
Atomization of hydride forming elements in dielectric barrier plasma discharges
Baranová, Barbora
The aim of this diploma thesis was to optimize the atomization conditions of two hydride forming elements - bismuth and tellurium in dielectric barrier discharge (DBD) plasma atomizers using atomic absorption spectrometry (AAS) as a detector. Two types of electrode constructions of planar DBD atomizers were studied: glued and sputtered electrodes while two construction of high voltage power supply sources were investigated employing either a sinusoidal or square wave modulation of high voltage function. The effect of the gas phase dryer included in the apparatus upstream the atomizer was also investigated. A nafion membrane tube dryer was identified as the most effective one. Its efficiency was verified using optical emission spectrometry. With the nafion tube included in the apparatus, two main parameters of DBD atomizers were optimized: the voltage of the power supply source and argon flow rate, which served as a discharge gas. Using optimal conditions, analytical characteristics were determined for all atomizers used and these were subsequently compared with those achieved in an externally heated quartz (multi)atomizer (MM)QTA. In the case of bismuth, the optimal argon flow rate was determined to be 75 cm3 min-1 for all atomizers. The optimal value for the power supply source with sinusoidal...
|
guest ::
