|
|
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.
|
|
|
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.
|
|
|
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.
|
|
|
Selected inorganic pollutants in foodstuffs
Kroupová, Kateřina ; Vítová, Eva (referee) ; Vitoulová, Eva (advisor)
This bachelor thesis is focus on occurrence of inorganic pollutants in foodstuffs. The introduction is dedicated to apperance of individual selected elements in foodstuffs. Concentration of these elements is very important factor for examination of toxic effects for the human organism. If we want to avoid the harmful effects to the human organism, we have to define border limits. Work is based on the legislative of Czech republic. Second part of this study is focused on the biological monitoring. The biological monitoring is important for precautionary measures. In the third part of this study are described toxical effects of these elements to the human organism. Before qualitative and quantitative analysis by instrumental techniques is important to properly take the sample. In the fourth and fifth part of this work are mentioned methods used for determination of these elements and metods of taking samples. This bachelor thesis provide complex view on the problems of pollutants in foodstuffs and it should be used as a base for following diploma thesis.
|
|
|
Determination of mercury in selected foods
HAVLOVÁ, Michaela
The thesis resolves problems about the contain of mercury in chosen articles of food. Mercury, hydrargyrum, is a heavy metal, which is an important pollutant of environment. Mercury was determined for comparision in all in nine common articles of food. In rice, mushrooms, fish, lentils, poppy seeds, soya, soya dehydrated slice and oat flakes. Mushrooms were collected in four different provinces of Czech republic. In Highlands, Central province, South Bohemia and in province of Liberec. For comparings were analyzed cultivated mushrooms, Agaricus bisporus, from supermarket. As a fish were analyzed lyofilized samples of catfish, Silurus glanis. The other articles of food were bought in supermarkets. On an atomic absorption spectometer AMA 254 (Altec, Prague, CR), was made validation of analytic method. Results: accuracy (97%), precision (3,33%), sensitivity (0,00251 l/kg), limit of detection ((LOD= 0,31 ?g/l), limit of quantification (LOQ= 1,04 ?g/l), linear dynamic range (LDR= 1,04 až 100 ?g/l) and correlation coefficient of linear part of calibration (0,9979). Measurement of all samples was done with spectometer AMA 254. By analysis of all materials was detected that increased concentration of total mercury in all occures especially in mushrooms. The highest measured value, 5,7 mg/kg, was found in a mushroom Xerocomellus chrysenteron from South Bohemia. Measured concentrations at lyofilized fish weren't important, it was only 0,04 mg/kg. In other articles of food weren't detected overlimited values. We obtained from acquired results, that the highest amount of mercury is contained in our conditions in mushrooms. According to World Health Organisation is determined that the highest tolerable concentration for articles of food is 0,5 mg/kg of mercury. In mushrooms was found after recalculation as a top limit 0,57 mg/kg of mercury. So, this result is overlimited.
|
|
|
The content of mercury in sediments washed out from the Jordán reservoir
JAHODOVÁ, Jana
The aim of this study was to examine if the sediments were washed out from the Jordán reservoir due to the rupture of the temporary dam to the Tismenický brook and then to the Lužnice river. The aim of the work was to assess the degree of their contamination with mercury and the possible environmental risk as well. The detailed literature research focused on determination of mercury in sediments was conducted at first. Then, the characteristics of the analytical method serving for mercury determination using an AMA 254 spectrometer were calculated. After that, the contents of mercury in individual samples of sediments were determinedand the degree of the environmental contamination was evaluated. Analytical andecological aspects of this study were taken into account. The measurements were related to samples taken from eight sampling sites during the six months from November 2013 to June 2014. The sediments were taken from four depths. Localities upstream the reservoir contained very low content of mercury. Its concentration corresponded to the natural background observed in sediments (the natural occurrence of Hg in the environment). The higher concentrations of Hg were determined in samples taken from sampling sites downstream the reservoir. However,these values corresponded to the natural occurrence of this element as well. The increased mercury concentrations (1.0365 mg/kg ? 0.0398) were obtained for samples taken from the site lying close ahead of the confluence of the Tismenický brook and the Lužnice river. This value exceeded the legislative limit (regulation No. 13/1994 Sb. The higher concentrations of mercury were determined for samples taken from the Lužnice river downstream the confluence compared to samples taken upstream the confluence. It is due to the rupture of the temporary dam (in December 2012 and June 2013) that resulted in washing out the sediments from the Jordán reservoir. This ecological disaster led to the change in natural mercury occurrence in localities downstream the reservoir.
|
|
|
Těžké kovy v sladkovodních rybách z lokalit okresu Žďár nad Sázavou
Vičarová, Petra
The work deals with the determination of heavy metals (mercury, cadmium and lead) in carp tissues by the use of atomic absorption spectrometry. The theoretical part is focused on the heavy metals and their forms in fishes and in the environment. The anatomy of fishes and the composition of the fish meat are also discussed. The practical part summarized the results of concentrations of studied heavy metals in the carp's tail muscles and in their liver. Carps were fished in two locations - The Pilský reservoir and Domanínský lake situated in Žďár nad Sázavou district. For mercury determination was used one-purpose atomic absorption spectrometer AMA 254. The amounts of cadmium and lead were measured by the electrotermal atomic absorption spectrometry by use of spectrometr ContrAA 700. The obtained results were discussed and evaluated. Obtained concentrations of mercury and lead did not exceed the regulation limits, only concentration of cadmium in liver exceeded these limits in all samples.
|
|
| |
|
| |
|
| |
guest ::
