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Metals Transport in the System Soil/Plant. Comparison of the Active and Passive Sampling Method (The Diffusive Gradients in Thin Films Technique)
Trávníčková, Jana ; Janoš, Pavel (referee) ; Chýlková, Jaromíra (referee) ; Čelechovská, Olga (referee) ; Dočekalová, Hana (advisor)
The doctoral thesis deals with comparison between copper uptake by radish (Raphanus sativus L.) and concentration of copper measured by a DGT-device and concentration of copper obtained by extraction with generally used extraction agents (HNO3, NaNO3 and water). Plants were cultivated in pot experiments on a tested non-treated and gradually spiked soil. The amount of copper was determined in various part of radish (whole plant, above- and below-ground part) after mineralization in the APION mineralizer by ET – AAS. The highest concentration was in belowground part, especially in root tissues and sheel of root bulb. It confirms copper is associated with cell walls. The amount of copper taken by radish up does not pass beyond sanitary standards not even in spiked soils and consummation of radish is not unhealthy. Good correlations were found between copper concentration in radish and the amount of copper extracted with HNO3, NaNO3 and water and the amount found in soil solution. Results of extraction with HNO3 confirmed the amount of copper was stable in spiked soils during the pot experiments. The DGT experiments have shown that the rate of resupply from the solid phase to soil solution is constant during the deployment time. Whereas the release of copper decreases after 24 hours in natural soil. Copper added to soil in form of cupric ions is present in the different form after one month-equilibration than copper present in unspiked soils. The results obtained by DGT measurements were approximately up to two orders of magnitude lower than copper concentration obtained by leaching with sodium nitrate. The extraction with sodium nitrate does not provide true reflection of metal availability to plant root system and soil microorganism. High values of correlation coefficients (R2 > 0,9) were found between concentration of copper in radish plant and the concentration of copper in soil solution measured by DGT technique. Concentration of copper in soil solution was three times higher than concentration measured by DGT technique. Soil solution contains species of copper that are not measured by DGT technique and available to plants. Concentration of metals obtained by DGT measurements is more closely to real concentration of bioavailable forms of metal in soil. Therefore it is possible to recommend the DGT technique as a technique for determination of bioavailable forms of copper in soils.
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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.
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Geochemical Study: Sediments as a Source and/or Trap of Mercury Contaminatin.
Májska, Milada ; Amouroux, David (referee) ; Zdeňka, Svobodová (referee) ; Dočekalová, Hana (advisor)
Rtuť je v přírodě přirozeně se vyskytujícím toxickým prvkem, jehož globální emise jsou ovlivňovány zejména antropogenními zdroji znečištění. Obrovský globální nárůst v usazování rtuti, zejména ve vodných ekosystémech, byl zaznamenán současně s počátkem průmyslové revoluce. Sedimenty jsou posledním místem úložiště nejrůznějších komplexů rtuti. Rtuť však zde může být přeměněna na toxičtější organickou formu, methylrtuť, pomocí transformačních procesů kontrolovaných různými fyzikálními, chemickými, ale i biologickými faktory. Navíc mohou být specie rtuti remobilizovány ze sedimentů pomocí difuze a resuspenzace a tak se sedimenty mohou stát i potenciálním zdrojem rtuti. Proces bioakumulace a bioobohacování tak pokračuje v potravním řetězci, ve kterém se člověk, i další zvířata, stává konzumentem methylrtuti. Stanovení celkové koncentrace rtuti není dostačující k porozumění osudu rtuti v přírodním prostředí a tak stanovení MeHg poskytuje nezbytnou doplňující informaci. Dostatečně citlivá a přesná analytická metoda pro stanovení specií rtuti je nezbytným nástrojem environmentální chemie. Metody vhodné pro stanovení specií rtuti v sedimentech jsou popsány v části metodologie disertační práce. Metoda stanovení methylrtuti v sedimentech pomocí automatické Headspace vybavené pastí („trap“) a spojené s plynovou chromatografií a fluorescenční detekcí je zde také popsána. Zvláštní pozornost je také věnována potřebám zásad čistého vzorkování, skladování vzorků a přípravě vzorků před samotou analýzou, jakož i samostatné části věnující se terénní studii rtuti a methylrtuti v sedimentech vytipovaných lokalit. Sedimenty jižní Moravy a severní Francie jsou srovnány z hlediska znečištění rtutí. Specie rtuti a další ukazatele (Fe, Mn, S) byly analyzovány v sedimentech, pórové vodě a povrchové vodě řek Dele a Lys (Francie) a Jihlava a Morava (Česká republika). Z hlediska posouzení vodních ekosystémů a jejich znečištění rtutí, je vhodné znát koncentraci rtuti v pórové vodě a posoudit dostupnost rtuti ze sedimentů. Technika difuzního gradientu v tenkém filmu je vhodným způsobem jak stanovit koncentraci rtuti v pórové vodě sedimentů. Do roku 2005 bylo použití této techniky pro měření rtuti značně limitováno. Ale nedávný pokrok především v dostupnosti možných sorpčních gelů vhodných pro stanovení rtuti umožnilo využití této techniky i pro stanovení rtuti. Byly použity různé sorpční gely: Spheron.Thiol, Duolite GT-73 a TiO2. Řeka Dele představuje past enormního množství antropogenní rtuti pocházející z průmyslových zdrojů a je považována za potenciální významný zdroj methylrtuti pro okolní prostředí a živé organismy především. Poslední část dizertační práce se zabývá aplikací dobře zavedeného experimentu využívajícím stabilní isotopy ke studiu metylačních a demethylačních procesů v sedimentech řeky Dele. Obohacené stabilní značkovače rtuti v anorganické formě (199Hg) and methylované formě (201MeHg) byly přidány do sedimentů. Tyto označené specie rtuti tak pomohly sledovat osud specií rtuti a vypočítat rozsah jejich přeměny v průběhu experimentu.
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Development of Gel Techniques for in situ Measurement of Bioavailable Metals in Soils and Sediments
Kovaříková, Vladěna ; Sommer, Lumír (referee) ; Janoš, Pavel (referee) ; Dočekalová, Hana (advisor)
The doctoral thesis deals with usage of gel techniques for in situ measurement of bioavailable metals in soils and sediments. The DGT technique was applied to soil samples from the localities of Zlín, Tuřany and Chrlice for estimation of bioavailable metals in soils. These soils were amended by sewage sludges in years 1980-1987. The experiment using diffusive gels with different pore size, APA and RG gels, has shown that the DGT can be used for assessment of trace metal soil complexes - small inorganic and larger organic. The results obtained by DGT measurements were approximately up to two orders of magnitude lower than metal concentrations obtained by leaching with sodium nitrate. The leaching with sodium nitrate does not provide true reflection of metal availability to plant root system and soil microorganisms and the DGT technique seems to be a better predictor of metal bioavailability. Only small differences between undisturbed and homogenized soil samples were found out by application of DGT to soil samples from localities of Veverská Bítýška and Ostrovačice. The undisturbed soil is not homogenous and the DGT unit gives information only about the part of the soil which is in direct contact with the unit. The procedure with soil slurry can be recommended for the characterization of large soil areas and estimation of bioavailable metals in soils. Gel techniques were also used for the study of processes occuring in sediments. Mercury species and other metals were analysed in surface water, pore water and sediments collected from two sampling sites in the Dele River in northern France. This river had been polluted during the last century by the activity of Métaleurop factory, which dealt with metal ore treatment. The application of DGT technique using two specific ion-exchange resins, Chelex-100 and Duolite GT-73, provided assessment of mercury in sediment pore water. DGT and DET techniques together with centrifugation provided also high resolution depth profiles of Fe, Mn, Zn, Pb, Cr and Cd in pore water. It is not possible to determine which sampling site was more contaminated. Only small differences in mercury species and metal content were observed between sampling sites. The Dele River can be classified as contaminated river according to total mercury content in sediments and as slightly contaminated river from the point of view of methylmercury content. Correlations between mercury species and sulphide content confirm that total mercury and sulphide content count among factors influencing the mercury release to pore water and controlling processes of methylation and demethylation. Only low toxicity of sediment slurries was found out by the bioluminiscence test with Vibrio fischeri. The results of doctoral thesis demonstrate gel techniques as a very good tool in environmental analysis.
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Study of Generation, Trapping and Atomization of Hydride Forming Elements for Atomic Spectrometry
Furdíková, Zuzana ; Sommer, Lumír (referee) ; Čelechovská, Olga (referee) ; Řehůřková, Irena (referee) ; Dočekalová, Hana (advisor)
Interference effects of co-generated hydrides of arsenic, antimony, bismuth and selenium on trapping behavior of selenium or antimony hydrides (analytes) within iridium modified, transversely heated graphite tube atomizer (THGA) was investigated. A twin-channel hydride generation system was used for independent separate generation and introduction of analyte and interferent hydrides, i.e. in simultaneous and/or sequential analyte-interferent and interferent-analyte mode of operation. Influence of the analyte and modifier mass, interferent amount, trapping temperature and composition of the gaseous phase was studied. A simple approach for elimination of mutual interference effects by modification of the gaseous phase with oxygen in substoichiometric ratio to chemically generated hydrogen is proposed and suppression of these interference effects is demonstrated. A hypothesis on mechanism of trapping and mutual interference effects is drawn.
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Reporting of the Selected Firm
Dočekalová, Hana ; Ronovský, Zbyněk (referee) ; Hanušová, Helena (advisor)
The diploma thesis deals with issues concerning reporting in the current business environment in a particular company. In the first chapter you can find theoretical knowledge regarding reporting. The second part focuses on an analysis of the current situation in reporting in a selected company. In the last part of the diploma thesis recommendations supporting further potential development of reporting in the selected company on the base of the analysis will be proposed.
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Determination of selected metals in unconventional fruit species
Křížová, Soňa ; Dočekalová, Hana (referee) ; Diviš, Pavel (advisor)
The aim of this diploma thesis is determination of selected metals in unconventional fruit species, specifically in cornelian cherry (Cornus mas), sea buckthorn (Hippophae rhamnoides) and medlar (Mespilus germanica).There is informationabout 16 analysed metals – As, B, Be, Cd, Co, Cr, Cu, Fe, Mn, Mo, Ni, Se, Sn, Pb, V, Zn. There are described analytical techniques for elemental analysis and methods for destruction biological material. Samples for analysis are prepared by using microwave mineralization and ICP-MS for detection. This is described in the experimental part of the diploma thesis. Analysis confirmed that unconventional fruits are rich sources of trace elements.
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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.
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Toxic metals in water and sediments of Brno water reservoir
Bořek, Tomáš ; Čelechovská, Olga (referee) ; Dočekalová, Hana (advisor)
Diploma thesis deals with usage of the diffusive gradients in thin films technique (DGT) for the determination of labile metal species in the surface water and sediments of Brno water reservoir. Sediment and water samples were collected on the selected sides of Brno water reservoir on September and October 2008. The DGT technique was used for determination of depth profiles of Fe, Mn, Pb, Cd, Zn, Cu, Ni and Al. The DGT probes with three different thicknesses of diffusive layer were applied into the sediment samples. The obtained results gave the information about release of metals from solid phase into the pore water of sediment. The concentrations of Fe, Mn, Pb and Cd in sediments were determined by atomic absorption spectrometry after microwave decomposition. The DGT technique was used also for determination of Fe, Mn, Pb and Cd in surface water from Brno water reservoir.
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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.
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