National Repository of Grey Literature 24 records found  beginprevious15 - 24  jump to record: Search took 0.01 seconds. 
Study of main mycoremediation aspects - effect of bioavailability, biodegradation and toxicity of organic pollutants
Čvančarová, Monika
Many organic compounds are released to the environment and can be harmful to living organisms. These compounds are often persistent and toxic. Some are mutagens, carcinogens, endocrine disruptors or they can cause an increase in bacterial resistance. They tend to accumulate in nature and their transformation is a long-term process. Therefore, various remediation techniques are needed for decontamination. Remediation and bioremediation processes depend on many factors which should be critically evaluated. This dissertation thesis studies the relationship between bioavailability, biodegradation and toxicity of polychlorinated biphenyls, polycyclic aromatic hydrocarbons and fluoroquinolone antibiotics. These compounds of different origin, character and properties were degradated by ligninolytic fungi. Desorption behaviour of pollutants from historically contaminated sites, degradation potential of ligninolytic fungi, ongoing degradation mechanisms, transformation products and their toxicity were studied as important factors for evaluation of mycoremediation and its environmental impact. The results show that determination of bioaccessible fraction by sequential supercritical fluid extraction is very useful for precise prediction of biodegradability of pollutants. The evidence that ecotoxicity and...
Environmental characteristics of mineral waste from metallurgy
Vítková, Martina ; Ettler, Vojtěch (advisor) ; Bollinger, Jean-Claude (referee) ; Dijkstra, Joris J (referee)
Mineralogical and geochemical characteristics of metallurgical wastes from the Cu-Co smelters situated in the Zambian Copperbelt have been investigated. A number of instrumental analytical methods (XRD, SEM/EDS, EPMA, TEM/EDS) has been used to identify primary and secondary phases in smelter slags and dusts. A set of leaching experiments (CEN/TS 14997 pH-static test, EN 12457 batch test) in combination with geochemical modelling has been performed, with the emphasis on the leaching behaviour of potential contaminants and their release as a function of the pH. The effect of sample preparation on metal leachability from slag was also evaluated, considering the grain size reduction required by the standardised leaching protocols. Environmental and health risk assessments of the dust samples have been performed. It was shown that the main carriers of metals in the studied slags were Cu sulphides (bornite, digenite, chalcocite), Co sulphides (cobaltpentlandite), Co-bearing intermetallic phases and alloys. Copper and cobalt were detected in major silicates and spinels, substituting for Fe or Mg in their structures, and in glass. The presence of secondary metal-bearing phases observed on the slag surfaces indicated the reactivity of the slags on contact with water/atmosphere. It was reported that in...
Speciation Analysis of Mercury concentrated on Selective and Sequential Extraction
Martinovský, Václav ; Mihaljevič, Martin (advisor) ; Holý, Martin (referee)
This bachelor thesis deals with methods of speciation analysis of mercury concentrated to selective and sequential extraction of mercury. The first part contains the basic information about characteristics, sources of pollution, toxicity and cycle of mercury in environment. The following part defined term of speciation and speciation analysis. Next chapters are concentrated to description and characterization appropriate and often used extraction reagents and procedures and schemes of selective and sequential extraction methods of speciation analysis. Specific procedures of SEA are described in this thesis and mentioned are their major advantages nad purphose. The last chapter is devoted to listing methods of instrumentation useful to determination of extractable forms of mercury.
Distribution, binding and mobility of Ni in soil in the closed Ni mining area in the vicinity of Křemže
Pipková, Zuzana ; Ettler, Vojtěch (advisor) ; Vaněk, Aleš (referee)
Soils in the vicinity of Křemže in the Southern Bohemia are developed on altered ultrabasic rocks. The occurrence of Ni-hydrosilicate and Fe-rich ores in this area lead to their mining mainly during 19th century, then during the World War II. This thesis is focused on distribution and availability of Ni, Cr and Co and accompanying elements in soils at former mine and prospection sites (2 soil profiles and 32 topsoil samples at historical surface mine area). In all soil samples, physico-chemical parameters (pH, TOC, TS) and bulk concentrations of Al, Ca, Co, Cr, Cu, Fe, Mg, Mn, Ni, Pb and Zn were measured. In addition, deionised water, DTPA and EDTA extracts were used to determine the (bio)availability and mobility of these elements. Some of trace elements were found in elevated concentrations in the mining area topsoils; mean Ni: 1175 mg/kg (range 545-2849 mg/kg), mean Cr: 416 mg/kg (240-849 mg/kg), mean Co: 127 mg/kg (65-238 mg/kg), mean Fe: 49155 mg/kg (30460-113800 mg/kg), mean Mg: 12648 mg/kg (8795-18770 mg/kg) and mean Mn: 1480 mg/kg (1028-2319 mg/kg). In soil profiles the Ni availability decreased with depth. In the uppermost organic O horizon in forest soil profile, 19.5 % and 23.8 % of total Ni was extracted by DTPA and EDTA, respectively. The extractabilities are decreasing down to mineral...
Biodosažitelné formy vybraných nutrientů v luštěninách
Landauf, Lukáš
This thesis deals with the quantitative determination of bioaccessible contents of selected elements (Cu, Fe, Zn) in legumes: chickpeas, pea, lentil, soybean, bean. The UBM in-vitro test was used for the study of bioaccessible forms. This method simulates human digestion using synthetic gastric juices. Atomic absorption spectrometry was used for the determination of the total content of selected elements in legumes and their bioaccessible contents in gastric and gastro-intestinal human tract. The results showed that copper was the most bioaccessible from green lentils and chickpeas. The lowest bioaccessibility of copper was from soybean. The highest bioaccessibility of zinc was from green lentil, soybean, yellow pea and color bean, but the lowest bioaccessibility was from the black lentils. The best bioaccessibility was from all lentils whereas the lowest iron bioaccessibility was from soybean, yellow pea and color bean. The biggest differences between the gastric and gastro-intestinal phases were in green lentils, yellow peas and chickpeas, while the closest contents in phases were in both types of beans.
Transport kovů v systému půda - rostlina
Kleckerová, Andrea
Transport of cadmium, mercury and lead from soil to plants was studied in urban area of Brno city. Five sites with different levels of contamination loading, with high traffic density, industrial production and population density were selected. The total contents of cadmium, lead and mercury in soils and plants (dandelion - Taraxacum officinale) were determined. Dandelion plants were used as biomonitoring organisms of environmental pollution. For the assessment of bioavailable metal forms, single extraction procedures, diffusive gradient in thin films technique (DGT) were used. The obtained results were correlated with metal contens in plants. In the second part, the leachability of cadmium, lead and zinc in samples of agricultural soils, highly contaminated by atmospheric deposition of two smelters in northern France, were investigated. The total contents of cadmium, lead and zinc in soils and plants (Miscanthus giganteus) were determined. Miscanthus plants were used as experimental fytoremediation plants. Pseudototal contents were compared with results from fractionation analysis obtained by sequential extractions, with bioaccessible contents determinated by UBM test (Unified Barge Method, in vitro test) and with bioavailable metal contents determined by diffusive gradient in thin films technique (DGT).
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.
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.
Bioavailability of metals species in water ecosystem
Tandler, Ágnes ; Řezáčová, Veronika (referee) ; Vávrová, Milada (advisor)
Koncentrace volných kovových iontů je často jen malou částí celkové koncentrace kovu v prostředí. Přes tento malý obsah, je ve většině případů koncentrace volných kovových iontů klíčovým faktorem při určování biodostupnosti a toxicity pro organizmus. Membránová technika Donnan se používá k měření koncentrace volných kovových iontů a v této diplomové práci je ověřena pro směsi kovů (Pb + Cu) při absenci a přítomnosti malých organických ligandů. Olovo a měď jsou environmentálně důležité kovy díky své toxicitě a rozdílným vazebným vlastnostem ve vztahu ke studovaným ligandům.
Cycling of selected metals in the environment.
Šebková, Michaela ; Diviš, Pavel (referee) ; Dočekalová, Hana (advisor)
This bachelor thesis deals with a group of selected metals (nickel, zinc, copper, cadmium and lead) in environmental components. It occupies with natural and anthropogenic inputs of metals to the atmosphere, the water und the soil and with their transport among them components. It engages too in a question of a penetration of metals to the biosphere and in their ensuant transport within the biosphere. At each metal is description of its natural sources, chemical and physical properties, inputs in environment, transport within the biosphere and positive and negative effects on living organism is described for each studied metal. The last chapter of this thesis deals with determination of selected metals in environmental components. It discribes procedures of determination from planning over sampling and processing of sample to the final determination of metals by instrumental methods.

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