National Repository of Grey Literature 133 records found  previous11 - 20nextend  jump to record: Search took 0.01 seconds. 
Perfluorinated and polyfluorinated substances in ski waxes
Hrubý, Martin ; Cajthaml, Tomáš (advisor) ; Semerád, Jaroslav (referee)
Perfluorinated and polyfluorinated compounds (PFAS) represent a group of thousands of anthropogenically produced substances. The strong bonding of carbon and fluorine gives these compounds unique properties, which have been used in ski waxes, among other applications. There is limited data on the specific PFAS used in wax production. This is due not only to the difficulty of analysis but also to the reluctance of manufacturers to disclose this information. The application of ski waxes has been associated with increased PFAS concentrations in the blood and some lung problems. Because of their persistence in ski areas, PFAS can be found in snow, soil, animals and plants. Although there is a gradual ban on the production and use of these substances, the issue of PFAS in ski waxes continues. This paper focuses on particular aspects of the issue. Key words: perfluorinated and polyfluorinated substances, PFAS, PFOA, ski waxes
Microplastics and their effects on the metabolism of animal cells
Fiedlerová, Gabriela ; Cajthaml, Tomáš (advisor) ; Černý, Jan (referee)
Microplastics are tiny particles smaller than 5 mm in size found in various environments, including seas, rivers and soil. These particles can be intentionally produced as part of cosmetic products or formed by the breakdown of larger plastic objects. Microplastics represent a serious threat to the environment and animals and could eventually reach humans through the food chain. This thesis deals with a critical and synthetic overview of the literature related to the influence of microplastics on the metabolism of animal cells. The thesis also considers the experimental conditions under which the data were obtained. In particular, factors such as the tested microplastics' shape, size and ageing are critically evaluated as these aspects are often neglected in the literature. Current knowledge shows that microplastics accumulate in the bodies of animals and cause physical and metabolic damage, inflammation, disruption of energy metabolism, protein metabolism and amino acid and lipid metabolism. The most serious effects of microplastics can be considered to be the formation of oxygen radicals, neurotoxicity, disruption of gametogenesis and offspring development.
Possibilities of perfluorinated organic compounds (PFCs) removal in drinking water treatment plants and their occurrence in drinking water sources in the Czech Republic
Čermáková, Lenka ; Fialová, Kateřina ; Prokopová, Michaela ; Semerád, Jaroslav ; Petříček, Radim ; Pivokonská, Lenka ; Cajthaml, Tomáš ; Pivokonský, Martin
This summary research report was implemented within the project TAČR TJ04000212 program to support applied research ZÉTA „Possibilities of perfluorinated organic compounds (PFCs) removal in drinking water treatment plants and their occurrence in drinking water sources in the Czech Republic“. This report is addressed to water treatment plant operators and serves as a basic material for optimizing the coagulation / flocculation and adsorption process in water treatment. The report explains in detail the issue of removal of perfluorinated organic substances (PFCs) in water treatment, especially the process of adsorption in pilot plant conditions. This report will be used as a theoretical basis for the operation of the water treatment plant in Kutná Hora operated by the Water Management Company Vrchlice - Maleč, a. s.
Mixture toxicity of estrogenic endocrine disruptors in samples from the Czech Republic
Černá, Tereza ; Cajthaml, Tomáš (advisor) ; Klusoň, Petr (referee) ; Šváb, Marek (referee)
The environment is contaminated by countless toxic chemicals of mainly anthropogenic origin; therefore, elucidating the impact of chemical mixtures is one of the biggest challenges of current research. Endocrine disruptors (EDs) acting through the oestrogenic nuclear receptor are typical representatives of the mixture toxicity concept of concentration addition, which can be accurately predicted using the latest mathematical models. Oestrogenic activity and oestrogenic EDs have been detected in many matrices across the globe in biologically relevant concentrations; therefore, they are considered a high risk. The presence of synthetic steroids in the aquatic environment in units of ng/l can disrupt the hormonal pathways of individuals and subsequently cause fatal changes in whole populations. However, if the exposure is terminated, the ecosystem will recover in a few years. Wastewater treatment plants (WWTPs) are able to remove a large number of chemicals, including synthetic and natural oestrogenically active compounds; nevertheless, their occurrence in WWTP effluents and in sewage sludges is frequent. Therefore, WWTPs are considered significant sources of agricultural and water ecosystem pollution. This dissertation thesis focuses on the mixture toxicity of oestrogenic EDs and their occurrence in...
Advanced remediation technologies for recalcitrant pollutants
Lhotský, Ondřej ; Cajthaml, Tomáš (advisor) ; Šváb, Marek (referee) ; Chrastný, Vladislav (referee)
Advanced remediation technologies for recalcitrant pollutants Studium pokročilých sanačních technologií pro rekalcitrantní polutanty Dissertation thesis Ing. Ondřej Lhotský Abstract This study focuses primarily on the testing and optimization of methods based on modifications to, and the targeted enhancement of, natural microbial processes for the removal of recalcitrant pollutants. Pilot tests were conducted of these innovative methods at real contaminated sites and matrices, and their effectiveness was monitored in the relevant environments. The pilot tests generally confirmed the potential of the modifications and bioremediation technology combinations by revealing significant increases in the removal efficiency for a number of recalcitrant contaminants. The study provides a general summary of the issue of soil and rock environment contamination by recalcitrant contaminants and familiarizes the reader with bioremediation technologies and their optimization for the removal of recalcitrant contaminants. Subsequently, a theoretical introduction is provided of the methods applied in 4 pilot tests of optimized and combined remediation methods at real contaminated sites in the Czech Republic. The pilot tests are described in detail in publications 1, 2, 4 and 5. Publication 6 covers a pilot test conducted on...
Environmental aspects of wastewater treatment and reuse in nature based technologies
Šereš, Michal ; Cajthaml, Tomáš (advisor) ; Uhlík, Ondřej (referee) ; Hanč, Aleš (referee)
In recent years, the issue of appropriate and efficient approaches to wastewater management and its potential reuse has become increasingly important in view of the geographical conditions of Central Europe, where, until recently, the problems associated with climate change and drought may not have seemed so pressing at first sight. Increasingly, so-called nature-based water management solutions, which help to both clean the water and retain it in the landscape, are being proposed. In drier, especially arid areas, this topic has been under discussion for many years and several examples of larger-scale applications are available. In the Czech Republic, on the other hand, mainly pilot applications only have been considered to date. However, the potential of nature-based solutions such as constructed wetlands, denitrification bioreactors, artificial wetlands and so-called reed bed units, is considerable. The advantages lie mainly in the robustness of these systems and their ability to mimic and intensify the natural water purification processes that occur in nature. They can be applied to waters contaminated with common fecal pollution or with higher nutrient content, as well as to waters contaminated with various types of micropollutants such as pharmaceuticals, hormonally-active substances and...
The issues of proving the use of pesticides in illegal poisoning of animals
Křížová, Iveta ; Cajthaml, Tomáš (advisor) ; Kukla, Jaroslav (referee)
Pesticide poisoning is a worldwide problem. Pesticides are chemicals designed to eliminate unwanted organisms. Many products are banned due to their toxicity, but they are still being abused. The problem arises in proving poisoning due to lack of evidence. Tracing chemicals using chemical attribution signatures is a relatively new method used in forensic sciences, but pesticides are understudied in this field. Characteristic compounds in chemicals are searched for that may provide the necessary information about produce and use illicit substances. This bachelor's thesis deals with the abuse of pesticide products in illegal poisoning of wildlife. Special attention is paid to carbofuran, which is the most frequently abused pesticide in the Czech Republic. The aim of the experimental part was to analyze carbofuran preparations and to prove that individual preparations differ qualitatively from each other.
Novel perfluorinated compounds in the environment
Leifertová, Karolína ; Cajthaml, Tomáš (advisor) ; Innemanová, Petra (referee)
Perfluorinated compounds are a broad class of manmade chemicals. Even though they have been linked to hepatotoxicity, neurotoxicity, nephrotoxicity and carcinogenicity, the mechanism of toxicity still remains unclear. Only recently, two compounds (perfluorooctanesulfonic acid and perfluorooctanoic acid) have been phased out. This has led to a production of so-called "novel perfluorinated compounds". This work focuses on the evaluation of toxicity for 4 perfluorinated compounds, including the novel perfluorinated compounds (perfluorooctanesulfonic acid PFOS, perfluorooctanoic acid PFOA, hexafluoropropylene oxide dimer acid GenX, and hexafluoropropylene oxide trimer acid HFPO-TA). Gonadal and liver cell lines of rainbow trout were used for testing. Relevant toxicity tests were performed, such as viability tests (carboxyfluorescein diacetate, alamar blue and neutral red uptake), cytochrome P450 1A activation (ethoxyresorufin-o-deethylase, EROD) and measurements of reactive oxygen species generation (2',7'-dichlorofluorescein diacetate). HFPO- TA dramatically reduced viability and resulted in a statistically significant increase in intracellular reactive oxygen species. GenX caused an increase in EROD activity, but no effect on viability or reactive oxygen species formation was observed. The...
Advances in applied research in the field of remediation of contaminated groundwater and industrial waste water
Kašparová, Johana ; Innemanová, Petra (advisor) ; Cajthaml, Tomáš (referee)
Water pollution is one of the most serious global problems in today's age. Contamination of water disrupts aquatic ecosystems and their surroundings. A major problem for people in some parts of the world is the decreasing availability of drinking water. In order to prevent further pollution, there are laws, mostly in developed countries, that try to protect water resources. Another procedure to reduce pollution is remediation methods. In the Czech Republic there are entities active in environmental protection deal with remediation technologies and inventories of contaminated sites such as state administration bodies, universities, academies of sciences and private entities. One of the projects that deals with research in the field of environmental damage removal is the "Environmental Research Center: Waste and Circular Economy and Environmental Safety" (No. SS02030008). A partial goal of the project is the inventory of available innovative solutions for contaminated sites for the needs of the state administration. As part of the solution of the submitted bachelor's thesis, the possibility of obtaining the necessary data from publicly available databases focused on applied research and development was verified. The theoretical part focuses on the general characteristics and protection of underground...
Ecotoxicity of herbicidal ionic liquids
Müllerová, Tereza ; Cajthaml, Tomáš (advisor) ; Klusoň, Petr (referee)
Herbicidal ionic liquids (HILs) are organic salts with herbicidal properties. Their anions are usually derived from traditional herbicides, and they are paired with cations of a synthetic or natural origin. Because of their hydrophobic nature and lower volatility, HILs are considered an environmentally friendlier alternative to traditional herbicides, which often persist in the environment, contaminate groundwater and are toxic even to non-targeted organisms. Nevertheless, the scientific research on HILs is mainly focused on their effects on plants. In this thesis, the hormonal activity of selected HILs was tested using human cell lines. In addition, the ecotoxic effect of HILs on soil microorganisms was assessed using the analysis of phospholipid fatty acids (PLFA). To study the ecotoxic effect, two different types of soil were incubated with HILs in a 28-day experiment. The soils were characterized by a different management approach - the soils were treated or untreated with pesticides in the past. The effect of the content of soil organic matter and clay minerals on how HILs interact with soil microorganisms was evaluated. The residual concentrations of HILs were quantified during the soil experiment to assess the effect of the management approach applied in the past on the degradation rate of...

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