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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
21

Posouzení ekotoxicity kontaminovaných matric vnášených do ekosystému / Ecotoxicological assessment of contaminated matrices discharged into the ecosystem

Urbanová, Veronika January 2015 (has links)
This diploma thesis evaluates the influence of contaminated matrices introduced into the ecosystem in terms of ecotoxicity. It is focused mainly on matrix generated by anthropogenic activities, especially waste of various origin - industrial, energetical, biodegradable and more. For experimental purposes sewage sludge as the bulk waste with the ever-increasing production was selected. Sewage sludge was tested at its most common use - application on the agricultural land. This application is limited by legislative through the concentration limits of hazardous elements. For this reason, the potential ecotoxicity of sludge was evaluated. Ecotoxicological evaluation was performed using the contact bioassays. As the test organisms Eisenia foetida, Folsomia candida, Heterocypris incongruens a plant Lactuca sativa were selected. Sludge from wastewater treatment plants Brno - Modřice, Valtice, Mikulov and Lednice was tested. Samples of sewage sludge showed no ecotoxicity, while respecting the application amount established by the regulation. On the contrary, it can be concluded that soils enriched by sewage sludge show positive effect on soil biota.
22

Posouzení vlivů běžně používaných hasiv na vybrané složky životního prostředí / Impact assessment of ordinarily used firefighting agents on selected environmental compartments

Jabandžievová, Barbora January 2017 (has links)
This diploma thesis is focused on the evaluation of effects of the most frequently used extinguishing agents in the South Moravian region on selected aquatic and terrestrial organisms. Extinguishing substances which have been tested are foaming agents Sthamex and Moussol, rigid wetting agent TS ECO and TS Turbo and ABC FAVORIT fire - extinguishing powder. Their effects have been tested on aquatic organisms Daphnia magna and Scenedesmus subspicatus and terrestric organisms such as Folsomia candida, Lactuca sativa, and Eisenia fetida. Validation test on standard substances have been performed to verify the validity of the test results. From the obtained results values of IC50, LC50 and EC50 were calculated, through which the impact of individual extinguishing agents on the components of the environment was assessed.
23

Ekotoxikologické posouzení bodových zdrojů znečištění v ekosystému / Ecotoxicological Assessment of Point Pollution in the Ecosystem

Doležalová, Šárka January 2018 (has links)
The main subject of this dissertation is the ecotoxicological evaluation of significant point sources of pollution. These include wildfires and wide fires of factories and also industrial and urban wastewater treatment plants. The local application of pyrolytic product obtained from sewage sludge as the point source of pollution was also included in the thesis. Tests in aquatic and contact arrangement with using both water and soil organisms for ecotoxicity evaluation of selected matrices were chosen. Crustaceans Thamnocephalus platyurus, Daphnia magna Straus and sea bacteria Vibrio fischeri were selected as representative organisms of water animals. Duckweed Lemna minor was chosen as water plant. Further collembola Folsomia candida and earthworm Eisenia fetida were chosen as representatives of soil animals. Finally onion Allium cepa L. and mustard Sinapis alba are representatives of terrestrial plants. Submitted thesis deals about analytes of interest, their properties and ways of distribution to the environments. The output of the thesis is a comprehensive assessment of the effects of selected point sources of pollution on aquatic and terrestrial ecosystems organisms and ecotoxicological risks assessment. The fire extinguishing agents have been proven to be the most stressful substances for all selecteded organisms.
24

Posouzení účinnosti čištění odpadních vod pomocí testů ekotoxicity / Assessment of the efficiency of wastewater treatment plant using ecotoxicity tests

Urminská, Barbora January 2015 (has links)
The possibilities of environmental pollution control are increasing and more advanced wastewater treatment methods are being emphasized, as well as more specific control of contaminants presence in treated waters. That is why it becomes relevant to perform not only chemical analysis but also ecotoxicological bioassays as the means of evaluation of biological effects caused by wastewater discharges to ecosystems. No wastewater treatment plant is able to treat the water perfectly – it can only decrease the pollution level to an acceptable value. Therefore it is important to find out if the treatment process is sufficient to provide a satisfactory decrease of ecotoxicity and also what effects to the organisms in recipient will be caused by wastewater discharges. The thesis is focused on the evaluation of wastewater ecotoxicity. In the experimental part of the thesis, wastewater samples were collected at four wastewater treatment plants in the Czech Republic. At one of them also the sludge samples were taken. The aim was to evaluate the efficiency of wastewater treatment by selected ecotoxicological bioassays. The results have shown that the efficiency of wastewater treatment plants with secondary treatment is sufficient to reduce acute toxic effects to the minimum. Average toxicity removal was over 80 % at three of four evaluated wastewater treatment plants. At the fourth WWTP it was 41 %, however, at this WWTP high efficiency of treatment is not necessary.
25

Studium hlavních aspektů mykoremediace - vliv biodostupnosti, biodegradace a toxicity organických polutantů / Study of main mycoremediation aspects - effect of bioavailability, biodegradation and toxicity of organic pollutants

Čvančarová, Monika January 2014 (has links)
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...
26

Využití tkáňových linií pro toxikologii v životním prostředí / Utilization of tissue cultures for toxicology of the environment.

Polanská, Daniela January 2020 (has links)
5 Abstract Five substances from the group of so-called personal care products, known for their low degradability and regular environmental detection, were tested for toxicity using two fish tissue lines (RTgill-W1 a RTG-2) isolated from rainbow trout (Oncorhynchus miykiss). The tested substances were hexadecylpyridinium chloride (HDP), chlorhexidine (CHX), octenidine (OCT), thymol (THM) and triclosan (TCS). A cell viability assay was performed with each of these compounds using Alamar Blue ™ (AB), 5-carboxyfluorescein diacetate acetoxymethyl ester (CFDA-AM) and neutral red (NR) protocols. The results were used to construct dose-response curves along with an EC50 value for each of these substances. The EC50 values ranged from 0,51 (HDP) to 33,75 µg.ml-1 (THM) for RTgill-W1 and from 0,31 (HDP) to 33,37 µg.ml-1 (THM) for RTG-2. The theoretical LC50 estimation was calculated according to Tanneberger et al. (2013). For all substances, cytochrome P450 1A activity was monitored using 7-ethoxyresorufin-o-deethylase (EROD), four out of five tested chemicals were statistically positive for EROD, the highest EROD response was observed for the most toxic compound - HDP. Only TCS did not show statistically significant cytochrome P450 1A activity. In addition, oxidative stress was measured with the fluorescent dye...

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