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Posouzení subchronické toxicity směsí pesticidů na raky
HOVORKOVÁ, Anna
Prometryn, belonging to the group of s-triazines, has been extensively used in the case of protection of maize production against broadleaf weeds and grasses. Its use was banned by the EU in 2004. Chloridazone is a pyridazone herbicide used to protect beet production and to control broadleaf weeds. Its properties increase the potential for the transfer of this pesticide to the aquatic environment. Together with its metabolites, it has been detected in groundwater in the Czech Republic. Its use in the Czech Republic has been banned since 2020. The adventitious properties and long-term use of these substances may increase the risk of contamination of non-target ecosystems by the pesticides used and their metabolites, which may form mixtures in this environment and thus have an even riskier impact on the environment. The aim of this work was to assess the subchronic toxicity of the pesticide mixture formed of the concentrations of these pesticides on the signal crayfish (Pacifastacus leniusculus) in comparison with the control and pesticides tested alone. A subchronic toxicity test of 20 days duration followed by 10 days depuration was used to obtain the results. The criteria evaluating the toxicity of the mixture were the biochemical profile of haemolymph, oxidative stress level and antioxidant enzyme activity from hepatopancreas, muscle and gill samples. The biochemical profile of haemolymph was significantly affected in individuals tested in the pesticide mixture. For biomarkers altered due to the mixture, suppression of the effect of prometryn in the mixture was observed in some cases. The analysis of antioxidant biomarkers did not show a higher toxicity of the mixture over the pesticides tested alone. In the case of antioxidants, a greater effect was observed for prometryn tested alone, where in some cases its presence in the mixture suppressed the effects of chloridazon in the mixture.
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Study of degradation of micropolutants in water using advanced oxidation processes
Brož, Tomáš ; Repková, Martina (referee) ; Mravcová, Ludmila (advisor)
This bachelor thesis is focused on the study of pesticide degradation using various advanced oxidation processes. Finding an effective method to degrade these micropollutants is very important with their increasing consumption in the agricultural and other industries, because their adverse effects on non-target organisms and humans are also expected. In this work, the herbicides metazachlor and chloridazon were studied. The first part of this work is conceived theoretically and is focused on a basic description of advanced oxidation processes, including characterization of individual types, description of pesticides and their distribution and a brief description of the used analytical methods. The second part deals with the experiment itself and the evaluation of the results. Three different types of advanced oxidation processes were used for degradation: UV, H2O2, UV/ H2O2. Liquid chromatography with tandem mass spectrometry (LC/MS) was used to determine the efficiency of the experiment. It was found that the most effective of the used degradation methods was the use of UV radiation with the addition of H2O2.
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Study of degradation of micropolutants in water using advanced oxidation processes
Brož, Tomáš ; Repková, Martina (referee) ; Mravcová, Ludmila (advisor)
This bachelor thesis is focused on the study of pesticide degradation using various advanced oxidation processes. Finding an effective method to degrade these micropollutants is very important with their increasing consumption in the agricultural and other industries, because their adverse effects on non-target organisms and humans are also expected. In this work, the herbicides metazachlor and chloridazon were studied. The first part of this work is conceived theoretically and is focused on a basic description of advanced oxidation processes, including characterization of individual types, description of pesticides and their distribution and a brief description of the used analytical methods. The second part deals with the experiment itself and the evaluation of the results. Three different types of advanced oxidation processes were used for degradation: UV, H2O2, UV/ H2O2. Liquid chromatography with tandem mass spectrometry (LC/MS) was used to determine the efficiency of the experiment. It was found that the most effective of the used degradation methods was the use of UV radiation with the addition of H2O2.
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