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Ecotoxicological evaluation of sediments
Dobešová, Zuzana ; Doležalová Weissmannová, Helena (referee) ; Zlámalová Gargošová, Helena (advisor)
Sediments of lotic and lentic water can be a reservoir of a number of contaminants, which can enter the aquatic ecosystem either due to the controlled discharge of waste water or leakage of various accidents or technological devices. Sediments can hereby affect not only the aquatic ecosystem, but also the terrestrial system in the case that they will be used as fertilizer or as a material for the recultivation. For this reason it is important to consider their potential ecotoxicity. Sediments were subjected to ecotoxicological bioassays and their potential ecotoxicity was assessed. The phytotoxicity assays on terrestrial plants Sinapis alba, Lactuca sativa and Allium cepa were used and the effects of aqueous extracts of sediments on the inhibition of growth their root were evaluated and the value of IC50 was determined. For the ecotoxicological assessment of sediments and determination of IC50 value also Lemna minor as a representative of aquatic plants was selected. For more objective assessment of the sediment ecotoxicity aquatic invertebrates as Artemia salina and Daphnia magna were selected and the value of LC50 or EC50 was determined.
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Industrial local exhaust ventilation
Brdečko, Radim ; Štětina, Josef (referee) ; Charvát, Pavel (advisor)
This bachelor‘s thesis deals with local ventilation in industrial working. At the start of work are listed the reasons why is the ventilation very important. In chapter are legislative terms and technical requirements to make humen general comfort during working. Local exhaust ventilation (LEV) is divided into some kinds and types. Filtration in industry is just for overview. The last part deals with appropriate local ventilation to certain technical operation.
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Occurrence of aflatoxin M1 in raw milk
UHLÍKOVÁ, Tereza
Mycotoxins, as secondary products of fungi, can contaminate feeds and enter the milk through the metabolic pathway in the cow's body. The most studied mycotoxin associated with milk contamination is aflatoxin M1 (AFM1). The review focuses on the identification of different types of mycotoxins and their transfer to milk, and attention is paid to a summary of the results of monitoring aflatoxins in milk and the negative effects of mycotoxins on health and the possibility of mycotoxins determination. The practical part of the thesis consists of two subchapters, namely monitoring AFM1 in raw milk of cows, sheep and goats in the years 2006-2020 from the data of the State Veterinary Administration of the Czech Republic, where the factor of the observed period and type of milk was evaluated for AFM1 content in raw milk. The second part interprets the results of AFM1 monitoring in purchased raw cow's milk delivered to the dairy factory.
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The evaluation of mycotoxins monitoring in selected raw materials
DYKOVÁ, Jitka
Contaminants in feed and food pose a long-term global issue that requires constant attention. The diploma thesis aimed to assess results of the monitoring of mycotoxin presence in feed, raw milk, and tissue of animals in the period 2015-2019 (from State Veterinary Administration of the Czech Republic), and further to evaluate notifications of danger in the period 2016-2019 in selected countries (from the Rapid Alert System for Food and Feed, RASFF). From the total of 1320 analysed feed samples during the period, there were 378 samples (28.6%) positive in mycotoxins. The highest presence was found for deoxynivalenol (143; 43.3%), on the contrary, the lowest number of positive samples was in aflatoxin B1 (25; 7.6%). From the total of 210 raw milk samples, only one positive sample was found, and it was even under the allowed hygiene limit, 0.05 ?g/kg. All liver tissue samples (n=130) were also in compliance with the hygiene limits. The total number of notifications during the evaluated period was 315 (2.2% in the EU). An alert which is the most serious type of notification presented 31% of total notifications. The alerts were caused mainly by the presence of Salmonellaspp. in poultry meat. The highest number of notifications were found in Germany (11.9% in the EU), the lowest number was reported in Slovakia (1.1% in the EU). Although the results of this thesis are very satisfactory, continuing regular contaminants monitoring is necessary to ensure food safety.
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Biochars - effective sorbents for pollutant removal.
Spáčilová, Markéta ; Krejčíková, Simona ; Čárský, Milan ; Soukup, Karel ; Šolcová, Olga
The growing amount of contaminants in the water has been a serious problem. Sorption is one of the effective methods for removal of various contaminants, such as drugs, detergents, or microplastics. Various sorbents are applied, whether commercial or laboratory prepared, as zeolites, bentonites, activated carbon and, more recently, various types of biochar, which are prepared by pyrolysis from variety of biomass residues. Their surface varies according to the preparation conditions (max SBET around 300 m2 / g) and there are tested under various conditions on variety of contaminants. Comparative studies of different types of biochar are rather lacking, similarly as their comparisons with commercial sorbents such as activated carbon.\nFor these reasons, this study aims to compare the sorption properties of three biochars prepared from different types of plant biomass (sunflower husks, seaweed Ecklonia Maxima and freshwater microalgae Chlorella Vulgaris), whose sorption properties were compared with commercial activated carbon, Supersorbon. The effectiveness of sorbents has been tested on diclofenac (a non-steroidal anti-inflammatory and anti-rheumatic drug) whose consumption is enormous worldwide and it is commonly found in water, owing to that most wastewater treatment plants do not capture it. All sorbents showed considerable efficiency, with the best results being obtained using a biochar prepared from freshwater microalgae (95%). Its high effectiveness has been verified in removing the contaminant triclosan (antibacterial and antifungal disinfectant). The concentration of contaminants (1 ppm) was chosen for testing, which corresponds to the concentrations commonly found in wastewater. Based on the result, it was found that all prepared sorbents are comparable effective with activated carbon, however, their preparation is more economically advantageous, because the price of activated carbon increases the need for subsequent activation. \n\n
Plný tet:  DOCX
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Chemical contaminants in milk
UHLÍKOVÁ, Tereza
The bachelor thesis is focused on the issue of contaminants in milk, such as pesticides, veterinary drugs, heavy metals, mycotoxins and their influence on milk quality. These substances present in milk have a negative impact on consumers health and for dairy cows health. The presence of contaminants in milk should therefore be monitored mainly to ensure the safe of the milk. An important group in terms of milk contamination are veterinary drugs. Their residues have a negative impact for milk processing and consumer health, but can also contribute to an increase in antimicrobial resistance. However, over-limit findings of veterinary drug residues in the Czech Republic have been on a low level in recent years. Special attention has been paid to milk contamination with mycotoxins because this problem is currently a very topical and discussed topic. Most of the work is focused on the contamination of milk with aflatoxin M1, which is the most explored milk-related mycotoxin.
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Contactless conductometry for shallow parts of geological medium
Podolník, Jan ; Dohnal, Jiří (advisor) ; Kněz, Jaroslav (referee)
The task is focused on the issue of contactless conductometry for shallow parts of geological medium and it consists of two connected parts, search and experimental. The first part includes fundamental theoretical principles of contactless conductivity measurement, summary of presently manufactured electromagnetic devices (ground conductivity meters) and finally it presents the potentialities of using conductometry for detection and monitoring of contaminants. The basis of the second part comprises the field test measurements with the instrument CMD (producer GF Instruments, s.r.o. Brno) on the selected locality, namely for several depth levels. The contents of this part include the field measurement, data processing and complex interpretation of the results in connection with geological conditions of the locality, petrophysical knowledge and with the stability of the device.
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