National Repository of Grey Literature 164 records found  beginprevious17 - 26nextend  jump to record: Search took 0.00 seconds. 
Study of selected antibiotics sorption on polyhydroxybutyrate
Amrichová, Anna ; Doležalová Weissmannová, Helena (referee) ; Řezáčová, Veronika (advisor)
The bachelor thesis deals with the issue of sorption of antibiotics on microplastics. Antibiotics and microplastics are now a highly studied topic, due to the positive and negative properties. Antibiotics with groups of sulfonamides and quinolones were selected for the experiment. From sulfonamides, sulfamethoxazole and trimethoprim were selected, and from the quinolones, enrofloxacin and ciprofloxacin, which have already been the impetus for some microplastic studies. Biodegradable polyhydroxybutyrate was used as the microplastic. Two experiments were performed in the laboratory. The first aimed to monitor the time dependence of antibiotic sorption on polyhydroxybutyrate, the second the concentration. The concentration dependence was subsequently evaluated using the Freundlich and Langmuir isotherms. The method of liquid chromatography with mass spectrometry was used for analyzes.
Spectrophotometric determination of chlorophyll
Rábová, Petra ; Vavrčíková, Veronika (referee) ; Řezáčová, Veronika (advisor)
This bachelor thesis is focused on determination of chlorophyll in leaves by the method of extraction spectrophotometry. The theoretical part provides information about photosynthesis, stress factors or plant adaptation, photosynthetic pigments (especially chlorophyll-a) and application of spectrophotometry and other methods of chlorophyll determination. The experimental part is focused on the application of the ecotoxicological test and, above all, it is evaluation by two independent methods. Specifically, it was determination of biomass growth inhibition and newly spectrophotometrical determination of chlorophyll mass. The results correlate with each other, therefore, the determination of chlorophyll seems to be an appropriate extension of usual evaluation methods of ecological tests.
Palladium in the environment
Hajdová, Jana ; Řezáčová, Veronika (referee) ; Komendová, Renata (advisor)
This work is focused on palladium in the environment. Its use is especially in the automobile industry as catalytic converters of motor vehicles, but also is applied in dental, jewelry making and electrical appliances. The release of this metal from automobile catalysts is getting into all environmental compartments (soil, road dust, water, plants), where goes to its accumulation. It can be a part of the food chain and cause health risks to humans. The work also focuses on methods of sampling, preconcentration and methods, which can determined palladium in environmental samples (spectrophotometric methods, AAS, ICP-AES and ICP-MS).
Organic tin compounds in the environment and the possibilities of their determination.
Fojt, Jakub ; Komendová, Renata (referee) ; Řezáčová, Veronika (advisor)
The aim of this thesis is elaboration literature search concerning the issue of organotin compounds in the environment. It mainly deals with use, properties and occurence of organotin in the environment and possible analytical ways to determine them. It also includes description of optimalized method to determination of trimethyltin chloride by capillary electrophoresis.
Study of the influence of polyethylene terephthalate recycling on the quality of the resulting recyclate
Mach, Jakub ; Řezáčová, Veronika (referee) ; Kučerík, Jiří (advisor)
Plastics and recycling of plastics is a frequently discussed topic. The output of sythetic polymers is rising exponentially every year. In accordance with the sustainable development, development of effective recycling techniques enabling to process these huge amounts of waste and convert it back into useful material is essential. The aim of this work was to study qualitative effects of production methods, various types of recycling processes and degree of degradation of polyenthylene terephtalate on results of differential scanning calorimetry (DSC) analysis. In experimental part, analyzes of 62 regranulates of recycled PET were performed. The samples from various manufacturers differed (manufacturers use different technologies) in terms of mechanical and physico-chemical properties or additives. The results confirmed that the properties of recycled PET have an impact on thermophysical properties recorded using DSC. A simple DSC run enables distinguishing a number of fundamental qualitative properties of PET, in particular crystallinity, melting point and enthalpy, temperature and enthalpy of crystallization and glass transition temperature and in this work we show that their mutual relationship enables to estimate the quality of recycled material and the possibilities of its further use.
Study of surface water quality in the Ivančice area
Jonášová, Simona ; Řezáčová, Veronika (referee) ; Komendová, Renata (advisor)
Selected physical and chemical water quality parameters were measured at four sampling localities on the Jihlava River. Using UV-VIS spectrophotometry, inorganic forms of nitrogen, chlorides, total phosphorus and CODCr were determined. BOD5 was determined by the dilution method. Na+, K+ and Ca2+ ions, whose concentrations ranged from 5,75–108 mgl 1, were measured by flame emission photometry. Selected metals (Cu, Ni, Pb, Zn, Hg, Cr, Fe, Mn) were determined in water by the ET-AAS method. Decomposed sediments were determined by the FAAS method. Concentrations of Cr, Cu, Pb and Ni in water were in the range of 0,05–2,84 gl1. Metal concentrations in sediments ranged from 0,02–293 mgkg1, where nickel concentrations were above the limit. The occurrence of iron and manganese is due to the geological subsoil. For the other elements, anthropogenic source is assumed. From the measured data, the water quality is slightly variable in this locality and is classified as fourth or fifth class, i.e. as highly polluted water.
Fate of microplastics in soil
Kameníková, Eliška ; Řezáčová, Veronika (referee) ; Kučerík, Jiří (advisor)
The problems with microplastics, small plastic particles contaminating the environment, is a subject of heated discussions today. It has been recognized that the microplastics are not inert, but instead they have an impact on all enviromnental compartments. There are studies describing the negative effects of microplastics, for example on fauna and flora or on human health, but the effects on soil quality have not been sufficiently described. The aim of this thesis was to assess the short and medium term effects that microplastics could have on the soil. In this work, a series of experiments were performed to elucidate the fate of microplastics in the soil. Changes in soil organic matter thermal properties, soil respiration, amount of water and soil aggregation depending on the incubation time were monitored. Three types of agricultural land (chernozem, cambisol and phaeozem), which were contaminated with different concentrations od PET and tyre rubber, were tested. The results confirmed the specific effects of microplastics on soil properties, which were observed in non-incubated samples (i.e. at the time of incubation 0 months), microplastics did not behave inertly in the soil and affected, for example, soil properties, texture and respiration.
Determination of platinum group metals in soils the city of Brno
Pavlíčková, Ivana ; Řezáčová, Veronika (referee) ; Komendová, Renata (advisor)
The diploma thesis focuses on identifying the presence of platinum in soil samples by absorption spectroscopy. The work is divided into two parts, the theoretical part is focused on the occurrence and behavior of platinum in the environment, the fundamental chemical and physical properties of platinum, its importance in catalytic converters in cars, on solid phase extraction method and the method for the determination of atomic absorption spectrometry. The second part is the practical part, focused on the determination of the platinum amount in the soil samples in the city of Brno.
Nitrogen and its compounds in wastewater
Venská, Petra ; Skoumalová, Marta (referee) ; Řezáčová, Veronika (advisor)
The bachelor thesis summarizes the possible forms of nitrogen and nitrogen compounds in wastewater and ways of elimination of these compounds including physical/chemical processes and biological processes. The physical/chemical methods described in the thesis are air stripping, breakpoint chlorination, sorption and membrane separation. The biological processes include nitrification, denitrification, anoxic ammonium oxidation and SHARON, CANON and OLAND systems. The experimental part is devoted to quantifying nitrates, nitrites and ammonium in wastewater samples using mobile analytical methods.
Study of microplastic sorption properties
Hlaváčková, Hana ; Kučerík, Jiří (referee) ; Řezáčová, Veronika (advisor)
There is currently an effort to replace conventional plastics with biodegradable products that will have the ability to replace these substances. One of the possible biodegradable felt, which is currently being studied in detail, is also poly (3-hydroxybutyrate), which is produced by bacteria. This bachelor thesis deals with the sorption of selected substances on poly(3-hydroxybutyrate) microparticles. Substances whose contamination of water sources is a significant problem today have been selected for this work. Specifically, the sorption of the nonsteroidal anti-inflammatory substance ibuprofen, the triazole fungicide tebuconazole and the most common drug caffeine on PHB particles, which fall in the size of the microplastic group, were studied. The method of liquid chromatography with mass detection was used for analyzes.

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10 ŘEZÁČOVÁ, Veronika
2 Řezáčová, Vendula
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