National Repository of Grey Literature 90 records found  1 - 10nextend  jump to record: Search took 0.01 seconds. 
Changes in oxidation-reduction potential in underground, mineral and bottled water and their practical relevance
Kassenov, Danay ; Komendová, Renata (referee) ; Řezáčová, Veronika (advisor)
This bachelor thesis deals with the redox potential of mineral waters and its use. The theoretical part summarizes basic information about water and redox potential. The experimental part is devoted to monitoring the time dependence of changes in the oxidation-reduction potential of different mineral waters. It was found that the values of the potential change with time, without a uniform specific trend. The findings may have further practical significance for water quality control and management.
Analysis of organic compounds in the soil-biochar-salad system
Hlaváčová, Josefína ; Řezáčová, Veronika (referee) ; Mravcová, Ludmila (advisor)
The bachelor’s thesis presented focuses on the analysis of polycyclic aromatic hydrocarbons extracted from lettuce, soil, biochar and soil mixed with biochar. Polycyclic aromatic hydrocarbons are introduced into the biochar during the production process, i.e., pyrolysis. After applying the biochar to the soil, the polycyclic aromatic hydrocarbons can be released into the soil and contaminate it. The theoretical part of the thesis focuses on the production and characterisation of biochar, its applications to the soil and subsequent changes it induces within the soil. The experimental part focuses on the optimization of the microwave-assisted extraction process. Furthermore, experiments were carried out, assessing the influence of the added biochar on the concentration of polycyclic aromatic hydrocarbons within soil and lettuce. The sample analysis included microwave-assisted extraction and quantitative and qualitative determination using GC/MS/MS. The samples analysed were assessed for the presence and concentration of 16 different polycyclic aromatic hydrocarbons, prioritised by the U.S. Environmental Protection Agency. The analysis of the samples of lettuce grown in the soil containing biochar display a higher concentration of polycyclic aromatic hydrocarbons compared to samples without biochar. The analysis of the lettuce roots showed identical results.
Intensive composting technologies and their applications
Kuba, Petr ; Kučerík, Jiří (referee) ; Řezáčová, Veronika (advisor)
This bachelor thesis deals with intensive composting. The theoretical part of the thesis summarizes information about the composting process and the possibilities of sanitation. The ability to sanitize is essential in the treatment of potentially hazardous biodegradable wastes. The theory also includes information on the preparation of the stockpile, the appropriate composition of materials and the influence of other factors - temperature, aeration rate and turning. It also explains the differences between manual and intensive composting technologies, gives examples of technologies and explains their principles. Last but not least, the advantages of applying compost to the soil are mentioned. The experimental part is devoted to the Multiferm device and the tests of the composting process carried out on this unit. The tests aim to find the optimal parameters for the whole composting process and to ensure the sanitation process. Although the parameters are influenced by several factors, the compost sanitation process is achieved in one of the tests.
Determination of trace amounts of mercury by voltammetry
Hudzíková, Veronika ; Mravcová, Ludmila (referee) ; Řezáčová, Veronika (advisor)
This bachelor thesis concentrates on the optimalization of conditions for voltammetric determination of mercury in water. The theoretical part describes fundamental characteristics of mercury as a chemical element, impact on the environment and possible analytical methods for determination with emphasis on voltammetry. The experimental part includes the description of the optimalization of analysis conditions, applied methods and the analysis of real samples.
Research on the release of nitrogen compounds from fertilizers
Cápková, Viola ; Řezáčová, Veronika (referee) ; Komendová, Renata (advisor)
This bachelor thesis deals with the monitoring of the release kinetics of ammonium, nitrate and phosphate ions from slow release fertilizers covered in potassium polyacrylate. Fertilizer samples were subjected to different extraction reagents and experimental conditions. The effect of dynamic and pressure conditions in comparison to the static conditions was investigated, same as exposion to distilled, drinking and atmospheric water. The change in concentration of each analyte was measured at regular intervals using molecular spectrophotometry. Distilled water was found to be the best extraction reagent, with no significant difference between the experimental conditions. Slow release of nutrients was proved for two fertilizer samples, the urea fertilizer and it’s modified form.
Microfiltration and filtration – the use in wastewater treatment technology
Čičatková, Dominika ; Řezáčová, Veronika (referee) ; Komendová, Renata (advisor)
This bachelor thesis deals with the issue of wastewater treatment using a membrane process called microfiltration. It focuses on the comparison of selected indicators of wastewater pollution, the values of which were determined in the influent and effluent samples of a microscreen drum filter and a disc filter at selected wastewater treatment plants. The treatment plants were selected based on whether they owned any of the listed filter types from IN-EKO TEAM s.r.o. The selected indicators were determined in a total of twelve samples from six wastewater treatment plants. From the data obtained, it was found that the above filtering devices contribute to improving the quality of the effluent discharged and can thus prevent problems associated with pollution of water recipients.
Influence of titanium dioxide nanoparticles on soil properties
Zoufalá, Anna ; Řezáčová, Veronika (referee) ; Kučerík, Jiří (advisor)
This masters thesis deals with the influence of TiO2 nanoparticles on soil properties. Even though synthetic nanoparticles pose potential environmental risk, their impact on the environment is not researched enough. TiO2 nanoparticles are one of the most used and widespread nanoparticles and contamination of the environment with these nanoparticles is inevitable. One of the properties, thanks to which these nanoparticles are used, is the possibility of photocatalysis when the nanoparticles are illuminated with light in the UV wavelength. During this process, especially in the presence of water, highly reactive radicals are formed, which can oxidize organic compounds, which is mainly used for the degradation of organic pollutants. Therefore it is possible that in soil contaminated with TiO2 nanoparticles photocatalytic degradation of soil organic matter could occur. On the other hand, it is possible that polymerization reactions occur too. Thus the aim of this work is to clarify which processes occur after irradiating soil contaminated with TiO2 nanoparticles. To asses the impact of TiO2 nanoparticles and UV irradiation were caried out experiments during which soil contaminated with TiO2 nanoparticles was irradiated at different humidities. These samples were analyzed using thermogravimetry and FTIR spectrometry. No changes caused by TiO2 nanoparticles and UV light were detectable using thermogravimetry. Data acquired from FTIR spectrometry were processed using two different statistical methods – correlation analysis and principal components analysis. Correlation analysis was found not to be suitable method of data evaluation for the purpose of this work. Principal components analysis proved, that higher concentration of nanoparticles (5 wt. %) in combination with UV light does have impact on the composition of soil organic matter and its decomposition occurs mainly.
Study of drugs intake by lettuce
Amrichová, Anna ; Zlámalová Gargošová, Helena (referee) ; Řezáčová, Veronika (advisor)
The aim of this thesis is to analyze the content of selected groups of drugs in cultivated lettuce. The theoretical part includes a chapter dedicated to the drugs used, their use, physicochemical properties, and their impact on the environment. Other chapters focused on analytical methods for determining drugs, hydroponic cultivation of lettuce, and some parameters of ecotoxicological tests. The experimental part began with the optimization of the QuEChERS extraction procedure. The optimized procedure was then applied to hydroponically grown samples of roots and leaves of lettuce containing selected groups of drugs, which were subsequently analyzed using liquid chromatography – mass spectrometry. The experimental part also addressed the ecotoxicological impact of different drug concentrations on hydroponically grown lettuce.
Simultaneous determination of ultratrace concentration of nitric acid and nitrates in air using chemiluminescent online analysers
Čmelíková, Dorota ; Řezáčová, Veronika (referee) ; Alexa,, Lukáš (advisor)
The diploma thesis is focused on the development, optimization and real use of a continuous flow analyser for online determination of nitric acid and nitrates in air. The principle of analysis is photolytic conversion of nitrate in solution to peroxynitrite with subsequent detection by chemiluminescence reaction with luminol. The main aim of this thesis was to optimize parameters of analyser followed by practical use for analysis of urban air. The detection limit of gaseous nitric acid was 0,13 g·m3, resp. 0,10 g·m3 for nitrates in aerosol. The measured online concentrations were compared with reference offline analysis. The analysis of urban air was realized in two campaigns (September 2022 and February 2023) at Institute of Analytical Chemistry of CAS in Brno. The apparatus was placed in laboratory on the second floor and samples were collected from the window at Veveří street.
Assessment of PHB effects at organismal and sub-organismal levels through E. fetida.
Demová, Kristína ; Řezáčová, Veronika (referee) ; Zlámalová Gargošová, Helena (advisor)
The use of biodegradable plastics, which are competitive with synthetic plastics and have the ability to be completely degraded by micro-organisms, is gaining ground. In real life conditions, biodegradation does not always proceed as expected, and these plastic particles may persist in the environment for long periods of time. Therefore, the verification of the safety of these plastics is the subject of many studies. This was also the aim of the present thesis, which deals with the impact of poly-3-hydroxybutyrate microparticles (representative of biodegradable plastics) on the organism Eisenia fetida (representative of soil organisms). Its effects were assessed using classical ecotoxicological tests. Methods to observe effects at the sub-organism level - using selected biomarkers - were also introduced and implemented. From the obtained results, no significant effect of the investigated biodegradable plastic on the test organism E. fetida was demonstrated, but the introduced methods can be used in the future to obtain more results to assess the effect at the sub-organismal level of the organism in a relevant way.

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2 Řezáčová, Vendula
9 Řezáčová, Veronika
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