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Influence of changes in concrerte pore structure on actually durability of reinforced and pre-stressed structures.
Kovalčíková, Hana ; Adámek, Jiří (advisor)
This master thesis deals with a durability of concrete, which has become the centre of the interests of international scientific insitutes during the last years. The resistence of reinforced concrete depends on the covercrete which the aggresive liquids and gases penetrate through from the environment to reinforcement. According to the ability of the covercrete to penetrate degradative species is possible to tell the durability of concrete constructions. In experimental part we look for the actual state of covercrete, ordinary and high strength, by combination of various experiments. We can find here the test´s results of water and gas permeability and absorbability and sorption of concrete which complete the permeability tests. In final part the impact of different concrete types on durability of reinforced concrete is discussed.
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Interactions of hormones and drugs with soil organic matter
Krajňáková, Soňa ; Enev, Vojtěch (referee) ; Klučáková, Martina (advisor)
This thesis is focused on the problem of interaction of hormones and drugs with a soil organic matter. The most commonly occurring drugs are described, as well as their features, behaviour and possible factors influencing this behaviour. These substances are frequently transported to the soil through a sewage treatment plant, as the cleaning process of wastewater is not effective enough to ensure complete removal of these substances. Once in the soil, the life of organisms in this environment can be negatively influenced. The soil used in experiments was not contaminated with any of these substances as it was used as a matrix for sorption and desorption. Two experiments were conducted using Ibuprofen, where its sorption and desorption on the soil was observed. The intention was to ensure detection of changes which occurred in the concentration of Ibuprofen after concluding these processes. Liquid chromatography method with mass spectrometric detection was used for a final analysis.
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Humic substances - colloidal transport system of plant nutrients
Hudlíková, Iva ; Pospíšilová, Ľubica (referee) ; Klučáková, Martina (advisor)
The thesis deals with humic substances as major components of soil organic carbon during nutrients transport to plants root system. Literature research is focused on humic substances, adsorbing complex and transport of soil substances to plants. The experimental part of the work concentrates on interaction of humic acid with nitrates. A part of the work was humic acid characterization, and determination of titratable acidity and acidity COOH values.
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Vliv tepelné a chemické modifikace na sorpční, difuzní a hygroexpazní vlastnosti dřeva
Imramovský, Pavel
This thesis dealed with the influence of heat and chemical modification on sorption, diffusion and hygroexpansion properties of wood. To this aim, a thermal modification of European beechwood was carried out at temperatures (180 °C, 200 °C, 220 °C) in the special modified chamber of Katres. Furthermore, chemical modification was required on individual samples using acetic acid anhydride. The individual samples had to be sliced in radial and tangential directions using microtoma. A dynamic vapour sorption (DVS) device was used to determine the sorption and diffuse properties of all these beech slices as well as the reference unmodified sample. In addition, dynamic swelling was determined for all groups studied in radial and tangential directions. In order to determine the rate of swelling, sample sizes were measured using a scaler in specified directions before and after the 24-hour period in the water. The results indicated that both heat- and chemically-treated beechwood scored better against moisture than reference untreated samples. The diffusion coefficient in the radial direction was also higher than in the tangential direction, which corresponds to the professional literature. The results indicate that heat- and chemically-treated beechwood resisted better moisture than the reference untreated samples. Within swelling, direction plays a large role, as measurements in the tangential direction are nearly twice as high as the radial. The possibilities of using modified wood in construction as well as from the perspective of the researched characteristic were considered. The statistics were performed in the ANOVA program.
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Mobility of pharmaceuticals in soil systems
Slaninová, Kristína ; Širůček, David (referee) ; Klučáková, Martina (advisor)
As a result of improper disposal, pharmaceuticals from households, industry or hospitals are discharged into the environment. Another source through which pharmaceuticals enter the environment is the fertilization of the soil with organic fertilizers or other natural fertilizers containing animal excreta. Medications penetrate into the environment through sewage, entering wastewater, groundwater, surface water, drinking water, and soil, posing an environmental threat. Chelating properties of the organic component of soil could potentially be a solution to the problem of medication presence in soil by preventing migration of the medication. Sulfathiazole is among the group of medications frequently detected in the environment. Sulfathiazole is a sulfonamide antibiotic primarily used in veterinary medicine. The aim of this bachelor's thesis is to determine the concentration profile of sulfathiazole in the soil column and to identify its diffusion coefficients. The thesis also includes a study of the sorption and desorption of sulfathiazole in soil.
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Možnosti využití vyhnilých kalů z městské čistírny k pyrolýze a jejich použití v sorpčních procesech na příkladu kyseliny šťavelové
PRAŽÁK, Jakub
This diploma thesis is focused on sludge management of waste water treatment plants. The research part of the thesis outlines the problems of sludge management in the Czech Republic and also deals with technologies and technical solutions related to the treatment and handling of sewage sludge for various purposes. Furthermore, the theoretical part describes the function of urban wastewater treatment plants and technological methods of wastewater treatment. I also focus on energy utilization of sewage sludge in pyrolysis processes. The result of these pyrolysis processes is called Biochar. Biochar is a carbon thick solid that arises from the pyrolysis of organic materials for application to soil and other uses such as biofuels. The carbon that remains in the solid forms stable aromatic structures that are more resistant to degradation in the natural environment. The mineral ash content of the original organic materials is preserved in the biochart and the volatile constituents of the raw material are lost during the pyrolysis process. In the second part of the work, the prepared and modified samples of the biochar are subjected to the determination of the sorption properties in order to determine whether the biochar is able to transfer the nutrients contained in it to the soil. If the biochar were able to transfer nutrients to the soil without any undesirable side effects, it could very much solve the problem of its future storage.
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Biochars as effective sorbents for pollutant removal.
Spáčilová, Markéta ; Krejčíková, Simona ; Čárský, Milan ; Soukup, Karel ; Šolcová, Olga
Contaminants in water, various drugs, detergents or microplastics, have been a constant problem. One of the effective methods of their removal is sorption by various active sorbents such as biochar. Four various sorbents were tested in this study. Three biochars prepared from different waste plant biomass (sunflower husks, seaweed and microalgae) and commercial activated carbon - Supersorbon. The effectiveness of the sorbents was tested by diclofenac (active substance) and triclosan (disinfectant) removal. The concentration 1 ppm, which corresponed to the commonly occurring concentration was chosen for tests.\nBased on obtained results, it was found that all biochar sorbents were comparatively effective as activated carbon and thanks to their lower price, also economically advantageous.\n
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Study of the medium influence on the pollutants sorption on microplastics
Hamplová, Marie ; Kučerík, Jiří (referee) ; Mravcová, Ludmila (advisor)
With the increasing production of plastic waste, the pollution of the environment by persistent microplastics is increasing simultaneously. Other environmental pollutants, such as various pharmaceuticals, can be sorbed on microplastics. This increases the toxicity of microplastics and their risk to living organisms. Nowadays, the use of so-called biodegradable polymers, which are supposed to degrade spontaneously, is expanding. However, their degradation can also produce microplastics. Therefore, this bachelor thesis deals with the sorption of drugs onto microplastics from biodegradable polyhydroxybutyrate (PHB) and with the influence of the surrounding aqueous environment on the rate and mechanism of sorption. Sorption of drugs onto microplastics made of synthetic polyethylene terephthalate (PET) was also carried out for comparison. The quantity of drugs was analysed by UPLC-ESI-TQ. Sorption was observed from the drug mixture for antibiotics tetracyclines. The pH value of the surrounding environment influenced the sorption rate of tetracyclines, the highest sorption occurred at acidic pH 4. According to the results of evaluation of sorption by Langmuir and Freundlich adsorption isotherms, PHB microplastics have a higher sorption capacity than PET microplastics. Therefore, PHB microplastics could be a risk for living organisms.
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Removal of metabolites of pesticides from groundwater during treatment for drinking water
Vaněk, Michal ; Repková, Martina (referee) ; Král,, Pavel (advisor)
The diploma thesis deals with the evaluation of the efficiency of pesticide metabolite removal at a water treatment plant. In the introduction, a research on the issue of pesticide substances in raw water, their removal during the treatment to drinking water and the basic classification of pesticides is made. The thesis includes an introduction to the issues at a specific water treatment plant, technological changes at the water treatment plant, tabulated and graphically processed measured values of pesticide metabolites in groundwater source and drinking water. In the conclusion of the thesis, individual pesticide metabolites are discussed, their sorption on granular activated carbon is assessed and conclusions are drawn.
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