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Hydrogels of Humic Acids - Experimental Model and Application Form
Sedláček, Petr ; Klučáková, Martina (advisor)
The thesis deals with a utilization of hydrogels made of humic acids in both basic and applied research of this valuable natural material. The attention is paid to an interaction between the humic gel and cupric ions as the model heavy metal. The main experimental part focuses on an optimation of simple laboratory diffusion methods which serve as an innovative tool for modeling pollutants’ transport in natural humic environments. Various techniques were used in order to determine a diffusion coefficient of cupric ions in humic gel; the value is closely linked with the studied interaction between solid content of the gel and the diffusing species. Consequently, the diffusivity can be used as a standard parameter for basic reactivity mapping studies concerning humic substances. The final chapter of the thesis deals with a preparation of mixed reversible hydrogels formed by a reaction between humic acids and chitosan. These materials represent a suitable colloidal form for humic acids’ industrial and agricultural applications.
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Thick-film sensors for heavy metals detection
Polický, Jiří ; Adámek, Martin (referee) ; Prášek, Jan (advisor)
This work covers an area of heavy metals detection using thick-film sensors. Fabrication of screen-printed thick-film sensor and electrochemical analytical methods for detection of chemical elements in aqueous solutions are described in this work. Several commercial and own prepared thick-film pastes were used for carbon based working electrodes. The electrochemical properties of the pastes were examined by cadmium ions detection in potassium chloride solution using differential pulse voltammetry. The best results were achieved on the electrode made of direct grown carbon nanotubes on the electrode layer NM22. A detection limit 20×10-6 mol l-1.was reached with this working electrode material during oxidation process.
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Chromium and chromium species cycle in environment
Nevrlá, Jana ; Sommer, Lumír (referee) ; Dočekalová, Hana (advisor)
This work focuses in the first theoretical part mainly on the possibility of entering various forms of chromium into the environment, their accumulation and transformation in environmental compartments. There are also described methods of sampling for analytical determination of chromium, the type of treatment of these samples and the most analytical methodologies for the determination of chromium in the oxidation stage III and VI. The experimental part is focused on the quantitative determination of Cr(III) and Cr(VI) in waste water, taken from the neutralizatoin station of the Chemical faculty of Brno University of Technology, by using selected spectrophotometric methods and the obtained results are compared with the results of analytical determination of total chromium by atomic absorption spectrometry.
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Analysis of thermal power plants environmental impacts using radioanalytical methods
Král, Dušan ; Ing. Ondřej Huml, Ph.D., KJR FJFI ČVUT v Praze (referee) ; Katovský, Karel (advisor)
Operation of classical power sources, like coal fueled thermal power plants, causes more or less strong impact on surrounded environment. Beside to the generally discussed CO2 emissions, there are CO, SOx, NOx too; and also fly ash emissions containing various trace elements depending on coal quality. Heavy trace elements carried by fly ash generate locally distributed fallout and contaminate soil in the power plant neighborhood for many years. These elements may be detected in soil samples as well as in biomass. Objectives of this work are to find and quantify trace elements in soil samples near Oslavany hard coal fueled thermal plant, which was in operation from 1913 to 1993. Power plant did not use any advanced fly ash filters. Hard coal was used as a fuel for power plant and it was mined locally in Rosice-Oslavany coal district in very deep mines (up to 1428 m). Coal contained a lot of trace elements. A mine as well as power plant is for more than 20 year closed, but trace elements can be still find in the environment. Main goal is to find these elements using activation analysis and gamma-ray spectrometry methodology. We have assembled thirty six soil samples in square lattice drawn around Oslavany power plant brownfield. On behalf of cooperation with colleagues from the Czech Technical University in Prague and their Open-Access project, we irradiated samples in three vertical channels of VR-1 research nuclear reactor. Irradiated samples were transported to gamma spectroscopy & activation analysis laboratory and measured by HPGe detector. Gamma spectra were analyzed and some trace elements identified. We have determine relative and absolute concentration of found elements. We observe and determine activity and weight of As, U, Ba, La, Eu, Mn, K, V, Mg and Na only. Results show a real suspicion for increase of trace elements in soil samples of hard coal power plant surroundings.
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Analysis of substances potentially dangerous to humans found in lipsticks
Horáková, Kristýna ; Kučerová, Simona (referee) ; Diviš, Pavel (advisor)
The diploma thesis deals with the determination of the content of risk elements and parabens in lipsticks and the assessment of possible negative effects on human health associated with the use of lipsticks. Parabens were analyzed by high performance liquid chromatography with diode array detection (HPLC-DAD). Aluminum, cadmium and lead were analyzed on an inductively coupled plasma mass spectrometer (ICP-MS). The mercury content was determined using an atomic absorption spectrometer with an UV detector (AAS-UV). A total of 36 lipstick samples from 22 cosmetic brands were selected for analysis, with a savings price in the range of CZK 50–1500. Based on the measured metal concentrations, the hazard quotients (HQ) for individual metals as well as the total hazard index (HI) for the sum of all metals were calculated. Metal concentrations in lipsticks were further processed using Kruskall-Wallis Anova to divide samples according to price categories. The relationship between the content of individual metals and the purchase price has not been proven. Furthermore, a Kolmogór-Smirnov test was performed on these data to compare groups with vegan and not vegan composition. The content of aluminum, which was about 2.5 times lower in vegan cosmetics, proved to be statistically significant for this distribution. Parabens were detected in the minimum number of lipsticks examined, but in some cases information on the content of parabens was missing on the product packaging.
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Barrier properties of hydrogels
Královič, Michal ; Kalina, Michal (referee) ; Klučáková, Martina (advisor)
The main objective of this thesis is to judge the barrier properties of hydrogels. It was examined in total six kinds of agarose hydrogels, of which five kinds of gels was enriched with humic acids isolated from various sources. Humic acids were selected from IHSS standards, specifically Leonardite, Elliott Soil, Suwannee River, Pahokee Peat and Nordic Lake. Using UV-VIS spectrometry, copper ion concentrations were used to serve as a diffusion solution. Results of diffusion coefficients were evaluated by several diffusion methods. The method of diffusion in the plane of the board and three possible diffusion solutions of the constant source were used.
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Absorption Cleaning of Flue Gases Arising from the Incineration of Wastes
Jecha, David ; Klemeš,, Jiří (referee) ; Žaloudík, Petr (referee) ; Bébar, Ladislav (advisor)
This doctoral thesis deals with potentials of methods for cleaning of flue gas from pollutants such as acidic components. Wet method of flue gas cleaning is analysed in detail with special focus on elimination of sulphur dioxide (SO2). Introduction presents advantages and disadvantages of thermal processing of waste and production of undesired pollutants. Following parts comprise facts about main pollutants produced from incineration. Legislation providing for emission of gaseous pollutants from incinerators is also given. Chapter concerning methods of pollutants elimination is mostly focused on absorption (wet and/or semidry scrubber) and adsorption methods. Several up-to-date technological procedures are mentioned; they have a multifunctional effect such as elimination of acidic components, heavy metals, polychlorinated dibenzo-p-dioxines and dibenzo-furanes from flue gas using single injection of suspense. Elimination of mercury (Hg) is among the technologies for heavy metal elimination which is described in detail. Main part of the thesis is related to experiments at two-stage flue gas cleaning equipment. Function of this experimental unit is described along with methods for measurement of individual quantities and detailed description of all the equipment and its components. Experimental measurements carried out at this equipment are explicated and assessed. Along with experimental work, the author has created a simulation model of wet flue gas cleaning in ChemCad programme. Particular operational parameters were tested on this model. This thesis contains results of the measurement which provide background for verification of the mathematical model. Further, the balance of heavy metals conducted on the basis of measurements in waste incinerator is displayed. Main contribution of the thesis may be summed up as follows: Author has designed and constructed experimental equipment for two stage flue gas cleaning. He also formed calculation for pressure drop of O-element prototype equipment and for packing column with FLEXIPAC structured packing. He created data file with measurements at the experimental unit. He determined temperature at outlet of a random device where liquid is injected into stream of hot flue gas. He designed a simulation model which is identical with experimental equipment and which usage enabled comparison of measured and calculated data; it also serves as a basis for industrial applications. Last part deals with creation off heavy metals balance in a case industrial waste incinerator.
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Biosorption ability of thermophilic cultures
Zichová, Miroslava ; Vránová, Dana (referee) ; Babák, Libor (advisor)
The aim of this master's thesis is to study the biosorption of heavy metals copper, lead and zinc on thermophilic bacteria of the genus Geobacillus – G. thermodenitrificans CCM 2566 and G. thermocatenulatus CCM 2809. Biosorption was carried out in a batch stirred system for each metal separately. The influence of pH, biomass concentration and initial metal concentration on sorption capacity of bacteria was investigated. For both bacteria the optimum biosorption pH values for copper, lead and zinc were 5; 4 and 5, respectively. Sorption capacity of both bacteria was higher at lower concentrations of biomass and increased with increasing initial metal concentration. The confrontation of sorption capacities showed that the bacterium G. thermocatenulatus has greater sorption potential than G. thermodenitrificans.
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Chemical and thermal stability of humic complexes
Nováková, Tereza ; Pospíšilová, Ľubica (referee) ; Klučáková, Martina (advisor)
The aim of this diploma thesis was the study of relation between chemical and thermal stability of complexes of humic acids with heavy metals, namely nickel, cobalt and copper. Complexes were prepared with metal solutions of three different initial concentrations. Through UV-VIS spectrophotometry were determined adsorbed amounts of incorporated metal ions in the structure of humic acid; it was affirmed that amount of bounded metal ions increases with increasing initial concentration. Chemical stability was determined as an amount of released metal ions, two of extraction agents were used (solution of MgCl2 and HCl), total bounded amount was distribute into three different fractions; residual fraction, strongly bound fraction and mobile and ion-exchangeable fraction. Changes that occured in the structure of humic acids after complexation and extraction were investigated by FT-IR spectrometry. Thermo-oxidative stability was tested through thermogravimetric analysis (TGA) and differential scanning calorimetry. The results of this diploma thesis has showed comparision of complexes of two different humic acids. They have confirmed an impact of each metal ion on thermo-oxidative stability of humic acids. The relation between chemical and thermal stability was compared through correlation of data obtained by these methods.
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