National Repository of Grey Literature 3 records found  Search took 0.01 seconds. 
Hair as a bioindicator of contamination of risk metals
Zmijová, Marie ; Řezáčová, Veronika (referee) ; Zlámalová Gargošová, Helena (advisor)
The use of hair as a bioindicator of environmental contamination by risk elements is becoming more and more common. This bachelor thesis deals with the use of this matrix for analysis using the voltammetric method. It focuses on the optimization of the method for determining the concentration of cadmium, copper, lead and zinc in real hair samples and monitors the effects on the incorporation of these elements into the hair fiber. The presence of zinc and copper was confirmed in all samples analyzed. Cadmium could only be quantified in one sample. The effect of gender and age on the concentration of elements has not been demonstrated. Concentration of lead has been linked to smoking, with higher concentrations found in smoker’s hair than in non-smoker’s.
Enzymatic Degradation of Biochar
Zmijová, Marie ; Enev, Vojtěch (referee) ; Kalina, Michal (advisor)
Human prosperity is inextricably linked to healthy soil. It turns out that the application of biochar improves soil properties and, as a result, also the growth and yield of plants. The presence and activity of soil biota contributes to soil quality, but it also excretes compounds that can degrade biochar. Experiments simulating the action of enzymes and root exudates were carried out in order to find out whether there are physico-chemical changes in biochar. Three biochars, which were chosen for this purpose were degraded using an H2O2 solution, simulating enzymatic action. Samples were subsequently analyzed using TGA, FTIR, SEM and contact angle measurement. It was found that the amount and type of degraded biochar matter depends on the parameters of its production. The amount of functional groups containing oxygen on the surface of biochar rises due to enzymatic oxidation and the surface’s hydrophobicity decreases as a result. An extraction test using citric acid, a root exudate representative, showed that the sample had been washed more effectively, leading to a higher proportion of organic matter in the biochars. In the obtained leachates, the amount of elements released from the biochar was monitored using ICP-OES. The initial washing led to the release of the largest amount of micro and macro elements, which caused a decrease in the pH value of the solution and an increase in conductivity. The pH value of the solution had a major influence on the amount of released multivalent elements (Ca, Mg). The combination of these changes that may occur in the soil system probably does not change the desired effect of biochar and its use may be beneficial in the long term.
Hair as a bioindicator of contamination of risk metals
Zmijová, Marie ; Řezáčová, Veronika (referee) ; Zlámalová Gargošová, Helena (advisor)
The use of hair as a bioindicator of environmental contamination by risk elements is becoming more and more common. This bachelor thesis deals with the use of this matrix for analysis using the voltammetric method. It focuses on the optimization of the method for determining the concentration of cadmium, copper, lead and zinc in real hair samples and monitors the effects on the incorporation of these elements into the hair fiber. The presence of zinc and copper was confirmed in all samples analyzed. Cadmium could only be quantified in one sample. The effect of gender and age on the concentration of elements has not been demonstrated. Concentration of lead has been linked to smoking, with higher concentrations found in smoker’s hair than in non-smoker’s.

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