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Bond strength of metal ions in humic gels
Potočková, Jana ; Sedláček, Petr (referee) ; Klučáková, Martina (advisor)
This thesis deals with the study of bond strength of Cu2+ ions in humic gels. Two methods of extraction were used during the study, sequential and fractional extractions. During the fractional extraction leaching of copper proceeds in single agents, whereas during the sequential extraction leaching proceeds gradually in all extraction agents. Destilled water, 1M MgCl2, 1M HCl and 0,025M NH4EDTA were applied like extraction reagents. Amounts of Cu2+ ions in leaches after extraction were measured by UV-VIS spectrometry. By using extractions was obtained the fractionation of Cu2+ ions according to bond strength in humic gel.
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Problems of humic matters as precursor of trihalomethanes (THMs) in water
Jelínková, Zuzana ; Dolejš, Petr (referee) ; Doležalová Weissmannová, Helena (advisor)
The bachelor’s thesis deals with qualities of humic matters, their origins, structures and occurrence in aquatic environment. There are suitable methods for determination of humic substances and processes used for their removing from water. The thesis describes disinfection of water and related origin of trihalomethanes. The aim of the experimental part of the thesis is to coagulate model humic water on the laboratory mixing column including suggestion of optimal dose of selected coagulation agent and comparison of effectivity of floccules separation by membrane filtration and centrifugation. Effectivity of the removal of humic matters was determined by measuring water absorbance at wavelengths 245 nm in a silica cuvette with optical 1 cm trajectory and at 387 nm in a glass cuvette with optical 5 cm trajectory. For evaluation of quality suspension concentration of residual iron of coagulation agent in water was determined.
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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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Study on phase transitions in humic substances
Grebíková, Lucie ; Šmejkalová, Daniela (referee) ; Kučerík, Jiří (advisor)
The work is aimed to examine the potential applications of temperature modulated differential scanning calorimetry in study on phase transitions in humic acids. Experiments will deal with both humic standards and the solid rests after sequential extraction of specific molecular fractions to reveal their role in secondary structure of humic acids.
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Influence of humic substance HS 1500 on tolerance of Sterlet to nitrite
BULÍČEK, Vojtěch
The aim of the thesis was to assess the effect of humic substance HS 1500 on the tolerance of Sterlet (Acipenser ruthenus) to nitrite. Preparation Huminfeed was used as a source of substance HS 1500. Tolerance of Sterlet to nitrite was assessed on the basis of the results of acute toxicity tests and the results of haematological and biochemical blood examination of fish that were exposed to increased concentrations of nitrite in the presence and absence of preparation Huminfeed.
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Influence of selected factors on reproduction of fish \kur{Betta splendens}
HOMOLKA, Václav
The Siamese fighting fish (Betta splendens; order Perciformes, family Osphronemidae) is a fish occurring in the area of south east Asia. Above branchial organ (so-called labyrinth) allowes it to breath an air oxygen. It is a territorial sort of fish, males are brawling to each other. In a breeding fish take alive or frozen food and also artificial feed. The fish is bubblenest, spawns are put into a foam nest, built by a male, that takes care about the posterity for some time. The task of the work was to verify the influence of chosen feeds sorts and concentration of humic substances in water for a success in reproduction of Betta splendens fish. The experiment was performed in an aquarium room at institute of biological disciplines AF USB. The experimental work started on 12. 12. 2011 and was finished on 25. 2. 2013. Tested fish were by particular couples put into tanks, at which there were breeding afterwards. It was evaluated the frequency of spawns and the number of embryos. From the result of the work there is obvious that the feeding by a beef heart was preferable for fish´s fertility in a monitored time area about approximatelly 75% in comparison to feeding by a chicken breasts muscles. The presence, or more precisely the concentration of humic substances obviously did not affected the fertility. All fish´s groups embodied higher grade of fertility at the beginning of the monitored time area (probably higher fertility at younger - more vital fish). Siamese fighting fish is very demanded fish at aquarists, this is why is very important to evaluate certain parameters of breeding and rearing of these fish.
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