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The influence of Biochar Cultivation in Soil on its Physicochemical Characteristics
Hladký, David ; Sovová, Šárka (referee) ; Kalina, Michal (advisor)
This bachelor thesis is focused on the effect of soil factors on the physical-chemical characteristics of biochar. It describes the change in biochar after a long-term cultivation experiment, as well as, sequential leaching that was implemented on a shorter time scale. The theoretical part describes individual physical-chemical characteristics, structure, possible applications and optimal methods of biochar characterization. In the thesis, we have learnt why biochar is called a soil conditioner, not a fertilizer. The experimental part deals with the study of changes in the physicochemical characteristics of biochar after the cultivation experiment. These results are compared with the sequential leaching of biochar in selected media (water, citric acid, hydrogen peroxide) that simulate the effects that can act on biochar in soil. The experimental results show the similarity of individual observed values of the samples after the long-term cultivation experiment and sequential extractions. It can be seen that the alkaline nature of biochar is caused by salts of alkali metal and alkaline earth metal. Mostly due to the presence of potassium in the biochar structure and then also the presence of calcium and sodium. These ions are also the explanation of the high conductivity, which together with pH, decreases significantly after five leaching cycles, and stabilize after a two-year cultivation period. All biochars samples used in the work have a high content of organic matter, which is a optimal prerequisite for the use in agriculture and the improvement of soil properties.
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Salt precipitation in subsurface zone of sandstone and other porous rocks and simulation of water transport and evaporation
Sommerová, Anna ; Bruthans, Jiří (advisor) ; Filippi, Michal (referee)
The main goal of this thesis was to find and compare salt-forming ions from samples of a subsurface zone of sandstone and other porous rocks. The surveyed samples came from different environments (humid and arid climate) from different locations in the Czech Republic, Jordan and the United States of America. Identification of various types of salt was based on evaluation of chemical analyzes of leached samples. Furthermore a laboratory experiment in which I used a fluorescein dye to observe the capillary rise and evaporation in unsaturated samples of sandstone was carried out. The salt content in the Czech Republic humid environment locations is generally lower than the one in foreign arid climate locations. Halit dominates in the locations Petra and Crystal Peak. In the other locations sulphate minerals dominate. The salts containing aluminum - alums were determined in the Czech Republic in the area of Czech Paradise and the surrounding. Relatively high concentrations of nitrate mineral nitratine were identified in the Devil's Pulpit location in Pilsen, the Czech Republic. From the observation of capillary rising experiments performed with artificially created honeycombs, I conclude that the height of the capillary rise is crucial for the transport of solution, and at a certain capillary height,...
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