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Influence of pH on Extraction of Matter from Biochar-Soil Complex
Jakubčeková, Kristína ; Enev, Vojtěch (oponent) ; Kalina, Michal (vedoucí práce)
Biochar is one of the possible solutions to improve the soil fertility, therefore it is necessary to investigate both its composition and the impact on the soil under various conditions. The aim of this bachelor thesis is to focus on the description of the influence of pH on the amount and type of substances (molecules, ions) that are leached from the biochar into the soil and thus consequently influence its properties. As a soil model it was chosen cambisol which is the most widespread soil in the Czech Republic. The selected pH values have been defined in such a way to cover the pH range that is common for various soil types in natural conditions. In the experimental part of this thesis the extracts from the used sample of biochar and soil were characterized first. These characteristics obtained in this way were subsequently compared with the data obtained for the biochar-soil complex extracts that was obtained after a defined period of cultivation of the mixture. For the characterization of extracts the basic physico-chemical methods (pH, conductivity, elemental and thermogravimetric analysis, UV-VIS) and also the analysis of leached ions and molecules by means of ICP/OES, GC-MS were used. Evaluated experimental data show that under the condition of cultivation experiments, the influence of biochar was observed only on the basic physico-chemical characteristics of the soil (mainly pH). On the other hand, there was no significant tendency of the impact of biochar on the representation of selected elements and on the content of organic matter in the soil. Long-term biochar-soil cultivation experiments could be a suitable solution.
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Use of various extraction techniques for the analysis of biochar extracts
Jakubčeková, Kristína ; Řezáčová, Veronika (oponent) ; Mravcová, Ludmila (vedoucí práce)
Biochar is a material whose properties, composition and impact on the environment are often discussed nowadays. The reason is its application as a soil conditioner. This leads to the need for qualitative as well as quantitative knowledge of its composition. This diploma thesis focuses on the qualitative analysis of biochar leachates processed by various extraction techniques. To approximate the real conditions, six aqueous mediums with different pH values is used, which a solid sample of biochar is exposed to. The prepared leachates are after that processed by extraction techniques, which are solid phase microextraction (SPME), single drop microextraction (HS-SDME), solid phase extraction (SPE) and liquid-liquid extraction (LLE). Analysis of the extracts was performed by gas chromatography-mass spectrometry (GC/MS). The measurements showed that the HS-SDME technique did not show a response. SPE was a rapid technique, but compared to other techniques, it acquired a smaller range of substances. Liquid-liquid extraction, a time-consuming technique, did not obtain as much analytes as SPME. By comparing these applied techniques, the SPME technique is the best choice. The most common determined analytes were those from the group of ketones and carboxylic acids and their derivatives.
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Use of various extraction techniques for the analysis of biochar extracts
Jakubčeková, Kristína ; Řezáčová, Veronika (oponent) ; Mravcová, Ludmila (vedoucí práce)
Biochar is a material whose properties, composition and impact on the environment are often discussed nowadays. The reason is its application as a soil conditioner. This leads to the need for qualitative as well as quantitative knowledge of its composition. This diploma thesis focuses on the qualitative analysis of biochar leachates processed by various extraction techniques. To approximate the real conditions, six aqueous mediums with different pH values is used, which a solid sample of biochar is exposed to. The prepared leachates are after that processed by extraction techniques, which are solid phase microextraction (SPME), single drop microextraction (HS-SDME), solid phase extraction (SPE) and liquid-liquid extraction (LLE). Analysis of the extracts was performed by gas chromatography-mass spectrometry (GC/MS). The measurements showed that the HS-SDME technique did not show a response. SPE was a rapid technique, but compared to other techniques, it acquired a smaller range of substances. Liquid-liquid extraction, a time-consuming technique, did not obtain as much analytes as SPME. By comparing these applied techniques, the SPME technique is the best choice. The most common determined analytes were those from the group of ketones and carboxylic acids and their derivatives.
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Influence of pH on Extraction of Matter from Biochar-Soil Complex
Jakubčeková, Kristína ; Enev, Vojtěch (oponent) ; Kalina, Michal (vedoucí práce)
Biochar is one of the possible solutions to improve the soil fertility, therefore it is necessary to investigate both its composition and the impact on the soil under various conditions. The aim of this bachelor thesis is to focus on the description of the influence of pH on the amount and type of substances (molecules, ions) that are leached from the biochar into the soil and thus consequently influence its properties. As a soil model it was chosen cambisol which is the most widespread soil in the Czech Republic. The selected pH values have been defined in such a way to cover the pH range that is common for various soil types in natural conditions. In the experimental part of this thesis the extracts from the used sample of biochar and soil were characterized first. These characteristics obtained in this way were subsequently compared with the data obtained for the biochar-soil complex extracts that was obtained after a defined period of cultivation of the mixture. For the characterization of extracts the basic physico-chemical methods (pH, conductivity, elemental and thermogravimetric analysis, UV-VIS) and also the analysis of leached ions and molecules by means of ICP/OES, GC-MS were used. Evaluated experimental data show that under the condition of cultivation experiments, the influence of biochar was observed only on the basic physico-chemical characteristics of the soil (mainly pH). On the other hand, there was no significant tendency of the impact of biochar on the representation of selected elements and on the content of organic matter in the soil. Long-term biochar-soil cultivation experiments could be a suitable solution.
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