|
|
Biochar effect on distribution of organic matter in soil
Haleš, Petr ; Širůček, David (referee) ; Kalina, Michal (advisor)
Biochar is a carbon-rich material that can be used in agronomy as a soil conditioner. The selection of the source biomass and the conditions used during pyrolysis (for example residence time and temperature) can have different effect on the physicochemical properties of this material. In this bachelor thesis biochar was produced from oat bran, woodchips, corn and compost by pyrolysis at 600 °C. The woodchips were also pyrolysed at temperatures in the range 400–700 °C. These biochar samples were subsequently leached with model rainwater. The main aim of this thesis was to assess how the conditions of biochar production influence the quantity and nature of substances, which can be released from this material. In the second part of this thesis, the commercial biochar Agrouhel (produced from sewage sludge at temperature 450–470 °C) was used (“Káňa”). This biochar was leached with model rainwater and dilute solutions of citric acid (which simulates root exudates) and hydrogen peroxide (which simulates enzymatic biochar degradation). Physicochemical characterization (pH and conductivity) of the extracts was realized after each leaching cycle. Additional analyses (UV-VIS and ICP-OES) of the solution were measured after the 1st, 5th and 10th cycle. The original solid biochar and biochar samples after the 10th cycle of leaching were used to determine the inorganic and organic fractions and to determine the elemental composition of the organic fraction (TGA and EA). The laboratory cultivation experiment with biochar Káňa was performed on the model plant (Lactuca sativa). Biochar obtained after termination of the cultivation was analysed (pH, conductivity, ICP-OES, TGA and EA) and the results were compared with data obtained for biochar Káňa leached by different model solutions. Fulvic and humic acids were extracted from the original biochar Káňa as well as from the biochar obtained after the termination of cultivation experiment. These samples were analysed on their inorganic and organic content and the abundance of organic elements (TGA and EA). Afterwards, the results were compared to each other and the correlations between the laboratory exposure to each soil factor and the cumulative exposure during the soil culture experiment were assessed.
|
|
|
Influence of pH on Extraction of Matter from Biochar-Soil Complex
Jakubčeková, Kristína ; Enev, Vojtěch (referee) ; Kalina, Michal (advisor)
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.
|
|
|
Use of thin layer chromatography for fractionation and characterization of organic matter isolated from alginite
Solanský, Pavel ; Sovová, Šárka (referee) ; Enev, Vojtěch (advisor)
This diploma thesis is focused on the study of structure and physicochemical properties of organic fractions of humic substances, which were obtained by the method of thin-layer chromatography. Humic substances, which were used in this study, were isolated from a sample of Slovak alginite based on the procedure of the International Humic Substances Society (IHSS). The following analytical techniques were selected for the characterization of isolated humic substances: thermogravimetric and elemental analysis, molecular absorption spectroscopy (UV/Vis), Fourier transform infrared spectroscopy (FTIR) and steady-state fluorescence spectroscopy. Each organic fraction of humic substances were characterized by molecular absorption spectroscopy (UV/Vis) and steady-state fluorescence spectroscopy. Using steady-state fluorescence spectroscopy, humic substances were found to be composed of fluorophores of humic and non-humic (protein) character. Organic fractions corresponding to the humic fluorophores were characterized by a higher content of oxygen substituents on the aromatic nukleus, a higher degree of aromaticity and also a higher molecular weight. The aim of this diploma thesis was to design and optimize the process of organic matter fractionation for the purpose of detailed understanding of the structure and properties of humic substances, which were isolated from the sedimentary rock alginite. Based on this, the practical applicability of the thin layer chromatography method to significantly reduce the molecular heterogenity of the studied humic substances was evaluated.
|
|
|
Study of decomposition of organic matter in soil using the method of "tea bags"
Lišková, Kateřina ; Sedláček, Petr (referee) ; Enev, Vojtěch (advisor)
The main aim of this master thesis was to introduce an optimal method which could be used for study of a decompostion of an organic matter in a soil. For this purpose was chosen based on a literaly review so-called tea bag method. With regard to the completeness of the work, a physico-chemical characterization of the soil environment and HS isolated from it was also performed. The degraded organic material was then further characterized using thermogravimetric analysis, elemental analysis, FT-IR spectroscopy, and the total content of water-extractable polyphenolic substances in the samples was also determined.
|
|
|
Study and characterization of organic substances in a biochar sample
Vojáčková, Beáta ; Kalina, Michal (referee) ; Enev, Vojtěch (advisor)
This bachelor thesis characterizes biochar from a physico-chemical point of view. The theoretical part deals with biochar as a soil conditioner, its properties, use, production, and last but not least, effect of its sorroundings. For better characterization of organic and inorganic matter a phosphate buffer was used. This buffer ensures their specific extraction due to a neutral pH. The second path is to use rainwater, which simulates the condition of the soil environment. In the experimental part are discussed both; purified buffer-extracted samples and rainwater samples, which were studied by thermogravimetric analysis (TGA), elemental analysis (EA) and by infrared spectroscopy with Fouier transform (FTIR-ATR). Conductivity and pH were also measured. Moisture and ash content, which represent the inorganic non-combustible fraction, were determined using thermogravimetry. The extraction yields were converted to ashless wt. % based on these values. Results of EA provided us with information on the content of biogenic elements and basic physico-chemical characteristics of biochar. In contrast, the FTIR method defined the presence of individual functional groups and specific constitutive units, which are present in the extracts. This information allows us to better understand the environmental impact of biochar on the soil ecosystem.
|
|
|
Phosphorus forms in river sediments
Schrimpelová, Kateřina ; Hrich, Karel (referee) ; Malá, Jitka (advisor)
Two main mechanism of immobilization of phosphorus in sediments are formation of insoluble phosphates of Ca, Mg, Fe, Al, and sorption. Phosphorus can be also immobilized as organic phosphorus contained in the biomass. This thesis is focused on searching of relationships between total, organic and inorganic phosphorus and iron, calcium and organic matter content in fluvial sediments. Within the framework of this thesis, samples of sediments have been collected and analyzed. The measured values have been filled by the data measured at the Institute of Chemistry in the years 2011-2012. Total number of samples is 48. Data have been statistically analyzed by Student’s t-test at the = 0,05 and = 0,01 levels of significance. The relationships between total phosphorus and iron and organic matter have been proven. Also the relationship between organic phosphorus and organic matter content has been proven and surprisingly the correlation with iron, too. The inorganic phosphorus indicated significant relationship with iron, but no significant relationship with the calcium content. At last there has been proven the correlation between inorganic phosphorus and the organic matter content.
|
|
|
Optimization of the Methodology for Assessment of Biochar Effect on the Growth of Model Plants
Štorková, Natálie ; Enev, Vojtěch (referee) ; Kalina, Michal (advisor)
This bachelor thesis is studying the effect of biochar on the growth of model plant and deals with the optimalization of the methods for assessing its impact. Theoretical part describes the properties and utilization of soil conditioners, special attention is focused on biochar. According to the literature research, maize (Zea mays) was chosen as a model plant for cultivation experiment and subsequently the application doses of biochar were also defined. The cultivation experiment took place in growing box under controlled illumination and irrigation. Plant dry weight weighing after cultivation, continuous measurement of plant height during the cultivation and also image analysis of the root system were used for evaluating the influence of biochar on quantitative and qualitative properties of model plants. From obtained data it can be summarized that the growth differences were influenced by the application dose, the type of biochar and also by type of soil, which was used for the cultivation experiment.
|
|
|
Distribution of the Organic Matter in a Sample of Biochar
Novotný, Maximilián ; Enev, Vojtěch (referee) ; Kalina, Michal (advisor)
This bachelor’s thesis is focused on characterization of the content and distribution of organic matter in a sample of biochar. For these purposes, the organic matter from a biochar sample was isolated using two procedures, specifically sequential chemical fractionation, and alkali extraction. Prepared samples were characterized by elemental analysis and thermogravimetry. Analysis results showed that sequential chemical fractionation brings higher yields than alkali extraction, moreover, it provides more detailed image of organic matter in biochar thanks to obtained separated fractions according to their linkage to the original biochar matrix. Secondly, studied biochar has a great potential as soil supplement, it contains almost 70 % of organic carbon, whilst isolated amount, which is available represent only small amount, the rest is strongly bound. On the other hand, the study showed that this specific biochar has rigid structure, which brings benefits in the context of using biochar in agriculture in long-term consideration.
|
|
|
Stability of humic substances
Nováková, Šárka ; Smilková, Marcela (referee) ; Klučáková, Martina (advisor)
This bachelor´s thesis is focused on the study of stability of humic acid. Thesis is divided in two parts, the first part is theoretical. In the theoretical part is dealing with the structure, property and point of humic acid and in the experimental part is dealing with stability of humic acid. The objective of this thesis was to investigate the effect of the extraction agents on stability of humic acid. 1M HCl, 1M MgCl2 and MiliQ water was used like extraction agents. Thermo-oxidative stability was tested trough thermogravimetric analysis (TGA) and differential scanning calorimetry (DSC). Changes of humic acid that occured after extraction were investigated by FT-IR spektrometry and elementary analysis. The results of the measuring were compared with original humic acid.
|
|
|
Study on the Effect of Biochar Application on Organic Matter in Soil
Kurková, Marie ; Sovová, Šárka (referee) ; Kalina, Michal (advisor)
This bachelor thesis studies the effect of the application of biochar on the composition of organic matter of two different soil samples. Specifically, the total content of organic matter in the soil and the ratio of humic and fulvic acids in these soils before and after the application of biochar were monitored. The composition of the soil mass was also observed thermogravimetrically and by using the certified method of humic and fulvic acids isolation from samples of studied soils. Furthermore, the effect of biochar on the growth of a model plant (maize – Zea mays) was observed. From this point of view, differences in plant growth were possible to observe from the beginning of the experiment, both in comparison with samples with and without biochar and in comparison with samples containing different doses of biochar. The type of soil used for cultivation experiments also influenced on plant growth.
|
guest ::
