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Hydration of biochar prepared by using microwave pyrolysis of municipal sludge
Miklasová, Marta ; Komendová, Renata (referee) ; Kučerík, Jiří (advisor)
Microwave pyrolysis represents a possible solution of municipal sludge disposal. One of the final products of pyrolysis is amorphous porous carbon material called biochar, which can be used in agriculture as a soil amendment. As a rule, biochar is hydrophobic, but its addition can lead to an increase in water holding capacity. However, reasons of this improvement cannot be explained only by its high porosity. This thesis aims to contribute to the understanding the interactions between biochar and water under various environmental-relevant conditions such as direct water addition method and water adsorption from ambient air at different relative humidity. The thermo-analytical methods are common for investigation of the relationship between water and organic materials. One of these methods, differential scanning calorimetry, was used in this thesis. The first experiment was focused on measuring of melting enthalpy of freezable water in biochar pores. The results reflect the influence of pore size and properties of ice structure. The extrapolation of concentration dependence to zero enthalpy was used to determine non-freezing water (0,13–0,15 mg·mg-1 biochar), which reflects microporosity of the biochar. The second experiment was focused on the determination of evaporation enthalpy of water from biochar, which is a measure of the strength of water binding in biochar. This value indirectly reflects the mechanisms of the intake and release of water by biochar. Comparing the results for bound and pure water showed that in biochar is water bound weaker about 10–20 %. This led to conclusion that biochar binds water relatively weakly and the water exchange between biochar and soil is fast, despite the biochar hydrophobicity.
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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.
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Analysis of organic substances present in biochar
Bača, Ondřej ; Řezáčová, Veronika (referee) ; Mravcová, Ludmila (advisor)
This master's thesis deals with the analysis of organic substances, which are present in biochar. Biochar contains a number of organic compounds, that can be toxic and also carcinogenic to living organisms. In order for biochar to be used to improve soil quality or to be used for other applications, its safety must be declared by European or international certifications. Relevant European and international standards have been created for the determination of organic substances, that could be present in biochar. The theoretical part of the thesis was focused on selected organic substances, the process of pyrolysis and thermochemolysis, biochar characterisation and the used analytical methods. The experimental part of the thesis consisted of extraction with toluene and after that the determination of concentration of the 38 polycyclic aromatic hydrocarbons was performed. Qualitative analysis was performed by two-dimensional gas chromatography. Biochar samples were also subjected to thermochemolysis method and then they were analysed on GC-MS again. In both analytical methods, a large number of substances from groups such as PAHs, carboxylic acids, amines, substituted naphthalenes etc. was found, as well as smaller number of eg. polychlorinated biphenyls.
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Activation of biochar from wheat bran
Sauchanka, Katsiaryna ; Kalina, Michal (referee) ; Pořízka, Jaromír (advisor)
This graduation work is devoted to the issue of biochar production from wheat bran and ways of its surface activation. The theoretical part summarizes information about biochar, its physico-chemical properties, production methods and surface modification options. It also contains description of EBC certificate, that sets requirements for biochar which is placed on the market. The practical part of the work focuses on activating of the biochar surface and comparing the results with the available literature and European biochar certificate.
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Risks associated with the use of biochar in the terrestrial ecosystem
Valeeva, Adeliia ; Řezáčová, Veronika (referee) ; Zlámalová Gargošová, Helena (advisor)
The aim of this bachelor thesis was to assess the ecotoxicity of biochar produced from sewage sludge in Ingolstadt. Biochar is one of the carbon storage options and it’s applied to the soil. Biochar has an effect not only on the terrestrial ecosystem in direct contact of organisms with the sample, but also on aquatic in the leaching of substances from biochar into water. Therefore, contact and aquatic tests were chosen to assess the ecotoxicological effect. The representative of the decomposers was the earthworm Eisenia fetida, the primary producer – the plant Lactuca Sativa and the Daphnia magna was chosen from the aquatic organisms. The test results differed slightly, but the lowest negative effect on the test organisms was shown by soil samples with the addition of 5 g/kg and 10 g/kg granular biochar.
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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.
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Ecotoxicological assessment of biochar from sewage sludge
Kotzurová, Iveta ; Vávrová, Milada (referee) ; Zlámalová Gargošová, Helena (advisor)
The aim of this diploma thesis is to assess the ecotoxicological effect of biochar produced from sewage sludge. In case of application of biochar to agricultural land, both the soil and aquatic ecosystem may be affected therefore contact and aquatic tests were chosen to assess the ecotoxicological effects. Representatives of soil invertebrates were earthworms Eisenia fetida; Daphnia magna and Artemia salina were chosen from aquatic animals and terrestrial plants were represented by Lactuca sativa, Sinapis alba and Allium cepa. The results of contact tests point out how ecosystem could be negatively affected by biochar dose. Through aqueous extract were shown differences in sensitivity of individual organisms in aquatic tests. Dried sewage sludge was found to be the biggest burden for all tested organisms. The pelletized biochar with the addition of an additive showed the lowest negative effect on tested organisms.
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Preparation and Characterization of Biochar - the Effect of Pyrolysis Conditions and the Source of Used Biomass
Novotný, Maximilián ; Pořízka, Jaromír (referee) ; Kalina, Michal (advisor)
This diploma thesis is focused on preparation of biochar samples, which were characterized to reveal influence of preparation conditions on biochar properties physical-chemical properties. Preparation conditions covered temperature range of 400 °C to 700 °C and 2 different residence times were used. Biochars from each source biomass has its own characteristics, however the similiarities between biochars from different sources were found. Biochar yields were specified and the minimum yield was at least 24 %. Analysis on content revealed, that oat brans, mixed wood and corn residue contain a lot of organic matter, relatively, and also contains a lot of organic carbon. Results of structural analysis confirmed individual structural properties, porosity and content of function groups in particular. Influence of higher pyrolysis temperature results in slightly lower yields, however it provides products with higher content of organic carbon and higher surface area, in majority of cases. Subsequently, it was found out that short residence time of 10 minutes does not have to be enough for all used biomasses. On the basis of gained data, the preparation or production can be optimalized in effort to make usage of residue biomass more effective in different application, not only in agronomy sector.
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Study of sorption properties of biochar
Kocinger, Oskar ; Řezáčová, Veronika (referee) ; Mravcová, Ludmila (advisor)
This diploma thesis deals with sorption properties of biochar produced from wood biomass treated with concentrated hydrochloric acid and activated carbon with respect to the triazine pesticide propazine. Although pesticides are widely used in both agriculture and the private sector worldwide, they pose a significant risk to ecosystems and human health. Propazine belongs to the group of chlorinated triazine herbicides, which pose a risk mainly as endocrine disruptors. The sorption of organic pollutants using pyrogenic carbonaceous materials promises an efficient and economically affordable solution, which has recently received increasing attention from the scientific community. In this work, we used isotherms to describe the equilibria of propazine sorption to given sorbents during vial experiments. Analysis of the propazine content in the model water solutions after reaching equilibrium was performed using high-performance liquid chromatography with mass detection.
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Biochar Effect on the Microbial Processes in Soil
Losová, Anežka ; Sovová, Šárka (referee) ; Kalina, Michal (advisor)
This bachelor thesis is focused on the investigation of the biochar effect on the microbial processes in soil. The theoretical part describes the properties of the soil, the characteristics of biochar, the definition of the methods of its production and the influence of biochar on microbial activity in soil. The experimental part was focused on optimization of the conditions for assessing of the effect of biochar on the rate of mineralization of soil organic matter through monitoring of the release of carbon dioxide from soil without biochar and from the biochar-amended soil with NPK fertilizer. Carbon dioxide was sorbed into sodium hydroxide during the incubation and the released amount was determined by titration. In the following part of the thesis, the experiments were focused on assessing the effect of increased soil temperature and humidity on the amount of CO2 released by soil respiration. Experimental data showed that biochar promoted the microbial activity and this effect was even enhanced by addition of NPK fertilizer to a defined amount of biochar. The increased temperature negatively influenced the microbial processes in soil, as the rate of soil respiration of carbon dioxide decreased. Excessive moisture had also a negative effect on microbial activity, resulted in the slowed rate of the soil respiration. In summary, biochar has a positive effect on microbial activity and the rate of mineralization of soil organic matter in a defined amount under the appropriate conditions and it can be used as a suitable soil conditioner in agriculture.
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