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Phosphorus recovery from liquid digestate
Heger, Jan ; Procházková, Michaela (referee) ; Touš, Michal (advisor)
The focus of this thesis is the posibility of obtaining phosphorus from liquid digestate. The theoretical part of the thesis is focused on summarizing the current situation regarding phosphorus recovery. The research summarizes the essential information about the method of struvite precipitation, by which phoshphorus is obtained in the form of struvite, which can be further used as a fertilizer. Based on the process information, an experimental device was designed to obtain phosphorus in the form of struvite, corresponding to industry standards. It is a cylindrical vessel with a conical bottom, in which the liquid digestate with the chemicals is mixed with a stirrer. The functionality of the device was tested experimentally on the created device. The results of the experiment were analyzed by XPS method, which confirmed the formation of struvite. For future operation, modifications of the device and pre-treatment of the liquid digestate were proposed, which could improve the whole process and its results.
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Fermentation remainder treatment in a biogas plant
Budín, Oto ; Touš, Michal (referee) ; Vondra, Marek (advisor)
This diploma thesis deals with dewatering technologies of fermentation residues from biogas plants and aims to design an integration of selected technology into the biogas plant. Fermentation residues (or digestate), which are a by-product of anaerobic biomass fermentation in biogas plants, contain a certain amount of nutrients and are usually used as agricultural fertilizers. However, the high-water content in digestate and the associated low nutrient concentration increase the cost of its storage and transport. Dewatering of fermented material could help reduce these costs. The main part of this work included the design of an integration of the selected dewatering technology into the biogas plant – its placement in a process, an addition of necessary appliances, the influence on material and energy flows. In this case, the fermentation residues are processed in two phases. First, a separation of the solid and the liquid fraction by a screw press. The second step is to thicken the liquid digestate by evaporation in a multistage evaporator. Evaluation of the design of a dewatering technology, including its impact on the economy of the biogas plant, is also part of the diploma thesis.
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Utilization of recycled brick waste for growing the agricultural plants
Šmírová, Barbora ; Másilko, Jiří (referee) ; Opravil, Tomáš (advisor)
The master thesis follows up on previous bachelor thesis, which dealt with the sorption capacity of brick recyclate. Brick recyclate, as same as brick, excel with very high porosity. For this reason this work deals with possible implementation of plant growth aids (fertilizers) on the inside surface of such highly porous material This thesis studies possibilities of preparation of brick recyclate with the content of components supporting plant growth. It is a material, that is able to bind water in the soil and nourish cultivated plants at the same time. Aim of the work is to find out, what maximum amount of supporting substances, that later will be released back into surrounding enviroment (soil), is possible to incorporate into the brick recyclate. Such prepared recyclate was added in different amounts into predefined substrates, where plants were grown. Subsequently, the growth course, germination and yields of selected crops were monitored. It was verified that the material based on recycled brick enriched with nutrients improves the distribution of nutrients in the soil and positively affects the germination, growth and yields of tested crops.
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The behavior of superabsorbent polymers in artificial soils
Männlová, Adriana ; Smilek, Jiří (referee) ; Kratochvílová, Romana (advisor)
This bachelor thesis deals with the study of superabsorbent polymers for environmental and agricultural applications. Generally thessis preparations are to perform the funciton of irrigation ,so that thanks to its unique properties , can absorb water in tha rainy season and keep it arend the root system as long as possible. Superabsorbent polymers can also perform the fiction of fertilizer carries and thus ensure its gradual release. These gel structures were subjected to testing of their swelling in environments with different ionic strenght. Subsequently, in the long term monitored thein ability to trap water in the soil environment model.
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Humic substances as transport medium for plant nutrition
Vlková, Markéta ; Solná, Irena (referee) ; Klučáková, Martina (advisor)
This bachelor thesis treats about humic matters and their application in agriculture by means of hydrogels transport medium. It studies progressive releasing of substances, which could be used as more common nutrition for plants, prepared from superabsorbent polymers. Research was implemented in collaboration with industrial partners. The substances are synthetically made of sodium Lignohumate and mixture of industrial fertilizer called NPK. Released substances were characterized by using some methods. First, there were measured qualities, which didn’t specify released compounds, like swelling, conductivity, pH and absorption of hydrogels with different wavelengths. More details came with methods ICP-OES and ion chromatography. Hydrogels which contained both mixtures of matters written up, were studied in water solution for 5 weeks and every week all characterization were measured. From the results we can see that both of the mixtures decrease ability of hydrogel’s swelling, mainly NPK. Measuring of absorption showed that the most of the substances released from sodium Lignohumate were from hydrogels without NPK. By other measuring, we noticed realizing of potassium and phosphorus elements. The most of them were from hydrogels containing NPK. By measuring ion chromatography, we found chloride, phosphoric, sulfuric and nitric ions in solution.
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Equipment for Thickening Waste Water from Biogas Plants
Vondra, Marek ; Bébar, Ladislav (referee) ; Hoffman,, Pavel (referee) ; Stehlík, Petr (advisor)
This dissertation thesis deals with the development of technology which could tackle two major issues related to biogas plants. These issues concern the insufficient use of waste heat from biogas combustion and its subsequent processing. It also concerns the use of the fermentation residues which are formed in large quantities and whose use is restricted by law. Based on a literary search of separation methods, a vacuum evaporator was selected as the most suitable technology. Its advantages include its simple construction, operational reliability and robustness, low costs of thickening medium pre-treatment, potential for a quick commercial application and, especially, the chance to use a low-potential waste heat. A primary purpose of this technological unit is the reduction in the volume of fermentation residues. Other benefits include the efficient use of waste heat from a biogas plant, which would otherwise be wasted. Evaporators with a low consumption of electrical energy (which is a main product of a biogas plant) seem to be the best option for applications in the biogas plants. Three of these technologies were subjected to a more thorough analysis, which included the development of computational models and their quantification for conditions in a sample biogas plant. A one-stage evaporator with a forced circulation (680 – 712 kWhth/m3, 25.9 – 30.5 kWhel/m3) was evaluated as the least suitable option in terms of energy demands. The energy intensity of a three-stage evaporator with a falling film (241 – 319 kWhth/m3, 12.0 – 23.6 kWhel/m3) and a nine-stage flash evaporator (236 – 268 kWhth/m3, 13.6 – 18.4 kWhel/m3) is significantly lower. A multi-stage flash evaporator (MSF) was then chosen for development and will form the central focus of this thesis. The reasons for the choice are as follows: the low requirements on the heat transfer surface, good operational experience in the field of desalination, its simple construction, modularity and evaporation outside the heat transfer surface. A thorough technical-economic evaluation was also performed on the integration of the evaporator into the biogas plant. The main part of the work included the experimental development of a MSF evaporator prototype. The main objective of this development was to achieve a stable flow rate of the thickening liquid digestate fraction and the continuous formation of the distillate. This was not an easy objective to achieve, especially due to the properties of the liquid digestate, which has a non-newtonian characteristic and increased density and viscosity compared to water. The tendency of the liquid digestate to form foam was also the subject of analysis. The development of the evaporator and first successful operational test are described in the thesis in detail. This required the use of an anti-foaming product. A fully-developed prototype of the MSF evaporator allowed us to achieve continuous operation with a distillate production, reaching from 5 to 10 kg/h at a liquid digestate flow rate of 0.4–0.5 m3/h. The main drawback of this technology is the pollution of the distillate with ammonia nitrogen, and it is for this reason that the basic procedures of its subsequent elimination was selected for further analysis.
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Vyhodnocení variabilní aplikace hnojiv ve vybraném zemědělském podniku
Necid, Václav
Precision agriculture with a focus on variable fertilization offers a sustainable approach to optimizing crop yields and minimizing environmental impact. This study aims to explore and evaluate the effectiveness of variable fertilizer application, assess its potential impacts on future agriculture, and guide sustainable and profitable agricultural practices. The objectives of this work include an extensive literature review on precision agriculture, plant nutrition with phosphorus and potassium, as well as an evaluation of the benefits of variable application of phosphate and potassium fertilizers. Field trials conducted between 2019 and 2021 on selected agricultural land with a total area of 103.09 hectares involved soil sample collection and the processing of results using the IDW interpolation method. In 2019 and 2020, variable application of stock fertilizers TSP (Triple Superphosphate) and DS (Potassium Salt) was carried out according to the created application maps and the given nutrient recommendation for the main cultivated crop, with a correction of the nutrient supply dose in the soil. The application was carried out using a Terra-Gator 8203 machine and an AirMax 2000 pneumatic spreader. Thanks to the RTK system and RAVEN GPS navigation, it was possible to achieve precise and uniform fertilizer application. The thesis includes an evaluation and determination of the value of spatial unevenness (coefficient of variation) of the land, indicating that targeted variable fertilizer application leads to a leveling of agrochemical properties of the soil. The economic evaluation of variable application showed that the yields of harvested crops were higher than the company's average, indicating efficient fertilizer use. The conclusion of the work compares the differences in costs between uniform and variable application.
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Preparation of soil conditioners and characterization of their nutrient release kinetics
Horváthová, Lenka ; Jančář, Josef (referee) ; Lepcio, Petr (advisor)
This diploma thesis deals with the preparation of multifunctional soil conditioners based on potato starch, in order to slow down the release of nutrients. Materials with different contents of superabsorbent polymer and zeolite were prepared. Spectra indicating the formation of new bonds were evaluated by infrared spectroscopy. The kinetics of nutrient release were observed in the prepared samples of soil conditioners in an aqueous medium, where nutrient retention was demonstrated. Other samples were tested on plants, which proved a mostly positive effect on growth and other factors.
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Preparation and characterisation of coatings for controlled-release fertilizers
Jašek, Vojtěch ; Sedláček, Petr (referee) ; Figalla, Silvestr (advisor)
The literary research of this Master's thesis is dedicated to controlled-release fertilizers (CRF). There is written the description of particular representatives of this kind of fertilizer and it also contains principles of nutrition's release mechanisms. Theoretical part is mainly focused on coated fertilizers, materials used for their production, coating technological processes and on a mathematical description of the diffusion transport which is the key of the mass transfer through polymer coatings. The laboratory preparation of innovative coatings based on modified vegetable oils is the main part of the experimental part of the thesis. It consists of the precursors' synthesis which can be applied on the fertilizer's surface in a liquid phase and polymerized by the UV-radiation in combination with an appropriate photoinitiator. There is described the synthesis of additional modifiers of precursors' viscosity and coatings' diffusive properties based on bio-source reactants such as sorbitol or ethyl lactate. The synthesized products are characterized by various methods such as volumetry, FTIR method or viscosimetry. The last part of the thesis contains the description of diffusive characteristics of coatings prepared out of the synthesized precursors.
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Use of wheat bran for fertilizer production
Maňáková, Helena ; Štursa,, Václav (referee) ; Diviš, Pavel (advisor)
This diploma thesis deals with the production of fertilizer from wheat bran and spent coffee grounds, which are produced in large quantities in the food industry. The efficiency of the removal of caffeine and phenolic substances from coffee grounds using the oxidation reason and the possibility of recycling the usable oxidizing effect were tested. We managed to oxidize almost all phenolic substances and a significant amount of caffeine from coffee grounds, even through the recycled oxidizing effect. Fertilizer in the form of pellets was subsequently formed from coffee grounds and bran. During pelleting, the optimal degree of wetting of the material was studied to achieve optimal yield of pellets and sufficiently strong pellets. Different ratios of substrates for pelletization were also studied and the quality of produced pellets was assessed. The content of macro and microelements in the prepared pellets was determined. Pellets have been shown to be a good source of elements important for plant growth.
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