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Porovnání různých systémů hnojení v podmínkách ekologického zemědělství
Antošovský, Jiří
The main treatment to ensure a sufficient nutrient in organic farming is realized by green manure crop cultivation, post-harvest residues incorporation to the soil and application of organic fertilizers. The aim of this long-term experiment was to compare two different production systems with and without livestock in terms of organic farming. The idea of this long-term experiment is to determine whether an organic farming can be sustainable without livestock production or not. Control variant with no fertilization (treatment 1) and incorporation of sole green manure crops (treatment 2) were also included. The production system without animal husbandry was based solely on the application of renewable external resources (compost or digestate) (treatment 3) and the same fertilization with the addition of auxiliary substances (AS) (treatment 4). The production system with animal husbandry included utilization of fertilizers produced on the farm (fermented urine or manure) using solely farm fertilizers (treatment 5) and in addition with AS (treatment 6). Each treatment had three replications. This work describes the average yields from four experimental years and five localities. Winter wheat, potatoes, winter wheat spelt and legume-cereal mix with corn were used and examined as model crops during the first four years of this long-term research. The highest average yield of winter wheat grain and potato tubers during the first two years of the experiment were obtained after the treatments 3 (7.1 t/ha grain, 33.9 t/ha tubers) and 4 (7.0 t/ha grain, 34.1 t/ha tubers). The several times higher nitrogen content in applied digestate and compost in addition with narrow C:N ratio of applied compost in comparison with fermented urine and manure were probably the reasons for such results. On the contrary, the results obtained from the third (spelt) and fourth (LCM and corn) experimental years was higher after treatment 5 (5.5 t/ha grain, 4.6 cereal unit/ha) and 6 (5.4 t/ha grain, 4.7 cereal unit/ha). After four experimental years, the presented results supported the application of farm fertilizers as a preferable option from the long-term point of view. The treatments with additional application of AS did not provide a higher yield, therefore, such an application seems unnecessary. The average yield after the fertilization with solely green manure crops was higher in comparison with control variant, but it was statistically insignificant.
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Lysimeters - composition of soil solution in its native form
Zikmund, Jiří ; Müllerová, Kristýna (referee) ; Enev, Vojtěch (advisor)
This bachelor’s thesis deals with the issue of soil solution with an emphasis on water-soluble fractions of humic substances. Humic substances are organic compounds that occur naturally in the soil and in the soil solution, and they play an important role in the physical, chemical and biological processes taking place in the soil. In the experimental part, samples of the soil solution originating from the experimental station of the Central Institute for Supervising and Testing in Agriculture in Hradec nad Svitavou were evaluated. These were samples coming from the control variant and from the variants fertilized with slurry and digestate. The pH and conductivity values of the soil solution were determined for the samples. Furthermore, the humic substances contained in the soil solution were analyzed using infrared, fluorescence and UV/Vis spectrometry methods.
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Membrane technologies for agricultural wastewater treatment
Uhlířová, Marcela ; Touš, Michal (referee) ; Vondra, Marek (advisor)
This thesis deals with an agricultural wastewater treatment (liquid digestate) by membrane technology. There is a fundamental description of characteristics of membrane technology with regard to application of agricultural wastewater treatment in this thesis. Experimental device for treatment of liquid digestate is designed and it consists of three steps – microfiltration, ultrafiltration and reverse osmosis. The first step consists of four filters with different pore sizes (80, 25, 10 and 5 µm). The second step is ultrafiltration and the third and key step is reverse osmosis. In the final step monovalent ions such as NH4+ are separated. Reverse osmosis consists of two stage system which results in higher recovery. Three experiments were carried out in order to verify the efficiency of separation dissolved solids.
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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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Treatment of waste from biogas plants
Budín, Oto ; Frýba, Lukáš (referee) ; Vondra, Marek (advisor)
This bachelor thesis is focused on options of treatment of waste from biogas plants. The first part of this thesis describes biogas plants and its working. The main target of the thesis deals with waste from biogas plants – its creation, properties, composition and application. The thesis also includes an overview of legislative and environmental restrictions applying to the treatment of waste from biogas plants. The bachelor thesis also comprises an information about biogas plants Stanoviště.
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Optimization of Gasification Process of Biodegradable Wastes
Elbl, Patrik ; Milčák, Pavel (referee) ; Lisý, Martin (advisor)
The aim of the diploma thesis is to discuss the gasification of biodegradable waste. The theoretical part deals with gasification with focus on gasification phases, types of gasification reactors and pollutants contained in the generated gas, especially tar. Further, there is listed the characteristic of alternative biomass fuels, namely digestate and sludge waste. The practical part is devoted to gasification on a fluidized bed reactor with the aim to test the possibilities of gasification of these fuels, to determine their specifications and the influence of various gasification media. In the final part there are discussed the results of the collected gases and tar.
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Integration of a technology for digestate thickening in a biogas plant
Miklas, Václav ; Touš, Michal (referee) ; Vondra, Marek (advisor)
This diploma thesis is mainly focused on the digestate thickening in a biogas plant. First, overview of the biogas technology in the Czech Republic is presented. Furthermore, problems with waste heat utilization and processing of fermentation residues (digestate) are described in more detail. Based on the research, multi-stage flash (MSF) evaporation was chosen as the technology for the digestate thickening. The main part deals with the integration of the chosen technology into a biogas plant process. The programming language Python was used to simplify the given task. In the preliminary stage, a complex mathematical model of a biogas plant was created, focusing particularly on the mass and energy balances. Subsequently, a computational model of the MSF evaporator was programmed. A procedure for the integration was suggested using the sensitivity analyses. Additionally, the model of a biogas plant was extended with the MSF evaporator. The key outcome of the thesis is a technical-economic analysis in which the impact of digestate transport price and electricity feed-in tariff on payback period is investigated. The results suggest profitability of MSF evaporator for biogas plants without subsidized feed-in tariff. Contrastingly, installation of MSF evaporator in older biogas plants with subsidized feed-in tariff can be economically viable only in cases of significantly longer transport distances.
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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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Energy use of digestate
Kaška, Zdeněk ; Štelcl, Otakar (referee) ; Baláš, Marek (advisor)
This bachelor thesis deals with the research of biomass in general, its types and processing. Nowadays, biomass appears to be an environmentally and financially acceptable substitute for fossil fuels due to increasingly stringent emissions standards. The second part deals with its particular type, digestate. It is investigated whether the fossil fuel can be replaced or how the energy production process could be changed.
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