National Repository of Grey Literature 52 records found  1 - 10nextend  jump to record: Search took 0.00 seconds. 
Microplastics in solid matrices of the environment
Pospíchalová, Eliška ; Cajthaml, Tomáš (advisor) ; Innemanová, Petra (referee)
Microplastics, plastic particles of 5 mm-1 nm in size, are now widespread across different ecosystems. The increasing amount of microplastic contamination of aquatic and terrestrial environments requires the development of standardized methods for their separation and analysis. One of the main vectors of microplastic input to terrestrial ecosystems is through sewage sludge. The sludge is recycled for fertilization and reclamation due to its high organic matter content. Scientists have already been able to quantify and identify a range of microplastics in sewage sludge of different sizes, polymer types, shapes, etc. This thesis focuses on the optimization of existing methodologies to extract microplastics from solid environmental samples and their subsequent qualitative and quantitative analysis. The steps required for sample pre-treatment prior to analysis, namely reduction in organic matter content by the Fenton reaction process and density-based separation of microplastics by flotation in saturated NaI solution (1.8 g/cm3 ) using centrifugation, were optimized. Microplastics in size fractions of 20-40 μm and 150-300 μm were fabricated and introduced into flotation and total recovery experiments of the methodology to determine the recovery. Fluorescence microscopy was chosen for quantitative...
Hygienization of dewatered sewage sludge using vermicomposting process under field conditions
Fojtová, Zuzana ; Innemanová, Petra (advisor) ; Grasserová, Alena (referee)
Sewage sludge is a waste material that is a valuable source of organic matter and nutrients and is used as a fertiliser on agricultural land in many countries around the world. However, the application of sewage sludge carries risks associated with the presence of pathogenic micro- organisms and other undesirable substances in this material and in many countries sewage sludge must meet limits for land application. Vermicomposting of these materials can be one effective way of reducing pathogens in sewage sludge. In this thesis, I investigated the effectiveness of sanitizing sewage sludge in the vermicomposting process under field conditions. The experiment was conducted in an earthen vermicomposter with a total working volume of 10.5 m3 near the village of Hrbov, near Lhenice in the South Bohemia region. Hygienization efficiency was measured using a test with an introduced microorganism (E. coli). The test was modified for the vermicomposting process. In the experiment, a mixture of sewage sludge mixed with birch chips in a ratio of 1:1.5 (sludge: chips) was (i) vermicomposted for six months, (ii) composted only, and (iii) composted for one month and then vermicomposted. In addition to the evaluation of the hygienisation efficiency of the different options, the stability and possible phytotoxicity...
Dosing of particulate matter in rotary driers and rotary kilns
Kubín, Pavel ; Hudák, Igor (referee) ; Bojanovský, Jiří (advisor)
The bachelor thesis is focused on particulate matter dosing into rotary dryers. In the theoretical part, the thesis focuses on the mechanical properties of particulate matter (PM), especially the flow properties. The method of determining these properties is also men-tioned. The following part deals with the currently used PM dosing methods. The basic methods of dosing are listed here and their combination can subsequently lead to a complex dosing system. The practical part contains two designs of sewage sludge dosing systems and a comparison of their advantages and disadvantages. It also lists the boundary conditions to be considered before starting the design of such a dosing device.
Sewage sludge – a secondary source of environmental contamination with heavy metals
Sysel, Petr ; Zlámalová Gargošová, Helena (referee) ; Komendová, Renata (advisor)
This work deals with the elementary trace analysis of sewage sludge as a potential source of risk elements when applied to agricultural land. A total of 24 samples were analyzed, divided into two sets with different collection dates. The total content of zinc, copper, chromium, lead, mercury and cadmium in sewage sludge, as well as amount of risk elements that are extracted from sludge to water in 24 hours, was determined. Atomic absorption spectrometry was chosen for the analysis. It was found that the risk elements are in sewage sludge in amounts and order Zn (254.68 – 3084.53 mg/kg) > Cu (6.18 – 961.89 mg/kg) > Cr (26.95 – 387 .91 mg/kg) > Pb (0.84 – 155.30 mg/kg) > Hg (0.50 – 4.12 mg/kg) > Cd (0.06 – 2.61 mg/kg). A lower amounts of analyzed metals in the aqueous extracts than their total amounts in sludges were observed. The concentration of mercury and cadmium in the aqueous extracts was below the detection limits. It was evaluated that the risk elements in sewage sludge are found in less water soluble compounds. The results also show that the concentration of risk elements in the sludge does not depend on the number of equivalent inhabitants for which the treatment plant is dimensioned.
Možnosti využití vyhnilých kalů z městské čistírny k pyrolýze a jejich použití v sorpčních procesech na příkladu kyseliny šťavelové
PRAŽÁK, Jakub
This diploma thesis is focused on sludge management of waste water treatment plants. The research part of the thesis outlines the problems of sludge management in the Czech Republic and also deals with technologies and technical solutions related to the treatment and handling of sewage sludge for various purposes. Furthermore, the theoretical part describes the function of urban wastewater treatment plants and technological methods of wastewater treatment. I also focus on energy utilization of sewage sludge in pyrolysis processes. The result of these pyrolysis processes is called Biochar. Biochar is a carbon thick solid that arises from the pyrolysis of organic materials for application to soil and other uses such as biofuels. The carbon that remains in the solid forms stable aromatic structures that are more resistant to degradation in the natural environment. The mineral ash content of the original organic materials is preserved in the biochart and the volatile constituents of the raw material are lost during the pyrolysis process. In the second part of the work, the prepared and modified samples of the biochar are subjected to the determination of the sorption properties in order to determine whether the biochar is able to transfer the nutrients contained in it to the soil. If the biochar were able to transfer nutrients to the soil without any undesirable side effects, it could very much solve the problem of its future storage.
Combustion of Solid Fuels in Rotary Kiln and Influence of their Composition on Emissions
Bojanovský, Jiří ; Jegla, Zdeněk (referee) ; Puchýř, Radim (referee) ; Máša, Vítězslav (advisor)
The work is focused on the study of the influence of solid fuel composition on the formation of pollutants during combustion in a rotary kiln. This is a highly topical issue related to the need to increase the share of alternative fuels as a substitute for fossil ones. The author builds on the research already carried out in this area, defines the basic characteristics of the problem under study and formulates hypotheses based on the summary of the current state of knowledge. The main hypothesis is ("The composition of the solid fuel mixture can be chosen in such a way as to reduce the generation of pollutants.") To verify this hypothesis, the author chooses experimental verification in combustion tests on a semi-operational experimental device. For the combustion tests, it was proposed to extend this equipment with apparatus that allows the evaluation of the fouling rate of heat transfer surfaces and the formation rate of particulate matter pollutants. This equipment was successfully used for combustion tests of 6 selected alternative fuels (refuse-derived fuel RDF, sewage sludge, and forest waste). Based on the combustion tests conducted with these sub-fuels, 6 fuel mixtures with high potential for industrial applications were defined. These mixtures were also burned in a rotary kiln. Based on the results obtained, the main hypothesis of the work was confirmed and the fuel mixture consisting of 70 wt.% forest waste, 20 wt.% RDF and 10 wt.% sewage sludge (MIX 6 in the work) was identified as the most suitable alternative to fossil fuels. This mixture did not show any operational problems and the best results were obtained in the formation of gaseous pollutants and particulate matter. The results of this work are a crucial point in the search for a methodology for the specification of suitable alternative fuel blends for combustion in the energy and manufacturing industries.
Utilization of waste in the context of current legislative measures and principles of circular economy
Dočekal, Petr ; Vymazal, Petr (referee) ; Chorazy, Tomáš (advisor)
This bachelor thesis deals with the use of selected types of waste under the conditions of current legislation in force in the Czech Republic. It focuses on plastic packaging waste and sewage sludge – waste generated from municipal wastewater treatment. The aim of the work was to process a search of current legislation and strategic documents in the field of waste management in the context of the principles of circular economy and then design and then critical evaluation of the optimal system of utilization of the above waste based on the principles of circular economy. Both its strengths and weaknesses as well as basic economic parameters were described. The first part of the work is a description and current methods of waste management and search for legislation and strategic documents at the EU and Czech level. In the second part, the optimal circulatory method of waste management is designed and evaluated. A delivery system is currently in place for plastic packaging waste. The bachelor work deals with a new system of taking back PET bottles and compares their strengths and weaknesses. For the sewage sludge, drying and subsequent pyrolysis were chosen as the optimal treatment method, which seems to be a very efficient method.
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.
Preprocessing of sewage sludge for pyrolysis process
Ševčík, Jan ; Rusník,, Igor (referee) ; Bodík,, Igor (referee) ; Hlavínek, Petr (advisor)
The concept of sludge management at the level of sludge treating technology of sewage treatment plants, as well as at national, continental or world level, requires fundamental improvement in the interest of sustainable development. Sewage sludge production is continuously increasing. Sewage sludge contains a number of pollutants but also a significant renewable resource for material transformation and / or energy recovery. Sewage sludge is composed of an inorganic mineral part and organic components. Its organic part is a source of energy and nutrients, but also contains harmful pollutants for exapmple heavy metals. However, there are technologies that offer the possibility of neutralizing pollutants while using other sludge components in terms of recycling energy, nutrients and other attractive sludge components. The mentioned technologies include mainly thermal methods of sewage sludge treatment and one of them is pyrolysis. Thessis focuses on sewage sludge prepartation for pyrolysis process, which includes mixing with additives and peletization of prepared mixture for purposes of agricultural or energetical utilisation. Technology for material transformation and energy utilization of sewage sludge, in particular the mentioned pyrolysis or torrefaction, require an insignificant degree of detailed research in order to expand it in the field of sludge management. Indeed, it is not only research that will enable direct correct use of this technology in practice. The results of such research are the basis for the drafting of the relevant legislation, which will subsequently enable the deployment of pyrolysis technologies in practice.

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