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Control methods for wastewater pH
Picka, Marek ; Vondra, Marek (referee) ; Miklas, Václav (advisor)
The bachelor thesis initially deals with the process of wastewater treatment with a focus on measurement, pH control and related issues. The pH value is an important parameter in wastewater treatment, which influences physical, chemical and biological processes as well as digestate treatment processes. This paper focuses on the process of thickening of digestate from a biogas plant by evaporation, which is normally associated with the leakage of volatile ammonia into the distillate. In order to eliminate this phenomenon, four methods of pH reduction were compared, which leads to the conversion of nitrogen from the volatile undesirable form 3 to the desirable form + 4 or 3 , which does not evaporate into the distillate during the evaporation process but remains in the concentrate, thus yielding a high quality fertilizer. Of the 4 methods discussed, the nitrification method appears to be the best in terms of the quality of the fertilizer output, but its disadvantage is the long retention time. From the point of view of flue gas utilization, lowering the pH by bubbling 2 and acidification with acid is a suitable method. For cases where speed and low acquisition costs are important, pH reduction with acid is preferable, unless high operating costs are a problem. In order to assess the correct method of pH reduction for a particular biogas plant, a techno-economic evaluation and consideration of other operational constraints is required and will be the subject of future work.
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Design calculation of an exmperimental striping unit
Florian, Tibor ; Miklas, Václav (referee) ; Touš, Michal (advisor)
The aim of this diploma thesis is to design a stripping column according to given requirements. At the beginning, the contaminant is described, in this case ammonia. Next section is putting emphasis on stripping columns, the principle, possible construction options etc. The main part of this thesis is focused on the design itself, including calculation of various parameters as well as simplified construction possibility. Drawing documentation is included in the attachment.
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Absorption of ammonia from an operational accident in the ice stadium
Ryšková, Marie ; Gal, Pavel (referee) ; Jecha, David (advisor)
This thesis deals with ammonia absorption in case of cooling machine breakdown at ice pool. Thesis is divided into four chapters. Theoretical part is focused on different methods of cooling an ice rink inside a stadium. Two basic principles are mentioned, how ice rink is created and what refrigerant is used. In the next part are listed valid standards, according to which the operators of ice pools proceed or may proceed to ensure technical safety. Essentials of emergency plan and breakdown preventions are also mentioned. Primary theoretical part focuses on gas cleansing by absorption and its basic principle, which includes Fick's first law, following with introduction to different kinds of absorption machines and its principles. Last chapter is a practical one, in which is the elimination of leaked ammonia by ventilation method and more ecological way – ventilation method with absorber. This cleansing method issue is dealt with mathematically by calculating absorbed gas to liquid using software MathCad.
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Chemorezistive gas sensor
Venkrbec, Lukáš ; Pytlíček, Zdeněk (referee) ; Prášek, Jan (advisor)
This thesis deals with the detection of gases. Based on the research, the theoretical part is devoted to the principles and construction of chemical gas sensors, especially the chemoresistive gas sensors, mainly with the active layer consisting of metal oxides and carbon nanotubes. In the second half of the theoretical part the carbon nanostructures, their properties and the methodology of preparation are reviewed. The experimental part deals with the type of support structure, preparation of the active layer and the method of its deposition and he principle of detection. In the results and discussion, the thesis focuses on the detailed processing of the results and the evaluation of the response ammonia, the impact of the modifications and procedures. In the end, the results obtained are compared, both with each other and with the relevant literature.
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Printed indicator of pH value designed for food packaging
Valíková, Michaela ; Kovalčík, Adriána (referee) ; Veselá, Mária (advisor)
The aim of this diploma thesis was to design an intelligent indicator of pH value for food packaging. Intelligent packaging is a new group of packaging that is able to provide costumers real-time information on the quality of packaged food through various indicators. In the theoretical part, a search was made on the topic of intelligent packaging with emphasis on freshness indicators. A smaller part was devoted to the issue of food spoilage. Emphasis was also placed on the description of the main components of the functional layer, and on the issue of chitosan crosslinking. In the experimental part, the crosslinking of chitosan with the addition of polyvinylalcohol using vanilin was studied. Prepared layers were monitored for their solubility and degree of crosslinking, which was determined using the ninhydrin method. To create a colorimetric pH indicator, an anthocyanin extract obtained by extraction from red cabbage was incorporated into the composition. A total of 3 anthocyanin extracts were prepared, for which the total anthocyanin concentration was determined by the difference method. The color of the prepared layers was evaluated spectrophotometrically under the action of various concentrations of the ammonia gas. The stability of the layers over time was also monitored. The last part of the experiment was the application of the prepared layers in a package with real meat.
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Wastewater stripping with the support of simulation software
Mader, Dan ; Touš, Michal (referee) ; Vondra, Marek (advisor)
The issue of increasing nitrogen in wastewater and at the same time growing demand for nitrogen fertilizers can be interconnected and solved by using stripping technology. This thesis deals with testing and modifications of the experimental unit for ammonia stripping in the Laboratory of Energy Intensive Processes, as well as the creation of a simulation of this unit in software ProMax. The batch mode unit was converted to continuous operation after several experiments with ammonia solution. The outcomes of the measurements from batch and continuous operation as well as from the simulation were subsequently compared and the obtained data show that continuous operation currently allows the removal of 94% of ammonia from the total input amount, while batch operation up to 98%. However, according to the simulation results, the lower efficiency of the continuously operating unit can be changed when certain operating parameters are increased. This knowledge can be used for further experiments or design of an industrial stripping column.
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Semiconductive gas sensors for detection of organic gases and vapours
Šedivý, Matúš ; Gablech, Evelína (referee) ; Gablech, Imrich (advisor)
This bachelor thesis is focused on gas sensors. Basic characteristics of sensors are discussed in the first part. Next part contains an overview of the most used types of gas sensors based on different physical principles. The main aim of thesis outlines last chapter where process of making gas sensors with different semiconductive metal oxides active layers is described. This thesis also describes measuring of their characteristics and characteristics of commercial gas sensor TGS 822 made by Figaro. Measured data are processed in graphs and tables and then were used for comparison with created sensors. In conclusion, there are discussed possibilities of improving selectivity of gas detection by using sensors with different active layer.
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The gas level measuring device with a capillary made by 3-D printing
Halva, Ondřej ; Búran, Martin (referee) ; Adámek, Martin (advisor)
This thesis is concerned with the experimental design, manufacture, and testing of a 3D printed prototype of a capillary. The aim is to introduce the reader to the issue of 3D printing related to the manufacture of capillaries and focus on chemiresist sensors. Furthermore, the features of microcontroller Atmel Atmega2560 and its applications in sensory technology will be described. In the second part of the thesis, the capillary for sample pre-processing with an output to a gas measuring device with an electrochemical sensor is designed and produced. For the control of the device, the Atmel Atmega 2560 microcontroller is to be used and the device must enable data transfer to PC. The possible applications of the capillary are to be evaluated.
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Protection of residents in case of development of a major emergency associated with a leakage of dangerous chemical substance in the area of a town Klatovy
ŠILHAVÁ, Markéta
This bachelor thesis deals with the issue of protection of residents in case of development of a major emergency associated with a leakage of dangerous chemical substance in the area of a town Klatovy. The theoretical part of the bachelor thesis describes the basic concepts that relate to the issue. There are also characterized by hazardous chemicals is incorporated herein their classification, characteristics or transport and marking. One theoretical chapter is devoted to the chemical ammonia, which is in the city is relatively widely used. The practical part shows the risks that threaten the city of Klatovy. The second part shows the results of a questionnaire survey that was conducted. The questionnaire contained 20 questions and was directed at residents of the town Klatovy. The total number of respondents who completed this questionnaire was 144. The aim of this text was to focus on the issue of leakage of dangerous chemicals substance in the area of a town Klatovy and evaluate information to citizens in case of emergencies associated with toxic chemicals. As part of the bachelor's thesis, one research question was asked: "Do the residents of the town of Klatovy have information on how to behave in the event of a leak of a dangerous chemical substance?". The set goal was fulfilled and the research question was answered. The benefit of this bachelor thesis is to obtain a summary of knowladge of residents of the town of Klatovy about how they behave and how they would proceed in an extraordinary event associated with toxic chemicals. The bachelor thesis can serve as a study material.
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