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Atmospheric deposition of nitrogen - application of stable isotopes
Hanzlová, Barbora ; Hůnová, Iva (advisor) ; Hovorka, Jan (referee)
Based on the literature review, the thesis summarizes the use of stable isotopes in the atmospheric deposition. According to the studies and empirical research, the origin and the extent of the pollution in the environment can be tracked down. Due to the different isotopic values, it is possible to evaluate the extent of human impact on the natural cycle of the ecosystem. Nitrogen can be found in all nature constituents where it gains different isotopic values. The objective of this work was to gather the information about the stable isotopes and to prove whether they are reliable indicators in determining the source of the nitrogen in the given area. By using the evaluated study, the difference in pollution within the coastal and continental areas in Central Europe was described. Keywords: atmospheric deposition, nitrogen cycle, stable nitrogen isotopes, fractionation
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Atmospheric aerosol: physical-chemical characterisation and source apportionment
Leoni, Cecilia ; Hovorka, Jan (advisor) ; Ždímal, Vladimír (referee) ; Lammel, Gerhard (referee)
Atmospheric aerosol is a ubiquitous component of the Earth atmosphere. By mass, aerosol natural sources override anthropogenic ones, the latter constituting less than 5% to the total aerosol loading (Jaenicke, 2008). Nevertheless, in urban environment the contribution can increase to 80-90%. Since anthropogenic sources are mostly associated with high temperature processes, urban aerosol number size distribution is usually dominated by ultrafine particles - UFPs (d<100 nm). The UFPs have the highest surface/mass ratios among aerosol particles and bond the highest pollutant loading as per particle mass. Additionally, the UFPs exhibit the highest deposition efficiency in deep region of the human respiratory tract. Therefore, this study focuses to urban aerosol particle spatial-temporal, physical and chemical characterization and source apportionment with special emphasis to the UFPs. The first study in residential district of Ostrava-Radvanice and Bartovice, an air pollution hot spot in Europe, identified industry being dominant sources of UFPs. High particle number concentrations (NC) were measured at the hot spot, with peaks up to 1.4x105 particles cm-3 during plume events, i.e. downwind an industrial facility. The plume-originating UFPs were mostly composed of 19−44 nm nanoparticles heavily...
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Study of aerosol properties with high time resolution
Kubelová, Lucie ; Ždímal, Vladimír (advisor) ; Hovorka, Jan (referee) ; Vojtíšek, Michal (referee)
This thesis focuses on physical and chemical characteristics of atmospheric aerosol measured with high time resolution. Size distribution, chemical composition, and volatility of submicron particles were studied in relation to meteorological conditions and other factors. To reach higher variability in ambient conditions, we considered atmospheric aerosol during two seasons of the year (summer and winter) and at two different locations (suburban site Prague Suchdol and rural site Košetice). Measurement during two different seasons enabled us to better distinguish the influence of seasonal sources such as domestic heating in winter and increased biogenic emissions in summer. Also, seasonal differences in meteorological conditions mainly in case of temperature, humidity, and solar radiation were shown to play a role in aerosol characteristics. A comparison of aerosol properties at two different measurement sites, namely a rural and suburban, enabled us to better characterize the role of background aerosol and the influence of the city. Furthermore, a transformation of aerosol particles entering indoors from outdoors was also studied within this thesis. The influence of indoor/outdoor temperature and humidity gradient as well as presence of new particle formation events on the indoor/outdoor ratio was...
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New low-cost polutant sensor evaluation
Sinkulová, Michaela ; Zíková, Naděžda (advisor) ; Hovorka, Jan (referee)
This bachelor thesis deals with the introduction and subsequent comparison of low-cost sensors measuring air pollutants, which were used in the Citi-sense project in Ostrava. The results of the measurements carried out in the period from 1st June 2015 to 7th September 2015, are compared with reference data measured by the Czech hydrometeorological institute during the same period. The data are analyzed to provide the basis for further research into low-cost devices monitoring air pollution. Basic parameters such as average values, correlation coefficient, slope of linear regression, reproducibility of results, RMSE, and weekly and daily cycle are calculated for all measured pollutants (O3, CO, NOx, NO2, NO, PM10). The results are graphically illustrated and commented. The thesis also discusses the concordance of concentrations measured by the sensors with the data from the reference instruments, and the use of these new sensors in air quality monitoring in the future. Key words: Low-cost sensors, pollutants, air pollution monitoring methods
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