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Dynamics of vertical and horizontal profiles of atmospheric aerosol in planetary boundary layer
Esterlová, Jana ; Hovorka, Jan (advisor) ; Jančík, Petr (referee)
The boundary layer of the atmosphere is a layer of air with thickness about 1 km above the ground. Open-cast mining is one of activities that polutes the air in this layer. It generates particulate matter (PM) mostly in size of aerodynamic diameter 1 - 10 µm - coarse patricles. The companies that does the mining pays for their emissions due to the law. However, these emissions are not experimentraly measured, they are calculated from given equation consisting of factors like the size of mining area, etc. Some papers have shown significantly higher concentrations of Coarse particles (or PM10) in surroundings of the mine. Other papers have found out that the origin of these high concentrations didn't come from the mining activities but is caused due to the activities at the place of measuring or nearby. There aren't many papers that measure the PM concentrations in the air in the mining area. This thesis shows the results of airship measurements in the air layers of the open-cast mine and above them. The experimentral site was brown coal mine Bílina in the North of The Czech Republic in important mining area. The measurements took place in December 2017. For measuring the number and mass concentrations was used APS - Aerodynamic Particle Sizes Spektrometr by TSI which sorts out the data into...
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Aerosol size distribution of PAH in urban atmosphere
Bendl, Jan ; Hovorka, Jan (advisor) ; Mikuška, Pavel (referee)
The aim of the study was to determine the 13 health risk PAHs (phenanthrene, anthracene, fluoranthene, pyrene, benzo(a)anthracene, chrysene, benzo(b)fluoranthene, benzo(k)fluoranthene, benzo(a)pyrene, dibenzo(a,h)anthracene, benzo(g,h,i)perylene, ideno(1,2,3-cd)perylene and coronene; c-PAU highlighted) in the fractions of size-segregated aerosol of the urban air in Ostrava (2012, 2014) and Mlada Boleslav (2013) at low temperatures in winter, and to verify experimentally a sampling artifact, i.e., to quantify PAHs in the gas phase. For the particle size separation high-volume cascade impactor Hi-Vol BGI 900 was used. PAHs were determined by HPLC-FLD/PDA. In Ostrava in 2012 during the winter inversion (up to -25 řC), mean concentration of 13 PAHs in aerosol was 432 ng.m-3 ; in fraction 10 - 1 µm 119 ng.m-3 , 1 - 0,5 µm 185 ng.m-3 , 0,5 - 0,17 µm 91 ng.m-3 , in fraction < 0,17 µm 37 ng.m-3 and in the gaseous phase of min. 40 ng.m-3 . In the most unfavorable day 2. 2. 2012 (-18.6 ř C) reached the 24-hour average of 13 PAHs 890 ng.m-3 , the sum of carcinogenic PAHs 237 ng.m-3 and benzo(a)pyrene 32.3 ng.m-3 . An irregular and different decline of PAHs concentrations after inversion was measured: in fraction 1 - 10 µm 2.8 times, 0.5 - 1 µm 4.2 times, 0.5 - 0.17 µm 4 times and for <0.17 µm up to 7.6 times....
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Atmospheric deposition of nitrogen - application of stable isotopes
Hanzlová, Barbora ; Hůnová, Iva (advisor) ; Hovorka, Jan (referee)
Human impact on particular parts of ecosystems has become a highly discussed topic. Due to different isotopic values of nitrogen, it is possible to evaluate the extent to which human influences the natural nitrogen cycle, using isotope measurements. Stable isotope measurement has been used in various scientific disciplines around the world. This thesis summarizes the findings about atmospheric deposition and the subsequent use of stable nitrogen isotopes. The objective of this work was to gather the information about the use of stable isotopes in the study of the atmospheric deposition and how to make better use of the information obtained from the measurements. Based on the literature review, it has been found that, unlike other countries, nitrate substances such as NH3 and HNO3 are not measured in the Czech Republic, which distorts the data on the nitrogen produced. The use of stable isotopes is a convenient method of measuring both not yet quantified substances as well as already measured substances contributing to atmospheric deposition. The stable isotope measurement method represents an improvement for the overall estimation of atmospheric deposition to provide more realistic values compared to the current approach. Key words: atmospheric deposition, nitrogen, stable isotopes
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Influence of local heating to PM10 levels in urban atmosphere
Píšová, Martina ; Hovorka, Jan (advisor) ; Škrabalová, Lenka (referee)
This master thesis evaluates the spatial variability of concentrations of PM10 on the area of towns Mladá Boleslav, Kosmonosy and small village Plazy during one month in the winter of 2013. Using a network measurements, we tried to determine whether sources of pollution are inside the city, or whether these harmful substances are transferred from the outside of the city to the area of the city. For the measurements we used a set of 9 portable laser nephelometers DustTrak (8520, TSI), which were placed on the roofs of schools. In the same time the device called beta-prachoměr (beta dust-meter) was continuously measuring concentrations of PM10, and we also monitored basic meteorological parameters (temperature, humidity, wind speed and direction). All these parameters were continuously measured at five minutes intervals. Also we did personal walks through the city, during which we measured personal exposure to PM10 concentrations. This exposure was compared with exposure of stationary monitors, and finally the differences were quantified. In Mladá Boleslav and in Kosmonosy, the same trend of concentrations of PM10 was observed at all selected locations in the city. Different trend of PM10 concentrations was observed in the village Plazy, where the peaks were higher and more frequent, especially in...
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Seasonal and microscale variability of PM1 and PM10
Grégr, Michal ; Hovorka, Jan (advisor) ; Braniš, Martin (referee)
The master thesis evaluates the middle scale spatial/seasonal variability of PM1 and PM10 at four sampling localities. Statistical significant differences in PM values could be crucial for a representative placement of a measuring station at the locality. A set of 7 portable laser nephelometers DustTrak - DT (8520, TSI) was used to record 5 minute integrates of PM1 and PM10 consecutively for each size for 3 days at 4 localities. The localities were rural, urban, background and freeway and contrasted as far as the main aerosol sources are concerned. At each locality, inter-DT distances ranged from 30 - 500m, 80 - 220m, 70 - 150m, and 30m and total area covered 290 000 m2 , 57 000 m2 , 29 000m2 , 240m2 in rural, urban, background and freeway locality, respectively. Wilcoxon signed-ranks test for 2 dependent samples was used to evaluate the variability. As expected, PM1 did not vary statistically significantly (α=0.05) among DT's at all localities in both winter and summer. Contrary to PM1, inter-DT PM10 values varied significantly at background and rural localities, according to the Wilcoxon test. These differences occurred in 3 out of 50 possibilities for winter measurements. However, there is no statistically significant difference in median values comparison.
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