|
|
A detailed study on aerosol particle size distribution in indoor and outdoor environments with attention to ammonium nitrate transormations
Talbot, Nicholas Philip ; Ždímal, Vladimír (advisor) ; Hovorka, Jan (referee) ; Vojtíšek, Michal (referee)
Due to its prevalence over large, densely populated areas, ammonium nitrate is an important chemical species in aerosol research. However, due to its volatility at ambient temperatures and over low temperature gradients, ammonium nitrate can be a difficult species to accurately measure. The volatility of ammonium nitrate is known to be dependent on temperature, relative humidity, the internal mixing state of the particle, and availability of the precursor gas constituents. The particle's physical state affects the equilibrium constant value of the ammonium nitrate - nitric acid / ammonia exchange and helps determine the dissociation rate. For indoor aerosol research, the outdoor originating aerosol particles' exposure to the new physical conditions indoors, such as changes in temperature, humidity, and particle-surface reactions within the microenvironment all accelerate ammonium nitrate dissociation. This increased rate of partitioning can generate artifacts on datasets, increase indoor particle formation, and accelerate the corrosion of cultural antiquities through acidification. The magnitude of these impacts is uncertain due to the current lack of knowledge on particle transformation processes when outdoor originating particles migrate indoors. To address this gap in knowledge, this thesis...
|
|
|
The impact of building isolation on CO2 concentration in flats
Čejková, Eliška ; Hovorka, Jan (advisor) ; Holcátová, Ivana (referee)
1 ABSTRACT This diploma work investigates the influence of thermal insolation at residential buildings on the concentration of CO2 (carbon dioxide) in indoor environment. The studied area is a housing estate of panel buildings (flats) in Sezimovo Ústí city. The present work notices a positive impact of thermal insolation on energy demands of buildings and it is mainly saving consumed heat energy which is also connected with emission lowering of carbon dioxide emissions. The main problem which is soluted in the work is that total insolation is usually done without any ventilation solution. It means that it has later a negative impact on indoor environment/air quality in flats. The main part if this work presents measurements of indoor air quality - CO2 concentration, air change rate, temperature and relative humidity in an insolated (with plastic windows) and a non-insolated (with the original wooden windows) flats. The measurement lasted for three days in selected pairs of flats - with plastic and wooden windows. The measuremet took place in bedrooms because the behaviour of residents of households was very similar during their sleep. The air change rate was then caculated from CO2 concentration decay during period of 3 hours without residents. The main aim is to quantify these differences. The conclusion...
|
|
|
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....
|
|
|
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...
|
|
|
Characteristic of aerosol particles in indoor environment of different types of libraries and archives
Mašková, Ludmila ; Smolík, Jiří (advisor) ; Hovorka, Jan (referee) ; Barták, Martin (referee)
Aerosol particles are one of the major pollutants in outdoor and indoor air. Particulate matter (PM) can be harmful for works of art by causing soiling and chemical damage, depending on particle size and chemical composition. This study includes indoor/outdoor monitoring of air quality in five archives in the CR, representing different outdoor environments: Zlatá Koruna (rural), Třeboň (small town), Teplice (industrial area), and two archives (National Library - NL and National Archives - NA) in Prague (large city with traffic). The NL and the archives in Zlatá Koruna, Třeboň and Teplice are only naturally ventilated, while NA in Prague is equipped with ventilation and filtration system. The measurements were performed during 4 intensive campaigns in different seasons of the year at every location. The measurements included particle number/mass concentrations, size distributions and chemical composition. Additional measurements were carried out in 2 museums, a depository, and a church. The aim of this study is to investigate concentrations, sources, and chemical composition of PM in the indoor environment, and to establish the relationship between the indoor and outdoor environment. The results showed that concentrations of fine particles in the indoor environment of the NA in Prague were...
|
|
|
Source apportionment of atmospheric aerosol fraction using by highly time resolved characterisation
Pokorná, Petra ; Hovorka, Jan (advisor) ; Havránek, Vladimír (referee) ; Schwarz, Jaroslav (referee)
The effective air quality management in the heavy polluted areas has to be based on high-quality monitoring with properly designed monitoring network and targeted measurements, which provided information required to source apportionment. The thesis aim was to apportion sources of atmospheric aerosol based on highly time resolved data of mass concentration of size segregated aerosol, its temporal and spatial variability, elemental composition, OC/EC and size distribution of carcinogenic polyaromatic hydrocarbons. Sampling campaigns went during winter and summer in small settlement Březno by Chomutov, residential area Ostrava - Radvanice a Bartovice and Mladá Boleslav in the years 2008 - 2010, 2012, 2013. We determined mass concentrations of PM10, PM1-10, PM1.15-10 and PM0.15-1.5 and their size fraction ratios. Based on the size ratios, the source apportionment of fine fraction (PM0.15-1.15) with focus on PM0.34-1.15 is crucial. We examined seasonal and spatial variability of PM10, PM.2.5, PM1 and PM1-10. Based on the examination, we obtained representative highly-time resolved data with regards to season and sampling locality. We analysed dynamic of size distribution of particle-bond eight carcinogenic polycyclic hydrocarbons. Based on the results the source apportionment of PM0.34-1.15 is crucial....
|
|
|
What is a connection between atmospheric aerosols, meteorological parameters and gaseous pollutants?
Slezáčková Zíková, Naděžda ; Ždímal, Vladimír (advisor) ; Hovorka, Jan (referee) ; Sedlák, Pavel (referee)
Title: What is the connection between atmospheric aerosols, meteorological pa- rameters and gaseous pollutants? Author: RNDr. Naděžda Slezáčková Zíková Department: Department of Meteorology and Environment Protection Supervisor: Ing. Vladimír Ždímal, Dr. Laboratory of Aerosol Chemistry and Physics, Institute of Chemical Process Fun- damentals, Czech Academy of Sciences, v.v.i. Abstract: Five years of atmospheric aerosol (AA) measurements at rural back- ground station Košetice were compared with meteorological records and gaseous pollutants concentrations. The sampling and data analysis of AA data is de- scribed, and the statistical evaluation is done. The variability in the AA con- centrations is significant; the long-term measurements of AA, over the period at least several years, and the differentiation according to the season of the year are thus necessary. The clearly expressed annual cycle of AA concentrations is mainly influenced by two phenomena. From April to September, the total AA concentration cycle is driven mainly by the new particles formation events, from October to March, the concentrations are strongly influenced by particles coming from long-range transport and/or from the regional pollution. The relationship between AA and meteorological parameters, however, is not only season...
|
|
|
Personal exposure to PM10 of selected workplaces in a coal strip mine determined by experiment
Basslerová, Barbora ; Hovorka, Jan (advisor) ; Hůnová, Iva (referee)
This thesis compares the experimentally determinated values of PM1, PM2,5, respirable fraction and PM10 between the cab drivers and the outdoor walkway of the bucket wheel excavator in the brown coal strip mine Doly Nástup Tušimice between March 16 and March 23, 2015. For the measurement of individual fractions, portable laser nephelometers were used. Superiority of coarse aerosol was confirmed outside from the total measurement time accounted for 82 %. PM10 fraction predominated outside and changed throughout the day depending on the activity carried out by a worker. Regular cleaning by sweeping stretches of dunes had an impact on PM10 concentrations. Fluctuations in the concentration of PM1 were detected in the driver cab due to smokers stay at this workplace. For these reasons there is a concentration difference between work shifts. Air temperature and relative humidity were also monitored in both types of work places. The air temperature average values reached over the range recommended for the optimal working environment in the driver cab. The thesis finds out personal exposure of a bucket-wheel excavator driver which is below the limit for the total concentration. Smaller fractions appears to be a potentially health risk. Powered by TCPDF (www.tcpdf.org)
|
|
|
Safety aspects of nanoaerosols in the work environment
Skřehotová, Marcela ; Hovorka, Jan (referee)
People have been exposed to aerosols since forever. However, the newly manufactured nanomaterials involve risks for those we are not ready. Although these are relatively new materials and technologies some of them have already demonstrated their serious health consequences. Therefore it is necessary to deal with the issues of human health protection from the unwilling effects. The present thesis summarizes selected safety aspects related to nanoaerosols exposure in the workplaces, which are currently the subject of attention. Thus the thesis presents the glossed results of author's previous professional work with reference to relevant publications.
|
|
|
Air quality at school
Hromádka, Jiří ; Braniš, Martin (advisor) ; Hovorka, Jan (referee)
(EN) Thesis describes air quality in schools, its main factors of interest and according to the longitudinal study it suggests possible solutions for improvement. The study had been done in Kladská elementary school, Prague, Czech Republic, based on the findings obtained from the initial literature review. Although many scientific papers have been published mainly during last decade, there is a very limited amount of information concerning this issue within a longer timescale and a complex point of view is missing. The school environment was chosen because children are one of the groups at higher risk when adverse health effects caused by inadequate indoor air quality are evaluated. Aerosol particles and carbon dioxide concentration, temperature and relative humidity levels are important factors of interest in this case and all of them were included in the study. 8 measuring campaigns, each of them took 1 week, had been done throughout the whole school year. The main aim of these campaigns was monitoring and describing the variability of all selected factors during the day or year as well as between different classrooms. Average aerosol particles concentration (PM10) didn't exceed 70µg.m-3 during most of the campaigns and the pupil's activity was evaluated as the main influencing factor. The...
|
guest ::
RSS feed.