Dissertations / Theses on the topic 'Atmospheric pollution and air quality'
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Assimakopoulos, Vasiliki. "Numerical modelling of dispersion of atmospheric pollution in and above urban canopies." Thesis, Imperial College London, 2002. http://hdl.handle.net/10044/1/8046.
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Grodzinsky, Gil. "Atmospheric organic nitrate photochemistry of the Southeastern United States." Diss., Georgia Institute of Technology, 1997. http://hdl.handle.net/1853/26229.
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Maxwell-Meier, Kari Lynn. "Urban Impacts On Atmospheric Chemistry: Surface Ozone in Large Versus Small Urban Centers and Urban Pollution in Asian Dust Storms." Diss., Available online, Georgia Institute of Technology, 2006, 2006. http://etd.gatech.edu/theses/available/etd-08012006-093354/.
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Thesis (Ph. D.)--Earth and Atmospheric Sciences, Georgia Institute of Technology, 2006.Rodney J. Weber, Committee Chair ; Michael E. Chang, Committee Member ; Judith A. Curry, Committee Member ; Ellery Ingall, Committee Member ; Michael H. Bergin, Committee Member.
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Al-Kandari, Mariam Hussain Murad. "Evaluation of the effect of air pollution on human health in Kuwait." Thesis, London School of Hygiene and Tropical Medicine (University of London), 1994. http://researchonline.lshtm.ac.uk/1620626/.
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Even before the 1990 war the populations of some areas of Kuwait was subject to severe atmospheric pollution. However, little was known about the effect of this pollution on health and on the use of health care. Three areas in Kuwait were chosen for study which were demographically similar and lay at a different distances to the north (i.e. usually downwind) of the industrial area. Plant in this area emits hydrogen sulphide, sulphur dioxide, hydrocarbons, nitrogen oxides, ammonia and carbon monoxide among other pollutants. A special survey was carried out to gather information on demographic, health and lifestyle factors including age, sex, place of residence, smoking, physical symptoms, psychological effects, life satisfaction, environmental problems, experience of air pollution and use of health care. A random sample of 136 households (1140 persons) was chosen from the three areas and studied over the period from lst February 1988 to 31st January 1989. Data on levels of pollution concentrations and meteorological conditions were also collected over the same period for each area studied. Data on use of health care were available from the health centres in the three areas studied and also from the population survey. The demographic similarity of the three areas studied was generally confirmed by the data from population survey. The relationships involved were examined for different age groups using cross tabulation, time series analysis and regression analysis. There were clear gradients with increased distance from the industrial area in levels of pollution, levels of selfreported physical and psychological symptoms and in the use of health care. Of the individual pollutants it appeared that carbon monoxide levels were most closely correlated with levels of symptoms. For those aged less than 18, the link to CO was closest for respiratory symptoms, while for those aged 18 to 64 the link was with headache. The use of primary care is more closely linked to H2S although this relationship is relatively weak. Consider the relationship between levels of pollution in the three areas studied and Kuwait City and the levels of pollution in Shuaiba area taking meteorological conditions into account. The purpose of this was to allow for estimates of the effect of pollution reduction in Shuaiba on the health of population elsewhere in the country. However, no way was and of making such estimates with sufficient prison. This analysis confirmed a number of recommendations that have been made by others.
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Valverde, Morales Victor. "Characterization of atmospheric pollution dynamics in Spain by means of air quality modelling." Doctoral thesis, Universitat Politècnica de Catalunya, 2016. http://hdl.handle.net/10803/393945.
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Atmospheric pollution causes large impacts on human health and societal economic interests and it is a threat for the ecosystems and the climate of the Earth. Improving the understanding of pollution dynamics is necessary to desing efficient air quality strategies that reduce the impacts of air pollution. This Ph.D. Thesis identifies the typical atmospheric conditions at synoptic scale that affect the Iberian Peninsula (IP) and uses them to explain the dynamics of the most relevant gaseous pollutants in Spain (nitrogen dioxide NO2, sulphur dioxide SO2, and ozone O3) by means of air quality modelling.
Circulation type classifications (CTC) summarise the continuum of atmospheric circulation into a discrete number of typical circulation types (CTs). For the 1983-2012 climatic period, a CTC is derived to be useful in the characterization of air quality dynamics over the IP. Sensitivity tests to classification techniques (principal components, correlation analysis, clustering) and other factors affecting the CTC (temporal and spatial resolution, domain size, etc.) are performed to objectivize the choice of the automatic set-up that maximizes its quality. The six identified CTs -described in terms of frequency, persistence, transitions, and location of pressure systems- are consistent with CTs found in the literature.
The temporal stability of the CTC, evaluated following a cross-validation process that compares the results of the climatic and yearly CTs, leads to the identification of a representative year (2012). A representative day for each CT in 2012 is identified using an objective score that minimizes the differences of the daily and the average surface pressure CT grid.
The study of NO2, SO2, and O3 dynamics performed on the representative day of each CT focuses on the biggest Spanish urban areas (Madrid and Barcelona) and heavy industrial/electricity-generation areas such as Asturias (northern Spain) and the Algeciras bay (southern Spain). The state-of-the-art CALIOPE Air Quality Forecast System (CALIOPE-AQFS) that provides high-resolution data on emissions, meteorology, and pollutant concentration over Spain is the main tool used in the characterisation of pollution dynamics. The modelling system is also used to quantify the contribution of specific sources of pollutants -coal-fired power plants and on-road transport- by means of a brute-force approach and an emission-based source apportionment, respectively.
The CTs control the transport patterns of SO2/NO2/O3 in Spanish continental and Atlantic areas, whereas in Mediterranean coastal areas and over complex-terrains a combination of synoptic and mesoscale dynamics (sea-land and mountain-valley breezes) explains the pollutant concentration patterns. The power plants' contribution to surface concentration (up to 55 µgSO2 m-3 and 32 µgNO2 m-3) occurs mainly close to the source (< 20 km) related to vertical diffusion when the emission is injected within the planetary boundary layer. However, the SO2/NO2 plumes can reach distances higher than 250 km. The daily maximum O3 concentration attributed to the on-road transport emissions from Madrid and Barcelona contribute up to 24% and 8% to total O3 concentration, respectively, but it is particularly significant (up to 80-100 µg m-3 in an hour) to the O3 concentration peak during the central hours of the day in April-September. The long-range transport of O3 to the IP is controlled by the CTs and its concentration is very significant in the area of influence of Madrid and Barcelona, particularly under cold CTs (70-96%).
This Ph.D. Thesis has proven that CALIOPE-AQFS (1) is useful to characterise the 3-D dynamics of primary and secondary pollutants in Spain under typical CTs; (2) is able to attribute and quantify air pollution to its sources via brute force and source apportionment; and (3) has the potential to help in the design of specific, science-based abatement strategies that minimize air pollution impacts.La contaminación atmosférica genera perjuicios en la salud humana, en los intereses económicos de la sociedad y constituye una amenaza para los ecosistemas y el clima de la Tierra. Avanzar en la comprensión de la dinámica de la contaminación facilita el diseño de estrategias de calidad del aire que reduzcan sus impactos. Esta Tesis Doctoral identifica objetivamente patrones típicos de circulación atmosférica (PT) que afectan a la Península Ibérica (PI) a escala sinóptica para explicar la dinámica de los principales contaminantes gaseosos en España (dióxido de nitrógeno NO2, dióxido de azufre SO2 y ozono O3) mediante modelización de la calidad del aire. Las clasificaciones sinópticas (CS) discretizan el continuo de la circulación atmosférica en un catálogo de PT. Para el período climático 1983-2012, se establece una CS útil para el estudio de la dinámica de la contaminación atmosférica en la PI. Tests de sensibilidad para técnicas automáticas de clasificación (análisis de componentes principales, de correlación y clustering) y para otros factores que afectan a la CS (resolución temporal y espacial, tamaño del dominio, etc.) objetivizan la elección de la configuración que maximiza su calidad. Los seis PT identificados - descritos en términos de frecuencia, persistencia, transiciones y ubicación de los sistemas de presión - son consistentes con la literatura. La evaluación de la estabilidad temporal de la clasificación, mediante un proceso de validación cruzada que compara los PT climáticos con PT identificados en CS anuales, permite identificar un año representativo (2012). Un día representativo de cada PT es elegido gracias a un algoritmo que minimiza las diferencias de la malla de presiones diaria respecto de la del PT promedio. El estudio de la dinámica de NO2, SO2 y O3 se realiza en el día representativo de cada PT focalizando en las principales áreas urbanas de España (Madrid y Barcelona) y en importantes áreas industriales y/o de generación eléctrica (Asturias, bahía de Algeciras). El sistema de CALIdad del aire OPeracional para España (CALIOPE) que proporciona datos de alta resolución sobre emisiones, meteorología y concentración de contaminantes es la principal herramienta utilizada en el estudio. CALIOPE permite cuantificar la contribución de determinadas fuentes de emisión, centrales térmicas de carbón y transporte rodado, mediante un enfoque de fuerza bruta y de asignación de fuentes, respectivamente. Los PT controlan el transporte de SO2/NO2/O3 en áreas atlánticas y continentales de España mientras que en zonas costeras mediterráneas y/o de topografía compleja, una combinación de procesos sinópticos y de mesoescala (brisas marinas y de valle) explica los patrones de contaminación. La contribución de SO2 y NO2 de las centrales térmicas a la concentración en superficie (hasta 55 µg m-3 y 32 µg m-3, respectivamente) se produce principalmente cerca de la fuente (<20 km) por difusión vertical de la emisión cuando ésta se inyecta en la capa límite planetaria. Sin embargo, los penachos de SO2/NO2 pueden alcanzar distancias superiores a los 250 km. La contribución máxima diaria de O3 atribuido a emisiones del transporte rodado de Madrid y Barcelona alcanza el 24% y el 8%, respectivamente pero es particularmente significativa (hasta 80-100 µg m-3 en una hora) a mediodía durante el pico de concentración de O3. El transporte a larga distancia de O3 hacia la PI es controlado por los PT y su contribución es muy importante en el área de influencia de Madrid y Barcelona, en particular bajo los PT fríos (70-96%). Esta Tesis Doctoral ha demostrado que CALIOPE es (1) útil para caracterizar la dinámica 3-D de contaminantes primarios y secundarios en España bajo diferentes PT; (2) capaz de atribuir y cuantificar la contaminación a sus fuentes a través de fuerza bruta y atribución de fuentes; y (3) potencialmente útil en el diseño de estrategias de mitigación específicas que minimicen los impactos de la contaminación atmosférica.
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Liu, Yuan. "Development of a tool to estimate the atmospheric emissions with high spatial and temporal resolution over the Macau SAR." Thesis, University of Macau, 2018. http://umaclib3.umac.mo/record=b3868750.
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Lai, Kwong-kei Murphy. "Two-dimensional computational study on indoor/outdoor air quality relationship in urban buildings." Click to view the E-thesis via HKUTO, 2007. http://sunzi.lib.hku.hk/hkuto/record/B38725149.
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Syarif, Laode Muhamad. "The implementation of international responsibilities for atmospheric pollution : comparison between Indonesia and Australia." Thesis, Queensland University of Technology, 1999.
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Al-Abri, Eman S. "Modelling atmospheric ozone concentration using machine learning algorithms." Thesis, Loughborough University, 2016. https://dspace.lboro.ac.uk/2134/25091.
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Air quality monitoring is one of several important tasks carried out in the area of environmental science and engineering. Accordingly, the development of air quality predictive models can be very useful as such models can provide early warnings of pollution levels increasing to unsatisfactory levels. The literature review conducted within the research context of this thesis revealed that only a limited number of widely used machine learning algorithms have been employed for the modelling of the concentrations of atmospheric gases such as ozone, nitrogen oxides etc. Despite this observation the research and technology area of machine learning has recently advanced significantly with the introduction of ensemble learning techniques, convolutional and deep neural networks etc. Given these observations the research presented in this thesis aims to investigate the effective use of ensemble learning algorithms with optimised algorithmic settings and the appropriate choice of base layer algorithms to create effective and efficient models for the prediction and forecasting of specifically, ground level ozone (O3). Three main research contributions have been made by this thesis in the application area of modelling O3 concentrations. As the first contribution, the performance of several ensemble learning (Homogeneous and Heterogonous) algorithms were investigated and compared with all popular and widely used single base learning algorithms. The results have showed impressive prediction performance improvement obtainable by using meta learning (Bagging, Stacking, and Voting) algorithms. The performances of the three investigated meta learning algorithms were similar in nature giving an average 0.91 correlation coefficient, in prediction accuracy. Thus as a second contribution, the effective use of feature selection and parameter based optimisation was carried out in conjunction with the application of Multilayer Perceptron, Support Vector Machines, Random Forest and Bagging based learning techniques providing significant improvements in prediction accuracy. The third contribution of research presented in this thesis includes the univariate and multivariate forecasting of ozone concentrations based of optimised Ensemble Learning algorithms. The results reported supersedes the accuracy levels reported in forecasting Ozone concentration variations based on widely used, single base learning algorithms. In summary the research conducted within this thesis bridges an existing research gap in big data analytics related to environment pollution modelling, prediction and forecasting where present research is largely limited to using standard learning algorithms such as Artificial Neural Networks and Support Vector Machines often available within popular commercial software packages.
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Lai, Kwong-kei Murphy, and 賴廣麒. "Two-dimensional computational study on indoor/outdoor air quality relationship in urban buildings." Thesis, The University of Hong Kong (Pokfulam, Hong Kong), 2007. http://hub.hku.hk/bib/B38725149.
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Cruvinel, Brandao Fonseca Marinho Rayssa. "Atmospheric Pollutant Levels in Southeast Brazil During COVID-19 Lockdown: Combined Satellite and Ground-based Data Analysis." Thesis, Virginia Tech, 2021. http://hdl.handle.net/10919/102026.
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With the ongoing COVID-19 pandemic being spread all over the world, lockdown measures are being implemented making air pollution levels go down in several countries. In this context, the air quality changes in the highly populated and trafficked Brazilian states of Sao Paulo (SP) and Rio de Janeiro (RJ) are hereby going to be addressed using a combination of satellite and ground-based data analysis. We explored nitrogen dioxide (NO2) and particulate matter (PM2.5) daily levels for the month of May during different years within 2015-2020. Daily measurements of NO2 column concentrations from the Ozone Monitoring Instrument (OMI) aboard NASA's Aura satellite were also gathered and averaged decreases of 42% and 49.6% were found for the year of 2020 compared to previous averaged 2015-2019 years. In parallel to the NO2 column retrieval, the ground-based data, measured by the Brazilian States Environmental Institutions, is analyzed, and correlated with satellite retrievals. Correlation coefficients between column and ground-based concentrations were 77% and 53% in SP and RJ, respectively. It was found a 13.3% (p-value = 0.099) and 18.8% (p-value = 0.077) decrease in NO2 levels for SP and RJ, respectively, in 2020 compared to 2019. For PM2.5, no significant change was observed for the same time period in the SP region, although the high number of fire burnings in the Southeast region seemed to be affecting PM2.5 levels. In addition to natural emissions (fire burnings), the combined data was also evaluated taking meteorological parameters, such as temperature and wind speed, into account. No interference of weather or fire was found in 2020 NO2 ground levels compared to previous years, This integrated analysis is innovative and has yet to be more explored in Brazilian studies. This is true specifically because the ground-based stations are spatially and temporally sparse in Brazil.Master of Science
This study aims to explore satellite data applied to the lockdown context resultant from the COVID-19 pandemic in Brazil. Satellite data usage in air quality management is yet to be explored to its full potential. Two highly populated states were chosen: Sao Paulo (SP) and Rio de Janeiro (RJ). Local governments have been imposing limitations on private and public vehicle circulation, inducing a decrease in atmospheric pollutant levels, specifically nitrogen dioxide (NO2), which is directly emitted to the air by fuel combustion. NO2 is also short-lived in the atmosphere, so its variation within days can be easily captured. PM2.5, a category of fine inhalable particles, can be produced by wildfires, in addition to fuel burning and mechanical processes such as resuspension by cars. Here we retrieved daily NO2 vertical column densities for the month of May within the 2015-2020 years from the OMI instrument onboard of NASA's Aura satellite. Ground daily NO2 and PM2.5 measurements were also collected from local environmental agencies. Results showed an average 42% decrease of the NO2 column values in SP in 2020 compared to 2015-2019. The decrease was 49.6% in RJ for the same timeframe. Correspondent surface data showed a decrease of 13.3% (p-value = 0.099) and 18.8% (p-value = 0.077) during 2020 compared to 2019 in SP and RJ stations, respectively. No significant divergence in PM2.5 values was found between 2019 and 2020. Finally, weather data was added to the pollutant analysis. PM2.5 concentrations were associated with wildfires, while the NO2 levels found in 2020 for SP and RJ were attributed to local lockdown decrees. Satellite retrievals showed significant potential in filling out ground datasets, correlating with the SP and RJ surface data in 77% and 53%, respectively.
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Weber, Eric E. Lupo Anthony R. "Classification of air pollution regimes in the Missouri region." Diss., Columbia, Mo. : University of Missouri--Columbia, 2009. http://hdl.handle.net/10355/6483.
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Title from PDF of title page (University of Missouri--Columbia, viewed on Feb 23, 2010). The entire thesis text is included in the research.pdf file; the official abstract appears in the short.pdf file; a non-technical public abstract appears in the public.pdf file. Thesis advisor: Dr. Anthony R. Lupo. Includes bibliographical references.
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Napelenok, Sergey L. "Sensitivity Analysis in Air Quality Models for Particulate Matter." Diss., Georgia Institute of Technology, 2006. http://hdl.handle.net/1853/14083.
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Fine particulate matter (PM2.5) has been associated with a variety of problems that include adverse health effects, reduction in visibility, damage to buildings and crops, and possible interactions with climate. Although stringent air quality regulations are in place, policy makers need efficient tools to test a wide range of control strategies. Sensitivity analysis provides predictions on how the interdependent concentrations of various PM2.5 components and also gaseous pollutant species will respond to specific combinations of precursor emission reductions. The Community Multiscale Air Quality Model (CMAQ) was outfitted with the Decoupled Direct Method in 3D for calculating sensitivities of particulate matter (DDM-3D/PM). This method was evaluated and applied to high PM2.5 episodes in the Southeast United States. Sensitivities of directly emitted particles as well as those formed in the atmosphere through chemical and physical processing of emissions of gaseous precursors such as SO2, NOx, VOCs, and NH3 were calculated. DDM-3D/PM was further extended to calculate receptor oriented sensitivities or the Area of Influence (AOI). AOI analysis determines the geographical extent of relative air pollutant precursor contributions to pollutant levels at a specific receptor of interest. This method was applied to Atlanta and other major cities in Georgia. The tools developed here (DDM-3D/PM and AOI) provide valuable information to those charged with air quality management.
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Kreuger, Jenny. "Pesticides in the environment : atmospheric deposition and transport to surface waters /." Uppsala : Swedish Univ. of Agricultural Sciences (Sveriges lantbruksuniv.), 1999. http://epsilon.slu.se/avh/1999/91-576-5485-9.pdf.
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Liu, Xiaoting. "Developing a scientific basis for utilisation of low-cost sensing technologies towards quantitative assessments of air pollution and its sources." Thesis, Queensland University of Technology, 2021. https://eprints.qut.edu.au/212115/1/Xiaoting_Liu_Thesis.pdf.
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This thesis develops a scientific basis for the use of low-cost sensing technologies for quantitative assessment of air pollution and its sources. It has extensively identified the capabilities and limitations of low-cost sensors in laboratory and field environments. Essentially, it has demonstrated that low-cost sensors are capable of monitoring air quality with a high degree of accuracy in different locations (e.g., highly polluted areas) and for different purposes (e.g., citizen science projects for raising environmental awareness).
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Finch, Douglas Peter. "The impact of boreal biomass burning on North American air quality." Thesis, University of Edinburgh, 2017. http://hdl.handle.net/1842/29536.
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Understanding the quality of the air we breathe is critical in quantifying the impact that atmospheric chemistry has on health. Poor air quality increases the risk of heart and lung diseases as well as having a detrimental effect on climate, ecology and the built environment. The burning of fossil fuels and plant matter (biomass burning) creates large quantities of gases and particulate matter that impact air quality and the air we breathe. Biomass burning is estimated to contribute 400 Tg of non-methane organic compounds, 40 Tg of methane and 7.1 Tg of nitrogen oxides to the atmosphere each year. This thesis aims to better understand the role of biomass burning on air quality and tropospheric chemistry. The in depth analysis presented here addresses of the impact of boreal biomass burning in North America on air quality, in particular, carbon monoxide (CO) and ozone (O3). By using a number of different modelling techniques along with data collected from a field campaign and satellites the transport and chemistry of biomass burning emissions were analysed and quantified. The first research chapter of the thesis used the GEOS-Chem atmospheric chemistry transport model to interpret aircraft measurements of CO in biomass burning outflow taken during the 2011 BORTAS-B campaign over Canada. The model has some skill reproducing the observed variability, but has a positive bias for observations < 100 ppb and a negative bias for observations > 300 ppb. It was found that observed CO variations are largely due to fires over Ontario, with smaller and less variable contributions from fossil fuel combustion from eastern Asia and NE North America. To help interpret observed variations of CO an effective physical age of emissions (¯A) metric was developed. It was found that during BORTAS-B the age of emissions intercepted over Halifax, Nova Scotia is typically 4–11 days, and on occasion as young as two days. The analysis shows that ¯A is typically 1–5 days older than the associated photochemical ages inferred from co-located measurements of different hydrocarbons. It is argued that a robust observed relationship between CO and black carbon aerosol during BORTAS-B (r² > 0.7), form the basis of indirect evidence that aerosols co-emitted with gases during pyrolysis markedly slowed down the plume photochemistry during BORTAS-B with respect to photochemistry at the same latitude and altitude in clear skies. The second research chapter focuses on O3 production downwind from boreal biomass burning. Using the GEOS-Chem model, the O3 chemistry within a biomass burning plume from a fire on 17 July 2011 in mid-Canada was examined. The model shows a significant positive bias (~20 ppb) in reproducingO3 mixing ratios over North America for July 2011 when compared to observations. Reducing NO emissions from lightning and fossil fuel by 50% and 54% respectively reduced this bias to ~10 ppb. The cause of the remaining bias is uncertain. Using a novel technique with the model, the centre of the biomass burning plume was tracked and O3 concentrations and chemistry was extracted from the centre of the plume. The biomass burning enhanced O3 concentrations throughout the plume by between 1 – 20 ppb when compared with the same plume path with no biomass burning. The plume was characterised as being NOx-rich for the initial four days of transport. The sensitivity of the O3 chemistry to different emissions was calculated and it was found that the O3 is initially highly sensitive to NO emissions from biomass burning and then to NO emissions from fossil fuels as it travels across an urban area surrounding Quebec City. The O3 net production was found to initially decrease with an increase in NO but increase further downwind. The final research chapter of the thesis uses long-term satellite observations to evaluate natural variability in CO concentrations over the North Atlantic. 15 years of MOPITT CO column observations were used along with modelled CO from the GEOS-Chem model. The model was evaluated against the MOPITT overpass and shows a negative bias of between -8% and -24% over the northern mid-latitudes with the largest bias seen in spring. The model has a large positive bias (8% – 40%) over the Amazon,West Africa and Indonesia through all seasons. Using Empirical Orthogonal Function (EOF) analysis on the MOPITT and GEOS-Chem CO columns shows the largest mode of variability seen in the North Atlantic to be the oxidation of methane for winter and spring, biomass burning during summer and fossil fuel combustion from East Asia during autumn.
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Alston, Erica J. "Aerosol characterization in the Southeastern U. S. using satellite data for applications to air quality and climate." Diss., Georgia Institute of Technology, 2012. http://hdl.handle.net/1853/43589.
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Tropospheric aerosol information from NASA satellites in space has reached the milestone of ten years of continuous measurements. These higher resolution satellite aerosol records allow for a broader regional perspective than can be gained using only sparsely located ground based monitoring sites. Decadal satellite aerosol data have the potential to advance knowledge of the climatic impacts of aerosols through better understanding of solar dimming/brightening and radiative forcings on regional scales, as well as aid in air quality applications. The goal of this thesis is to develop and implement methodologies for using satellite remotely sensed data in conjunction with ground based observations and modeling for characterization of regional aerosol variations with applications to air quality and climate studies in the Southeastern U. S. This region is of special interest because of distinct aerosol types, less warming climate trends compared to the rest of U.S., and growing population.
To support this primary goal, a technique is developed that exploits the statistical relationship between PM2.5 (particulate matter that has an aerodynamic radius of 2.5 µm or less) and satellite AOD (Aerosol Optical Depth) from MODIS (Moderate resolution Imaging Spectroradiometer) where a probabilistic approach is used for air quality assessments in the metropolitan Atlanta area. The metropolitan Atlanta area experiences the poorest air quality during the warmer seasons. We found that satellite AODs capture a significant portion of PM2.5 concentration variability during the warmer months of the year with correlation values above 0.5 for a majority of co-located (in time and space) ground based PM2.5 monitors, which is significant at the 95% confidence interval. The developed probabilistic approach uses five years of satellite AOD, PM2.5 and their related AQI (Air Quality Index) to predict future AQI based solely on AOD retrievals through the use of AOD thresholds, e.g., 80% of Code Green AQI days have AOD below 0.3. This approach has broad applicability for concerned stakeholders in that it allows for quick dissemination of pertinent air quality data in near-real time around a satellite overpass.
Examination of the use of multiple satellite sensors to aid in investigating the impacts of biomass burning in the region is performed. The utility of data fusion is evaluated in understanding the effects of the large wildfire that burned in May 2007.
This wildfire caused PM2.5 in the metropolitan Atlanta area to exceed healthy levels with some measurements surpassing 150 µg/m3 during the month. OMI (Ozone Monitoring Instrument) AI (Aerosol Index), which qualitatively measures absorbing aerosols, have high values of more than 1.5 during May 26 - 31, 2007. CALIPSO (Cloud-Aerosol Lidar and Infrared Pathfinder Satellite Observations) a space based lidar was used to determine the vertical structure of the atmosphere across the region during the active fire period. CALIPSO was able to identify wildfire aerosols both within the planetary boundary layer (likely affects local air quality) and aloft where aerosol transport occurs. This has important implications for climatic studies specifically aerosol radiative effects.
In-depth analysis of the satellite and ground based aerosol data records over the past decade (2000 - 2009) are performed from a climatic perspective. The long temporal scale allowed for better characterization of seasonality, interannual variability, and trends. Spatial analysis of ten years of AOD from both MODIS and MISR (Multi-angle Imaging Spectroradiometer) showed little variability of AOD during the winter with mean AOD below 0.1 for the entire region, while the summer had decidedly more variability with mean AOD around 0.33 for MODIS and 0.3 for MISR. Seasonal analysis of the PM2.5 revealed that summer means are twice as high as winter means for PM2.5. All of the datasets show interannual variability that suggests with time AOD and PM2.5 are decreasing, but seasonal variability obscured the detection of any appreciable trends in AOD; however, once the seasonal influence was removed through the creation of monthly anomalies there were decreasing trends in AOD, but only MODIS had a trend of -0.00434 (per month) that statistically significant at the 95% confidence level.
Satellite and ground-based data are used to assess the radiative impacts of aerosols in the region. The regional TOA (Top Of the Atmosphere) direct radiative forcing is estimated by utilizing satellite AOD from MODIS and MISR both on Terra, along with satellite derived cloud fraction, surface albedo (both from MODIS), and single scattering albedo (SSA) from MISR data from 2000 - 2009. Estimated TOA forcing varied from between -6 to -3 W/m2 during the winter, and during the warmer months there is more variation with ΔF varying between -28 to -12.6 W/m2 for MODIS and -26 to -11 W/m2 for MISR. The results suggest that when AOD, cloud fraction and surface albedo are all consider they add an additional 6 W/m2 of TOA forcing compared to TOA forcing due to aerosol effects only. Varying SSA can create changes in TOA forcing of about 5 W/m2. With removal of the seasonal variability timeseries anomaly trend analysis revealed that estimated TOA forcing is decreasing (becoming less negative) with MODIS based estimates statistically significant at the 95% confidence level.
Optical and radiative 1-D radiative transfer modeling is performed to assess the daily mean TOA forcing and forcing at the surface for representative urban and background aerosol mixtures for summer and winter. During the winter, modeled TOA forcing is -2.8 and -5 W/m2 for the WB and WU cases, and the modeled summer TOA forcings (SB = -13.3 W/m2) also generally agree with earlier estimates. While surface forcings varied from -3 to -210 W/m2. The radiative forcing efficiency at the TOA (amount of forcing per unit of AOD at 550 nm) varied from -9 to -72 W/m2 τ-1, and RFE at the surface varied from -50 to -410 W/m2 τ-1. It was found that the forcing efficiency for biomass burning aerosols are similar to the forcing efficiency of background aerosols during the summer that highlights the importance of possible increased biomass burning activity. Ultimately, the methodologies developed in this work can be implemented by the remote sensing community and have direct applicability for society as a whole.
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Liu, Nairui. "Novel applications of modelling techniques to understand and predict global urban air quality trends." Thesis, Queensland University of Technology, 2021. https://eprints.qut.edu.au/208434/1/Nairui_Liu_Thesis.pdf.
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The aim of this study was to explore novel applications of modelling techniques to advance analytical methods towards addressing urban atmospheric environment problems and possible solutions. Four selected models known as SVR, STL, WRF, and LSTM were used to investigate: the correlation between social development and air quality, the trend of severe air pollution episodes on a global scale, urban heat island effect mitigation measures, and how to extend the use of air quality monitoring data. This study led to improved analysis of global urban atmospheric environment problems and the formulation of more effective urban air quality management policies.
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Huang, Min. "A multi-scale modeling study of the impacts of transported pollutants and local emissions on summertime western US air quality." Diss., University of Iowa, 2012. https://ir.uiowa.edu/etd/2898.
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The impacts of transported and locally-produced pollutants on western US air quality during summer 2008 are studied using the multi-scale Sulfur Transport and Deposition Modeling system. Transported background (TBG) is an indicator of the influences from extra-regional emissions or the lower stratosphere. The magnitude of TBG is expected to increase as the emissions from international sources grow. This trend is especially important in the context of US air quality standards, which tend to become more stringent to protect human health and ecosystems. Forward sensitivity simulations in which the model boundary conditions and emissions are perturbed show that TBG strongly and extensively affect western US surface ozone (more than half of the total), compared to other contributors to background ozone (North American, NA, biomass burning, BB and biogenic emissions), and the impacts differ among various geographical regions and land types. The stratospheric ozone impacts are weak. The TBG ozone contributes most to western US ozone among all TBG species, and TBG peroxyacetyl nitrate is the most important species among ozone precursors. Compared to monthly mean 8-hour daily maximum ozone, the secondary standard metric "W126 monthly index" shows larger responses to TBG perturbations and stronger non-linearity to the size of perturbations. Overall the model-estimated TBG impacts negatively correlate to the vertical resolution and positively correlate to the horizontal resolution. The estimated TBG impacts weakly depend on the magnitude of uncertainties in the US anthropogenic emissions. The transport/subsidence processes that link airmasses aloft with the surface pollution level are analyzed by trajectories, time-lag correlation and adjoint sensitivity analyses. Various types of observations are used to identify source regions and transport processes, and to improve model prediction using the four-dimensional variational data assimilation during a long-range transport episode.
The sectoral and geographical contributions to summertime US black carbon (BC) distributions are studied. NA emissions heavily (>70%) affect the BC levels from the surface to 5 km, while non-NA plumes compose more than half of the BC above 5 km. NA and non-NA BB, NA transportation and non-NA residential emissions are the major contributing sectors. Aircraft measurements during the California phase of the Arctic Research of the Composition of the Troposphere from Aircraft andSatellites (ARCTAS-CARB) field campaign show that BC/(organic matter + nitrate + sulfate) mass ratios fairly well represent BC's warming potential over southern California, which can be approximated by BC/(organic matter + sulfate) and BC/sulfate for plumes affected and unaffected by fires, respectively. The responses of BC/(organic matter + sulfate) and BC/sulfate to removing each emission sector indicate that mitigating NA transportation emissions has the highest potential for regional air quality and climate co-benefits. Contributions from NA BB and extra-regional emissions differ for summer and spring (April 2008).
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Boubrima, Ahmed. "Deployment and scheduling of wireless sensor networks for air pollution monitoring." Thesis, Lyon, 2019. http://www.theses.fr/2019LYSEI018.
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Les réseaux de capteurs sans fil (RCSF) sont largement utilisés dans les applications environnementales où l’objectif est de détecter un phénomène physique tel que la température, l’humidité, la pollution de l’air, etc. Dans ce contexte d’application, l’utilisation de RCSF permet de comprendre les variations du phénomène et donc être en mesure de prendre des décisions appropriées concernant son impact. En raison des limitations de ses méthodes de suivi traditionnelles et de sa grande variabilité spatiale et temporelle, la pollution de l'air est considérée comme l'un des principaux phénomènes physiques qui restent à étudier et à caractériser. Dans cette thèse, nous considérons trois applications concernant l’utilisation de RCSF pour le suivi de la pollution de l’air : la cartographie en temps réel de la qualité de l’air, la détection de dépassements de seuils des polluants et la correction de modèles physiques qui simulent le phénomène de dispersion de la pollution. Toutes ces applications nécessitent de déployer et d’ordonnancer minutieusement les capteurs afin de mieux comprendre la pollution atmosphérique tout en garantissant un coût de déploiement minimal et en maximisant la durée de vie du réseau. Notre objectif est de résoudre les problèmes de déploiement et d'ordonnancement tout en tenant compte des caractéristiques spécifiques du phénomène de la pollution de l’air. Nous proposons pour chaque cas d'application une approche efficace pour le déploiement de noeuds capteurs et puits. Nous proposons également une approche d’ordonnancement adaptée au cas de la correction de modèles physiques. Nos approches d'optimisation prennent en compte la nature physique de la pollution atmosphérique et intègrent les données réelles fournies par les plateformes existantes de suivi de la qualité de l’air. Dans chacune de nos approches d’optimisation, nous utilisons la programmation linéaire en nombres entiers pour concevoir des modèles d’optimisation adaptés à la résolution de petites et moyennes instances. Pour traiter les grandes instances, nous proposons des heuristiques en utilisant des techniques de relaxation linéaire. Outre nos travaux théoriques sur le suivi de la pollution atmosphérique, nous avons conçu et déployé dans la ville de Lyon un réseau de capteurs de pollution économe en énergie. Sur la base des caractéristiques de notre système et des jeux de données de la pollution atmosphérique, nous avons évalué l’efficacité de nos approches de déploiement et d’ordonnancement. Nous présentons et discutons dans cette thèse les résultats d'évaluation de performances ainsi que des lignes directrices pour la conception de systèmes de suivi de la pollution de l’air. Parmi nos principales conclusions, nous soulignons le fait que la taille optimale du réseau de capteurs dépend du degré de variation des concentrations de pollution dans la région de déploiementWireless sensor networks (WSN) are widely used in environmental applications where the aim is to sense a physical phenomenon such as temperature, humidity, air pollution, etc. In this context of application, the use of WSN allows to understand the variations of the phenomenon over the monitoring region and therefore be able to take adequate decisions regarding the impact of the phenomenon. Due to the limitations of its traditional costly monitoring methods in addition to its high spatial and temporal variability, air pollution is considered as one of the main physical phenomena that still need to be studied and characterized. In this thesis, we consider three main applications regarding the use of WSN for air pollution monitoring: 1) the construction of real time air quality maps using sensor measurements; 2) the detection of pollution threshold crossings; and 3) the correction of physical models that simulate the pollution dispersion phenomenon. All these applications need careful deployment and scheduling of sensors in order to get a better knowledge of air pollution while ensuring a minimal deployment cost and a maximal lifetime of the deployed sensor network. Our aim is to tackle the problems of WSN deployment and scheduling while considering the specific characteristics of the air pollution phenomenon. We propose for each application case a new efficient approach for the deployment of sensor and sink nodes. We also propose a WSN scheduling approach that is adapted to the case of physical models’ correction. Our optimization approaches take into account the physical nature of air pollution dispersion and incorporate real data provided by the existing pollution sensing platforms. As part of each approach, we use integer linear programming to derive optimization models that are well adapted to solving small and medium instances. To deal with large instances, we propose heuristic algorithms while using linear relaxation techniques. Besides our theoretical works on air pollution monitoring, we design from scratch and deploy in the Lyon city a cost-effective energy-efficient air pollution sensor network. Based on the characteristics of our monitoring system in addition to real world air pollution datasets, we evaluate the effectiveness of our deployment and scheduling approaches and provide engineering insights for the design of WSN-based air pollution monitoring systems. Among our conclusions, we highlight the fact that the size of the optimal sensor network depends on the degree of the variations of pollution concentrations within the monitoring region
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Ngagine, Soulemane Halif. "Chemical heterogeneity of atmospheric particles in urbanized and industrialized environments during pollution events." Thesis, Littoral, 2022. http://www.theses.fr/2022DUNK0617.
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Ce travail de thèse vise à améliorer notre connaissance des sources proches et lointaines contrôlant le dépassement des seuils réglementaires de qualité de l’air, tels qu’ils peuvent être appréciés par les réseaux de mesure existants, sur le site fortement industrialisé et urbain du Grand Dunkerque. Il s’agit notamment de s’appuyer sur le calcul d’un indice d’état de mélange des particules, prenant en compte l’hétérogénéité de leur composition élémentaire, celle-ci étant liée à leur temps de séjour dans l’air et à la distance entre les sources et le site récepteur étudié. Pour répondre à cette problématique, il a fallu dans un premier temps développer un impacteur séquentiel de particules à haute résolution temporelle, nommé TRAPS, qui répondait au besoin de suivre les changements rapides observés au sein des particules atmosphériques lors d’épisodes de pollution. Couplé à un granulomètre et après analyse individuelle des particules prélevées par microscopie électronique (MEB-EDX), le TRAPS permet de rendre compte de l’évolution physico-chimique des particules atmosphériques au cours du temps. Dans la première partie de cette thèse, des expériences menées en laboratoire et une campagne de terrain ont permis de valider notre prototype, de rendre compte de la dynamique de dépôt des particules sur les zones d’impaction et de vérifier les diamètres de coupure des étages grossier et fin du TRAPS, déterminés respectivement à 1.32µm et 0.13µm. Une étude statistique des épisodes de pollution aux PM₁₀ survenus sur le grand dunkerquois a ensuite été réalisée sur 3 ans, entre 2018 et 2020. Elle nous a permis d’identifier 12 principaux types d’épisodes sur la base de leur étendue spatiale, mais aussi des conditions locales de dispersion des polluants. On a pu ainsi identifier des épisodes locaux et des épisodes régionaux observés, soit en conditions atmosphériques stationnaires ou au contraire en conditions de dispersion des pollutions à plus grande échelle. Alors que 78 % des jours de dépassement du seuil réglementaire des PM₁₀ correspondent à des épisodes locaux, les 22.4% restant correspondent à des panaches de pollution d’étendue au moins régionale, avec une proportion égale des jours de dépassements en condition de dispersion et en conditions stationnaires. Hormis les épisodes très localisés, une étude fine de la variabilité temporelle des concentrations en particules fines (PM₂.₅) montre la présence systématique d'une période d'accumulation progressive des polluants, pouvant atteindre une dizaine d'heures et caractérisée par une contribution importante de ces particules. La dernière partie de ce travail a consisté en l'étude de la composition et l'état de mélange des particules individuelles collectées lors d'évènements de pollution sur la zone du Grand Dunkerque en 2021. La campagne a permis l'échantillonnage et la caractérisation de 5 épisodes de pollution durant lesquels le TRAPS était déployé en parallèle d'autres instruments fournissant des informations complémentaires sur la granulométrie des aérosols, la météorologie ou la dynamique atmosphérique. Près de 28000 particules individuelles ont été caractérisées par MEB-EDX. Avec plus de 90% des échantillons associés à des valeurs de l'indice d'état de mélange chimique supérieures à 0.5, il est possible d'affirmer que les particules collectées sur la zone du Grand Dunkerque, durant ces épisodes de pollution, sont, en général, de composition très hétérogène à l'échelle de la particule individuelle (particules dites "en mélange interne"). Les résultats obtenus montrent en outre une influence de l'origine, locale ou transportée, des particules sur leur composition chimique et par là même sur l'indice d'état de mélange chimique de la population de particules échantillonnées. Une évolution croissante de l'indice d'état de mélange avec le temps de résidence des particules dans l'atmosphère lors de ces évènements est notamment observéeThis thesis aims at improving our knowledge of the near and distant sources controlling the exceedance of the regulatory thresholds of air quality, as detected by the air quality monitoring networks, at the strongly industrialized and urban site of Great Dunkirk Area (GDA). This appreciation is notably based on the calculation of a mixing state index of the particles, taking into account the heterogeneity of their elementary composition, this one being related to their residence time in the atmosphere and the distance between the sources and the studied receptor site. To do that, it was firstly necessary to develop a time resolved cascade impactor with high temporal resolution, named "TRAPS", which answered the need to follow the rapid changes observed within the atmospheric particles during pollution episodes. Coupled with a particle size analyser and after individual analysis of the collected particles by electron microscopy (SEM-EDX), TRAPS allows to report the physicochemical evolution of atmospheric particles over time. In the first part of this thesis, laboratory experiments and a field campaign allowed to validate our prototype, to report the dynamics of particle deposition on the impaction stages and to verify the cut-off diameters of the coarse and fine stages of TRAPS, determined respectively at 1.32µm and 0.13µm. A statistical study of PM₁₀ pollution episodes occuring over the GDA was then carried out over 3 years, between 2018 and 2020. It allowed us to identify 12 main types of episodes based on their spatial extent, but also on the local conditions of pollutant dispersion. We were able to identify local episodes and regional episodes observed, either in stationary or dispersive atmospheric conditions. While 78% of the PM₁₀ exceedance days correspond to local episodes, the remaining 22% correspond to pollution plumes with at least a regional extent, with an equal proportion of exceedance days in dispersion and stationary conditions. Except for very localized episodes, a detailed study of these pollutions episodes shows the systematic presence of a period of pollutant accumulation, of about 10 hours, characterized by an important contribution of fine particles (PM₂.₅) except for episodes of limited spatial coverage. The last part of this work consisted in the study of the composition and mixing state of the individual particles collected during pollution events in the GDA in 2021. The campaign allowed the sampling and characterization of 5 pollution episodes, during which TRAPS was deployed in parallel with other instruments providing complementary information on aerosol granulometry, or atmospheric dynamics. Nearly 28000 individual particles were characterized by SEM-EDX. With more than 90% of the samples associated with values of the mixing state index higher than 0.5, it can be said that the particles collected in the GDA during pollution episodes are in general of very heterogeneous composition at the particle scale (internal mixing). Nevertheless, the results show an influence of the local or transported origin of the particles on their chemical composition, but also on the mixing state index. An increasing evolution of this index with the particles residence time during these events is observed
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Diaz, Gerardo Jr. "Analysis of 2017 Multi-Agency Field Campaign Data for Wintertime Surface Pollution in the Cache Valley of Utah." TopSCHOLAR®, 2019. https://digitalcommons.wku.edu/theses/3112.
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Atmospheric motions resulting from rising airborne parcels help to scatter emissions, including PM, away from their sources, decreasing local pollution levels. However this pattern shifts during the wintertime, as cold air damming and inversion layers create stable conditions that limit the vertical transport of air masses. Both point and area sources of emissions currently dot the western United States and are responsible for the production of the vast majority of agricultural pollution in the region. At the same time, population-growth has resulted in an ever-increasing amount of urbansource emissions. The entrapment of PM, which are produced when a wide array of urban and agricultural emissions series are released onto a valley floor, aggregate until they become singular particles which vary in size and can negatively affect the human respiratory system. As such, this goal of this study was to investigate the processes that lead to poor wintertime air quality conditions in the Mountain West and primarily in Cache Valley, which experiences some of the worst air quality in the United States during the winter season. Several results, including the observation of chemical reactions such as the production of the NO3 radical, along with the discovery of significantly high levels of DMS in an area that is not known for its production, all suggest that the chemical behaviors of Cache Valley are rather complex and play a critical role in poor wintertime air quality conditions. Furthermore, the presence of DMS at such high concentrations could be due to its being produced on the valley floor. As such, we hope that these results will help in improving our understanding of the physical and chemical dynamics of the Valley during the winter season, which will in turn aid in our ability to forecast such conditions and also properly plan future industrial and commercial projects that will inevitably be introduced into the region as it continues to grow.
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Avenas, Arthur. "Qualitative analysis of a regional public policy for air quality : A case study of Normandie, France." Thesis, KTH, Hållbar utveckling, miljövetenskap och teknik, 2021. http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-292693.
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Today, outdoor air quality occupies an important place into civic dialogue because of the many impacts of atmospheric pollution on health. Different legislations and strategies have thus been implemented across the world to improve outdoor air quality. Analysing and comparing the different strategies can help adopting the best practices in favour of air quality. In France, in particular, the national air quality policy is reflected at a regional scale through legislative documents called Atmosphere Protection Plans (PPAs). The analysis of such a document thus represents a powerful way to assess a regional air quality policy. Here, Normandie’s PPA has been analysed through a literature review, working meetings as well as qualitative interviews. The study highlighted that Normandie’s air quality policy had to answer a complex legislative ecosystem of international, national and local documents. The analysis also underlined that the questions of the perimeter of action of the policy and the targeted pollutants were as central as the measures implemented to improve air quality. The working meetings and the qualitative interviews led to consensus that Normandie’s air quality policy should target 3 atmospheric pollutants: nitrogen dioxide, particulate matter 10 and particulate matter 2.5. If road traffic has been identified as the major emitting source of the first, particulate matter emitting sources were pointed as varied and multi-sectoral. Finally, some measures of Normandie’s air quality policy appeared to be particularly efficient and advanced, such as agricultural measures. Yet, many difficulties were encountered when implementing several measures of the policy. The main difficulties were the lack of financial resources, the lack of project leader and the lack of technical expertise. More than a basic analysis of an air quality public policy, these results can also be perceived as a sharing of experience on how a region addresses air quality issues. Because a work of collection of best practices and best strategies to improve air quality is more than ever needed, further research can build on this study to elaborate a relevant air quality policy.Luftkvaliteten visar den antropogena nedbrytningen av det naturliga tillståndet för luft. Detta ämne har spelat en allt viktigare roll i den offentliga debatten under de senaste decennierna, på grund av de olika effekterna som luftföroreningar har på hälsan. I denna masteruppsats har Normandies politik för luftkvalitet analyserats. I Frankrike regleras nationell luftkvalitetspolitik i regional skala genom lagstiftningsdokument som kallas Atmosphere Protection Plan (PPA). Analysen av detta dokument gör det möjligt att bedöma den regionala luftkvalitetspolitiken. Således har hela studien baserats på analysen av Normandies PPA. Här har Normandies PPA analyserats genom litteraturöversikt, arbetsmöten och kvalitativa intervjuer. Först och främst belyste litteraturöversikten att Normandies PPA måste ta hänsyn till ett komplext lagstiftningsekosystem, allt från internationell till lokal skala. I synnerhet är Normandies PPA-huvudmål att uppnå de tröskelvärden som definieras av de europeiska direktiven. I ett andra steg tillät en granskning av PPA från sex franska regioner att jämföra Normandies luftkvalitetspolitik med andra regioners politik. Under denna fas har såväl strukturer dokumenterats som de presenterade åtgärderna utvärderats med avseende på strukturerna och åtgärderna för de andra PPA. I synnerhet har återkommande kategorier och underavsnitt identifierats i de sex PPA. Dessutom tycktes motiveringen av applikationomkrets vara central, liksom de riktade atmosfäriska föroreningarna. På samma sätt tillät jämförelsen av åtgärderna för de sex PPA att identifiera de relevanta och banbrytande åtgärderna i Normandies PPA, som tillhör hamnsektorn och de sektorsövergripande åtgärderna. Omvänt verkade åtgärderna av Normandies PPA vara otillfredsställande inom industri- och transportsektorn. En mer fördjupad analys genomfördes genom arbetsmöten och kvalitativa intervjuer. Flera frågor har bedömts, till exempel applikationomkrets och PPAs struktur. I synnerhet har man dragit slutsatsen att minskningen av applikationomkretsen som Normandie avsåg var relevant och förhindrade PPAs komplikationer. Dessutom påpekade deltagarna att om Normandies PPA-struktur var ganska tydlig, saknades fortfarande viktiga underavsnitt i Normandies PPA och de bör läggas till. Arbetsmötena liksom de kvalitativa intervjuerna gjorde det också möjligt att ta upp frågan om de riktade föroreningarna och deras källor. Alla deltagare och intervjuade gick med på att rikta in NO2, PM10 och PM2.5 i Normandies PPA. Integrationen av SO2 och O3 har dock diskuterats mer, den första har endast släppts ut i skadlig mängd under industriella olyckor, och den andra var för svår att hantera eftersom den är en sekundär förorening. När det gäller utsläppskällorna visade studien att en hög atmosfärisk koncentration av NO2 främst berodde på vägtrafik. Utsläppskällorna PM10 och PM2.5 identifierades som mer varierade och flersektoriella. Slutligen tillät de kvalitativa intervjuerna att avgöra vilka åtgärder av Normandies PPA som har slutförts eller inte, och att identifiera varför. Åtgärder inom jordbrukssektorn nämndes som de mest avancerade åtgärderna i Normandies PPA. Omvänt har två åtgärder övergivits helt, en inom hamnsektorn, den andra inom transportsektorn. Några skäl som förklarade varför alla åtgärder inte har genomförts var bristen på ekonomiska resurser, bristen på projektledare och bristen på teknisk expertis. Mer allmänt verkar det vara avgörande att involvera de olika intressenterna från varje utsläppssektor och sätta dem runt ett bord för att skapa effektiva åtgärder till förmån för luftkvaliteten.
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Campbell, Steven John. "Novel methods to characterise atmospherically relevant organic radicals and reactive oxygen species." Thesis, University of Cambridge, 2018. https://www.repository.cam.ac.uk/handle/1810/274099.
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A key reaction in the troposphere involves the oxidation of biogenic and anthropogenic alkenes with ozone, which contributes to local photochemical smog. It is generally accepted that this reaction proceeds via a reactive intermediate often called the Criegee intermediate (CI). This reaction is known to produce a plethora of oxidised organic compounds, which contribute to ozone formation and secondary organic aerosol production, two of the main characteristics of a polluted atmosphere. Furthermore, epidemiological studies have shown a close correlation between exposure to ambient organic aerosol and adverse human health effects. The toxicological mechanisms leading to this observation are still poorly characterised, although studies suggest that reactive oxygen species present in organic aerosol are a major contributor. Reactive oxygen species and reactive intermediates represent a large uncertainty in tropospheric chemistry, and pose an analytical challenge due to their high reactivity and typically low concentrations. This emphasises the need for the development of new methods to characterise the chemistry of these species. In this thesis, several novel laboratory based techniques have been developed in order to characterise and quantify reactive intermediates and reactive oxygen species. New methods to facilitate the detection of CIs in both the gas and particle phase are presented. Spin trap molecules are used to scavenge CIs to form stable 1:1 adducts which are subsequently detected and quantified using mass spectrometry. The chemistry of CIs with spin traps is extensively investigated. The unique capability of this technique to simultaneously characterise multiple CIs generated from a variety of atmospherically relevant organic precursors in the gas phase is demonstrated. This technique was further developed to facilitate the detection of CIs in secondary organic aerosol, representing the development of a method capable of characterising low volatility CIs and other reactive intermediates in the condensed phase. Furthermore, two new chemical fluorescence assays have been developed to quantify both organic radicals and reactive oxygen species in organic aerosol. A novel profluorescent spin trap assay was applied to quantify radical concentrations in organic aerosol. A series of experiments were then devised to investigate the lifetime of organic radicals in secondary organic aerosol. A second assay, based on physiologically relevant ascorbic acid chemistry, was also developed to measure the concentrations of toxicologically relevant reactive oxygen species in secondary organic aerosol. The quantitative capability of this assay was extensively characterised. The assay was incorporated into a prototype instrument capable of measuring particle-bound reactive oxygen species on-line, and the assays’ sensitivity to secondary organic aerosol was demonstrated.
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Souza, Edmilson de. "Inventário de emissões atmosféricas e avaliação de condicionantes meteorológicas: estudo de caso de Três Lagoas." Universidade de São Paulo, 2009. http://www.teses.usp.br/teses/disponiveis/18/18147/tde-13012011-154040/.
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Desde a década de 1930 distintos estudos têm fortemente aumentado o conhecimento acerca da atmosfera da Terra. De fato, nos últimos trinta anos, devido ao intenso avanço científico e tecnológico um progresso real ocorreu nesta área; incluindo os efeitos da poluição do ar. No entanto, os efeitos da poluição do ar, principalmente em regiões urbanas, ainda exigem uma melhor compreensão. No Brasil, grandes áreas metropolitanas como as cidades de São Paulo e Rio de Janeiro possuem significativas pesquisas sobre a atmosfera local; elas estão entre as regiões onde a qualidade do ar é mais bem monitorada no país. Por outro lado, em algumas regiões como o centro-oeste brasileiro, tais estudos são modestos ou mesmo inexistentes. Devido a fatores geográficos e econômicos, algumas regiões do país como a cidade de Três Lagoas (20 \'GRAUS\' 47\' S, 51 \'GRAUS\' 42\' W), leste do Estado de Mato Grosso do Sul, passa por relevantes transformações nos últimos dez anos. Fontes potenciais de poluição do ar e/ou seus precursores surgem através da instalação de novas indústrias (incluindo uma termoelétrica de 240 MW), crescimento da frota veicular, extensas áreas de plantio de floresta de eucalipto para uso industrial (hidrocarbonetos biogênicos), um grande reservatório de hidroelétrica (emissão de metano) e ocorrências sazonais de queimadas. Os resultados obtidos foram organizados em inventários de emissões atmosféricas. Também foram analisadas as concentrações de poluentes e parâmetros meteorológicos. Entre as fontes analisadas, a frota veicular foi considerada a majoritária, sendo responsável por 97% da descarga de monóxido de carbono e cerca de 53% dos óxidos de nitrogênio na atmosfera local. Para os gases poluentes monitorados, as concentrações médias, no período analisado (2005 e 2006), medidos em ppbv foram: \'O IND.3\' = 25 \'+ OU -\' 14,4, NOx = 9,4 \'+ OU -\' 6,6 e \'CO\' = 166,5 \'+ OU -\' 49,8. Outros resultados confirmam a correlação estatística entre parâmetros meteorológicos e a concentração de poluentes. O ozônio, durante setembro/2005, apresentou forte correlação linear com a temperatura (0,76) e média com a radiação solar (0,58). A análise do transporte de hidrocarbonetos biogênicos (floresta de eucalipto) e da pluma de NOx (usina termoelétrica) indica uma participação secundária dessas fontes. De fato, os resultados indicam que os níveis da qualidade do ar de Três Lagoas atendem à legislação vigente no país.Since the 1930\'s, several studies have strongly increased the knowledge about the Earth atmosphere. Indeed, in the last thirty years, due to intense scientific and technologic improvements a real progress happened in this area; including the effects of air pollution. However, the effects of air pollution, mainly around urban zones, still require a better understanding. In Brazil, large metropolitan areas like São Paulo and Rio de Janeiro already have a good deal of research on their local atmosphere; they are among the regions where air quality is better monitored in country. On other places, like brazilian mid-west, such studies are modest or inexistent. Due to factors as geographical and economical, some regions of the country as the city of Três Lagoas (20 \'GRAUS\' 47\' S, 51 \'GRAUS\' 42\' W), east of Mato Grosso do Sul state, undergone strong transformations in the last ten years. Potential sources of air pollutants and/or its precursors began to show up, brought by the installation of new industries (including a 240MW power-plant), increase of the vehicle fleet, extensive conifer plantation for industrial use (biogenic hydrocarbons), a large hydropower reservoir (methane) and the seasonal occurrence of vegetation burning. The research results were organized on atmospheric emissions inventories. It was also analyzed the pollutants concentrations and meteorological parameters. Among the emissions sources, the vehicle fleet turned to be the major source. It is responsable for 97% of carbon monoxide and 53% of nitrogen oxides of the total mass of pollutants released into local atmosphere. Concerning to the pollutants gases monitored, the mean concentrations, in the analyzed period (2005 and 2006), was measured in ppbv: \'O IND.3\' = 25 \'+ OU -\' 14,4, NOx = 9,4 \'+ OU -\' 6,6 e \'CO\' = 166,5 \'+ OU -\' 49,8. Statistical correlation between meteorological parameters and the pollutants concentration was also confirmed by others research results. The ozone, during September/2005, showed strong linear correlation with temperature (0,76) and moderate to solar radiation (0,58). The transport analyze of biogenic hidrocarbon (eucalyptus forest) and NOx (thermopower plant) plume points to a supporting role of this sources. Indeed, the results proved that the air quality levels of Três Lagoas city is in accordance with the current country legislation.
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Acosta, Navarro Juan Camilo. "Anthropogenic influence on climate through changes in aerosol emissions from air pollution and land use change." Doctoral thesis, Stockholms universitet, Institutionen för miljövetenskap och analytisk kemi, 2017. http://urn.kb.se/resolve?urn=urn:nbn:se:su:diva-137077.
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Particulate matter suspended in air (i.e. aerosol particles) exerts a substantial influence on the climate of our planet and is responsible for causing severe public health problems in many regions across the globe. Human activities have altered the natural and anthropogenic emissions of aerosol particles through direct emissions or indirectly by modifying natural sources. The climate effects of the latter have been largely overlooked. Humans have dramatically altered the land surface of the planet causing changes in natural aerosol emissions from vegetated areas. Regulation on anthropogenic and natural aerosol emissions have the potential to affect the climate on regional to global scales. Furthermore, the regional climate effects of aerosol particles could potentially be very different than the ones caused by other climate forcers (e.g. well mixed greenhouse gases). The main objective of this work was to investigate the climatic effects of land use and air pollution via aerosol changes. Using numerical model simulations it was found that land use changes in the past millennium have likely caused a positive radiative forcing via aerosol climate interactions. The forcing is an order of magnitude smaller and has an opposite sign than the radiative forcing caused by direct aerosol emissions changes from other human activities. The results also indicate that future reductions of fossil fuel aerosols via air quality regulations may lead to an additional warming of the planet by mid-21st century and could also cause an important Arctic amplification of the warming. In addition, the mean position of the intertropical convergence zone and the Asian monsoon appear to be sensitive to aerosol emission reductions from air quality regulations. For these reasons, climate mitigation policies should take into consideration aerosol air pollution, which has not received sufficient attention in the past.
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Arasa, Agudo Raúl. "Modelització i simulació fotoquímica mesoscalar del transport del material particulat i gasos a l’atmosfera." Doctoral thesis, Universitat de Barcelona, 2011. http://hdl.handle.net/10803/83297.
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Durant les últimes dècades la quantitat de gasos i partícules contaminants que s’han injectat a l’atmosfera ha augmentat considerablement. Evidència d’aquesta informació són les elevades concentracions de diòxid de nitrogen o partícules amb una grandària inferior a 10µm (PM10) que es mesuren habitualment en zones urbanes i industrials, o les també altes concentracions d’ozó en moltes zones rurals situades a sobrevent de zones urbanes o industrials, on les concentracions dels seus precursors, fonamentalment òxids de nitrogen, són molt baixes en condicions normals.
Paral•lelament però, a l’augment de la concentració de contaminats, s’ha potenciat de forma considerable la sensibilització de la població i de l’administració a la qualitat de l’aire que respirem. D’aquesta manera és ja una necessitat en els països desenvolupats el poder disposar d’eines de control, gestió i avaluació de la contaminació atmosfèrica. Aquest fet ha impulsat que en els darrers anys s’hagin produït importants avenços en els sistemes per a la modelització de la qualitat de l’aire fins a esdevenir eines de gestió i pronòstic ambiental que ofereixen resultats força precisos. A més, la modelització de la qualitat de l’aire s’ha convertit en una eina totalment necessària per poder conèixer els nivells d’immissió a zones on no es disposa d’estacions de mesura i per poder crear plans d’actuació per tal de poder combatre nivells elevats dels diversos contaminants.
És per aquest motiu que en aquesta tesi doctoral es descriu la recerca i el desenvolupament d’un sistema de modelització de la qualitat de l’aire. S’ha utilitzat com a punt de partida els treballs anteriors, i es descriu l’acoblament dels diferents models que el componen. Els models són adaptats a la zona d’estudi mitjançant l’ajust de diversos paràmetres i són utilitzats de forma depenent entre ells. L’avaluació estadística dels pronòstics del sistema s’utilitza com el camí per a la localització d’incerteses i posterior refinament del model. Aquest procés d’acoblament i execució del sistema per períodes llargs de temps, validació dels resultats, localització d’incerteses i anàlisi de sensibilitat, esdevé un procés continu i cíclic durant la tasca de recerca del doctorand, fins a obtenir resultats dels paràmetres estadístics dins de les recomanacions de la comunitat científica i acomplint els requeriments de la legislació per a la utilització operativa del sistema.
Degut a la problemàtica comentada en l’apartat anterior, cada vegada són més els estudis que es realitzen per investigar iniciatives de reducció de la contaminació atmosfèrica i per implementar models de pronòstic de qualitat de l’aire. És per aquests motius que l’objectiu final i fonamental d’aquesta tesi ha estat implementar un sistema de pronòstic de la qualitat sobre l’àrea d’interès que sigui actual, àgil i efectiu.
Assolir aquest ambiciós objectiu ha suposat per al doctorand anar assolint reptes i metes durant la fase de recerca.
El document s’estructura en deu capítols diferents, incloent la introducció i la bibliografia.During the last decades the amount of gaseous and particulate pollutants that have been injected into the atmosphere has increased significantly. Evidence of this information is the high concentration of NO2 and aerosols that are usually measured in urban and industrial areas, or high concentrations of ozone in many rural areas. Parallel to this increase in concentration of pollutants, has been enhanced significantly the sensibility and management to the air quality. Thus it is necessary now in developed countries have the tools to control, management and evaluation of air pollution. In this way, the modelling of air quality is absolutely necessary to know the levels of gases and aerosols in areas where there are not measurement stations, and also to combat high levels of these pollutants. The photochemical models are tools of environmental management and forecasting that in recent years have been refined to provide quite accurate results. We need to adapt the models to each area by adjusting parameters and the study of characteristics of pollution episodes. For this reason, this doctoral thesis describes research and development of a air quality modelling system. We have been used as a starting point the previous work and we describe the coupling of different models. The models are adapted to the area of interest by setting different parameters and are used in a dependent relationship between them. The statistical evaluation of the forecasting system is used as a way to locate uncertain and further refinement of the model. This process of engagement and implementing the system for long periods of time, validation of results, location of uncertainties and sensitivity analysis is an ongoing, cyclical during the doctoral research.
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Thomason, Krista A. "Trends Analysis and a Yearly Comparison of Point Sources of Atmospheric Mercury Using HYSPLIT Back Trajectories Focused in Athens, Ohio." Ohio University / OhioLINK, 2019. http://rave.ohiolink.edu/etdc/view?acc_num=ohiou1557161272706908.
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Brines, Pérez Mariola. "From ultrafine to coarse particles: variability and source apportionment of atmospheric aerosol levels in the urban Mediterranean climate." Doctoral thesis, Universitat de Barcelona, 2015. http://hdl.handle.net/10803/384537.
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Air pollution is a major environmental and public health concern, especially in urban areas where both emission sources and population are concentrated. The pollution sources and the evolution of aerosols and gaseous pollutants once emitted into the atmosphere depend on geographical, climatological and meteorological conditions of the study area. In the Western Mediterranean Basin, the coastal city of Barcelona (Spain) is characterized by a warm dry climate, scarce precipitation and high urban density, as well as being geographically constrained by the coastal range thus hindering the dispersion of pollutants.
Within this context, the intensive SAPUSS (Solving Aerosol Problems by Using Synergistic Strategies) campaign developed in October 2010 in Barcelona consisted on concurrent aerosol measurements at different sites in the city region, with the aim of studying the aerosol temporal variability and spatial distribution, progressively moving away from urban aerosol sources. Several sites were selected: Road Site (RS) and Urban Background (UB) were located on ground levels, whereas Torre Mapfre (TM) and Torre Collserola (TC), representative of the urban/suburban environment were located at certain height (150 m a.s.l. and 415 m a.s.I., respectively). Finally, the Regional Background site (RB) located 50 km from the city allowed for the study of the transport of urban emissions outside the city.
Results from simultaneous measurements of aerosol size distributions at the RS, UB, TC and RB with a Scanning Mobility Particle Sizer (SMPS) were studied after performing a k-means cluster analysis on the combined data sets. This allowed the classification of all size distributions in 9 clusters: three clusters account for traffic conditions (30% of the time), three account for background pollution (54%) and three described specific special cases (16%). Traffic emissions heavily impact the closest sites, and some of these particles evaporate when the air mass move away from the traffic hot spots.
The analysis of long term SMPS data sets in the high insolation urban environments of Barcelona, Madrid, Brisbane, Rome and Los Angeles also by k-means clustering analysis revealed traffic and nucleation events as the two most relevant sources of ultrafine particles (44-63% and 14-19% of the time, respectively). Moreover, nucleation particles accounted for 21% of total N, evidencing the importance of nucleation processes to ultrafine particles concentrations in high insolation urban areas. The urban nucleation events consist on particles bursts starting around midday and lasting 3-4 hours while growing to 20-40 nm, opposite to regional nucleation “banana shape” events which usually grow to larger sizes.
Regarding the composition of the PM1 fraction (PM mass levels below 1 μm) at the RS and UB during SAPUSS, a source apportionment PMF analysis was carried out. The resulting 9 factors could be broadly grouped in the following categories: road traffic (23-36% of PM1 mass), industrial and shipping emissions (42%), secondary aerosols (29%) and biomass burning (1%). The joint analysis of organic and inorganic species was able to identify a high number of sources resulting in in a more complete and realistic study of the aerosol sources in Barcelona.
The study of the PM10 fraction (PM mass levels below 10 μm) at the RS, UB, TM and TC during SAPUSS by means of a PMF source apportionment study enabled the assessment of the spatial variability in vertical and horizontal levels. The 8 resulting factors accounted for primary traffic emissions (Exhaust and wear and Road dust, 19- 38% of PM10 mass), primary inorganic aerosols (Mineral dust and Aged marine, 28- 39%), industry (Heavy oil and Industrial, 5-7%) and secondary aerosols (Sulphate and Nitrate,28-36%). The main factors influencing the different sources concentration at each site were: proximity to the emission source, air mass origin and meteorological parameters.
The complete study of aerosol fractions affecting the urban area of Barcelona and similar urban environments (Madrid, Brisbane, Roma and Los Angeles), from ultrafine to coarse particles, enables the identification of the main sources affecting each size fraction in particular and aerosols in general. Owing to the results obtained and the different techniques applied, recommendations regarding air pollution studies and air quality measures have been proposed.La contaminació atmosfèrica en ambients urbans és motiu de preocupació pel seu impacte en el medi ambient i en la salut de la població. Les fonts d'emissió d'aerosols atmosfèrics i la seva evolució a l'atmosfera depenen de factors geogràfics així com de les condicions climàtiques i meteorològiques de l'àrea d'estudi. A la conca Mediterrània Occidental, i a la ciutat de Barcelona en particular, el clima càlid, l'escassa precipitació, l'alta densitat de població i determinats factors geogràfics que poden dificultar la dispersió dels contaminants i influenciar molt marcadament els nivells i composició dels aerosols. En aquest context es va desenvolupar la campanya intensiva SAPUSS (Solving Aerosol Problems by Using Synergistic Strategies) a Barcelona a l'octubre de 2010, que consistia en mesures simultànies d'aerosols a diversos llocs de la ciutat, amb l'objectiu d'estudiar la variabilitat espacial i temporal dels aerosols. L'estudi dels nivells d'aerosols en funció de la mida de les partícules a 4 ciutats més amb un clima d'alta insolació similar al de Barcelona (Madrid, Brisbane, Roma i Los Angeles) ha permès avaluar les fonts que afecten a la variabilitat de partícules ultrafines en aquests ambients urbans. En particular s'han estudiat les característiques dels episodis de nucleació urbans (formació de noves partícules), així com la seva freqüència. També s'han caracteritzat les principals fonts d'aerosols de diàmetre inferior a 1µm i 10 iim (PM1 i PM10, respectivament) en diverses ambients urbans de Barcelona durant SAPUSS. Això ha permès estudiar la variabilitat a nivells horitzontal i vertical dins l'atmosfera urbana. L'estudi de les fonts que afecten els aerosols de l' àrea urbana de Barcelona i ambients similars en funció de la seua mida (des de les ultrafines fins a les grolleres) ha permès identificar les principals fonts que afecten a cada fracció en particular i als aerosols en general i per tant proposar mesures aplicables per a l'avaluació i millora de la qualitat de l'aire.
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Ferrari, Christophe. "Mise en évidence de composés organiques volatils provenant de la combustion d'un biocarburant, le diester : mesure des constantes de photodégradation de composés spécifiques émis." Université Joseph Fourier (Grenoble ; 1971-2015), 1995. http://www.theses.fr/1995GRE10195.
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La deterioration de la qualite de l'air est attribuee a un accroissement des emissions des sources mobiles. L'utilisation de nouveaux carburants d'origine vegetale est testee sur les flottes de transports en commun afin de reduire ces emissions polluantes. Une comparaison des emissions entre d'une part le gazole et d'autre part un melange compose de gazole et d'esters methyliques provenant de l'huile de colza est realisee. Cette comparaison a porte sur les composes organiques volatils types alcanes, alcenes, alcynes, aromatiques, sur les aldehydes ainsi que sur les hydrocarbures aromatiques polycycliques et les particules. A cette occasion, il a ete mis en evidence des molecules specifiquement emises par ce biocarburant. Ces dernieres sont des esters methyliques a courtes chaines (de trois a six atomes de carbone). Ces composes ont fait l'objet d'etudes sur leurs interactions avec le radical hydroxyle. Leurs temps de vie dans la troposphere ont ete determines
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Silva, Moacir Ferreira da. "Reatividade fotoquímica da atmosfera de Cubatão e a influência de fontes exógenas." Universidade de São Paulo, 2013. http://www.teses.usp.br/teses/disponiveis/6/6134/tde-02042013-111100/.
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Objetivo. Demonstrar que a ocorrência de episódios críticos de poluição por ozônio na região de Cubatão-Centro é influenciada pelo aporte externo de poluentes, que participam dos processos físico-químicos de formação e remoção de reagentes fotoquímicos na atmosfera. Métodos. O estudo envolveu a obtenção e o tratamento de dados meteorológicos e de concentrações de poluentes fornecidos pela rede de monitoramento da qualidade do ar, bem como a realização de campanhas de amostragem passiva de ozônio (O ) e ativa de COVs, aldeídos e etanol na atmosfera da região. A amostragem de O VI 3 foi realizada com amostradores tipo Ogawa® e as concentrações foram determinadas por cromatografia iônica, com detecção por condutividade elétrica. Na amostragem de COVs foram utilizados tubos de aço contendo o adsorvente Tenax-GR, e a quantificação das amostras foi realizada por cromatografia gasosa e espectrometria de massas. A amostragem de aldeídos foi realizada com cartuchos de sílica gel revestido com 2,4 DNPH, e a quantificação realizada por cromatografia liquida de alta performance, com detector ultravioleta (UV/VIS). A amostragem de etanol foi realizada com cartuchos revestidos de florisil, e a quantificação realizada por flame ionization detector. O transporte de massas de ar foi analisado com base em backward trajectories, calculadas pelo modelo STILT. A interpretação dos dados foi realizada por estatística descritiva, boxplot, análise de correlação e análise multivariada (clusters). Resultados. A maioria dos episódios de ultrapassagem do PQAr de ozônio ocorreu no verão, entre 15h e 16h, com ventos predominantes de S/SE e velocidades superiores a 2,5m/s, típicos de períodos diurnos (brisa marítima). As espécies orgânicas precursoras de ozônio mais importantes foram: formaldeído, acetaldeído, tolueno, 1,2,3-trimetilbenzeno, m-xileno, etanol, oxileno, etilbenzeno, 1,3,5-trimetilbenzeno e benzeno. A retrotrajetória das massas de ar que chegam à Cubatão-Centro comprovou a influência de emissões exógenas. Os resultados obtidos na circulação de mesoescala, simulada pelo modelo BRAMS, concordam com os resultados obtidos por JAESCHKE (1997), onde apenas uma parcela da concentração média de poluentes de Cubatão-Centro era oriunda de fontes locais, sendo o restante decorrente do transporte de massas, com ocorrência de elevadas concentrações de poluentes com fluxo de direção norte-noedeste (brisa terrestre) e sul-sudeste (brisa marítima)Objective. Demonstrate that critical episode occurrences of air pollution are influenced by external input of pollutants that participate in the processes of atmospheric photochemical reagent formation and removal. Methods. The study involved meteorological data collection and processing of pollutant concentration data gathered by the air quality monitoring network. Campaigns of passive sampling of O and active sampling of VOCs, aldehydes and ethanol in the atmosphere of the region were also performed. The O 3 sampling was conducted with the Ogawa ® type samplers and the concentrations were determined by ion chromatography with electrical conductivity detector. VOCs sampling was performed using steel tubes containing Tenax GR adsorbent, and quantification was done by gas chromatography and mass spectrometry. Aldehyde sampling was performed with silica gel cartridges coated with 2,4 DNPH and quantification done by High Performance Liquid Chromatography (HPLC) with ultraviolet detector (UV / VIS). Ethanol sampling was performed with florisil coated cartridges and quantification by flame ionization detector. The transport of air masses was analyzed based on Backward trajectories calculated by the model STILT. Interpretation of the data was performed using descriptive statistics, boxplots, correlation analysis and multivariate analysis (clusters). Results. Most episodes of Ozone exceeding Air Quality Standards occurred in the summer, between 15h and 16h, with prevailing winds from S / SE and with velocities greater than 2.5 ms -1 , typical of day periods (sea breeze). Major ozone precursor organic species are: formaldehyde, acetaldehyde, toluene, 1,2,3-trimethylbenzene, m-xylene, ethanol, xylene, ethylbenzene, 1,3,5trimethylbenzene and benzene. The retro trajectory of air masses arriving at Cubatão-Center proved the influence of exogenous emissions. Results in the mesoscale circulation given by model simulation by BRAMS, agree with the results obtained by JAESCHKE (1997), showing that only a portion of the average concentration of pollutants Cubatão-Centro was due to local sources, with the rest resulting from the transport of masses, with the occurrence of high concentrations of pollutants resulting when flow directions are from NW (land breeze) and SE (sea breeze).
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Siqueira, Ligia Cristina Gonçalves de. "Avaliação do impacto das emissões de metais geradas no coprocessamento de resíduos em fábricas de cimento." Universidade de São Paulo, 2005. http://www.teses.usp.br/teses/disponiveis/6/6134/tde-10092008-144735/.
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Objetivo. Desenvolver um procedimento para a estimativa das emissões de metais resultantes do coprocessamento em fábricas de cimento para avaliação do seu impacto na atmosfera. Metodologia. Foram pesquisados os tipos de processo de produção de clínquer e a origem dos metais no sistema. Os teores de metais das correntes de entrada e saída do processo foram determinados por meio de coleta e análise de amostras das mesmas. Com esses dados foi realizado um balanço de massa para determinar a distribuição (%) dos metais, baseada na retenção em cada corrente. Depois foi realizada a estimativa das emissões de cada elemento, para comparação com padrões de emissão. As emissões estimadas e dados meteorológicos e topográficos, aplicados num modelo de dispersão atmosférica, permitiram a predição das concentrações de metais na atmosfera para avaliação de impactos. Foi realizado um estudo de caso com dados secundários para a aplicação da metodologia proposta. Resultados. Para alguns metais as emissões estimadas ultrapassaram limites estabelecidos na legislação estadual e federal. Com a aplicação do modelo de dispersão, também houve ultrapassagem da concentração de referência de alguns metais na atmosfera. Conclusão. O procedimento proposto foi válido para a estimativa das emissões e para avaliação do impacto da concentração de metais na atmosfera. Para melhor análise dos resultados, recomenda-se o desenvolvimento de Padrões de Qualidade do Ar para metais adequado à realidade brasileira ou procedimentos para análise de risco atmosférico no caso de metais tóxicos. Os resultados de impacto são válidos nas condições do estudo de caso e necessitariam ser verificados caso a casoObjective. Develop a procedure to estimate metal emissions into the atmosphere, resulting from cement mill coprocessing, in order to evaluate their impact in the atmosphere. Methodology. Clinker production process types, and metal origin in the system were researched. Process material input, and output flow metal contents were determined by collecting, and analyzing samples obtained from them. With these data we calculated a mass balance to obtain each element\'s distribution (%), based on metal retention of each flow. Thus, each element\'s emission estimate was achieved, to be compared with emission standards. The estimated emissions, together with meteorological, and topographical data, applied to a model of atmospheric dispersion, permitted the forecasting of metal concentrations in the atmosphere, to asses their impacts. A case study with secondary data was performed to apply the proposed methodology. Results. For some metals, the estimated emissions would not comply with limits established in state, or federal legislation. Applying the dispersion model, we observed that some metals exceeded their reference atmospheric concentration in the atmosphere. Conclusion. The proposed procedure was valid to estimate emissions, and to asses metal concentration impact in the atmosphere. For a better analysis of the results, we recommend the development of Air Quality Standards for metals, appropriate to Brazilian reality, or of procedures to analyze atmospheric risk in the case of toxic metals. The results of the impact are valid in the case study conditions, and need to be checked case by case.
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Fraigneau, Yann. "Etudes numériques de l'évolution diurne de l'ozone dans la région d'une agglomération." Rouen, 1996. http://www.theses.fr/1996ROUES063.
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Des études de scénarios ont été réalisées par simulations numériques sur l'évolution diurne de l'ozone dans la région d'une agglomération. L'objectif de ce travail a consisté à mettre en évidence les tendances exercées par quelques-uns des nombreux facteurs susceptibles d'influencer l'évolution des champs de concentration d'ozone au cours d'une journée, au niveau des localités se trouvant directement sous le vent d'une zone urbaine. Plus particulièrement, les études se sont portées sur les répercussions engendrées sur l'ozone par les variations que peut subir la couche limite atmosphérique dans son évolution journalière, sous l'influence de différents paramètres. Ces derniers sont : la stabilité thermique matinale, la hauteur initiale de la couche d'inversion synoptique, le gradient thermique de l'atmosphère libre et le phénomène d'évaporation. Les conséquences pouvant résulter d'une réduction exclusive des émissions urbaines d'oxyde d'azote ont aussi été examinées. Les simulations ont été effectuées pour des conditions météorologiques anticycloniques, typiques des périodes d'été, propices au développement de la pollution photo-oxydante. Parallèlement, des études numériques en situation de réacteur homogène fermé ont été réalisées afin d'analyser individuellement l'influence de certains paramètres sur l'évolution chimique de l'ozone. Ces paramètres sont : l'éclairement solaire, l'humidité, la température et le rapport des concentrations des composés organiques volatils et des oxydes d'azote. Enfin, des simulations numériques ont été entreprises afin de déterminer les effets du micromélange au voisinage d'un site urbain, c'est-à-dire sur l'impact des fluctuations de concentrations engendrées par la turbulence sur le taux de réaction moyen des espèces. Cette étude, à caractère fondamental, a été réalisée dans le cadre d'une couche limite atmosphérique considérée dans un état neutre et stationnaire. Les processus chimiques sont uniquement assimilés au cycle de Chapman, les espèces réactives prépondérantes au voisinage d'une zone urbaine étant les oxydes d'azote et l'ozone.
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Fujii, Reinaldo Keiji. "Avaliação da qualidade do ar em duas estações do metrô de São Paulo." Universidade de São Paulo, 2006. http://www.teses.usp.br/teses/disponiveis/6/6132/tde-15092011-112332/.
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Objetivo. Comparar a qualidade do ar externo com o ambiente interno das estações Clínicas e Praça da Sé do Metrô de São Paulo, quantificando e qualificando os contaminantes microbiológicos e atmosféricos. Propõe-se com este estudo promover o conhecimento de fatores sobre a qualidade do ar e das condições de higiene e saúde destes locais, contribuindo para a melhoria da qualidade de vida dos trabalhadores e usuários do sistema. Métodos. As amostras foram realizadas no período de Julho a Novembro de 2005. Os fungos foram coletados com o impactador de Andersen de um estágio com volume de aspiração de 28 l/min por um tempo de 10 minutos por amostra, e como meio de cultivo Agar Sabouraud Dextrose a 4 por cento . A quantificação e identificação foram feitas por meio de análises de lâminas do material microbiológico em microscópio óptico, coradas com azul de lactofenol. Para o dióxido de nitrogênio utilizou-se difusor passivo com trietanolamina como substância adsorvente e as análises foram realizadas por espectrofotometria. O difusor passivo para avaliação da concentração de benzeno é do tipo membrana, com carvão ativado como substância adsorvente e a análise por cromatografia gasosa. O tempo de exposição para estes amostradores foi de 30 dias. O PM10 foi medido com um monitor contínuo, com leitura direta. Foram instalados dois equipamentos em cada estação por um período de 7 dias. Resultados. Os estudos indicam a presença de fungos comuns com predominância para o Cladosporium sp (52 por cento ), Alternaria sp (17 por cento ) e Penicillium sp (13 por cento ) e em proporções semelhantes interna e externamente às estações. A concentração média de NO2 no interior das estações, foi de 73,9JPñ (VWHV YDORUHV Vão semelhantes às medições externas realizadas com o equipamento de Espectroscópia de Absorção por Diferencial Óptico (DOAS) e os valores medidos pela estação de monitoramento da CETESB, instalado na FSP/USP. Os valores viii máximos encontrados para o benzeno foram de 5,7JPñ QR LQWHULRU GDV estações e 6,2JPñQRDPELHQWHH[WHUQR230LQGLFRXYDORUHVHOHYDGRV sendo o valor médio, para a estação Clínicas de 312,4JPñ PHGLGRV QD SODWDIRUPDHJ/m³ no mezanino, na estação Praça da Sé verificamos a concentração de 150,9JPñ QD SODWDIRUPD GD OLQKD H JPñ QD plataforma da linha 3. Conclusões. O presente estudo possibilitou a avaliação e comparação dos níveis de poluição ambiental interno e externo às estações. A constatação da predominância de fungos comuns no ar não indica a ausência de riscos para a saúde humana, pois o seu impacto depende da suscetibilidade dos indivíduos expostos. A concentração de NO2 e benzeno encontradas no ambiente interno e externo são de mesma ordem de grandeza, o que indica que estes contaminantes têm a mesma fonte de origem. A alta concentração de PM10 representa uma maior preocupação. Para este contaminante deve-se avaliar a composição do material encontrado e seu grau de toxicidadeObjective. Compare the air quality outdoors with the indoors environment at Clínicas and Praça da Sé Stations of the São Paulo Subway, measuring the quantity and quality of the existing microbiological and atmospheric contaminants. The purpose of this study is to promote the knowledge of factors related to the air quality and the health and hygiene conditions in these places, contributing to the improvement of the quality of life of employees and users of the system. Methods. The samples were taken from July to November 2005. The fungi were taken by one-stage Andersen impactor with aspiration volume of 28 l/min for a period of 10 minutes per sample, making use of Agar Sabouraud Dextrose at 4 per cent for the culture. The quantification and identification are done by the analysis of slides with the microbiological material in an optical microscope, colored with lactofenol blue. For the nitrogen dioxide, a passive diffuser was used with triethanolamine as absorbing substance and the analysis was done by spectrophotometry, the passive diffuser used to evaluate the concentration of benzene is the membrane type with activated carbon as absorbing substance making use of gas chromatography analysis. The exposure period for these samplers was 30 days. The PM10 was measured with a continuous monitor, with direct reading. This equipment uses fibreoptic sensors for the identification of the size and concentration of the particles which are sucked by a diaphragm pump, passing through a measuring chamber which also measures the temperature and the air humidity. Two pieces of this equipment were installed in each station for a period of seven days. Results. The studies indicate the presence of ordinary fungi with the prevalence of Cladosporium sp (52 per cent ), Alternaria sp (17 per cent ) and Penicillium sp (13 per cent ) in similar proportions both indoors and outdoors. The indoor average concentration of NO2 was 69,5g/m³. These values are similar to the outdoor x results obtained with the equipment for Differential Optical Absorption Spectroscopy (DOAS) and the values measured by CETESB control station, located at FSP/USP. The values found for benzene ranged from 3,8 to 6,2g/m³, indicating an average of 5,0g/m³. The PM10 indicated high values with an average, at Clínicas Station, of 312,4 g/m³ measured in the platform and 243,9 g/m³ in the mezzanine. At Praça da Sé Station the concentration on the platforms was 150,9 g/m³ for line 1 and 124,2 g/m³ for line 3. Conclusions. The present study permitted the assessment and comparison of the environmental pollution levels inside and outside the stations. The verification of the predominance of common fungi in the air doesn\'t indicate the absence of risks for the human health, because it impact depends on the exposed individuals\' susceptibility. The concentration of NO2 and benzene found in the internal and external atmosphere are of same order of greatness, what indicates that these pollutants have the same origin source. The high concentration of PM10 represents a larger concern. This pollutant it should be evaluated the composition of the found material and his toxicity degree
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Oyama, Beatriz Sayuri. "Identificação de fontes de partículas finas na atmosfera urbana de São Paulo." Universidade de São Paulo, 2010. http://www.teses.usp.br/teses/disponiveis/14/14133/tde-22072013-104205/.
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Muitos estudos têm sido desenvolvidos com o intuito de descrever a química da fase gasosa na atmosfera da Região Metropolitana de São Paulo (RMSP). Contudo, o tratamento do material particulado (PM) ainda é feito de forma simplificada em modelos de transporte e químicos atmosféricos, apesar do grande conhecimento já adquirido na caracterização da sua composição elementar e da sua estrutura física. Tendo isso em vista, o objetivo do presente estudo é identificar as principais fontes emissoras do material particulado fino, em especial as fontes veiculares que apresentam muitas dificuldades para sua identificação por não haver medidas de traçadores específicos para os combustíveis utilizados. Neste trabalho foram realizadas amostragens, que duravam 24 horas, próximas a uma avenida de intenso tráfego (Avenida Dr. Arnaldo, na Faculdade de Medicina da Universidade de São Paulo) no período de junho de 2007 a agosto de 2008. Com os dados de composição dessas amostras, a identificação das possíveis fontes foi realizada por modelos receptores; mais especificamente foram utilizados: Análise de Fatores (AF) e Positive Matrix Factorization (PMF), uma nova ferramenta estatística, que ainda não havia sido aplicada no estudo do material particulado em São Paulo. O número de fontes identificadas por essas duas ferramentas estatísticas não foi o mesmo: na AF foram extraídos 4 fatores (solo, queima de óleo combustível e dois fatores que se dividiram, identificando a emissão de veículos leves e pesados não diferenciados), enquanto que o PMF identificou 6 (as mesmas fontes identificadas pela AF, com a diferenciação da emissão veicular (leves e pesados) e ainda a queima de biomassa). Houve concordância entre as duas análises que a maior participação para formação de material particulado fino é da emissão por veículos. A comparação entre os modelos mostrou que os resultados obtidos pelo PMF apresentaram uma melhor divisão das fontes, principalmente na identificação das frotas veiculares. Isso se deve ao fato do PMF considerar na análise o erro de cada concentração medida como um peso para cada variável, além de não permitir a ocorrência de fatores negativos, caracterizando melhor as fontes através da presença desses vínculos físicos.Several studies have been developed in order to describe the gaseous phase of atmospheric constituents in the Metropolitan Region of Sao Paulo (RMSP). However, the aerosol description remains simplified in chemical models, despite the knowledge acquired in its characterization and composition analyses. Facing these limitations, the objective of this work is to identify the main emission sources of fine particulate matter, specially the vehicular ones that present a lot of difficulties due to the fact that the characteristic trace elements are unknown for these sources. It was used in this work 201 samples collected in 24-hour period each at Dr. Arnaldo Avenue, a large and busy avenue in the city of São Paulo, from June 2007 to August 2008. The source identification was accomplished considering the samples composition and using receptor models: Factor Analysis (FA) and Positive Matrix Factorization (PMF) techniques. PMF was a new statistical tool in the study of particulates in the city of São Paulo. The number of sources identified by these two models was different. The FA technique identified 4 factors, (soil, fuel burning, and 2 factors combining in light and heavy-duty vehicles), whereas PMF identified 6, the same as FA (light and heavier vehicles differentiated) and biomass burning. There was concordance between the two techniques, considering that both found that vehicular emission is the major contribution for concentration. The comparison between the models indicated that PMF model present a better source classification, mainly for the vehicular identification. The PMF technique considers the error of each sample in the analysis, weighting the variables and imposing that all the factors must be positive. This mechanism provides a better characterization of sources linking the results with the physics of the process.
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Lannuque, Victor. "Formation de l’aérosol organique secondaire dans les modèles de qualité de l’air : développement d’une paramétrisation sur la base de simulations explicites." Thesis, Paris Est, 2017. http://www.theses.fr/2017PESC1129.
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L’oxydation gazeuse des composés organiques émis dans l’atmosphère mène à la formation de milliers de composés organiques secondaires (COS). Une fraction de ces COS est peu volatile, et peut se partager entre la phase gazeuse et la phase particulaire formant ainsi des aérosols organiques secondaires (AOS). Les AOS contribuent majoritairement à la composition des particules, participant entre 20 et 80 % à la masse totale des aérosols fins et influencent ainsi leurs impacts sur l’environnement, en particulier sur la qualité de l’air et le climat. Ces impacts sont quantifiés à l’aide de modèles de chimie-transport (CTM). Les comparaisons avec les mesures in situ montrent que les variations spatiales et temporelles de la masse d’AOS ne sont pas correctement simulées par les CTM. Dans ces modèles, la formation d’AOS est représentée de façon simplifiée à l'aide de paramétrisations empiriques développées sur la base d'observations en chambres de simulation atmosphérique. Il est donc primordial de repenser et d’améliorer la représentation des aérosols organiques dans les CTM pour diagnostiquer l’origine de la pollution atmosphérique par les particules fines, améliorer la fiabilité de la prévision des épisodes de pollution et évaluer l'impact des aérosols sur l'environnement. Les objectifs de cette thèse sont de :• explorer l’influence des conditions environnementales sur la formation et les propriétés des AOS,• développer une nouvelle paramétrisation de formation de l’AOS sur la base d’une représentation déterministe de la chimie atmosphérique,• évaluer cette paramétrisation en CTM par comparaison avec des mesures in-situ.Les modèles déterministes permettent de représenter la non-linéarité des processus de formation de l'AOS. Le modèle déterministe GECKO-A (Generator for Explicit Chemistry and Kinetics of Organics in the Atmosphere) est un outil de modélisation numérique qui intègre les données élémentaires (cinétiques et thermodynamiques) issues des études en laboratoire. Dans le cadre de cette thèse, des scénarios d’oxydation en conditions environnementales ont été développés et GECKO-A a été utilisé pour étudier l’impact des facteurs environnementaux (température, teneur en NOx, ensoleillement...) sur la formation et les propriétés des AOS. Sur la base de ces simulations, une nouvelle paramétrisation pour la formation d’AOS a été développée: VBS-GECKO. L’évaluation de la VBS-GECKO en modèle de boîte a montré une bonne reproduction des concentrations en aérosols organiques (AO) avec une RMSE inférieure à 20%. La VBS-GECKO a été intégrée au CTM CHIMERE pour simuler les concentrations estivales d’AO au dessus de l’Europe. Son utilisation conduit à une sensible amélioration de la masse d’AO simulée par rapport à la paramétrisation de référence utilisée dans CHIMERE. La VBS-GECKO a également été utilisé pour étudier (i) les sources et propriétés des AOS et (ii) différentes représentation des émissions de composés organiques semi-volatils et de volatilité intermédiaire par le trafic routierThe gaseous oxidation of organic compounds emitted into the atmosphere leads to the formation of thousands of secondary organic compounds (SOC). A fraction of these SOC is low volatile, and can partition between the gaseous phase and the particulate phase, forming secondary organic aerosols (SOA). The SOA are a main component of the particles, representing between 20% and 80% of the total mass of fine aerosols. Therefore, SOA contribute to the impact of aerosols on the environment, in particular air quality and climate. The quantification of the SOA impacts is estimated using chemical-transport models (CTM). Comparisons with in situ measurements show that the spatial and temporal variations of SOA mass are not correctly simulated by CTM. In these models, the SOA formation is represented in a simplified way, using empirical parameterizations developed on the basis of observations performed in atmospheric simulation chambers. Improving the representation of organic aerosols in CTM is therefore required to diagnose the origin of air pollution by fine particles, improve the reliability of pollution episode prediction and assess the impact of aerosols on the environment. The objectives of this thesis are :• to explore the influence of environmental conditions on SOA formation and properties,• to develop a new parameterization of SOA formation based on a deterministic representation of atmospheric chemistry,• to evaluate this parameterization in CTM by comparison with in-situ measurements. Deterministic models represent the non-linearity of SOA formation processes. The model GECKO-A (Generator for Explicit Chemistry and Kinetics of Organics in the Atmosphere) is a numerical modelling tool that integrates the elementary data (kinetics and thermodynamics) from laboratory studies. In this thesis, oxidation scenarios representative of various environmental conditions were developed and GECKO-A was used to study the impact of environmental factors (temperature, NOx concentrations, solar radiations, etc.) on the formation and the properties of the SOA. On the basis of these simulations, a new parameterization for SOA formation was developed: VBS-GECKO. The evaluation of the VBS-GECKO in box model has shown a good reproduction of the organic aerosol (OA) concentrations with RMSE lesser than 20%.The VBS-GECKO was integrated into the CHIMERE CTM to simulate summer concentrations of OA over Europe. Simulated OA are significantly improved compared to the reference parameterization used in CHIMERE. The VBS-GECKO was also used to study (i) the sources and properties of SOA and (ii) different representations of emissions of semi-volatile and intermediate volatility organic compounds by road traffic
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Поленкова, М. В. "Оцінка стану атмосферного повітря чернігівського регіону та заходи щодо його покращення." Thesis, Чернігів, 2020. http://ir.stu.cn.ua/123456789/21055.
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Поленкова, М. В. Оцінка стану атмосферного повітря чернігівського регіону та заходи щодо його покращення : магістерська робота: 05 Соціальні та поведінкові науки / М. В. Поленкова; керівник роботи Хоменко І. О. ; Національний університет «Чернігівська політехніка», кафедра теоретичної та прикладної економіки. – Чернігів, 2020. – 85 с.Об’єктом дослідження є стан атмосферного повітря Чернігівської області. Предметом дослідження є моніторинг стану атмосферного повітря Чернігівської області. Мета дослідження – комплексна і цілісна оцінка фактичного стану забруднення атмосферного повітря в Чернігівській області. Дослідження спрямоване на обґрунтування практичних рекомендацій щодо обґрунтування механізму проведення моніторингу атмосферного повітря у Чернігівській області. Інформаційною базою дослідження слугували наукові праці вітчизняних та зарубіжних науковців, нормативні та законодавчі акти у сфері охорони та якості атмосферного повітря, Директиви Європейського Союзу, спрямовані на регулювання кількості викидів забруднювальних речовин в атмосферне повітря та його охорону, матеріали науково-практичних конференцій, збірники та видання Державної служби статистики України та Чернігівської області, Департаменту екології та природних ресурсів Чернігівської ОДА, матеріали з інформаційної мережі Internet.
The object of research is the state of the atmospheric air of Chernihiv region. The subject of the study is the monitoring of atmospheric air in the Chernihiv region. The purpose of the study is a comprehensive and holistic assessment of the actual state of air pollution in the Chernihiv region. The study is aimed at substantiating practical recommendations for substantiating the mechanism of air monitoring in Chernihiv region. The information base of the study was the scientific works of domestic and foreign scientists, regulations and legislation in the field of air protection and quality, EU Directives aimed at regulating the amount of pollutant emissions into the air and its protection, materials of scientific conferences, collections and publications State Statistics Service of Ukraine and Chernihiv region, Department of Ecology and Natural Resources of Chernihiv Regional State Administration, materials from the Internet.
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Zhang, Yujie. "Atmospheric measurements and degradation mechanisms of a number of volatile organic compounds." Thesis, Orléans, 2012. http://www.theses.fr/2012ORLE2048.
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Les composés organiques carbonylés et les BTEX (Benzène, Toluène, Éthylbenzène et Xylènes) représentent une classe importante de composés organiques volatils dans l’atmosphère. Ils sont émis par des sources anthropogénique et biogéniques. Leur dégradation atmosphérique conduit à la formation d’ozone, de phooxidants et d’aérosols organiques affectant ainsi la qualité de l’air aux échelles locales et régionales ainsi que la santé humaine. Il est donc important de mesurer leurs concentrations et évaluer leur devenir atmosphérique. Dans la présente thèse, nous avons conduit une étude systématique qui a permis de mesurer les concentrations de ces composés et identifier leurs sources à Pékin (Juillet 2008-Août 2010) et évaluer l’importance des caractéristiques météo. Nous avons aussi mené des études sur la dégradation atmosphérique de trois formates (isoproyle, isobutyle et n-propyle) en utilisant la chambre de simulation atmosphérique d’ICARE (CNRS, Orléans)Carbonyls and BTEX (Benzene, Toluene, Ethylbenzene, and Xylenes) represent an important class of VOCs (volatile organic compounds) in the atmosphere. They are emitted into the atmosphere through anthropogenic and biogenic sources. Their atmospheric degradation leads to the formation of ozone, photooxidants and organic aerosols affecting the air quality at the local and regional scales and human health. It is, hence, of importance to measure their atmospheric concentrations and investigate their fate. In the present thesis, we have conducted a systematic measurement study of carbonyls and BTEX in Beijing during the period of Jul 2008-Aug 2010 in order to evaluate their ambient levels, possible sources and the influence of characteristic weather conditions. In a separate work, we performed a series of experimental studies on the OH-initiated oxidation of isopropyl formate, isobutyl formate, and n-propyl isobutyrate using the ICARE-CNRS (Orleans) simulation chamber from which we derived the product yields. The data obtained are presented and discussed
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Albuquerque, Edler Lins de. "Compostos organicos volateis na atmosfera urbana da região metropolitana de São Paulo." [s.n.], 2007. http://repositorio.unicamp.br/jspui/handle/REPOSIP/266356.
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Orientador: Edson TomazTese (doutorado) - Universidade Estadual de Campinas, Faculdade de Engenharia Quimica
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Resumo: Realizou-se um estudo experimental dos Compostos Orgânicos Voláteis (COV) encontrados na atmosfera urbana da Região Metropolitana de São Paulo (RMSP). O objetivo principal foi medir as concentrações de COV, procurando identificar, por meio de análises multivariadas, relações entre estas concentrações, parâmetros meteorológicos e concentrações de outros poluentes. Métodos de amostragem passiva e ativa foram empregados utilizando tubos de aço contendo o sólido adsorvente TENAX TA. A quantificação das amostras ocorreu por dessorção térmica automática e cromatografia gasosa com detecção por ionização em chama. Analisou-se COV selecionados, incluindo alcanos, cicloalcanos e compostos aromáticos. Diversos aspectos foram investigados em estudos específicos: emissão veicular, variabilidade diária das concentrações, emprego da amostragem passiva, potencial para formar ozônio etc. As concentrações registradas em cada campanha variaram bastante em função de aspectos associados a características locais das fontes de emissão, horários de coleta, fatores sazonais e meteorológicos. Verificou-se que tolueno, m,p-xilenos, n-hexano, etilbenzeno e 1,2,4-trimetilbenzeno foram os COV encontrados em maiores concentrações na maioria dos estudos realizados, estando os mesmos entre os mais emitidos pelos veículos e entre aqueles com maior potencial para formar ozônio. No local monitorado, o perfil de variação temporal das concentrações de COV foi diferente em função de condições sazonais e/ou meteorológicas. A validação da amostragem passiva possibilitou estimar taxas de amostragem dos COV, as primeiras da literatura científica para vários compostos e as primeiras obtidas numa atmosfera urbana de cidades brasileiras. Isto viabilizou a realização de um monitoramento passivo simultâneo em oito locais diferentes, permitindo verificar as vantagens deste tipo de coleta. Acredita-se que os resultados desta pesquisa possam auxiliar na criação de planos de monitoramento para os COV
Abstract: The aim of this research was an experimental study of Volatile Organic Compounds (VOCs) found in the urban atmosphere of Metropolitan Area of São Paulo (MASP). The main purpose was to measure atmospheric concentrations of VOCs. Multivariate analyses were used to identify relationships among VOCs concentration, meteorological parameters and concentrations of other pollutants. Passive and active sampling methods were applied. Steel tubes packed with adsorbent TENAX TA were employed. The samples were quantified by automatic thermal desorption and gas chromatography with flame ionization detection. Selected VOCs were analyzed, including alkanes, cycloalkanes and aromatic compounds. Many topics related to VOCs were investigated: vehicular emissions, time variation of concentrations, employ of passive sampling, potential of ozone formation etc. For this, some specific studies were conducted. VOCs concentration vary a lot in each campaign in function of aspects associated to local characteristics of emission sources, sampling time, season and meteorological factors. In most of performed studies toluene, m,p-xylenes, n-hexane, ethylbenzene and 1,2,4-trimethylbenzene were VOCs found in higher concentrations. Additionally, such compounds were also found among VOCs with higher vehicular emission factors and higher ozone forming potentials. At the monitoring site, VOCs concentrations have shown distinct profile of time variation for different seasonal and meteorological conditions. VOCs uptake rates were estimated from the validation of passive sampling process. These uptake rates were the first found for many VOCs and the first found in an urban atmosphere of Brazilian cities. This fact became possible to perform a simultaneous passive monitorization campaign in eight different sites at MASP, verifying the advantages of this type of sampling strategy. It is believed that the results of this research may aid in the creation of monitoring programs for VOCs
Doutorado
Desenvolvimento de Processos Químicos
Mestre em Engenharia Química
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Čėglytė, Aurelija. "Atmosferos apsaugos struktūros valdymo tobulinimas." Master's thesis, Lithuanian Academic Libraries Network (LABT), 2007. http://vddb.library.lt/obj/LT-eLABa-0001:E.02~2007~D_20070104_115109-14230.
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Nowadays much attention is paid to air pollution in the world. Effective and suitable management of atmosphere protection is very important, because climate change, human health and survival of biodiversity depends on it. For these reasons atmosphere protection management should get our special interest.
The aim of this work is to analyse the structure of atmosphere protection in Lithuania and to provide proposals on how to improve it. This work also suggests how to improve the policy of atmosphere protection and ensure appropriate air quality in Lithuania.
This master‘s work consists of four parts, which are designated to analyse the structure of atmosphere protection management and cooperation between institutions, to make systematic analysis of atmosphere protection laws and examine possible inaccuracies, to find inaccuracies in institutional, legal and financial systems, which are related to the management of atmosphere protection and to sugest some improvements on how to improve the structure of atmosphere protection management and the policy of atmosphere protection.
Implementing the tasks of this master‘s work, the importance of atmosphere air management was taken into consideration in the context of sustainable development, Lithuanian and European Union laws and Lithuanian institutional structure of atmosphere protection management were analysed and suggestions related to the improvement of atmosphere protection management structure improvement were given. The... [to full text]
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Maestas, Melissa May. "Air pollution and gastrointestinal diseases in Utah." Thesis, The University of Utah, 2017. http://pqdtopen.proquest.com/#viewpdf?dispub=10246554.
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The valleys of northern Utah, where most of Utah’s population resides, experience episodic air pollution events well in excess of the National Ambient Air Quality Standards. Most of the events are due to an accumulation of particulate matter during persistent cold air pools in winter from both direct emissions and secondary chemical reactions in the atmosphere. High wintertime ozone concentrations are occasionally observed in the Uintah Basin, in addition to particulate matter. At other times of the year, blowing dust, wildland fires, fireworks, and summertime ozone formation contribute to local air pollution. The objective of this dissertation is to investigate one facet of the health effects of Utah’s air pollution on its residents: the acute impacts of air pollution on gastrointestinal (GI) disease.
To study the health effects of these episodic pollution events, some measure of air pollution exposure must be matched to the health data. Time and place are used to link the health data for a person with the pollution data. This dissertation describes the method of kriging data from the sparse pollution monitoring network to estimate personal air pollution history based on the zip code of residence. This dissertation then describes the application of these exposure estimates to a health study on GI disease.
The purpose of the GI study is to retrospectively look at two groups of patients during 2000-2014: those with autoimmune disease of the GI tract (inflammatory bowel disease, IBD) and those with allergic disease of the GI tract (eosinophilic esophagitis, EoE) to determine whether disease exacerbations occur more commonly during and following periods of poor air quality compared to periods of good air quality. The primary analysis method is case crossover design. In addition to using the kriged air pollution estimates, the analysis was repeated using simpler empirical estimation methods to assess whether the odds ratios are sensitive to the air pollution estimation method.
The data suggests an association between particulate matter smaller than 2.5 microns and prednisone prescriptions, gastrointestinal infections in general, clostridium difficile infections specifically, and hospitalizations among people who have at least five entries of IBD diagnosis codes in their medical records. EoE exacerbations appear to be associated with high concentrations of particulate matter as well as ozone.
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Schenck, Charles. "Pollution saline de l'eau souterraine et de l'air liee aux activites economiques en haute alsace : incidences agronomiques." Université Louis Pasteur (Strasbourg) (1971-2008), 1987. http://www.theses.fr/1987STR13220.
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De par ses caracteristiques physiques, la vallee de l'ill en haute alsace est particulierement sensible a la pollution. Dans cette region a vocation industrielle et agricole la contazmination du milieu se traduit par une forte mineralisation de l'eau souterraine et des retombees atmospheriques solubles, diluees mais acides. La composition naturelle: bicarbonatee calcique de l'eau de la nappe phreatique est modifiee par une charge chloro-sodique et nitrique non negligeable. Quant aux retombees, elles provoquent au sol, des apports d'elements mineraux parmis lesquels predominent les chlorures, les sulfates, les nitrates, le calcium, le potassium et le sodium
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Smith, Kim Anne. "Transportation and air quality." Thesis, Georgia Institute of Technology, 1991. http://hdl.handle.net/1853/19915.
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Kammer, Julien. "LANDEX : étude des aérosols organiques secondaires (AOS) générés par la forêt des Landes." Thesis, Bordeaux, 2016. http://www.theses.fr/2016BORD0402/document.
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L’objectif de ce travail de thèse est d’améliorer l’état de nos connaissances sur les processus de formation et du devenir de l’AOS, en lien avec la réactivité des COVB avec les oxydants de l’atmosphère et en particulier l’ozone, en utilisant le potentiel de l’écosystème landais en tant que source d'AOS biogénique. Pour cela, des campagnes de terrain ont été menées sur un site de mesure en forêt landaise, écosystème particulièrement approprié pour l’étude de la formation et du devenir des AOS. Au cours de ces campagnes, différents paramètres physico-chimiques complémentaires ont été mesurés, tels que les concentrations et les flux de particules, d’oxydants et de COVB. Des épisodes nocturnes de formation de nouvelles particules ont été mis en évidence, ce qui constitue un résultat original car les évènements rapportés jusqu’ici dans la littérature étaient principalement diurnes. La contribution importante de l’ozonolyse des monoterpènes émis par les pins maritimes, dominés par l’α- et le β-pinène, à la formation nocturne de nouvelles particules a également été démontrée. Les mesures de flux de particules réalisées suggèrent que les particules formées au cours de la nuit sont transférées depuis la canopée vers les plus hautes couches de l’atmosphère. Une production d’ozone a également été démontrée par la comparaison des mesures de flux d’ozone à un modèle physique de dépôt. Cette source d’ozone pourrait être liée à la photooxidation des COVBForest ecosystems affect air quality and climate, especially through the emissions and the reactions of biogenic volatile organic compounds (BVOCs) with the atmospheric oxidants, known to generate Secondary Organic Aerosols (SOAs). This work aims to improve our knowledge on the processes involved in biogenic SOA formation and fate. Two field campaigns have been conducted in the Landes forest. In a first step, the measurement site was characterized by a statistical study of local meteorological conditions. During these campaigns, complementary physical and chemical measurements have been carried out, implying measurements of fluxes and concentrations of particles, BVOCs and oxidants. The results evidenced nocturnal new particle formation, which is an original result as this process was usually only reported during daytime. The strong contribution of BVOCs (dominated by α- and β-pinene) ozonolysis to nocturnal new particle formation has been demonstated. Particle flux measurements suggested that particles are transfered from the canopy to the higher atmospheric surface layer. The comparison between ozone fluxes and a physical ozone deposition model also highlighted an ozone production source. This ozone production might be related to BVOC photooxidation
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GOMES, Valério de Araújo. "Modelagem e simulação da dispersão das emissões de fluoreto gasoso de uma redução eletrolítica de alumínio." Universidade Federal de Campina Grande, 2007. http://dspace.sti.ufcg.edu.br:8080/jspui/handle/riufcg/303.
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A determinação de concentração de poluentes lançados na atmosfera é um elemento importante na previsão de impactos ambientais causados por emissões de efluentes industriais, sendo fundamental na avaliação de viabilidade de novas plantas, ou mesmo para plantas existentes. Em função da ampliação dos parques industriais e da aproximação dos centros urbanos, cada vez mais fica evidente a necessidade de dispor de dados de simulações da qualidade do ar, para tomar decisões em relação ao tipo de tratamento dos efluentes gasosos, posicionamento de plantas, projetos de chaminés (altura), e principalmente do tipo de controle e processo que será necessário para minimizar as concentrações lançadas no meio ambiente. O presente trabalho teve como objetivo, principalmente, desenvolver uma rotina aplicada as emissões de fluoreto gasoso proveniente de reduções eletrolíticas de alumínio. A referência adotada foi o modelo desenvolvido pela Environmental Research & Technology Inc. chamado BLP – Buoyant Line and Point Source (modelo fundamentado na distribuição gaussiana), aplicando algumas considerações específicas. A implementação foi realizada utilizando o Mathcad 11 Enterprise Edition. Posteriormente ao desenvolvimento foram feitas várias simulações com informações coletadas pelo programa de monitoramento de fontes estacionárias da Alumar e comparados com os dados coletados na estação de monitoramento contínuo de qualidade do ar localizada na vila de Coqueiro (intermediações do limite da fábrica, 2,500 Km). Complementarmente, também foi realizada uma simulação para comparar o resultado do modelo proposto com os resultados do CALPUFF (software comercial referendado pela EPA – Environmental Protection Agency) que foi utilizado durante a elaboração do estudo de impacto ambiental da complementação da sala de cubas – linha 3. O modelo proposto apresentou uma correlação de 82% com os dados históricos coletados na estação localizada na vila de Coqueiro e um erro de 4,35% quando comparado com as simulações do CALPUFF.
The determination of the pollutants concentration released into the atmosphere is an important element in the prediction of environmental impacts caused by emissions from industrial effluents, being fundamental in the feasibility evaluation of new plants, or even for existing plants. Due to the industrial parks expansion and the approximation of urban centers, it is increasingly evident that there is a need for air quality simulation data to make decisions regarding the type of treatment of gaseous effluents, plant positioning, chimneys dimensions (height), and especially of the type of control and process that will be necessary to minimize the concentrations released in the environment. The main objective of this work was to develop a routine applied to the emission of gaseous fluoride from electrolytic smelting of aluminum. The reference adopted was the model developed by Environmental Research & Technology Inc called BLP - Buoyant Line and Point Source (model based on the Gaussian distribution), applying some specific considerations. The implementation was performed using Mathcad 11 Enterprise Edition. After the development, several simulations were carried out with information collected by Alumar's stationary source monitoring program and compared to the data collected at the continuous air quality monitoring station located in the village of Coqueiro (distant 2,500 km). In addition, simulations were also carried out to compare the results of the proposed model with the results from CALPUFF (commercial software endorsed by the EPA - Environmental Protection Agency) that was used during the elaboration of the environmental impact study of the complementation of the potroom - line 3. The proposed model presented a correlation of 82% with the historical data collected at the station located in the village of Coqueiro and an error of 4.35% when compared to the simulations of the CALPUFF.
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江顯其 and Hin-kee Kong. "Air pollution impacts as indicated by roadside air quality monitoring stations." Thesis, The University of Hong Kong (Pokfulam, Hong Kong), 1999. http://hub.hku.hk/bib/B3125424X.
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Shahgedanova, Maria. "Climatology of air pollution in Moscow." Thesis, University of Oxford, 1996. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.320808.
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Halliday, Norman. "The detection of atmospheric vapours using optical waveguide sensors." Thesis, University of Manchester, 1988. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.329774.
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Lelas, Vedran. "Chance constrained models for air pollution monitoring and control /." Digital version accessible at:, 1998. http://wwwlib.umi.com/cr/utexas/main.
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Boylan, James W. "Integrated modeling of air pollution dynamics in the Southern Appalachian Mountains." Diss., Georgia Institute of Technology, 2002. http://hdl.handle.net/1853/22217.
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