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1
Land, Eva Miriam. "Photocatalytic degradation of NOX, VOCs, and chloramines by TiO2 impregnated surfaces." Thesis, Georgia Institute of Technology, 2010. http://hdl.handle.net/1853/34857.
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Experiments were conducted to determine the photocatalytic degradation of three types of gas-phase compounds, NOX, VOCs, and chloramines, by TiO2 impregnated tiles. The oxides of nitrogen NO and NO2 (NOx) have a variety of negative impacts on human and environmental health ranging from serving as key precursors for the respiratory irritant ozone, to forming nitric acid, which is a primary component of acid rain. A flow tube reactor was designed for the experiments that allowed the UV illumination of the tiles under exposure to both NO and NO2 concentrations in simulated ambient air. The reactor was also used to assess NOx degradation for sampled ambient air. The PV values for NO and NO2 were 0.016 cm s-1 and 0.0015 cm s-1, respectively. For ambient experiments a decrease in ambient NOx of ~ 40% was observed over a period of roughly 5 days. The mean PV for NOx for ambient air was 0.016 cm s-1 and the maximum PV was .038 cm s-1. Overall, the results indicate that laboratory conditions generally simulate the efficiency of removing NOx by TiO2 impregnated tiles. Volatile organic compounds (VOC's) are formed in a variety of indoor environments, and can lead to respiratory problems (US EPA, 2010). The experiments determined the photocatalytic degradation of formaldehyde and methanol, two common VOCs, by TiO2 impregnated tiles. The same flow tube reactor used for the previous NOX experiments was used to test a standardized gas-phase concentration of formaldehyde and methanol. The extended UV illumination of the tiles resulted in a 50 % reduction in formaldehyde, and a 68% reduction in methanol. The deposition velocities (or the photocatalytic velocities, PV) were estimated for both VOC's. The PV for formaldehyde was 0.021 cm s-1, and the PV for methanol was 0.026 cm s-1. These PV values are slightly higher than the mean value determined for NO from the previous experiments which was 0.016 cm s-1. The results suggest that the TiO2 tiles could effectively reduce specific VOC levels in indoor environments. Chlorination is a widespread form of water disinfection. However, chlorine can produce unwanted disinfection byproducts when chlorine reacts with nitrogen containing compounds or other organics. The reaction of chlorine with ammonia produces one of three chloramines, (mono-, di-, and tri-chloramine). The production of chloramines compounds in indoor areas increases the likelihood of asthma in pool professionals, competitive swimmers, and children that frequently bath in indoor chlorinated swimming pools (Jacobs, 2007; Nemery, 2002; Zwiener, 2007). A modified flow tube reactor in conjunction with a standardized solution of monochloramine, NH2Cl, determined the photocatalytic reactions over the TiO2 tiles and seven concrete samples. The concrete samples included five different concrete types, and contained either 5 % or 15 % TiO2 by weight. The PV for the tiles was 0.045 cm s-1 for the tiles manufactured by TOTO Inc. The highest PV from the concrete samples was 0.054 cm s-1. Overall the commercial tiles were most efficient at reducing NH2Cl, compared to NOX and VOC compounds. However, the concrete samples had an even higher PV for NH2Cl than the tiles. The reason for this is unknown; however, distinct surface characteristics and a higher concentration of TiO2 in the concrete may have contributed to these findings.
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Won, Doyun. "The effects of adsorptive sinks on human exposure to VOCs in indoor air /." Digital version accessible at:, 1999. http://wwwlib.umi.com/cr/utexas/main.
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Vice, Scott Jackson. "Indicators of Mold Growth in Indoor Environments." Thesis, Virginia Tech, 2000. http://hdl.handle.net/10919/35048.
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The following investigation stems from the idea of using metabolic byproducts produced by mold as indicators of its presence in indoor environments in place of investigating airborne fungi by traditional particulate sampling techniques. VOCs and carbon dioxide are both examined in order to evaluate their usefulness as possible metabolic indicators of mold growth. A specially designed purge and trap laboratory setup was built and operated for the study of molds growing on specific media. Key variables for the operation of the apparatus include sampling time and sampling flow rate as well as other environmental conditions such as temperature. Carbon dioxide serves as a good marker for fungal activity, but is difficult to attribute to mold growth when studying non-closed loop systems. Many VOCs were collected but detection limits were often too high for the quantities collected.Master of Science
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Saffarian, Saman. "A LCA Study of Activated Carbon Adsorption and Incineration in Air Pollution Control." Thesis, Högskolan i Borås, Institutionen Ingenjörshögskolan, 2010. http://urn.kb.se/resolve?urn=urn:nbn:se:hb:diva-19680.
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The main purpose of this thesis was to compare GAC adsorption method, VOCs incinerationmethod and Non-treatment alternative by using LCA to find which method or alternative isenvironmentally preferable. The LCA framework proposed by ISO 14040 (1997) has beenconsidered in this research. The comparison was made by considering a flue gas contaminatedby toluene (with three different concentration 100, 1000, 2000 mg/m3). The plant locationwhere the polluted flue gas is emitted has been assumed to be located in Borås, Sweden. Theflow rate of emitted flue gas was 10000m3/hr. The present thesis report contains two mainparts.The results of LCA showed that when the toluene concentration is low (< 100 mg/m3), GACadsorption method, Non-treatment alternative and VOCs incineration method are respectivelypreferable from environmental point of view. On the other side, when the tolueneconcentration of inlet stream is high (>1000 mg/m3), the order of GAC adsorption method,incineration and Non-treatment alternative is more desirable. Furthermore, the resultsillustrated that as toluene plays the role of fuel as a hydrocarbon, VOCs incineration methodis much more suitable when toluene concentration is high due to lower demand on additionalfuel. In the other words, high toluene concentration of influent leads to less environmentalimpact when VOCs incineration method is exploited. Conversely, the environmental impactof GAC adsorption method is increased when the inlet concentration of toluene is escalated.In overall, the weighted result showed that GAC adsorption method is the most preferablemethod while Non-treatment alternative is the worst.
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Santos, Rafaela Souza. "Estudo da composição de material particulado e compostos orgânicos voláteis no ar em Catalão - GO." Universidade Federal de Goiás, 2015. http://repositorio.bc.ufg.br/tede/handle/tede/5121.
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Coordenação de Aperfeiçoamento de Pessoal de Nível Superior - CAPES
The issue of pollution is not new. The burning of biomass used for heat generation already was beginning to anthropogenic processes of air pollution. The pollutants are in the atmosphere in solid, liquid and gaseous state. The set of solid and liquid particles is called particulate matter (PM), and the other form the set of gaseous pollutants. The MP covers a range of 0.1-100 microns and varies greatly in size composition, emission sources and adverse effects on health. The gaseous compounds are formed mostly of volatile organic compounds (VOCs), which are organic compounds which are gaseous at room temperature. These pollutants can be emitted by natural and anthropogenic sources, among which stand out the combustion processes and soil dust resuspension by wind action. The city of Catalão - GO has grown greatly in recent years, mainly due to the arrival of mining in the city exploring the carbonatite complexes Catalão I and Catalão II. The aim of this study was to monitor the atmospheric air in a region of the city of Catalan through the sampling and analysis of PM and VOCs. Samples MP, which occurred every six days over a period of 24 hours, were carried out for TSP, PM10 and PM2,5 in HI-VOL samplers suitable for each particle size. Gravimetric analysis indicated that the measured concentrations are in accordance with the standards set by law. The elementary MP analysis was performed by EDXRF technique and indicated that the elements present are mostly from vehicle emissions and resuspended soil dust by the wind. Sampling was performed by VOCs microextraction technique of solid phase (SPME - solid phase microextraction) twice a week for 12 hours. The analysis of the sampled VOCs was performed by gas chromatography-mass spectrometry (GC / MS - gas chromatography mass spectrometry) in which the compounds were identified by comparison with a NIST library / MS (National Institute of Standards and Technology / Mass Spectral) present in the equipment. The identification of these compounds indicated a strong influence of vehicle emissions in the composition of atmospheric air.
A questão da poluição não é algo recente. A queima de biomassa utilizada para geração de calor já dava início aos processos antrópicos de poluição atmosférica. Os poluentes encontram-se na atmosfera nos estados sólido, líquido e gasoso. O conjunto das partículas sólidas e líquidas constitui o chamado material particulado (MP), e as demais formam o conjunto de poluentes gasosos. O MP abrange uma faixa de tamanho entre 0,1-100 e varia em tamanho, composição, fontes de emissão e efeitos adversos causados a saúde. Os compostos gasosos são formados em sua maioria pelos compostos orgânicos voláteis (COVs), que são compostos orgânicos que encontram-se no estado gasoso em temperatura ambiente. Esses poluentes podem ser lançados na atmosfera por fontes naturais e antrópicas, dentre as quais destacam-se os processos de combustão e ressuspensão da poeira do solo por ação dos ventos. A cidade de Catalão GO tem crescido bastante nos últimos anos, principalmente devido a chegada de mineradoras na cidade que exploram os complexos carbonatíticos de Catalão I e Catalão II. O objetivo deste trabalho foi realizar o monitoramento do ar atmosférico em uma região da cidade de Catalão pela amostragem e análise de MP e COVs. As amostragens de MP, que aconteceram a cada seis dias por um período de 24 horas, foram realizadas para PTS, MP10 e MP2,5 em amostradores de grande volume adequados para cada tamanho de partícula. A análise gravimétrica indicou que os as concentrações medidas estão de acordo com os padrões definidos pela legislação. A análise elementar do MP foi realizada pela técnica de EDXRF e indicou que os elementos presentes são, em sua maioria, provenientes da emissão veicular e poeira ressuspensa do solo pela ação dos ventos. A amostragem dos COVs foi realizada pela técnica de microextração por fase sólida (SPME do inglês solid phase microextraction), duas vezes por semana por 12 horas. A análise dos COVs amostrados foi realizada por cromatografia gasosa acoplada a espectrometria de massas (GC / MS - do inglês gas chromatography mass spectrometry) em que os compostos foram identificados por comparação com a biblioteca NIST / MS (Nacional Institute of Standard and Technology / Mass Spectral) presente no equipamento. A identificação desses compostos indicou uma forte influência das emissões veiculares na composição do ar atmosférico.
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Hunter, Paige Holt. "Control of Volatile Organic Compound (VOC) Air Pollutants." Diss., Virginia Tech, 2000. http://hdl.handle.net/10919/38614.
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A variety of methods exist to remove volatile
organic compound (VOC) air pollutants from
contaminated gas streams. As regulatory and
public opinion pressures increase, companies are
searching for more effective methods to control
these emissions. This document is intended as a
guide to help determine if existing systems are
adequate and to provide additional information to
improve the efficiency of the systems. It
explores conventional methods of controlling VOC
emissions, as well as innovative technologies
including membrane separation, plasma destruction,
and ozone catalytic oxidation. The conventional
technologies covered include condensation,
adsorption, absorption (or scrubbing), thermal
incineration, flaring, catalytic incineration,
and biofiltration. Each chapter includes a
description of the technology, a discussion of
the types of systems available, notes on the
design of the system, economic estimates, an
explanation of potential problems, and a list of
considerations for installation and maintenance
concerns. The final chapter is dedicated to the
preparation and characterization of metal
catalysts which were developed to improve the
reaction rate of VOCs using ozone as an oxidant.Ph. D.
7
Vincent, Guillaume. "Procédé d'élimination de la pollution de l'air par traitement photocatalytique : application aux COVs." Thesis, Vandoeuvre-les-Nancy, INPL, 2008. http://www.theses.fr/2008INPL037N/document.
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L’oxydation photocatalytique des Composés Organiques Volatils (COVs) apparaît comme un procédé très prometteur pour la réduction de la pollution atmosphérique. Ce travail avait pour objectif d’étudier l’oxydation photocatalytique de plusieurs COVs au sein d’un réacteur annulaire: méthyléthylcétone (MEK), acétone, 1-propanol ou encore triéthylamine (TEA). Dans une première partie, l’influence de plusieurs paramètres cinétiques tels que la concentration en polluant, l’intensité lumineuse, le temps de contact et le taux d’humidité a été étudiée. Un mécanisme de dégradation photocatalytique a été établi pour chaque polluant en fonction des sous-produits détectés par GC/MS. Dans une seconde partie, la diffusion de radicaux hydroxyles OH• dans la phase gazeuse, après activation photonique du TiO2, a été mise en évidence par Fluorescence Induite par Laser (LIF). Pour la première fois, ces radicaux OH• ont été détectés à des pressions proches des conditions atmosphériques. Dans ce cas, nous pouvons en conclure que la dégradation photocatalytique des COVs pourrait être partiellement due à une réaction en phase gazeuse entre les COVs et les radicaux OH•Photocatalytic oxidation of airborne contaminants appears to be a promising process for remediation of air polluted by Volatile Organic Compounds (VOCs). The aim of our study is the photocatalytic oxidation of several VOCs using an annular reactor: methylethylketone (MEK), acetone, 1-propanol and triethylamine (TEA). First, the influence of different kinetic parameters such as pollutant concentration, incident light irradiance, contact time and humidity has been studied. A mechanistic pathway has been indeed proposed for each pollutant according to the produced intermediates species detected by GC/MS. Second, the diffusion of hydroxyls radicals OH• in gas phase, after photonic activation of TiO2, has been highlighted using Laser-Induced Fluorescence (LIF). For the first time, OH• radicals have been detected at atmospheric pressures, close to the major photocatalytic oxidation conditions, leading to the assumption that the photocatalytic degradation of VOCs might be at least partially occurs between pollutants and OH• radicals in gas-phase
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Monteiro, Mônica Domingues. "Avaliação das concentrações de BTEX em ambiente indoor: estudo de caso da sala de spinning de uma academia de ginástica Rio de Janeiro / RJ." Universidade do Estado do Rio de Janeiro, 2011. http://www.bdtd.uerj.br/tde_busca/arquivo.php?codArquivo=4477.
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Muitos dos locais onde as atividades são realizadas nas academias de ginásticas são salas pequenas e fechadas com sistema de climatização artificial, freqüentados por um grande número de alunos realizando seus exercícios e profissionais auxiliando as atividades. Com isso, há uma intensa transpiração desses indivíduos, uma freqüente rotina de limpeza do piso e de equipamentos com pequenos intervalos, possibilitando a alterações da qualidade do ar indoor. O presente trabalho busca mostrar as tendências de variações nos valores das concentrações dos poluentes atmosféricos BTEX em ambiente indoor, especificamente na sala de spinning de uma academia de ginástica do Rio de Janeiro. Para o monitoramento da qualidade do ar foram utilizados cartuchos de carvão ativado SKC, acoplado a uma bomba KNF com vazão de 1l min. Para a extração de cada amostra foi feita a análise cromatográfica com cromatógrafo a gás modelo 6890 acoplado a um espectrômetro de massa modelo 5973 da marca Agilent. Foram analisadas 34 amostras coletadas na salas de spinning durante as aulas com atividades aeróbicas, o que intensificava a respiração dos indivíduos, possibilitando uma maior inalação destes COVs. Em contrapartida, também foram coletadas 5 amostras outdoor, 4 delas pareadas indoor/ outdoor para uma análise comparativa das concentrações destes poluentes. Dentre os compostos orgânicos voláteis analisados, o tolueno é o BTEX mais abundante obtido neste trabalho, representando 81% destes COVs indoor. Todas as amostras medidas em pares indoor/ outdoor tiveram concentrações maiores no interior, exceto para o benzeno no dia 3/12/2010. Simples atividades usualmente realizadas pelo homem, como a inserção de piso emborrachado, manutenção do sistema de climatização artificial, e limpeza podem alterar o ar indoor. As conclusões alcançadas após as medições das concentrações de BTEX foram de que o ar indoor estava mais poluído do que o outdoor. Este monitoramento da qualidade do ar indoor ainda é escasso no Brasil. Alguns esforços tem sido feito em relação a ambientes confinados como a Portaria n˚3523 do Ministério da Saúde, regulamentando o controle dos ambientes climatizados e a Resolução n˚9 da Agência Nacional de Vigilância Sanitária, além da Resolução CONAMA n ˚3 estabelecendo padrões de qualidade do ar para alguns compostos químicos, porém muitos compostos químicos ainda não são legislados ou não possuem a devida atenção, não sendo suficientes para contemplar a complexidade do assuntoIn many gyms work-out activities take place in small enclosed rooms where the climate is controlled artificially. Normally, those rooms are full of students doing their workout and trainers helping them. Intense human transpiration requires a frequent floor and equipment cleaning routine. This routine, performed at short intervals can affect the indoor air quality. This study is aimed at showing varying concentration levels of the BTEX air pollutant at a gym in Rio de Janeiro, Brazil, specifically the spinning room. To monitor the air quality, activated charcoal cartridges (SKC) were used, coupled to a KNF pump with a flow rate of 1l min. For the extraction of each sample, a gas chromatographic analysis machine model 6890 was used coupled to an Agilent mass spectrometer model 5973. We analyzed a total of 34 air samples collected in the spinning room during active aerobic classes; the increased respiration from the subjects allow for a greater inhalation of VOCs. In Contrast, five samples were also collected outdoors; four of them were paired indoor / outdoor for comparative analysis of these pollutants. Among the volatile organic compounds analyzed, toluene was the most abundant BTEX found in this study, representing 81% of indoor VOCs. In all the indoor / outdoor paired samples, the concentration was higher in the interior samples, with one exception, benzene on 3/12/2010. Simple changes that can easily be done by man, such as the installation of rubberized flooring, regular maintenance of the air acclimatization equipment, and general cleanliness can greatly affect the indoor air quality. The conclusion achieved after looking at the BTEX measurements was that the indoor air was more polluted than the air outdoors. This air quality monitoring is still scarce in Brazil. Some efforts have been made in relation to confined spaces such as Ordinance n˚ 3523 from the Ministry of Health, which regulates the air of air-conditioned environments and Resolution n˚ 9 of the National Agency for Sanitary Vigilance, as well as Resolution CONAMA n˚ 3 by setting standards for air quality for some chemical compounds, unfortunately many chemical compounds are not yet legislated or receive proper attention in this matter, therefore not giving this indoor air pollution matter enough grounds to address the complexity of the subject
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Dubuisson, Candice. "Impact de la pollution atmosphérique par l’ozone sur la communication chimique plante-pollinisateur : le cas de deux interactions emblématiques en Méditerranée." Thesis, Université de Montpellier (2022-….), 2022. http://www.theses.fr/2022UMONG001.
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Parmi les polluants présents dans la troposphère, l’ozone (O3) est probablement l’un des plus stressant pour les organismes, du fait de son fort potentiel oxydant. Par exemple, de fortes concentrations d’O3 ([O3]) peuvent affecter l’émission des composés organiques volatils (COVs) permettant aux plantes de communiquer avec leur environnement. De plus, l’O3 peut réagir avec ces COVs dans l’atmosphère pour créer de nouvelles molécules, modifiant ainsi le signal chimique émis par les plantes. Or, ce signal est déterminant dans les interactions plantes-insectes. De nombreuses études ont montré les effets de l’O3 sur les parties végétatives des plantes mais très peu se sont intéressées aux parties reproductives, généralement responsables de l’attraction des pollinisateurs. L’objectif de cette thèse est donc d’améliorer nos connaissances sur l’effet de l’O3 dans les étapes de la communication chimique plantes-pollinisateurs, à savoir (i) l’émission par la plante des COVs floraux, (ii) le signal chimique lors de son transport dans l’atmosphère et (iii) la reconnaissance de ce signal par les pollinisateurs.En Méditerranée, les interactions entre le figuier méditerranéen, Ficus carica (Moraceae), et son pollinisateur très spécifique, Blastophaga psenes (Agaonidae), et entre la lavande vraie, Lavandula angustifolia (Lamiaceae) et son pollinisateur très généraliste l’abeille domestique, Apis mellifera (Apidae), sont les deux modèles d’études emblématiques choisis pour répondre aux objectifs de cette thèse, de par leur degré de spécificité, et la fréquence et l’intensité des pics de pollution à l’O3 dans cette région.Ces travaux de thèse ont combiné des études descriptives et expérimentales afin de déterminer (i) le rythme journalier d’émission des COVs chez la lavande et le figuier, (ii) les variations in natura d’émission des COVs floraux de figuiers exposés de façon chronique ou ponctuelle à une pollution à l’O3 et à d’autres facteurs du changement climatique, (iii) la réponse des deux espèces exposées, en conditions contrôlées, à un pic de pollution à l’O3 en terme d’émission de leurs COVs floraux, (iv) la réaction de l’O3 avec les COVs floraux dans une atmosphère contrôlée et (v) les conséquences de ces deux effets sur l’attraction de leurs pollinisateurs.Les résultats mettent en évidence (i) pour les deux modèles, un rythme d’émission de COVs a priori corrélé à l’intensité lumineuse mais avec différents pics d’émission dans la journée selon les COVs ; (ii) pour le figuier, une variation saisonnière très marquée de l’émission des COVs floraux in natura, en lien avec la température, la sécheresse et les pollutions chroniques et ponctuelles à l’O3 ; (iii) qu’une exposition en conditions contrôlées des deux espèces pendant 5 h à 200 ppb d’O3 ([O3] maximale répertoriée dans les 15 dernières années en méditerranée) n’a pas d’effets immédiats sur l’émission de leurs COVs floraux, mais que (iv) ces COVs seuls exposés à différentes [O3] réagissent différentiellement avec l’O3 pour former de nouvelles molécules, ceci faisant varier les proportions de COVs dans le mélange dès 40 ppb d’O3, et enfin, (v) chez le figuier, que ces variations de COVs inhibent l’attraction du pollinisateur. Cette étude a mis en évidence des sources de variations dans l’émission des COVs floraux chez les deux espèces modèles mais a également permis d’avoir une vision intégrative de l’effet d’un pic de pollution à l’O3 sur la concentration des COVs autour de ces plantes. Plus généralement, ces travaux de thèse soulignent l’importance d’étudier les facteurs du changement climatique co-occurant in natura, notamment les effets de la concentration de différents polluants atmosphériques, sur la communication chimique dans différentes interactions plantes-pollinisateurs afin de mettre en place des mesures de protection de ces interactions face aux changements environnementaux actuels et futursAmong the pollutants present in the troposphere, ozone (O3) is probably one of the most stressful for organisms, owing to its strong oxidizing potential. For example, high concentrations of O3 ([O3]) can affect the emission of volatile organic compounds (VOCs) that allow plants to communicate with their environment. Moreover, O3 can react with these VOCs in the atmosphere to create new molecules, thus degrading the chemical signals upon which plant-insect interactions, including plant-pollinator interactions, depend. Many studies have shown the effects of O3 on the vegetative parts of plants but very few have studied their effects on their reproductive parts, which are generally responsible for the attraction of pollinators. This work therefore aims to provide knowledge on the effect of O3 in plant-pollinator chemical communication, namely, its effects on (i) the emission of floral VOCs by the plant, (ii) the chemical signal during its transport in the atmosphere and (iii) the recognition of this signal by pollinators.In the Mediterranean region, the interactions between the Mediterranean fig tree, Ficus carica (Moraceae), and its specific pollinator, Blastophaga psenes (Agaonidae), and between the true lavender, Lavandula angustifolia (Lamiaceae), and its generalist pollinator, the honeybee, Apis mellifera (Apidae), are the two emblematic study models chosen to meet the objectives of this dissertation, owing to their specificity and to the frequency and intensity of O3 pollution peaks in this region.This work combined descriptive and experimental studies to determine (i) the daily rate of VOCs emission from flowering plants, (ii) the in natura variation in emission of floral VOCs from fig trees exposed chronically or punctually to O3 pollution and other variables affected by climate change, (iii) the response of plants exposed under controlled conditions to a peak of O3 pollution, in terms of their emission of floral VOCs, (iv) the reaction of O3 with floral VOCs in a controlled atmosphere, and (v) the consequences of these two effects on the attraction of pollinators.The results show that (i) for both models, VOCs emission is correlated with light intensity but also shows different emission peaks during the day, depending on identity of the VOCs; (ii) for F. carica, there is marked seasonal variation in the emission of VOCs in natura, with light intensity, temperature, drought and chronic and acute source of O3 pollution responsible for variations in the emission of floral VOCs; (iii) for both species, exposure under controlled conditions for 5h to 200 ppb O3 (maximum ([O3] recorded in the last 15 years in the Mediterranean region) has no immediate effect on emission of floral VOCs, but (iv) floral VOCs alone exposed to different [O3] react differentially with the pollutant to form new molecules, thus modifying the proportions of VOCs in the mixture at [O3] as low as 40 ppb, and finally, (v) in F. carica, these modifications of VOCs significantly inhibit the attraction of the specific pollinator. This study highlights sources of variation in floral VOC emission in the two model species but also provides an integrative view of the effect of acute exposure to high [O3] on the concentration of VOCs around these plants. Behavioral tests with different pollinators are now essential to characterize the resilience of these interactions to the [O3]-induced variations in VOCs highlighted in this study. More generally, this work points to the importance of studying factors of climate change co-occurring in natura, including the effects of the concentrations of different air pollutants, on chemical communication in different plant-pollinator interactions in order to define measures to protect these interactions in the face of current and future environmental changes
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Claeson, Anna-Sara. "Volatile organic compounds from microorganisms : identification and health effects." Doctoral thesis, Umeå : Univ, 2006. http://urn.kb.se/resolve?urn=urn:nbn:se:umu:diva-880.
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Abd, Allah Zaenab. "Non-thermal atmospheric pressure plasma for remediation of volatile organic compounds." Thesis, University of Manchester, 2012. https://www.research.manchester.ac.uk/portal/en/theses/nonthermal-atmospheric-pressure-plasma-for-remediation-of-volatile-organic-compounds(2826f483-e29f-402e-93a7-5f73818c4292).html.
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Non-thermal plasma generated in a dielectric barrier packed-bed reactor has been used for the remediation of chlorinated volatile organic compounds. Chlorinated VOCs are important air pollutant gases which affect both the environment and human health. This thesis uses non-thermal plasma generated in single and multiple packed-bed plasma reactors for the decomposition of dichloromethane (CH2Cl2, DCM) and methyl chloride (CH3Cl). The overall aim of this thesis is to optimize the removal efficiency of DCM and CH3Cl in air plasma by investigating the influence of key process parameters. This thesis starts by investigating the influence of process parameters such as oxygen concentration, initial VOC concentration, energy density, and plasma residence time and background gas on the removal efficiency of both DCM and CH3Cl. Results of these investigations showed maximum removal efficiency with the addition of 2 to 4 % oxygen to nitrogen plasma. Oxygen concentrations in excess of 4 % decreased the decomposition of chlorinated VOCs as a result of ozone and NOx formation. This was improved by adding an alkene, propylene (C3H6), to the gas stream. With propylene additives, the maximum remediation of DCM was achieved in air plasma. It is thought that adding propylene resulted in the generation of more active radicals that play an important role in the decomposition process of DCM as well as a further oxidation of NO to NO2. Results in the single bed also showed that increasing the residence time increased the removal efficiency of chlorinated VOCs in plasma. This was optimized by designing a multiple packed-bed reactor consisting of three packed-bed cells in series, giving a total residence time of 4.2 seconds in the plasma region of the reactor. This reactor was used for both the removal of DCM, and a mixture of DCM and C3H6 in a nitrogen-oxygen gas mixture. A maximum removal efficiency of about 85 % for DCM was achieved in air plasma with the use of three plasma cells and the addition of C3H6 to the gas stream. Nitrogen oxides are air pollutants which are formed as by-products during the decomposition of chlorinated VOCs in plasmas containing nitrogen and oxygen. Results illustrate that the addition of a mixture of DCM and C3H6 resulted in the formation of the lowest concentration of nitric oxide, whilst the total nitrogen oxides concentrations did not increase. A summary of the findings of this work is presented in chapter eight as well as further work. To conclude, the maximum removal efficiency of dichloromethane was achieved in air plasma with the addition of 1000 ppm of propylene and the use of three packed-bed plasma cells in series. The lowest concentration of nitric oxide was formed in this situation.
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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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Hairie, Clara. "La dégradation de Byne : efflorescences de sels de calcium sur les collections de micropaléontologie." Electronic Thesis or Diss., université Paris-Saclay, 2023. http://www.theses.fr/2023UPAST084.
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L'apparition d'efflorescences cristallines sur des objets calcaires stockés dans des environnements pollués, communément appelée "dégradation de Byne", résulte de l'émission de composés organiques volatils (COV) acides par les matériaux de stockage. Ces acides réagissent avec le carbonate de calcium en formant des sels organiques de calcium, dont des acétates et des sels mixtes acétate-formiate, qui provoquent une détérioration irréversible du substrat. Jusqu'à présent, seuls des objets macroscopiques subissant la dégradation de Byne avaient été décrits dans la littérature.Ce travail vise à comprendre comment la dégradation de Byne peut aussi affecter des spécimens calcaires microscopiques présents dans les collections de micropaléontologie. Il a été initié par la numérisation de la collection de foraminifères d'Alcide d'Orbigny (1802-1857), conservée au Muséum national d'Histoire naturelle (MNHN), qui a révélé des dommages importants liés à la présence d'efflorescences salines.Un constat d'état a été mené sur l'ensemble de la collection d'Orbigny (plus de 3600 spécimens), mettant en évidence que les altérations, à la fois anciennes et évolutives, sont influencées par la cristallinité des tests et l'origine des lieux de prélèvement des foraminifères. Des collections voisines ont été examinées à titre comparatif et des recherches en archives ont permis de retracer l'histoire de la collection depuis son entrée au MNHN. Elles mettent en évidence de nombreux déménagements et des accidents tels que la crue de la Seine de 1910, qui expliquerait l'humidité particulièrement élevée à l'intérieur des tubes où sont conservés les foraminifères. Des variations importantes de température, combinées à la présence de matériaux émetteurs de COV introduits à la fin du XIXe siècle dans le montage des spécimens, sont ainsi à l'origine de la pollution acide et de la prolifération des sels.Parallèlement à cela, une procédure de vieillissement artificiel a été élaborée pour reproduire la dégradation de Byne sur des foraminifères sains. Les produits de dégradation formés sur les spécimens vieillis, ainsi que sur une sélection représentative de spécimens historiques, ont été analysés de manière non invasive et sans contact par spectroscopie micro-Raman et par diffraction des rayons X sur rayonnement synchrotron. Ces analyses ont mis en évidence des phases minéralogiques différentes de celles observées dans la littérature sur les collections macroscopiques. Ce sont ainsi des formiates de calcium qui prédominent, et tout particulièrement le polymorphe tétragonal [β-Ca(HCOO)2] connu pour être instable lorsqu'il est synthétisé en laboratoire. Aucun acétate ou sel mixte de calcium n'a pu être identifié sur les foraminifères de la collection d'Orbigny. Les vieillissements montrent que l'humidité relative et la taille des spécimens jouent un rôle primordial dans la formation des sels : des conditions humides favorisent la cristallisation du formiate de calcium sur le spécimen, tandis que l'acétate, très hygroscopique, est sujet aux cycles de déliquescence-cristallisation qui le conduisent à se disperser autour de l'échantillon lorsque celui-ci est de très petite taille.Enfin, pour mieux comprendre la prédominance du formiate de calcium [β-Ca(HCOO)2], différentes solutions de formiate de calcium ont été laissées à évaporer et placées dans des environnements à humidité variée afin d'étudier la transformation vers la phase stable [α-Ca(HCOO)2]. L'analyse semi-quantitative des produits montre que la présence d'ions tels que ceux trouvés dans les coquilles de foraminifères (Mg2+, Sr2+...) favorise la formation de la phase métastable, et ralentit la transition β-->α.Ce travail montre que la nature des sels formés par la dégradation de Byne n'est pas seulement tributaire des COV présents mais dépend aussi de la taille des spécimens, leur composition, la cristallisation de leur test et des cycles d'humidité et de température auxquels ils ont été soumisThe appearance of crystalline efflorescence on calcareous objects stored in polluted environments is commonly referred to as "Byne's decay". It results from the emission of acidic volatile organic compounds (VOCs) from storage materials, which react with calcium carbonate to form organic calcium salts. This includes acetates and mixed acetate-formate salts that cause irreversible deterioration of the substrate. Until now, only macroscopic objects undergoing Byne's decay had been reported in the literature.This work focuses on how Byne's decay can also affect microscopic calcareous specimens from micropaleontology collections. It was initiated by the digitization of the foraminifera collection of Alcide d'Orbigny (1802-1857), housed at the Muséum national d'Histoire naturelle (MNHN), which revealed significant damage due to the presence of saline efflorescences.A condition report was carried out on the whole of the d'Orbigny collection (more than 3600 specimens), highlighting that the alterations, both ancient and evolutionary, are influenced by the crystallinity of the tests and the origin of the places where the foraminifera were collected. Similar collections closely located were examined for comparison and archival research was conducted to trace the material history of the collection since its entry into the MNHN. They highlight several moves and accidents such as the flooding of the Seine in 1910, which would explain the particularly high levels of humidity inside the tubes where the foraminifera are kept. Significant variations in temperature, combined with the presence of VOC-emitting materials introduced at the end of the 19th century in the assembly of the specimens, are thus at the origin of the acid pollution and the proliferation of salts.At the same time, an artificial aging procedure was developed to reproduce Byne's decay on unaltered specimens. The degradation products formed on the aged specimens, as well as on a representative selection of historical ones, were analysed non-invasively and without contact by using micro-Raman spectroscopy and synchrotron X-ray diffraction. These analyses revealed mineralogical phases different from those observed in the literature on macroscopic collections. Thus, calcium formates and especially the tetragonal polymorphic phase [β-Ca(HCOO)2] known to be unstable when synthesized in laboratory conditions, predominate. No calcium acetate or mixed salt could be identified on d'Orbigny's foraminifera. Aging shows that the relative humidity and the size of the specimens play a primordial role in the formation of the salts: humid conditions favour the crystallization of calcium formate directly on the specimen, while acetate, very hygroscopic, is subject to deliquescence-crystallization cycles that lead to its redispersion around micrometer-scale specimens.Finally, to better understand the predominance of calcium formate [β-Ca(HCOO)2], different calcium formate solutions were left to evaporate and placed in environments with different humidity to study the transformation towards the stable phase [α-Ca(HCOO)2]. Semi-quantitative analysis of the products shows that the presence of ions such as those found in foraminiferal shells (Mg2+, Sr2+…) favours the formation of the metastable phase and slows down the transition β-->α.This work shows that the nature of the salts formed by Byne's decay is not only dependent on the VOCs present, but also on the size of the specimens, their composition, their test crystallization, and the moisture and temperature cycles to which they were exposed
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Boulon, Julien. "Approche multi-échelle de la formation des particules secondaires." Phd thesis, Université Blaise Pascal - Clermont-Ferrand II, 2011. http://tel.archives-ouvertes.fr/tel-00697022.
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Dans le cadre de l'étude de l'évolution du système climatique terrestre, comprendre la composition gazeuse et particulaire de l'atmosphère est un enjeu majeur dans notre compréhension de la Terre et de son atmosphère, de son passé et de son évolution à venir. Les aérosols secondaires, i.e. formés par nucléation, représentent la source la plus importante en nombre des aérosols atmosphériques mais prédire où, quand et en quelle proportion ces aérosols sont formés dans l'atmosphère demeure à ce jour un exercice peu fiable. C'est dans ce contexte que cette étude s'est attachée à compléter nos connaissances des processus conduisant à la formation et à la croissance des particules atmosphériques secondaires. Des études réalisées à partir de mesures de terrain à long terme sur différents sites d'altitude en Europe ont permis de mettre en évidence différentes spéciations verticales de la nucléation démontrant que ce phénomène semble être jusqu'à deux fois plus fréquents à la frontière avec la basse troposphère libre que dans la couche limite planétaire. D'autre part ces mêmes études ont pu mettre en évidence que les mécanismes conduisant à la nucléation de nouvelles particules se différencient avec l'altitude impliquant un rôle plus important de la voie de formation induite par les ions ainsi que des composés organiques volatils. La contribution de cette dernière famille de composés à la nucléation a été également testée durant plusieurs campagnes d'expérimentation en systèmes réactifs ainsi qu'en chambre de simulation atmosphérique. Différents comportements et paramétrisation de la nucléation selon la nature chimique du composé parent ont pu être mis en évidence. Enfin, des études numériques réalisées à partir de données de terrain et d'expérimentation ont permis d'explorer, d'infirmer, de confirmer et de proposer différentes approches numériques afin de simuler les évènements de formation des aérosols secondaires.
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Kandiah, Morgan Dharmaratnam. "Indoor air quality, house characteristics and respiratory symptoms among mothers and children in Tamil Nadu State, India." Thesis, Curtin University, 2010. http://hdl.handle.net/20.500.11937/1890.
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Air pollution is a problem affecting developing and developed countries concerned about the adverse health effects associated with exposure to indoor and outdoor air pollutants. In developing countries like India, the problem, particularly domestic air pollution, is worsened by the use of unprocessed solid fuels for cooking. Other indoor environmental risk factors include the characteristics of housing conditions, household activities, and low Socio-economic status (SES). The potential irritants include nitrogen dioxide (NO[subscript]2), formaldehyde (HCHO), volatile organic compounds (VOCs), indoor smoking, and particulate matter (PM[subscript]2.5-10) and carbon monoxide (CO).Indoor air pollutants, especially those in domestic households are major problems that can contribute to respiratory symptoms and poor health in mothers and children and, in particular, those who live in poorer households in developing countries. There is consistent evidence that mothers and young children from these countries spend more than 80% of their time indoors, especially in the kitchen. Therefore, domestic air quality may be related to the increase in the prevalence of respiratory symptoms and other allergic conditions. In this context, this study established risk factors in the domestic environment that can determine the concentrations of domestic air pollutants and prevalence of respiratory symptoms in mothers and children. Cooking for a long time, keeping young children and infants in cooking areas, the inadequacy of ventilation, and the use of biomass fuels can relate to debilitating health problems, especially respiratory symptoms among poor households’ mothers and children particularly in developing countries.This study is cross-sectional and aims to determine that domestic concentrations of fine particles (PM[subscript]2.5), carbon monoxide (CO), and the socio-economic status (SES) and/or poverty levels, house and kitchen characteristics and households’ activities, may have a detrimental role in the prevalence of respiratory symptoms among mothers and children. One hundred and seventy households (N=170) with young children (n=299) under 15-years-of-age were selected randomly from the City of Tirupur in Coimbatore district, Tamil Nadu in South India. This city was chosen as it has diversity in terms of its ethnic mix, economic activities, physical characteristics and income disparities. Each participating household was visited and 170 households’ mothers were interviewed using a questionnaire. During the visits, study data was also collected in 80 households by measuring of indoor concentrations of PM[subscript]2.5, CO and the physical parameters, humidity and temperature.According to the statistical analysis, using biomass for cooking affects mothers’ and children’s respiratory symptoms. The results of this study show that median exposure to fine particles (PM[subscript]2.5) (1.18mg/m[superscript]3) exceeds the recommended WHO standards. CO concentrations did not have any significant relationship with mothers’ and children’s respiratory symptoms as mean concentrations of CO were 4.63ppm or 8.80mg/m[superscript]3. The study shows that kitchens with brick/stone walls and tile roofs are associated with reduced concentrations of PM[subscript]2.5 (p=0.033). If a kitchen has mud walls, a thatched roof and a floor of clay/mud, the indoor air has higher concentrations of PM[subscript]2.5 (p=0.014), Floors, such as cement, can lower the domestic air concentration of PM[subscript]2.5, (p=0.014). The study finds that lower concentrations of PM[subscript]2.5 were also found when windows were open (OR=0.14), (p=0.018).The study shows that there is a significant relationship between the prevalence of asthma in children in relation to CO and more than one time (OR=1.19) with p=0.021. In this study, it was shown that mothers with lower incomes had shortness of breath (p=0.003), almost six times higher than mothers with higher incomes. Children with allergies (78.9%) in the current study came from families where the mothers were employed as labourers and their children had respiratory symptoms such as coughing (p=0.001) and wheezing (p=0.002). The most (p=0.001) significant respiratory symptom of children from families who did not own house/unit or land was a cough: 56 (42.4%) as they usually live either in semi-open air or very badly constructed dwellings).High R/H (%) and T[superscript]oC also seem to have an effect on domestic concentrations of PM[subscript]2.5. As revealed by the statistical analysis, high T[superscript]oC and RH (%) were associated with significant impacts on mothers’ respiratory symptoms but did not have any significant impact on children’s respiratory symptoms. High-income households’ mothers and children were seen to have less significant respiratory symptoms than low-income households’ mothers. Evaluation of the literature also assessed the extent to which SES and/or poverty levels and house and kitchen characteristics and households’ activities affected respiratory symptoms in mothers and children.In conclusion, this study’s results further highlight the role of susceptibility risk factors for respiratory symptoms and show that domestic environmental factors contribute as risk factors for respiratory symptoms in mothers and children, especially in poor households. In order to improve domestic air quality and thus decrease the prevalence of respiratory symptoms, much more effort needs to be made. Because the air quality in the domestic environment is modifiable, there may be opportunities for intervention to reduce respiratory symptoms and this needs greater attention. Low SES and/or poverty levels may cause greater susceptibility to disease through malnutrition, access to health care, better housing and children’s and adult education.This study also provides recommendations how to reduce the prevalence of respiratory symptoms by improving households’ SES and/or poverty levels, one of the main risk factors for adverse health effects of respiratory symptoms in mothers and children from Tamil Nadu, South India. Since the quality of the domestic environment is very important, further intervention is needed to reduce respiratory symptoms in mothers and children, particularly young ones at a time when immune deviation usually occurs, regarding where they grow and spend most of their time. Finally, in order to reduce indoor air pollutants and respiratory symptoms in mothers and children, much more effort and greater attention needs to be paid to improve households’ low SES and/or poverty levels. The main goal should be sustainable development and poverty reduction that will enable people eventually to switch to clean fuels. SES was the most significant predicator of cooking fuel choice to ensure good health.
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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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Speirs, Lucinda J. "Wake dispersion on process plant : enhancing VOC emissions control." Thesis, University of Surrey, 1998. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.265655.
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Radford, Michael. "A Study of Central Florida Nonroad VOC and NOs Emissions and Potential Actions to Reduce Emissions." Master's thesis, University of Central Florida, 2009. http://digital.library.ucf.edu/cdm/ref/collection/ETD/id/2472.
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Ground-level ozone is harmful to the human respiratory system, as well as the environment. The national EPA 8-hour ozone standard for ground-level ozone was reduced from 85 parts per billion (ppb) to 75 ppb in 2008, and trends from previous years show that some of the counties in Central Florida could be in danger of violation. Violation means "non attainment" status; in which the county is ordered by EPA to develop specific implementation plans to reduce its emissions. The objective of this study was to compile an emissions inventory of volatile organic compounds (VOCs) and nitrogen oxides (NOx) from nonroad equipment in Osceola, Seminole, and Orange Counties (OSO) in Central Florida, and to develop possible action steps to reduce those emissions. This is important because VOC and NOx emissions are precursors to ground-level ozone. Thus, compiling emissions inventories is important to identify high VOC and NOx emitters. Mobile and point sources have long been the highest emitters of VOC and NOx and have therefore been targeted and monitored since the Clean Air Act of 1970, but the nonroad sources (such as construction and lawn equipment) have only been regulated since the 1990s. Using the NONROAD and NMIM modeling programs, the highest nonroad emitters of VOC for Central Florida were found to be lawn/garden equipment, and boating equipment, emitting a combined percentage of 77% of the total nonroad mobile source VOC. Construction equipment contributed 67% of the total nonroad mobile source emissions of NOx in Central Florida. The components of these categories were also analyzed to find the largest individual sources of VOC and NOx. Of the individual sources, lawn mowers and outboard boat engines were found to be the largest sources of VOCs. Of the NOx sources, all the construction equipment components had a relatively similar level of NOx emissions. Next, action steps were developed to reduce emissions, focusing on the high emitters, along with an estimated cost and feasibility for each measure. Of these steps, implementing a ban on leafblowers, and reducing use of lawn mowers, edgers, trimmers, etc. seemed to be the most effective for reducing VOCs. Although these are effective measures, the cost and feasibility of both pose challenges. The best action step for reducing NOx emissions in construction equipment seemed to be by simply reducing idling of equipment on job sites. This also poses challenges in feasibility and enforcement by management. Further, constant on/off cycles could result in decreasing the useful life of the older construction equipment. Finally, a survey was conducted with various construction managers and companies to find out the typical equipment and quantity needed for land clearing/grubbing, as well as the typical use, idling time, and total project time for each piece of equipment on a 10-acre site, under various conditions. The purpose of the study was to develop a rough estimate for the average amount of VOC and NOx emissions that will be produced per acre of land clearing activities, and to estimate the emissions reductions and cost savings if idling of the equipment was reduced.M.S.Env.E.
Department of Civil and Environmental Engineering
Engineering and Computer Science
Environmental Engr MSEnvE
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Elkilani, Amal Sayed. "Modelling indoor volatile organic compound (VOC) levels based on experimentally determined parameters." Thesis, University of Bath, 1999. https://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.299681.
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Järnström, Helena. "Muovimattopinnoitteisen lattiarakenteen VOC-emissiot sisäilmaongelmatapauksissa /." [Espoo, Finland] : VTT, 2005. http://www.vtt.fi/inf/pdf/publications/2005/P571.pdf.
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Björkman, Joanna. "Utsläpp av Flyktiga Organiska Föreningar och Partiklar i Falun : Trafiken och industrins bidrag av PM10 och VOC." Thesis, Umeå University, Department of Ecology and Environmental Sciences, 2009. http://urn.kb.se/resolve?urn=urn:nbn:se:umu:diva-35419.
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Emissions from Particles and Volatile Organic Compounds (VOC) in Falun.-How is the emission divided between particles and VOC?
This study investigates the air quality in Falun, a small city in central Sweden, with a focus on particles and volatile organic compounds (VOC). Falun is located in a valley which makes it sensitive to inversions, when the vertical mixing of air over the city is prevented. When this happens emissions over the city can stay for days and the pollution levels can be high. The report is based upon a literature review, calculation of emissions from traffic and a survey of industrial emissions. Emission of VOCs can be dangerous to people and contributes to the production of ground- level ozone. Particles can be a carrier for other dangerous compounds. The result shows that high pollution levels caused by inversions can happen. The temperature, wind and temperature differences show that inversions during the winter months are possible up to half of the time. Emissions from cars and industries are a problem. The municipality forced to control air pollution and in Swedish law there is a threshold value for both particles and the volatile organic compounds benzene. Spreading of pollution in air in Falun is centered around the emission sourses. Because it´s hard to prevent inversions, the municipality must focus on reducing emission of pollutants. This can be done through road planning and diverting traffic to other routes around the city.
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Hoffmann, Stefanie. "Einfluss der Exposition mit flüchtigen organischen Verbindungen im Innenraum auf akute Bronchitis und allergische Erkrankungen von Kindern im 4. Lebensjahr – LISA-Studie." Doctoral thesis, Universitätsbibliothek Leipzig, 2011. http://nbn-resolving.de/urn:nbn:de:bsz:15-qucosa-69368.
Full textAbstract:
Flüchtige organische Verbindungen (Volatile organic compounds (VOC)) sind ubiquitär vorkommende kohlenstoffhaltige Substanzen. Untersuchungen haben relevante VOC-Konzentrationen im Inneren von Gebäuden nachgewiesen. Da der Innenraum zum typischen Aufenthaltsort des modernen Menschen geworden ist, sind diese Schadstoffe in das Interesse der Forschung gerückt. Kinder reagieren unter Schadstoffexposition besonders sensibel, denn viele wichtige Organsysteme befinden sich noch in ihrer Entwicklung.
In der vorliegenden Arbeit wurden Leipziger Daten der LISA-Studie („Einfluss von Lebensbedingungen und Verhaltensweisen auf die Entwicklung von Immunsystem und Allergien im Ost-West-Vergleich“) hinsichtlich möglicher Effekte einer VOC-Exposition auf Erkrankungen der Kinder im 4. Lebensjahr analysiert. Bei der LISA-Studie handelt es sich um eine multizentrische prospektive Geburts-Kohortenstudie, in die von November 1997 bis Januar 1999 insgesamt 3097 gesunde und reife Neugeborene deutscher Herkunft mit einem Geburtsgewicht > 2500 g rekrutiert wurden. Die Berechnungen der vorliegenden Arbeit erfolgten mit VOC-Messwerten um den 3. Geburtstag der Kinder. Die jeweiligen logistischen Regressionsmodelle wurden auf das Geschlecht, die atopische Familienanamnese, eine passive Tabakrauchexposition, das Aufstellen neuer Möbel im Kinderzimmer, Renovierungen und die Erneuerung des Fußbodenbelags in der Wohnung adjustiert.
Es ließen sich VOC bestimmen, die bei Konzentrationserhöhungen eine erhöhte Chance für eine akute Bronchitis zur Folge hatten. Als Risikofaktor einer akuten Bronchitis ließ sich außerdem die Erneuerung des Fußbodenbelags in der Wohnung ermitteln. Während sich für eine akute Bronchitis in Abhängigkeit der VOC-Konzentration erstmals eine Dosis-Wirkungs-Kurve ableiten ließ, war dies für allergische Erkrankungen nicht möglich.
Weitere Untersuchungen sind notwendig um Pathomechanismen der VOC-Einwirkungen auf den kindlichen Organismus aufzuklären.
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Le, Bechec Mickael. "Pollution de l’air intérieur : mesure, impact sur la santé et traitement par méthodes photochimiques." Thesis, Pau, 2016. http://www.theses.fr/2016PAUU3012/document.
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L’accroissement de la population humaine, l’agriculture intensive et le développement industriel créent une pollution de l’air qui aujourd’hui devient préoccupante pour notre santé et notre environnement. Si la qualité de l’air extérieur fait l’objet depuis plusieurs décennies de règlementations qui permettent aujourd’hui de constater une diminution globale de la pollution dans les grandes agglomérations européennes, la pollution de l’air intérieur a quant à elle été longtemps sous-estimée. En effet, avec le développement de matériaux composites pour la construction et l’ameublement, la gamme de polluants de l’air intérieur s’est très largement agrandie et les concentrations ont globalement augmenté. Plusieurs études ont ainsi montré que de nombreux composés organiques volatils étaient détectés dans l’air intérieur à des concentrations bien plus élevées qu’à l’extérieur. D’autre part, la modification des modes de vie sédentaires et citadines ont pour conséquence une augmentation du temps passé dans des espaces confinés comme les logements, les lieux de travail et les transports en commun. Le simple renouvellement de l’air intérieur par de l’air extérieur devenant de moins en moins satisfaisant dans les grandes agglomérations, de nouvelles méthodes de traitement sont actuellement développées pour diminuer les concentrations de ces polluants tout en limitant la consommation d’énergie. La photocatalyse, en tant que procédé d’oxydation avancé fait partie des technologies intéressantes pour minéraliser des composés organiques volatils (COV). Après un rapide rappel du contexte sociétal de la pollution atmosphérique, les conditions de mesures et les méthodes possibles pour le traitement de cette pollution sont présentées. Le chapitre suivant regroupe les résultats sur le développement de matériaux photocatalytiques innovants et la mesure de leur efficacité. La première partie de ce chapitre fait le bilan des réacteurs photocatalytiques adaptés à l’étude de réactions à l’interface solide-gaz et résume les nombreuses difficultés liées à l’évaluation des performances de divers matériaux dans des conditions le plus souvent difficilement comparables. Dans la seconde partie, un premier matériau composite constitué de film polymère et de dioxyde de titane a été caractérisé par sa capacité à oxyder un composé volatil, le diméthyle disulfure, utilisé en agriculture pour la fumigation. Le développement d’un second matériau photocatalytique original, constitué de fibres de TiO2 pur a, quant à lui, été caractérisé par sa capacité à minéraliser des COV représentatifs de la pollution de l’air intérieur (acétone, heptane, toluène). Les deux dernières parties de ce chapitre se situent à l’interface entre la photochimie et la biologie. Dans un premier temps, la capacité d’inactivation bactérienne d’un textile « intelligent » sur lequel sont fixées des particules de dioxyde de titane couplées à un photosensibilisateur a été étudiée et l’efficacité sous rayonnement visible de ce tissu original a été analysée. L’impact de la pollution de l’air intérieur sur des cellules de la peau fait l’objet de la dernière partie de ce chapitre. Pour cela un montage permettant d’exposer des cellules de kératinocytes en culture, mais également des biopsies de peau humaine, à des concentrations contrôlées en COV a été mis au point. Nous avons ainsi pu mettre en évidence une réponse cellulaire à ce stress environnemental et préciser l’origine de ce stress. Enfin ce travail se termine par une ouverture sur des projets de recherche actuellement en cours ayant pour objet la mesure des espèces réactives de l’oxygène impliquées dans les réactions photochimiques et le développement de nouveau matériaux hybrides polymère/photosensibilisateurs. Des idées de projets à l’interface de la photochimie et de la biologie ouvrent de nouvelles perspectives à la suite de ces premiers résultatsThe increase of human population, the modern agriculture and industrial development generate air pollution, which is nowadays worrying for health and environment. Since several decades, outdoor air pollution has been regulated giving rise a global decrease of pollution in the most important European cities. However indoor air pollution was neglected for a long time. Indeed with development of composite materials for building and furnishing, the number of air pollutants strongly increased together with their concentrations. Several studies have thus demonstrated that numerous volatile organic compounds (VOC) were detected indoor at much higher concentration than outdoor. Moreover, due to the modification of sedentary and urban lifestyles, the time spent in confined spaces like housing, working places and public transportation increases. It is less and less satisfactory to simply renew indoor air with outdoor air in most of urban agglomerations. Accordingly, new processes for air treatment are developed in order to decrease indoor air pollutant concentrations while limiting energetic consumption. Photocatalysis is an advanced oxidation process potentially interesting for VOC removal. After a short reminder on the societal context of atmospheric pollution, measurement and treatment methods are presented in chapters I and II. The following chapter gathers the results obtained on the development of new photocatalytic materials and on the measure of their efficiency. The first part of this chapter is devoted to an overview of photocatalytic reactors for gas solid reactions and summarizes the numerous problems arising from the comparison of different materials under various conditions, which are not always similar. In the second part, a composite material made of titanium dioxide encapsulated in a polymer film is characterized and used for the oxidation of a volatile compound used for agricultural fumigation, dimethyl disulfide. The spectroscopic analysis led to the optimization of the material as a function of its thickness and its titanium dioxide loading. A second innovative photocatalytic material made of pure TiO2 fibers is characterized by its mineralization ability of representative indoor air VOC (acetone, heptane, and toluene). The performance of this material is compared to that of a commercial one, Quartzel ® made of TiO2 deposited on quartz fibers, under strictly identical conditions. The two last parts of this chapter are at the interface between photochemistry and biology. In a first strep, bacterial inactivation by a smart textile where titanium dioxide particles coupled with a photosensitizer is studded under visible light. In the last part, the impact of indoor air pollution on skin cells is presented. A dedicated device allowing keratinocytes culture cells and skin biopsies exposures to controlled VOC concentrations is developed. It is thus possible to evidence and to determine the origin of the cellular response to this environmental stress. At last, new research projects for a near future are then presented. They concern the determination of reactive oxygen species involved in photochemical reactions and the development of new hybrid polymers encapsulating photosensitizing molecules. Prospective ideas at the interface of photochemistry and biology conclude this memory
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Hirota, Keiko School of Architecture UNSW. "Indoor air quality and post-disaster public housing: a case study of a Japanese post-disaster public housing on the effect of VOC emissions from building materials." Awarded by:University of New South Wales. School of Architecture, 2006. http://handle.unsw.edu.au/1959.4/26010.
Full textAbstract:
Since the beginning of the 20th century indoor air has produced distinctive pollution problems. The most critical pollutants in relation to indoor air quality (IAQ) are chemical contaminants which, in the form of volatile organic compounds (VOCs), have been identified as arising mainly from building materials. Conventional solutions such as ventilation systems and bake-out processes have been developed, but the IAQ problem, often reported as sick building syndrome (SBS), still persists. This study set out to establish to what extent VOCs may affect the health of occupants in a particular built environment, and how much architectural design factors, the use of particular building materials, and human activities may contribute to the problem of SBS. A further question was to establish to what extent current attempted solutions to IAQ problems, namely ventilation and bake-out, were in practice effective in a specific built environment. While previous research and attempted solutions have focused on work places as areas of concern for SBS, the problem is especially significant in residential housing and is particularly concentrated in post-disaster public housing (PDPH). For this reason the research was based on the case of a PDPH project in Abuta, Japan. To analyse the separate components of the problem, several distinct studies were undertaken. The level of pollutants in the air was analysed by means of chemical sampling of VOCs in two units of the PDPH, while the a SBS survey and assessment of the residents of the entire project, as well as interviews with the building professionals involved was designed to identify the human causes and effects of the situation. The effectiveness of the attempted solutions to the problem were considered by means of a study of the bake-out procedure, and finally an airflow simulation by computational fluid dynamics (CFD) was conducted to consider the design and ventilation features of the units in relation to IAQ. The study results have indicated that IAQ problems existed after the completion of construction. It was found that certain VOC levels were far above the guidelines, and the health hazard symptoms known for these VOCs matched the SBS symptoms found in participants??? health complaints. Interviews with building professionals involved in the project revealed that the lifestyles of the occupants were not seriously considered in the project design. The results of the airflow simulation also revealed problematic aspects of the planning design, exacerbating rather than limiting the pollution problem as intended. The study concludes with a number of recommendations for taking these inter-related aspects of the problem into consideration in future, so that the health of residents is not adversely affected.
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Dogan, Guray. "Determination Of Ambient Levels And Sources Of Volatile Organic Compounds In Izmir-aliaga Region." Phd thesis, METU, 2013. http://etd.lib.metu.edu.tr/upload/12615633/index.pdf.
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In this study, atmospheric levels and sources of VOCs at Aliaga industrial area was investigated. For this, VOC concentrations were measured at two monitoring stations through winter and summer campaigns in 2005 and 2006. Sampling stations were located in downtown Aliaga and downwind of industrial facilities, approximately 500 m to the south east of Horozgedigi village. After the summer sampling, another temporary station was installed in between PETKIM and TÜPRAS, named as TÜ
PRAS Station to generate TÜ
PRAS and PETKIM profiles. More than 50 species were measured in all stations. In all stations, toluene has the highest contribution to total VOC concentration. Toluene is followed by m,p-xylene and benzene. While higher concentrations of traffic related VOCs were measured at Aliaga station, VOCs from industrial solvents and industrial processes were higher at Horozgedigi station. The concentration levels in Aliaga and Horozgedigi are found to be comparable to the other industrial regions reported in the literature. Investigation of episodes, diurnal variations of VOCs and meteorological parameters showed that PETKIM and TÜ
PRAS emissions affect the concentrations levels at Horozgedigi and Aliaga stations. Source profiles of PETKIM and TÜ
PRAS are determined by using the TÜ
PRAS station data set. 2-methyl-hexane, benzene and 2,2,3-tri-methyl-butane+2,3-di-methyl-pentane are found to be good markers of PETKIM emissions. Ten different VOC sources were identified in the region. These were gasoline exhaust, diesel exhaust, natural gas use, gasoline evaporation, industrial emissions-1, natural gas construction, non-industrial solvent use, industrial emissions-2, PETKIM emissions, and mixed emissions from PETKIM and shipbreaking facilities.
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Languille, Baptiste. "Caractérisation des variabilités temporelle et spatiale de la pollution en Île-de-France : De la mesure de l'exposition individuelle à la définition des sources." Thesis, Université Paris-Saclay (ComUE), 2019. http://www.theses.fr/2019SACLV071/document.
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La pollution atmosphérique résulte d’un mélange complexe de composés, des gaz et des particules, dont les effets sont notoirement néfastes. Les composés organiques volatils (COV) tiennent un rôle prépondérant dans la chimie atmosphérique et sont précurseurs d’ozone et d’aérosols organiques secondaires (AOS). En Île-de-France, l’exposition à la pollution est préoccupante ; or, des incertitudes significatives sont toujours associées aux sources de polluants, ainsi qu’à leur intensité et leurs variabilités à différentes échelles de temps et très peu d’investigations ont porté sur la quantification de l’exposition individuelle. Dans ce contexte, cette thèse a cherché à mieux caractériser les variabilités temporelle et spatiale de la pollution en Île-de-France.La fiabilité discutable des capteurs portables a été dépassée par l’élaboration d’un protocole de sélection et de qualification comprenant différents tests en mesures fixes, en chambre et en mobilité. Cette nouvelle méthodologie, basée notamment sur l’utilisation d’un outil combinant différents indicateurs statistiques, a été appliquée pour retenir l’AE51, le Cairclip et le Canarin, mesurant respectivement le carbone suie (BC), le dioxyde d’azote (NO2) et les particules (PM).Ces trois capteurs ont été déployés au cours de campagnes de mesures impliquant une trentaine de volontaires. L’exposition individuelle ainsi quantifiée est plus élevée à l’automne qu’au printemps et varie de manière substantielle en fonction des différents environnements fréquentés. La proximité de la circulation routière (pour le BC et le NO2) ainsi que les activités de cuisine et la fumée de tabac (pour les PM) présentent des contributions importantes à l’exposition totale (jusqu’à 34 %, 26 % et 44 % respectivement), alors même que le temps passé dans ces environnements est faible.En plus du trafic routier, le BC est traditionnellement imputé au feu de bois. Une campagne hivernale de mesures (3,5 mois) a permis d’imputer respectivement 22 % et 47 % des COV mesurés à ces deux sources. Certains composés ont été mesurés et associés au feu de bois pour la première fois en air ambiant comme le benzènediol et le méthylbutènone. Une comparaison avec l’inventaire régional des émissions a permis d’identifier des similitudes et des différences pour proposer des améliorationsAir pollution results from a complex mixture of compounds, gases and particulate matter, whose effects have proven to be harmful. Volatile organic compounds (VOCs) play a major role in atmospheric chemistry and are precursors of ozone and secondary organic aerosols (SOAs). In Île-de-France, exposure to pollution is a concern; however, significant uncertainties are still associated with the pollutants’ sources, as well as their intensity and variability at different time scales, and very few investigations have focused on quantifying personal exposure. In this context, this research sought to better characterize the temporal and spatial variabilities of pollution in Île-de-France.The questionable reliability of portable sensors has been addressed by the design of a selection and qualification protocol including various tests in static measurements, controlled chamber and mobility. This new methodology, based in particular on the use of a tool combining different statistical indicators, was applied to choose the AE51, Cairclip and Canarin, measuring black carbon (BC), nitrogen dioxide (NO2) and particulate matter (PM) respectively.These three sensors were deployed during measurement campaigns involving about thirty volunteers. The personal exposure thus quantified is higher in fall than in spring and varies substantially according to the different environments frequented. Proximity to road traffic (for BC and NO2) as well as cooking activities and tobacco smoke (for PM) make significant contributions to total exposure (up to 34 %, 26 % and 44 % respectively), even though the time spent in these environments is short.In addition to road traffic, BC is traditionally attributed to wood burning. A winter measurement campaign (3.5 months) attributed respectively 22 % and 47 % of the measured VOCs to these two sources. Compounds including benzenediol and methylbuteone were measured and associated with wood burning for the first time in ambient air. A comparison with the regional emissions inventory identified similarities as well as differences and suggested improvements
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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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Alvarez, Elsa. "Traitement de l'air habitacle par des matériaux hybrides de type Metal-Organic Frameworks." Thesis, Université Paris-Saclay (ComUE), 2016. http://www.theses.fr/2016SACLV006/document.
Full textAbstract:
La sensibilisation du grand public à la pollution intérieure, les exigences croissantes des réglementations/recommandations le tout combiné à une nécessité de se démarquer de la concurrence, font de la limitation de la concentration des COV (COV : Composés Organiques Volatiles) dans l’air habitacle un enjeu crucial pour l’industrie automobile. En effet, à l’intérieur des véhicules, les COV sont principalement issus de l’air extérieur par combustion et évaporation du carburant mais, contrairement aux autres polluants, peuvent également avoir une origine intérieure à l’habitacle de par la désorption de substances chimiques utilisées lors de la fabrication des matériaux présents dans le véhicule. La capture des COV par adsorption sur charbons actifs ou zéolithes est à ce jour l’une des techniques d’abattement des COVs les plus efficaces et les moins coûteuses mais souffre de certaines limitations (sélectivité, régénération). L’objectif de cette thèse a consisté à étudier une alternative avec l’emploi d’une autre classe d’adsorbants ‘hybrides’ : les Metal-Organic Frameworks (MOFs). Formés de briques inorganiques connectées par des ligands organiques, ces matériaux poreux cristallisés présentent une grande diversité structurale ainsi qu’une composition chimique (métal, ligand) et une porosité (taille des pores, surface spécifique et volume poreux) extrêmement modulables. Cela vient de la possibilité quasi-infinie de faire varier à la fois le centre métallique et le ligand organique, ce que l’on ne retrouve pas à cette échelle chez les zéolithes et les charbons actifs. Le travail a consisté à évaluer les performances d’une série d’une dizaine de MOFs, possédant des propriétés chimiques (acidité, redox, hydrophiles/hydrophobes, …) et structurales (taille et forme des pores, réseaux rigides ou flexibles…) différenciées mais aussi de leur stabilité avérée (eau, température) et mise à l’échelle déjà établie. En plus des caractérisations usuelles (diffraction des rayons X, analyse thermogravimétrique, spectroscopie Infra-Rouge, porosimétrie N2 à 77K), la spectroscopie Infra-Rouge operando a été utilisée pour simuler le comportement de ces MOFs en présence de COV dans des conditions aussi proches que possible de la réalité. Les adsorbants les plus prometteurs ont ensuite été mis à l’échelle (50-100 g) et mis en forme (pastilles) puis testés en chambre de simulation environnementaleThe indoor air pollution awareness of general public and the increasing demands of regulations / recommendations, combined with a need to stand out from the competition, make limiting the concentration of VOCs (VOCs : volatile organic compounds ) in the air cockpit crucial for the automotive industry. For example, inside a vehicle, the VOCs are originated from the outside air by combustion and evaporation of fuel. However, unlike other pollutants, it may also have an inner origin from the desorption of existing chemical substances used in the manufacture of the vehicle. Thus, the capture of VOCs by adsorption is one of the challenging techniques today. In this context, activated carbon and zeolite based VOC abatement are effective and least expensive but suffers some limitations in stability, selectivity and regeneration. The aim of this thesis was to study an alternative class of 'hybrid' adsorbents i.e. Metal-Organic Frameworks (MOFs). These porous crystalline materials are built by the association of inorganic bricks connected by organic ligands. They have highly tunable structural diversity,chemical composition (metal:ligand) and porosity (pore size, surface area and pore volume). Moreover, they possess almost infinite ability to vary both the metal center and the organic ligand that is not found at this level in zeolites and activated carbons. The work was to evaluate the performance of a series of ten MOFs, having diverse architecture (size and shape of the pores, rigid or flexible networks ...), chemical properties (acidity, redox, hydrophilic / hydrophobic, ...) and stability (water temperature). In addition to the usual characterization (X-ray diffraction, thermogravimetric analysis, infrared spectroscopy, porosimetry N2 at 77K), Infra-Red spectroscopy operando was performed to simulate the behavior of these MOFs in the presence of VOCs in conditions as close as possible to the reality. Furthermore, the most promising adsorbents were scaled up (50-100 g) and formatted/fabricated as pellets and tested for environmental simulation chamber
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Lim, Guo Quan. "Evaluation of the Influence of Non-Conventional Sources of Emissions on Ambient Air Pollutant Concentrations in North Texas." Thesis, University of North Texas, 2015. https://digital.library.unt.edu/ark:/67531/metadc804841/.
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Emissions of air pollutants from non-conventional sources have been on the rise in the North Texas area over the past decade. These include primary pollutants such as volatile organic compound (VOC) and oxides of nitrogen (NOx) which also act as precursors in the formation of ozone. Most of these have been attributed to a significant increase in oil and gas production activities since 2000 within the Barnett Shale region adjacent to the Dallas-Fort Worth metroplex region. In this study, air quality concentrations measured at the Denton Airport and Dallas Hinton monitoring sites operated by the Texas Commission on Environmental Quality (TCEQ) were evaluated. VOC concentration data from canister-based sampling along with continuous measurement of oxides of nitrogen (NOx), ozone (O3), particulate matter (PM2.5), and meteorological conditions at these two sites spanning from 2000 through 2014 were employed in this study. The Dallas site is located within the urban core of one of the fastest growing cities in the United States, while the Denton site is an exurban site with rural characteristics to it. The Denton Airport site was influenced by natural gas pads surrounding it while there are very few natural gas production facilities within close proximity to the Dallas Hinton site. As of 2013, there were 1362 gas pads within a 10 mile radius to the Denton Airport site but there were only 2 within a 10 mile radius to Dallas Hinton site. The Dallas site displayed higher concentrations of NOx and much lower concentrations of VOC than the Denton site. Extremely high levels of VOC measured at the Denton site corresponded with the increase in oil and gas production activities in close proximity to the monitoring site. Ethane and propane are two major contributors to the measured VOC concentration, suggesting the influence of fugitive emissions of natural gas. In Dallas, the mean and maximum values of ozone had decreased since 2000 by about 2% and 25%, respectively. Similarly NOx decreased by 50% and 18% in the mean and maximum values. However, the mean VOC value showed a 21% decrease while the maximum value increased by about 46%. In Denton, the change in percentage of ozone and NOx were similar to Dallas but the mean VOC concentration increased by about 620% while the max value increased 1960%. Source apportionment analysis confirmed the findings by identifying the production of natural gas to be the primary source of VOC emissions in Denton, while traffic sources were more influential near the Dallas site. In light of the recent proposal by EPA to revise the ozone standard, the influence of these new unconventional sources should be further evaluated.
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Bikbajeva, Žana. "Research of volatile organic compounds from petrol filling stations." Master's thesis, Lithuanian Academic Libraries Network (LABT), 2008. http://vddb.library.lt/obj/LT-eLABa-0001:E.02~2008~D_20080627_142040-20633.
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The research focuses on the environmental problem of volatile organic compounds in ambient air of petrol filling stations. The literature review of the issues, arising from petrol-related VOCs, with actual and proposed VOC emissions trends in Europe, have been performed. Besides petrol filling station’s typical technology layout, petrol nature and composition, applicable petrol vapour recovery solutions and their efficiency were examinated. The volatile organic compounds’ experimental research in two petrol stations of typical technology layout in Vilnius city under similar extreme meteorological conditions (VOC air pollution episodes with low winds, stable stratification and suspended photochemical removal) is done. The emitted from petrol stations VOC experiment is based on air pumped sampling in glass gas pipette and further determination using gas chromatography with flame ionization detector. The experimental results, presented by means of tables and diagrams, are analysed and discussed. The available results of the experiment are loaded into the environmental model “ALOHA” for air pollution evaluation and concentrations prediction in the ambient air under different meteorological conditions and technological emergency situations (petrol spillage) at petrol filling station. The research is summarized in conclusions and recommendations.Tyrimas skirtas aplinkos oro taršos problemai lakiaisiais organiniais junginiais, išsiskiriančiais nuo benzino degalinių. Atlikta svarstomos aplinkosauginės problemos literatūros apžvalga. Apžvelgti oro taršos pasekmės skatinamos LOJ išsiskyrimų nuo benzino degalinių, aktualios ir numatomos LOJ emisijų tendencijos Europoje, tipinis benzino degalinės technologijos išsidėstymas, benzino sudėtis ir svarbiausios LOJ garų formavimui benzino savybės, taikomi garų grąžinimo sprendiniai ir jų efektyvumas. Detaliai aprašytas LOJ eksperimentinis tyrimas, atliktas dviejose Vilniaus miesto tipinės technologijos degalinėse esant panašioms kraštutinėms (LOJ taršos epizodai prie silpnų vėjų, stabilios stratifikacijos ir suspenduoto fotocheminio šalinimo) meteorologiniams sąlygoms. LOJ mėginių ėmimui panaudotas aktyvus metodas su aspiracija į dujines pipetes, LOJ koncentracijos nustatytos dujinės chromatografijos su liepsnos jonizacijos detektoriumi metodu. Tyrimo rezultatai, pateikti lentelių ir diagramų pavidalu, aptarti ir įvertinti. Eksperimento duomenys įkelti į oro kokybės modelį “ALOHA”, siekiant nustatyti LOJ pernašą ir sudaryti LOJ koncentracijų prognozė benzino degalinių aplinkos ore prie skirtingų meteorologinių parametrų ir avarinių technologinių situacijų (benzino išsiliejimas). Tiriamąjį darbą reziumuoja išvados ir rekomendacijos.
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Xiang, Yang. "Analyse dynamique en champ proche de la contribution des sources de composés organiques volatils, en région urbaine sous influence industrielle." Thesis, Littoral, 2011. http://www.theses.fr/2011DUNK0408.
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À ce jour, l'identification des sources de Composés Organiques Volatils (COV) a fait l'objet de nombreuses études, afin de déterminer leur contribution à la pollution atmosphérique. Néanmoins, le comportement dynamique de l'atmosphère, dans sa dimension micro-météorologique, n'a jamais été pris en compte dans une approche sources-récepteur. Celui-ci est pourtant essentiel dans l'interprétation des mesures physico-chimiques de la pollution de l'air en champ proche, dans une région urbaine sous influence industrielle. La complexité de ces zones d'études provient non seulement des différents modes d'émissions et de la variété des activités industrielles, mais aussi des phénomènes météorologiques à multi-échelles, qui influent la dispersion et le transport à petite échelle spatiale (typiquement quelques kilomètres). En nous appuyant sur la mesure de 85 COV (dont 23 COV oxygénés) sur une durée de plusieurs mois, nous avons développé une méthodologie novatrice, associant lors de l'analyse des résultats d'un modèle sources-récepteur PMF (Positive Matrix Factorization) des grandeurs météorologiques, pour identifier des sources et comprendre leur comportement dynamique. En introduisant la turbulence verticale, pour la première fois dans ce type d'analyse, la température et le rayonnement solaire, comme paramètre d'analyse des facteurs de comportements ont pu être différenciés, permettant de distinguer les modes d'émissions diffuses et canalisées. Ainsi, nous avons pu classer les sources des COV par nature et par mode d'émissions, et également mettre en évidence des masses d'air âgées contenant des espèces secondairesRecently, sources apportionment of Volatile Organic Compounds (VOC) has been the subject of a great numbers of studies, in order to determine their contributions to atmospheric pollution. However, the dynamical behavior of atmosphere, within its micro-meteorological scale, has never been taken into account in the sources-receptor approach, yet it is the main factor to interpret near-field physic-chemical measurements of air pollution, in an urban area under industrial influences. The complexity of such a study area results from not only the emission modes and the various industrial activities, but also the meteorological phenomenon in multi-scale, which influences the dispersion and transport in a small scale (tipically several kilometers). With measurements of 85 VOC (including 23 oxygenated VOC) during several months, we have developed an innovative methodology, associating the results of the PMF (Positive Matrix Factorization) modeling and the meteorological parameters, in order to identify the sources and to understand their dynamical behaviors. By introducing the vertical turbulence for the first time in this kind of analysis, the temperature and the solar radiation, as parameters of factor analyses, two behaviors have been distinguished, leading to identify the emissions near ground and in the upper part of surface layer. In this way, we have labeled the sources according to their nature as well as their emission mode, and we have highlighted the aged air mass containing secondary pollutants
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Olivet, Lilian. "Élaboration de matériaux innovants pour l'élimination de polluants organiques de l'air intérieur : application à l'oxydation catalytique du formaldéhyde." Thesis, Poitiers, 2019. http://www.theses.fr/2019POIT2312.
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La pollution de l’air fut considérée comme responsable de 7 millions de morts prématurées en 2015 et provient de deux origines principales : l’air extérieur ou intérieur. En effet, le manque de renouvellement d’air dans des espaces clos tels que les maisons, les bureaux, les écoles, ... conduit à des concentrations en polluants plus importantes que dans des espaces ouverts. Les composés organiques volatils sont considérés comme l’une des plus grandes familles de polluants. Parmi eux, le formaldéhyde, qui provoque des irritations à de faibles teneurs et qui est depuis peu classé comme produit cancérogène 1B, peut se retrouver en quantité non négligeable dans des espaces clos suite à des phénomènes de combustion, par relargage des plastiques, meubles en bois, produits d’entretien ou encore matériaux isolants.La catalyse hétérogène peut être un moyen efficace d’éliminer ces molécules nocives en transformant le formaldéhyde en dioxyde de carbone à la plus basse température possible. Dans le but de remplacer les métaux nobles, à l’activité très élevée mais dont le coût et la rareté sont des freins à leur utilisation, l’étude de 3 familles de matériaux a été abordée au cours de ce travail. Dans un premier temps, l’utilisation de zéolithes de type H-ZSM5 modifiée par substitution isomorphe post synthèse semblait être une solution intéressante de par les propriétés adsorbantes du matériau parent d’une part et d’autre part grâce à la fonction oxydante apportée par la présence de nouveaux éléments tels que le cobalt, le fer, le manganèse ou encore le cérium. La modification de la zéolithe mère a conduit à une amélioration nette de l’activité catalytique puisque la conversion totale a été atteinte dans le cas des zéolithes modifiées à l’aide du manganèse, du fer et du cérium dès 300°C pour l’échantillon le plus actif tandis que le matériau parent permettait d’obtenir une conversion de seulement 70 % à 500°C. L’échantillon au manganèse s’est toutefois démarqué par son activité bien plus importante que les autres matériaux de la série. Cependant, les activités catalytiques observées étaient bien loin des performances observées sur des échantillons contenant des métaux nobles.Un second volet de cette étude concernait les matériaux à base d’oxydes de cérium qui semblaient également être de bons candidats pour des réactions d’oxydation du fait de leur capacité à stocker et déstocker de l’oxygène. Ces matériaux, préparés par sol-gel par voie époxyde à base de cérine-zircone dopée par du cuivre, cobalt, fer ou manganèse ont montré que les conditions de synthèse utilisées conduisaient principalement à l’obtention de composés mixtes d’oxydes non homogènes. Les tests catalytiques ont montré que l’ajout d’un métal de transition à des matériaux de type cérine-zircone améliorait l’activité catalytique. Le matériau le plus actif pour la réaction d’oxydation du formaldéhyde était celui contenant du cuivre. La principale amélioration a résidé dans la sélectivité de la réaction. En effet, le dopage par ces métaux de transition conduit principalement à la formation de CO2 accompagné d’acide formique, de CO mais également d’un produit de réduction, le méthanol, conduisant à confirmer l’une des rares études présente sur le sujet dans la littérature.Enfin, des études antérieures ayant mis en évidence l’existence d’un effet de synergie dans des matériaux de type CuO-ZnO-Al2O3 pour la réaction d’hydrogénation du CO2 en méthanol, une partie plus exploratoire a alors été dédiée à l’étude de ces solides dans la réaction d’oxydation catalytique du formaldéhyde. Il a pu être observé que les matériaux contenant de l’oxyde de cuivre permettaient d’obtenir les meilleures activités catalytiques tout en évitant la formation de co-produits de réaction indésirables.Cette étude a montré le fort potentiel de ces matériaux pour l’oxydation du formaldéhyde avec des métaux peu chers et très abondants, actifs et très sélectifs en CO2, réduisant ainsi la pollution intérieureAir pollution was considered responsible for 7 million premature deaths in 2015 and comes from two main sources: outdoor and indoor air. Indeed, the lack of air renewal in confined spaces such as houses, offices or schools leads to higher pollutant concentrations than in open spaces. Volatile organic compounds are considered to be one of the largest families of pollutants. Among them, formaldehyde, which causes irritation at low levels and has recently been classified as a carcinogenic 1B, can be found in significant amounts in confined spaces following combustion phenomena, from plastics, wooden furniture, cleaning products or insulating materials.Heterogeneous catalysis can be an effective way to remove these harmful molecules by transforming formaldehyde into carbon dioxide at the lowest temperature possible. In order to replace noble metals, whose activity is very high but whose cost and rarity are obstacles to their use, the performances of 3 families of materials were discussed during this work. At first, the use of zeolites of the H-ZSM5 type modified by post synthesis isomorphic substitution seemed to be an interesting solution due to the adsorbent properties of the parent material on the one hand and on the other hand thanks to the oxidative function provided by the presence of new elements such as cobalt, iron, manganese or even cerium. The modification of the parent zeolite led to a clear improvement in catalytic activity since the total conversion was achieved in the case of zeolites modified with manganese, iron and cerium from 300°C for the most active sample while the parent material allowed a conversion of only 70% at 500°C. However, the manganese sample stood out for its much higher activity than the other materials in the series. However, the catalytic activities observed were far from the performance observed on samples containing noble metals.A second part of this study concerned materials based on cerium oxides which also seemed to be good candidates for oxidation reactions due to their ability to store and remove oxygen. These materials, cerina-zirconia doped with copper, cobalt, iron or manganese, prepared by an epoxid sol-gel method, showed that the synthesis conditions used mainly led to the production of mixed non-homogeneous oxides. Catalytic tests have shown that the addition of a transition metal to ceria-zirconia materials can improve their catalytic activity. The most active material for the oxidation reaction of formaldehyde was copper-containing material. The main improvement was the selectivity of the reaction. Indeed, doping with these transition metals mainly leads to the formation of CO2 while forming formic acid and CO, but also to reduction product, methanol, which confirms one of the few studies on the subject in the litterature.Finally, previous studies having shown the existence of a synergistic effect in CuO-ZnO-Al2O3 materials for the hydrogenation reaction of CO2 to methanol, a more exploratory part was then dedicated to the study of these solids in the catalytic oxidation reaction of formaldehyde. It has been observed that materials containing copper oxide provide the best catalytic activities while avoiding the formation of undesirable reaction co-products. This study showed the high potential of these materials for the oxidation of formaldehyde with cheap, very abundant, active and highly CO2 selective metals, thus allowing to reduce indoor pollution
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Baudic, Alexia. "Caractérisation expérimentale et statistique des sources de Composés Organiques Volatils (COV) en région Île-de-France." Thesis, Université Paris-Saclay (ComUE), 2016. http://www.theses.fr/2016SACLS537/document.
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Les composés organiques volatils (COV) jouent un rôle majeur au sein du système atmosphérique puisqu’ils interviennent en tant que précurseurs d’ozone troposphérique et d’aérosols organiques secondaires (composés aux divers impacts sanitaires et climatiques) ; d’où le réel besoin de mieux les caractériser. A ce jour, de fortes incertitudes demeurent quant à leur nature, leur quantification et la contribution de leurs sources d’émissions respectives.Cette thèse propose, au travers d’expérimentations de laboratoire et de terrain, une caractérisation exhaustive des COV et de leurs principales sources d’émissions en région Île-de-France. Les méthodes mises en place dans ce travail de thèse reposent sur la détermination de profils de spéciation caractéristiques du trafic routier, du chauffage au bois et du gaz naturel à partir d’investigations en champ proche (en tunnel, en cheminée et à partir d’un conduit de gaz domestique). Ces différents profils de source ont été utilisés comme empreinte chimique de référence pour l’identification des principales sources d’émissions de COV, dont les contributions respectives ont été estimées à l’aide du modèle source-récepteur Positive Matrix Factorization (PMF), appliqué sur une année d’acquisition de mesures COV (HCNM+COVO) à Paris. Ce travail de thèse a ainsi permis, pour la première fois, d’étudier la variabilité saisonnière des COV et de leurs sources majeures. Les émissions liées au trafic routier ont été révélées comme la principale source de COV d’origine locale/régionale à Paris (contribuant à ¼ des émissions totales à l’échelle annuelle). L’impact prépondérant du chauffage au bois en hiver (50 % de la masse totale COV mesurée) a également été mis en évidence. Les résultats de cette étude de répartition de sources ont été confrontés à l’inventaire des émissions d’Airparif. Nous avons souligné un bon accord entre nos observations et l’inventaire pour les sources liées au trafic automobile et au chauffage au bois.Cette évaluation indépendante des inventaires est essentielle puisque ces derniers sont aujourd’hui utilisés comme données d’entrée au sein des modèles de prévision de qualité de l’airVolatile organic compounds (VOCs) play a key role within the atmospheric system acting as precursors of ground-level ozone and secondary organic aerosols (causing health and climatic impacts); hence the growing interest of better characterizing them. Significant uncertainties are still associated with compounds speciation, quantification and respective contributions from the different emission sources.This thesis proposes, through several laboratory and intensive field campaigns, a detailed characterization of VOCs and their main emissions sources within the Île-de-France region. We used methods based on the determination of speciation profiles indicative of road traffic, wood burning and natural gas sources obtained from near-field investigations (inside a tunnel, at a fireplace and from a domestic gas flue). These different source profiles were used as chemical fingerprints for the identification of the main VOC emission sources, which respective contributions were estimated using the Positive Matrix Factorization (PMF) source-receptor model applied to one-year VOCs (including NMHC+OVOC) measurements in Paris. This thesis allowed, for the first time, to evaluate the seasonal variability of VOCs and their main emission sources. Road traffic-related emissions are major VOC local/regional sources in Paris (contributing to a quarter of total annual emissions). The important impact of wood burning in winter (50 % of the VOC total mass) was observed. Results obtained from this approach were compared with the regional emissions inventory provided by the air quality monitoring network Airparif. Finally, a good agreement was found between our observations and the inventory for road traffic and wood burning-related sources.This independent assessment of inventories is of great interest because they are currently used as input data within air quality prediction models
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Koeta, Ouya. "Élimination des polluants par plasmas froids et association à la catalyse : acétaldéhyde et phénol." Thesis, Paris 11, 2015. http://www.theses.fr/2015PA112131/document.
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L'objectif de ce travail était d'une part d'étudier la dégradation du phénol en milieu aqueux par un plasma GlidArc d'air humide et d'autre part d'étudier la conversion de l'acétaldéhyde dans des gaz atmosphériques par un plasma DBD généré par une haute tension impulsionnelle. Les résultats de l'étude paramétrique de la dégradation du phénol ont montré une augmentation de l'efficacité en fonction de la concentration initiale et du débit d'air humide. L'augmentation du gap entre les électrodes à occasionné celle de la concentration des ions nitrates. La majeur parie des nombreux produits de réactions est constituée d'acides carboxyliques mais aussi d'hydroquinone, de para-nitrophénol et de para-nitrosophénol. Cette identification a permis de dresser un schéma réactionnel de la dégradation du phénol. La conversion de l'acétaldéhyde a été effectuée dans des conditions de température allant de l'ambiante jusqu'à 300°C et dans deux types de mélanges: CH3CHO/N2 et CH3CHO/N2/O2 (jusqu'à 10% O2). Les résultats ont montré que le coût énergétique baisse en présence d'oxygène dans le mélange et également lorsque la température augmente. Les principaux sous-produits identifiés dans CH3CHO/N2 sont CO, H2, CH4, HCN, C2H6, CH3CN tandis que dans les mélanges oxygénés, CO2 et CO, CH2O, CH3OH sont les sous-produits les plus importants. L'étude cinétique menée à la suite de cette analyse grâce à un modèle 0D simplifié a permis de mettre en évidence le rôle primordial de la dissociation par quenching des états métastables d'azote et de l'oxydation notamment par O et OH dans la conversion de l'acétaldéhyde. La modélisation a aussi permis de comprendre les processus de formation des sous-produits majoritaires. Des catalyseurs à base de MnO2 ont été placés en aval de la zone de décharge pour décomposer l'ozone qui se forme abondamment dans les mélanges oxygénés surtout à basse température. L'oxygène atomique produit lors de cette décomposition oxyde l'acétaldéhyde résiduel et ses sous-produits. Le coût énergétique a ainsi été diminué et les concentrations des sous-produits comme CH2O et CH3OH ont été réduitesThis work aimed to study the degradation of aqueous phenol by humid air GlidArc plasma and to study the removal of acetaldehyde in atmospheric gas by pulsed DBD plasma. The parametric study of phenol degradation showed an increase in efficiency as a function of the initial concentration and humid air flow. The increase of the inter-electrodes gap has increased nitrate ions concentration. The numerous reaction products formed consist mostly of carboxylic acids. Other byproducts identified are hydroquinone, para-nitrophenol and para-nitrosophenol. By-products identification enabled drawing a reaction scheme of phenol degradation. The acetaldehyde removal has been achieved in temperature conditions ranging from ambient to 300°C and in two types of mixtures: CH3CHO/N2 and CH3CHO/N2/O2 (up to 10 % O2). The results showed that the energy cost decreases in the presence of oxygen in the mixture as well as when the temperature increases. In CH3CHO/N2, the main by-products are CO, H2, CH4, HCN, C2H6, CH3CN whereas in oxygenated mixtures, CO2 and CO, CH2O, CH3OH are the most important by-products. The kinetic study following this analysis, by using a simplified 0D model has highlighted the key role of the quenching of nitrogen metastables states and that of the oxidation of acetaldehyde, caused in particular by O and OH. The modeling also helped understanding the formation processes of major by-products. A MnO2 based catalyst was placed downstream of plasma zone in order to decompose ozone that is abundantly formed in oxygenated mixtures especially at low temperature. The atomic oxygen produced during this decomposition is used to oxidize the residual acetaldehyde and its by-products. The energy cost was thus decreased and the concentrations of certain by-products such as CH2O and CH3OH have been reduced as well
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Pham, Huu Thien. "Contribution à l'étude de la dépollution de l'air chargé en composés organiques volatils par un procédé associant un plasma de décharge à barrière diélectrique impulsionnelle et des catalyseurs." Thesis, Orléans, 2014. http://www.theses.fr/2014ORLE2022/document.
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Cette thèse s’inscrit dans le cadre général de la dépollution d’effluents gazeux faiblement chargés en Composés Organiques Volatils (COV). L’étude concerne l'oxydation de trois COV cibles (méthane, propène, et toluène) dans l'air à la pression atmosphérique dans d'une part un réacteur plasma de décharge à barrière diélectrique (DBD) pulsée et un réacteur catalytique utilisés séparément et d'autre part, dans un réacteur hybride associant le réacteur plasma aux catalyseurs dans deux configurations: le catalyseur au coeur de la décharge et le catalyseur en post-décharge. Les catalyseurs sont à base de Pd, Mn, Cu, et Co supportés sur des billes de Al2O3. Ils ont été caractérisés par ICP-OES, TEM/EDX, XRD, XPS, et DRIFTS. L’efficacité de conversion des COV, la sélectivité en CO/CO2, ainsi que la nature et les concentrations des produits formés pour les trois molécules avec les trois systèmes ont été étudiées en fonction de la température du gaz, de l'énergie injectée, de la concentration des COV, de la taille du support, du type de métal et sa teneur, et de la vitesse volumique horaire. Dans tous les cas, l’activation des catalyseurs à basse température a été démontrée quand ces derniers sont couplés au plasma et les principaux produits de réaction identifiés et quantifiés par spectroscopie infrarouge à transformée de Fourier. Le couplage plasma-catalyseur améliore de façon significative l’efficacité de conversion du méthane, du propène, et du toluène dans l’air ainsi que la sélectivité en sous-produits. L'effet de synergie entre le plasma et les catalyseurs pour la conversion des COV a été démontré dès lors que le plasma est généré directement au sein du réacteur catalytiqueThe focus of this thesis is the application of non-thermal plasma and catalysis in chemical processing, in particular for the removal of Volatile Organic Compounds (VOC) diluted in air. In a first part, the oxidation of three pollutants (methane, propene, and toluene) is studied experimentally in a pulsed dielectric barrier discharge (DBD) reactor and in a catalyst reactor working independently. In a second part, a hybrid plasma-catalyst reactor either in a single-stage or in a two-stages configuration, in which the catalyst is located inside or downstream from the plasma reactor, respectively. Catalyst materials based on Pd, Mn, Cu, and Co supported on alumina beads were tested and characterized by ICP-OES, TEM/EDX, XRD, XPS, and DRIFTS. Products were analyzed and quantified by infrared spectroscopy. Achieved VOCs removal efficiencies and CO/CO2 selectivity, as well as nature and concentrations of the formed products, were evaluated as function of many factors, particularly the specific input energy, the gas temperature, the initial VOCs concentration, the nature of catalyst (size support, metal loading), and the hourly space velocity. It has been successfully demonstrated that the combination of plasma and catalyst in the both configurations has many benefits compared to traditional thermal-catalysis and plasma alone treatment including a lowering of the catalyst operating temperature, an improvement of the conversion of VOCs at similar temperatures, and a better end-products selectivity and energy efficiency. The mutual interaction lead to a synergistic effect in plasma-catalysis especially when the discharge is in direct contact with the catalyst whatever the VOCs studied
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Matin, Maleeha. "A study of the impact of unconventional sources within a large urban area: evidence from spatio-temporal assessment of volatile organic compounds." Thesis, University of North Texas, 2016. https://digital.library.unt.edu/ark:/67531/metadc849645/.
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Conventional sources of emissions have been a prime target for policymakers in designing pollution control strategies. However, the evolution of shale gas activities is a growing concern over the impact of unconventional sources on urban and regional air quality. Owing to the development of Barnett Shale production, the fast-growing Dallas-Fort Worth (DFW) metroplex has encountered both types of these emissions. Oil and gas activities result in emissions of ozone precursors, notably volatile organic compounds (VOC). The major objective of this study was to evaluate the spatio-temporal distribution of VOC in order to highlight the influence of unconventional emissions. The study utilized measurements from automated gas chromatography (AutoGC) monitors to analyze the patterns of the total non-methane organic compounds (TNMOC) and relative contributions from marker species of traffic versus oil and gas activities. In this study, data from 2001-2014 was obtained from the Texas Commission on Environmental Quality (TCEQ) for fifteen monitoring sites within the North Texas region. With over a thousand wells in a 10 mile radius, two of the rural sites measured twice as much TNMOC as compared to the urban site in Dallas. Source apportionment analysis was conducted using Positive Matrix Factorization (PMF) technique. The target site located in the urban zone resolved an eight factor model. Natural gas signature was the dominant source of emission with a 52% contribution followed by 31% from two separate traffic-related sources. Considering ethane to be the dominant species in oil and gas emissions, it was observed that the rising ethane/NOx ratio correlated with increasing annual average ozone post-2007. In this period, higher concentration of ozone was found to be associated with stronger winds from the Barnett Shale area – a region that did not seem to contribute to high ozone during 2001-2007. With traffic emissions having flattened over the years, the recent increase in oil- and gas-related emissions has a negative impact on the air quality in this area. Results indicate that the area has failed to observe a declining trend in ozone despite effective reductions in NOx and traffic-related VOC emissions. The findings of the study would be helpful in proper evaluation of the ozone-forming potential of unconventional VOC emissions. Although these emissions may not be strong enough to cause harm through direct exposure, underestimating their potential towards ozone formation could hinder the progress in ozone attainment in growing urban areas. After all, a major portion of the study area continues to be in nonattainment of the EPA designated ozone standards. The study therefore draws the attention of policymakers towards the new influx of emissions that have emerged as a powerful source within the DFW metropolitan area.
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Medvedskienė, Jūratė. "Taršos lakiaisiais organiniais junginiais valdymas." Master's thesis, Lithuanian Academic Libraries Network (LABT), 2007. http://vddb.library.lt/obj/LT-eLABa-0001:E.02~2007~D_20070104_095838-61976.
Full textAbstract:
Along with industrial and economic growth there is a persistent risk of permanently increasing air pollution. Air pollution has especially grown in the second half of the 20th century due to intense development of energy, industry and transport sectors. These pollution sources still remain the largest air polluters.
Solvents, paints, glues, ink and other substances, emitting volatile organic compounds to air are used in such industries like reel, metal and wood coating, covering with glue sticks, footwear production, production of pharmaceutical products, printing, dry (chemical) surface cleaning etc. Emissions of volatile organic compounds make harm both to people and environment as well as damage the ozone layer. Volatile organic compounds also affect smog formation and green house effect.
In the paper it is hypothesised that after implementation of EU legislation, observing the given emission limit values, improving technologies and implementing new treatment technologies, applying the measures to reduce pollution with volatile organic compounds and replacing the materials, emitting volatile organic compounds, with less polluting ones or those without pollution, air emission of volatile organic compounds will reduce dramatically.
This master’s paper reviews the measures and ways to manage pollution with volatile organic compounds (VOC): directives and their requirements, transferred to the national laws of the member states, addressed to solve the VOC pollution problem... [to full text]
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Mierzwiak, Sara M. "The Development of the Contaminant Exceedance Rating System (CERS) for Comparing Groundwater Contaminant Data." University of Toledo / OhioLINK, 2012. http://rave.ohiolink.edu/etdc/view?acc_num=toledo1345227410.
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Lee, Chia-Chung, and 李家中. "Feasibility of Combining Emissions Trading with Air Pollution Fee System of VOCs." Thesis, 2010. http://ndltd.ncl.edu.tw/handle/62545751624114115408.
Full textAbstract:
碩士國立交通大學
工學院碩士在職專班永續環境科技組
98
In Taiwan, the environmental loading is growing with the growth of economics. With the promotion of various air pollution control strategies by Taiwan EPA, the air quality is getting better for most of the criteria air pollutants, but the O3 concentration in the ambient air is continuously increasing. The VOCs (Volatile Organic Compounds) is one of the most important O3 precursors, therefore the reduction of VOCs is a key issue to reduce the O3 ambient concentration. From Jan. 01, 2007, the Taiwan EPA has levied air pollution fee for VOCs so that all the VOCs emitting factories can reduce their VOCs emissions. This study proposed a policy that combines air pollution fee and emissions trading. Hsin-chu city was selected to be the case study area. The installation cost and the operation & maintaining cost functions of prior investments on the best available technology for the VOCs air pollution control device in Taiwan semiconductor and opto-electronic factories were established. And the feasibility of the combined policy of emissions trading and air pollution fee was evaluated and compared with that of the present air pollution fee policy. The results showed that the reduction potential of combined system is more than the current employing air pollution fee policy and it could reduce the investment costs of the factories. Under this combined system, the government expense of air pollution will be decreased. But it has high incentive for the polluters to reduce VOCs emissions, therefore it is concluded that the combined policy of emissions trading and the air pollution policy has a potential to be applied in the future.
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Chou, Yu-chuan, and 周玉娟. "Efficicncy Evaluation on air Pollution Control Fee of VOCs for printing Industry." Thesis, 2011. http://ndltd.ncl.edu.tw/handle/47790381030291970251.
Full textAbstract:
碩士國立臺北大學
自然資源與環境管理研究所在職專班
99
Air, one of the key elements of the ecosystems, is crucial to human health. The air quality has deteriorated due to the rapid economic development and population growth in Taiwan. Thus, the air quality control has become one of the major environmental policies of Environmental Protection Administrator (EPA). The air pollution control strategy in the early stage was focused on administrative control measures, such as the setup of emission standards for a variety of fixed and mobile sources of air pollution and the control on pollution behavior. However, following the continuous economic development which accompanied with the increasing of air pollution sources, the administrative control measures alone are not sufficient to inhibit the deterioration of air quality or to meet the expectations of air quality improvement from the general public. Therefore, it has become an advanced air pollution control strategy to introduce on the basis of the existing control measures some more flexible and proactive control measures with economic incentives, such as the levy of air pollution fees and setting total emission cap on air pollutants, etc. Among the many air pollutants, volatile organic compounds (VOCs) are known to cause not only ozone problems through photochemical reactions but also potential hazard to human health. Thus, VOCs has become one of the main pollutants to be levied air pollution fee. This research focus on the study of the policy and effectiveness of levying air pollution fee on VOCs emitted by the printing industry. The results of the cost-effectiveness analysis on VOCs mitigation will provide valuable information to the environmental authority as well as the printing industry on formulating the related policies and strategies.
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Olson, David Alan. "In-home formation of halogenated volatile organic compounds (VOCS) implications for human exposure and indoor air quality /." Thesis, 2002. http://wwwlib.umi.com/cr/utexas/fullcit?p3086783.
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Li, Pei-Yu, and 李珮瑜. "Air Pollution Control Fee and Cost-benefit Assessment of VOCs Abatement For Printing and Metallic Coating Industry." Thesis, 2013. http://ndltd.ncl.edu.tw/handle/50241295576748010145.
Full textAbstract:
碩士國立中興大學
環境工程學系所
101
Due to ozone concentration has increased year by year and volatile organic compounds (VOCs) are the ozone precursor, the Environmental Protection Administration has started to impose air pollution fee in 2007. Imposing VOCs air pollution fee, the VOCs emission has to be calculated according to the VOCs contents in raw material or product. Therefore it is important to validate the correctness of the VOCs contents. This research has analyzed the VOCs contents in raw material from five printing factories and five metallic coating industries in order to estimate the air pollution fee. The concentration of VOCs before and after the air pollution control devices are also measured. The results show that ink is the major source of VOCs for printing factory, while the coating material is the major source for metallic coating industry. The VOCs contents in the gravure printing process and the lithographic printing process were 54~59% and 1.5~15%, respectively. However the synthetic coating material contains VOCs contents for the metallic coating industry ranges 14~52.4%. Regarding the cost for reducing per unit pollutants by using catalytic oxidizer, regenerative thermal oxidizer and scrubber, the cost benefit increases with the operating time. Based on the assessment, it takes 16 to 29 years to even the cost and the imposed air pollution fee. However the operating cost of active carbon adsorption tower is much more than the imposed air pollution fee, therefore the cost and the air pollution fee cannot be evened. This study also indicates that under the reduction benefit of printing and metallic coating industry, VOCs can be reduced 159.47 ton per year. But it is not regulated under current environmental laws to measure the VOCs contents in raw material. Therefore, an explicit regulation should be legislated in the future in order to control effectively VOCs emissions.
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Huang, Chimg-Ling, and 黃青嶺. "TFT-LCD Industry Prevention Of VOCs Air Pollution Using Control Equipment TO And RRTO Performance Comparison Analysis Research." Thesis, 2009. http://ndltd.ncl.edu.tw/handle/65417315501168286056.
Full textAbstract:
碩士朝陽科技大學
環境工程與管理系碩士班
97
Organic solvents have been largely used in the manufacturing process in TFT-LCD photoelectric industry. Therefore, large amounts of volatile organic compounds (VOCs) may be produced in the production process if not properly controlled. These VOCs contain (CH3)2SO, C2H7NO, C8H18O3, (CH3)2S2, (CH3)2S, C8H8, (CH3)2CHOH and (CH3)2CO that may cause unpleasant odor and affect human health. Rotary regenerative thermal oxidizer (RRTO) has been found to be efficient to remove these VOCs in the semiconductor manufacturing industry accounting for 60%. Around 90% of VOCs removal efficiency can be achieved via RRTO air pollution control device (APCD). It is found suitable to be the best available control technology for the VOCs control. RRTO APCD can meet the emission standard of VOCs in photoelectric industry promulgated and regulated by Taiwan EPA in 2006. In this study, removal efficiency, operational performance and energy saving of RRTO and TO APCDs were investigated. Results showed that RRTO could remove VOCs to an extent of 90% better than TO. In addition, RRTO can reduce the energy consumption compared to TO. Via this study, it is evident that operational performance of RRTO is better than that of TO and therefore it can be used and referred to future APCD installation. RRTO can meet the national VOCs emission standard and it also can meet the policy of energy saving and carbon reduction.
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Chen, Ching-Chuan, and 陳清泉. "TFT-LCD Industry Prevention Of VOCs Air Pollution Using Control Equipment Of Flameless RRTO Performance Comparison Analysis Research." Thesis, 2013. http://ndltd.ncl.edu.tw/handle/40097117818200251215.
Full textAbstract:
碩士朝陽科技大學
環境工程與管理系碩士班
101
This paper aims at investigating the removal efficiency of volatile organic compounds (VOCs) produced from Thin Film Transistor Liquid Crystal Display (TFT-LCD) by using Flameless Rotary Regenerative Thermal Oxidizer (RRTO). Temperature in the furnace of RRTO was maintained at 860℃~920℃. Rotary speed of RRTO was operated in 2.5 revolution/hr. Inlet gas was 1,380 m3/min and adsorption gas was 91 m3/min. Rotary concentrated ratio was 1/15. Adsorption temperature was set at 200℃. VOCs such as NBA, PGME, PGMEA and IPA were analyzed with GC-FID. Removal efficiency of NBA, PGME, PGMEA, and IPA were found to be 99, 84, 94, and 99% respectively. Results implied that flameless RRTO could improve the removal of VOCs efficiently. The flameless RRTO improved the original RRTO fire operation disadvantage with more energy-saving features and the increase of treatment efficiency.
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Chang, Jen-Chih, and 張仁智. "Efficiency Improvement for regenerative thermal oxidizer (RTO) in volatile organic compounds (VOCs) air pollution control equipment - Case study of a optoelectronic plant." Thesis, 2016. http://ndltd.ncl.edu.tw/handle/ykn78r.
Full textAbstract:
碩士國立屏東科技大學
環境工程與科學系所
104
Since the worldwide demand for high-tech products, photoelectric industry following the semiconductor manufacturing industry, to become another booming rapidly emerging high-tech industries. Optoelectronic industry it remains one of the major industries in Taiwan, and its related industries, the extensive use of volatile organic compounds which contain liquid photoresist with the liquid, organic solvent cleaning agents, which we can not ignore the impact on the environment ,so the EPA announcement "photovoltaic materials and manufacturing components of air pollution control and emission standards (95,0105 FEHD empty word article 0950000717 Order)", Specification photoelectric materials related industries and device manufacturing emissions of volatile organic compounds (volatile organic compounds, VOCs), reduce the impact of air pollutants arising due to production activities on the environment. The actual operation and equipment of the optoelectronic industry research that is related to the industry VOCs control equipment to enhance performance improvement process, Finally, a cost-effective method for the modification of equipment and comply with the requirements of environmental regulations.
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Shy-Yuan, Lo, and 羅詩源. "Development and Application of VOC''s Speciation Model for Air Pollution Emission Sources." Thesis, 1998. http://ndltd.ncl.edu.tw/handle/30185803494944720388.
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碩士國立雲林科技大學
環境與安全工程技術研究所
86
The emission database of VOC''s species hasn''t been built for Taiwan.However,it is important to assist the control strategy of VOCs and the explore the ozone problem. It would take a lot of time to estimate the database and may make some mistakes if using existing software of computer, such as Microsoft Excel, Dbase and etc. If the database can be established by a computer model that will decrease a lot of time consumption and reduce the artificial mistakes. This study is subjective to build a computer model for estimating the VOC''s species emission for Taiwan using the SPECIATE software, established by USEPA,and Taiwan Emission Data System (TEDS), established by CTCI. When the emission data of VOC''s species are estimated, the Maximum Incremental Reactivity (MIR) and Incremental Reactivity (IR) data proposed by Carter is used to calculate their ozone formation potential, and they are lumped into the species of RADM2 chemistry mechanism to provide as one of emission input of TAQM. The model has been established and contains several functions as following: (1)the spatial distribution of THC that emitted from each emission type, (2)the spatial distribution of VOCs that emitted from specific emission process, (3)the spatial distribution of ozone formation potential of VOCs that emitted from each emission process, (4)the ozone formation potential of VOCs that emitted from each emission process, (5)the ozone formation potential of VOCs that emitted from each region,(6)the summary of ozone formation potential of VOCs that emitted from each region, (7)the spatial distribution of RADM2 species that emitted from each emission type,(8)the RADM2 species that emitted from each region, and (9)the RADM2 species emitted from each emission process. The result shows that toluene is the maximum emission species for anthropogenic sources in Taiwan, but ethylene has maximum ozone formation potential. The maximum emission of RADM2 species is HC8 for anthropogenic sources in Taiwan.
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Chang, Jen-Kai, and 張仁愷. "The Indoor VOC Air Pollution Diffusion Modeling and Source Tracking in Wireless Sensor Network." Thesis, 2014. http://ndltd.ncl.edu.tw/handle/48125722690005417325.
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碩士國立中央大學
通訊工程學系
102
Owing to the rising awareness of environment protection and the trend of global warming, more and more people increase awareness of air pollution. Because most of air quality monitoring stations set up in outdoor to monitor pollution and greenhouse gases of metropolitan area, that ignore the importance of indoor air quality (IAQ). However, damage and number of deaths of indoor air pollution are more than outdoors, but sensing device rarely for a long time monitoring. In this study, we focus on volatile organic compounds (VOC) for a long time monitoring in indoor environment. This study uses experimental data to establish indoor Gaussian diffusion model and proposes prediction method to track sources of VOC air pollution. From simulation results of indoor VOC air pollution diffusion and source tracking to verify our proposed method. This system builds on an open architecture for Arduino AVR(Microcontroller) as the main operational unit with ZigBee module (802.15.4) to transit and receive data in wireless sensor network (WSN). The sensing element uses a metal oxide semiconductor sensor element called TGS-2602 via ADC to get measured value.
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Lin, Min-Rui, and 林旻叡. "Analysis the regional impacts due to emission from the VOCs and odor pollutions in the semiconductor packaging processes using the ISCST3 model." Thesis, 2016. http://ndltd.ncl.edu.tw/handle/enx4z8.
Full textAbstract:
碩士國立中山大學
環境工程研究所
104
Isopropyl alcohol (IPA), ketones, and other volatile organic compounds (VOCs) are often used during wafer processing, packaging, test, and cleaning processes in the semiconductor industry. Many of these VOCs tend to undergo photo reactions with nitrogen gas to form ozone and other photochemical smog. Sulfides or amines such as dimethyl sulfide (DMS) and trimethylamine (TMA) with low odor detection threshold values could generate strong smells and public complaints even when only small amounts of such chemical were released into the atmosphere. This study therefore used detection values and diffusion modes (ISCST3) in order to evaluate the impacts of such malodorous compounds when released into the surrounding environment. Improvement measures were proposed as well. This study investigated the concentrations of VOCs, IPA, DMS, and TMA at the emissions outlets for 2 processes within a selected semiconductor packaging and test facility. Results from 2 measurements taken at the Factory A (M21) process showed a total VOC (TVOC) of 707.8 to 7,763.5 ppb. Major components within the gas emissions were: ketones (28.78 to 75.62%) and alcohols (23.83 to 65.62%). Results from 2 measurements taken at the Factory B (M02) process showed a TVOC of 976.7 to 1,110.2 ppb. Major components within the gas emissions were: ketones (34.00 to 47.70%), alcohols (12.70 to 39.27%), and nitriles (6.56 to 49.35%). TMA released from the wastewater treatment pools of these 2 processes were lower than the detection threshold (MDL = 1.49 ppb). However, concentrations of DMS released from the wastewater treatment pools of Factory A and Factory B were 0.0195 and 1.43 ppm respectively, greatly exceeding the odor detection threshold ( = 0.001 ppm). The ISCST3 diffusion model was used to simulate regional impact resulting from the simultaneous release of methanol, acetone, and DMS from Factory A and Factory B. Simulation results showed that maximum ground level concentrations were 0.0011 ppm, 0.0038 ppm, and 0.0035 ppm for methanol, acetone, and DMS respectively, and occurred 200 meters downwind of the factory area. In the public housing area 300 meters downwind of the factories, ground level concentrations were 0.0001 ppm, 0.003 ppm, and 0.003 ppm for methanol, acetone, and DMS respectively, showing that only DMS concentration exceeded the odor detection threshold ( = 0.001 ppm). Simulations were carried out again with the assumption that volume reduction measures were in place, helping to limit DMS concentrations to below 0.45 ppm at the emission outlets for both Factory A and Factory B. Outcomes showed that ground concentrations of DMS in the public housing area 300 meters downwind of the factories became lower than the odor detection threshold.
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Ng, Shu-Xin, and 黃淑欣. "A Field study and Statistical Data Analysis of VOC Pollution Employing Cloud-based Synchronized Dual µGCs." Thesis, 2017. http://ndltd.ncl.edu.tw/handle/5gxsxf.
Full textAbstract:
碩士國立臺灣師範大學
化學系
105
In this study, two µGCs are used to analyze VOCs concentrations real-time and continuously at a 15 minutes interval in a school adjacent to an industrial area located at northern Taiwan for 16 days. Meteorological data are also collected to know its impact on VOCs concentration. The key VOCs were acetone, methyl acetate, butanone, hexane, benzene, toluene and m/p-xylene by canister/GC-MS confirmation, their concentrations measured by μGC ranged from units digit to hundreds ppb. The concentration of acetone, methyl acetate and butanone were higher in µGC-1 than in µGC-2, which means µGC-1 was near to the pollution source of these VOCs. On the other hand, the concentration of hexane, benzene, toluene and m/p-xylene were higher in µGC-2 than in µGC-1, which means µGC-2 was near to the pollution source of these VOCs. Among the various meteorological information that we had, we observed the wind direction is the main determinants of VOC concentrations which pointed to the possible source of pollution. The direction of high concentration sources of each VOC can be determined from the pollution rose plots. Butanone, hexane, benzene and toluene were mainly came from southwestern direction in both µGCs, m/p-xylene were mainly came from northwestern direction in both µGCs. The main pollution source of acetone and methyl acetate were different in both µGCs, which indicates the sources of these VOCs may be varied. These observations can be presented and analyzed by statistical method in detail: correlation analysis, cluster analysis and principle component analysis. In correlation anaylsis, the correlation of acetone and methyl acetate in both µGCs were low, the other VOCs were high correlated in both µGCs. In cluster anaylsis, three cluster of VOCs are grouped for both µGCs with distance of eight: methyl acetate in one cluster, m/p-xylene in one cluster, the rest of the compounds in one cluster. However, the result of component plot of VOCs for both µGCs are different in principle component analysis. By refering the component score of 16 main wind directions, we can observe that the methyl acetate was contributed by both southwestern and northwestern wind in both µGCs; m/p-xylene was contributed by northwestern wind in both µGCs; butanone, hexane, benzene, toluene were contributed by southwestern wind in both µGCs; acetone was more contributed by southwestern wind in µGC-1 than µGC-2. Besides, probability distribution maps of emission source were drawn for each VOC to know the highest probability of emission source of different VOCs. For acetone, methyl acetate, butanone, hexane, benzene and toluene, the probability were found in both southwest and southeast, but the probability of southwest is higher than southeast. Although they were all having high pobability in southwest, but they have different specific degree in southwest. For m/p-xylene, the highest probability were found in northwest. In summary, this study reveals plenty of data can be collected in a short period of time which can apply them with statistical method and calculate the probability distribution in order to study the relationship between VOC and wind direction, these results can be used as a reference for air pollution management.
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Borwankar, Dhananjai. "Design and Performance of a VOC Abatement System Using a Solid Oxide Fuel Cell." Thesis, 2009. http://hdl.handle.net/10012/4715.
Full textAbstract:
There has always been a desire to develop industrial processes that minimize the resources they use, and the wastes they generate. The problem is when new guidelines are forced upon long established processes, such as solvent based coating operations. This means instead of integrating an emission reduction technology into the original design of the process, it is added on after the fact. This significantly increases the costs associated with treating emissions.
In this work the ultimate goal is the design of an “add-on” abatement system to treat emissions from solvent based coating processes with high destruction efficiency, and lower costs than systems in current use. Since emissions from processes that utilize solvent based coatings are primarily comprised of volatile organic compounds (VOCs), the treatment of these compounds will be the focus.
VOCs themselves contain a significant amount of energy. If these compounds could be destroyed by simultaneously extracting the energy they release, operational costs could be substantially reduced. This thesis examines the use of model-based design to develop and optimize a VOC abatement technology that uses a Solid Oxide Fuel Cell (SOFC) for energy recovery. The model was built using existing HYSYS unit operation models, and was able to provide a detailed thermodynamic and parametric analysis of this technology.
The model was validated by comparison to published literature results and through the use of several Design of Experiment factorial analyses. The model itself illustrated that this type of system could achieve 95% destruction efficiency with performance that was superior to that of Thermal Oxidation, Biological Oxidation, or Adsorption VOC abatement technologies. This was based upon design criteria that included ten year lifecycle costs and operational flexibility, as well as the constraint of meeting (or exceeding) current regulatory thresholds.