Дисертації з теми "Volatile Carbonyl Compounds"
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Cosseron, Anne-Flore. "Evaluation et traitement des polluants émis par un moteur thermique fonctionnant avec des biocarburants." Phd thesis, Université de Haute Alsace - Mulhouse, 2012. http://tel.archives-ouvertes.fr/tel-00860233.
Повний текст джерелаJiang, Zhaohui. "Atmospheric measurements of a series of volatiles organic compounds." Thesis, Orléans, 2014. http://www.theses.fr/2014ORLE2014.
Повний текст джерелаCarbonyls and BTEX (benzene, toluene, ethyl-benzene and xylene) are two important groups of Volatile Organic Compounds (VOCs) present in the atmosphere. They have a significant contribution to the formation of oxidants such as ozone, PAN and other photooxidants in the troposphere. In addition, they have adverse effects on human health. In this work, atmospheric concentrations of carbonyls and aromatic hydrocarbons were measured and quantified using GC-MS and HPLC techniques at a semi-urban site in Orleans (ICARE, France), from June 2010 to August 2011. Urban ambient air sampling was also performed in 6-28th June 2013 in Beijing (RCEES-CAS, China). It has been conducted in order to compare the measured concentrations of the investigated species in two different sites using the same analytical techniques. All results are presented and discussed
Petroni, Ivan Alexandre. "Poluição do ar por compostos orgânicos voláteis (COV) em ambiente interno hospitalar." Universidade de São Paulo, 2009. http://www.teses.usp.br/teses/disponiveis/46/46133/tde-05102009-100831/.
Повний текст джерелаThe quantification of 11 carbonyl compounds (formaldehyde, acetaldehyde, acrolein, acetone, propionaldehyde, crotonaldehyde, butiraldehyde, benzaldehyde, isovaleraldehyde, valeraldehyde and 2,5-dimethylbenzaldehyde) and the identification of another 43 volatile organic compounds (alkanes, alkenes, aromatic, halogenated and nitrogenated compounds) have been done with samples of 9 different indoor places inside the University Hospital at USP in São Paulo. Among the carbonyl compounds, there where found higher quantities of formaldehyde, acetone, acetaldehyde and acrolein in this order. The highest ratios of formaldehyde mixture have been observed at the Macroscopic room (169.88 and 90.2 ppbv) and Histological Techniques (11.7 and 58.7 ppbv), due to the routine activities of these places. At the Macroscopy room, the level of formaldehyde identified (100 ppbv) was above the international limits established to non-industrial internal places. The ratios of the mixture of indoor and outdoor places, I/O, indicate the biggest presence of carbonyl compounds in internal places. Acrolein has been identified (6.4 to 9.3 ppbv) at indoor places. At the external area, there where found similar values (6,4 to 6,8 ppbv), and the ratio I/O obtained is near to 1. The origin of these compounds is possibly construction materials, smoke of cigarettes, adhesives, metabolism of microorganisms or they may have come from the outdoor to the indoor
Conte, Ludivine. "Emissions océaniques de gaz d’intérêt pour la chimie atmosphérique - Modélisation des dynamiques océaniques du CO, de l’isoprène et du DMS." Electronic Thesis or Diss., université Paris-Saclay, 2020. http://www.theses.fr/2020UPASV007.
Повний текст джерелаPhytoplankton activity is responsible for the oceanic production of volatile compounds which, once released into the atmosphere, have an impact on its oxidative capacity, on aerosol formation and on climate evolution. The oceanic emissions of most of these compounds are, however, poorly known because of a low number of in situ observations and a lack of knowledge in the oceanic processes involved. In a first step, I studied the oceanic cycles of carbon monoxide (CO) and isoprene (C5H8). In order to re-evaluate their emissions to the atmosphere, the sources and sinks of these gases in the water column have been embedded into the 3-D ocean circulation and marine biogeochemistry model NEMO-PISCES. In parallel, I compiled in situ measured oceanic concentrations and laboratory results from the literature to better constrain these oceanic processes. I produced the first spatialization of CO and isoprene emissions based on a 3-D ocean model and not relying on satellite data for the calculation of concentrations. For CO, global emissions are estimated to 4.0 Tg C yr-1, with a spatial dynamic reflecting its photochemical source. This dynamic is very different from the one produced in the 80s, which was the only one available to the atmospheric chemistry community. For isoprene, I showed the importance of water temperature in regulating the phytoplankton production. Global emissions are estimated to 0.66 Tg C yr-1, with a spatial dynamic reflecting this source. For both compounds, I also showed the importance of ocean circulation and mixing in determining surface concentrations and therefore emissions to the atmosphere. In a second step, I studied the responses of oceanic emissions of CO, isoprene and dimethyl sulfide (DMS) to climate change. This leads to an increase in the emissions of the 3 gases (+9.4, +4.2 and +6.5% for CO, isoprene and DMS in 2100 for a scenario with high emissions of greenhouse gases). Emissions tend to increase at high latitudes and decrease at lower latitudes. Global changes are mainly controlled by changes in water temperature, while changes in spatial distribution are controlled by a redistribution of phytoplankton production. Even if the uncertainties in modeling these cycles are still important, this work should allow integrating these cycles into an Earth System model coupling marine biogeochemistry and atmospheric chemistry, in order to better quantify the potential role of these interactions on the evolution of atmospheric chemistry and climate
Zhang, Yujie. "Atmospheric measurements and degradation mechanisms of a number of volatile organic compounds." Thesis, Orléans, 2012. http://www.theses.fr/2012ORLE2048.
Повний текст джерелаCarbonyls and BTEX (Benzene, Toluene, Ethylbenzene, and Xylenes) represent an important class of VOCs (volatile organic compounds) in the atmosphere. They are emitted into the atmosphere through anthropogenic and biogenic sources. Their atmospheric degradation leads to the formation of ozone, photooxidants and organic aerosols affecting the air quality at the local and regional scales and human health. It is, hence, of importance to measure their atmospheric concentrations and investigate their fate. In the present thesis, we have conducted a systematic measurement study of carbonyls and BTEX in Beijing during the period of Jul 2008-Aug 2010 in order to evaluate their ambient levels, possible sources and the influence of characteristic weather conditions. In a separate work, we performed a series of experimental studies on the OH-initiated oxidation of isopropyl formate, isobutyl formate, and n-propyl isobutyrate using the ICARE-CNRS (Orleans) simulation chamber from which we derived the product yields. The data obtained are presented and discussed
Velasco, Saldaña Hector Erik. "Urban flux and concentration measurements of volatile organic compounds and CO₂ in Mexico City." Online access for everyone, 2005. http://www.dissertations.wsu.edu/Dissertations/Fall2005/h%5Fvelasco%5F121305.pdf.
Повний текст джерелаSzabó, Emese. "Atmospheric kinetics and photochemistry of oxygenated volatile organic compounds." Thesis, Lille 1, 2011. http://www.theses.fr/2011LIL10099/document.
Повний текст джерелаOxygenated volatile organic compounds (OVOCs) are important constituents of the atmosphere. They include, e.g., aliphatic alcohols, aldehydes, ketones, and organic acids. In the free troposphere, the abundance of OVOCs is higher than that of the non-methane hydrocarbons and their overall reactivity with OH is comparable with that of methane, in contrast that methane is present in much higher concentration. Degradation of OVOCs in the atmosphere takes place via the reaction with OH radicals and, in the case of photochemically active molecules, via photolysis. Free radicals are formed in the photooxidative degradations of the oxygen containing organics which basically determine the oxidative capacity of the atmosphere, the transformation of nitrogen oxides and the concentration of OH radicals and tropospheric ozone. Ozone is the third most important greenhouse gas in the atmosphere, it is one of the toxic components of urban smog and so it is related to such grave environmental problems as global warming and the quality of air. The aim of this work is to contribute to the understanding of the atmospheric behaviour of a few OVOCs by measuring their kinetic and photochemical parameters. One of the major goals of a laboratory basic research in atmospheric chemistry is to provide kinetic and photochemical data for computer modelling and to deduce atmospheric transformation mechanisms in the case of some important chemicals
Ying, Fang. "Au/CeO₂ based catalysts for catalytic oxidation of volatile organic compounds and carbon monoxide." HKBU Institutional Repository, 2010. http://repository.hkbu.edu.hk/etd_ra/1185.
Повний текст джерелаMiguet, Marianne. "Adsorption de COV issus d'eaux souterraines et régénération des charbons actifs par voie solaire." Thesis, Perpignan, 2015. http://www.theses.fr/2015PERP0029/document.
Повний текст джерелаThis manuscript focuses on a comprehensive and durable treatment of polluted groundwater. The target contaminant, tetrachlorethylene, is a volatile organic compound. The first step in the treatment is the separation of contaminants. It was carried out by adsorption on activated carbons in a fixed bed column. The results obtained in the laboratory on the adsorption capacity and kinetics have shown the efficiency of this process. A mathematic model represented properly the various operating conditions corresponding to those used in the industry. This model has been validated by a pre-industrial pilot installed onsite and operating in real conditions. Management of spent activated carbons was studied. The thermal regeneration was chosen because it has the interest to restore the adsorption capacity of adsorbents and to collect the pollutants in a liquid phase. Although preferable to the production of activated carbons, it could still be economically more competitive and more sustainable by performing the heat treatment by solar means. It has been shown that the regeneration rate is the same for the solar and classical regenerations. It is therefore possible, in the case of tetrachlorethylene, to replace a fossil energy source by the sun.The distillate solution obtained during the regeneration can be mineralized by heterogeneous photocatalysis. This operation was carried out in the laboratory with a lamp reproducing the solar spectrum. The feasibility of solar photocatalysis on the final residue of the water treatment has been shown
Dib, Hadi. "Traitement catalytique des émissions issues de la combustion de la biomasse." Thesis, Littoral, 2019. https://documents.univ-littoral.fr/access/content/group/50b76a52-4e4b-4ade-a198-f84bc4e1bc3c/BULCO/Th%C3%A8ses/Toxicologie/These_DIB_Hadi.pdf.
Повний текст джерелаBiomass burning, in particular wood, is an attractive alternative to the utilization of fossil fuels for energy supply, as it is renewable and does contribute to any additional CO₂ emission into atmospher. However, it is known that heating appliances using biomass generate large amounts of Volatile Organic Compounds (VOCs) and carbon monoxide (CO) during the combustion cycle. A catalytic post-treatment is one of the most promising technologies to limit the emissions of these pollutants. This project aims to develop active and selective catalytic materials with enhanced redox properties in order to achieve the total oxidation of VOCs and CO at low temperature. Noble metals based catalysts are considered as good candidates for such types of reactions. However, these catalysts are very expensive for adaptation to domestic heating device. The objective of our work is focused on the synthesis and development of innovative and cheaper catalytic materials composed of transition metal oxides that could be used as alternatives to noble metal catalysts. In order to obtain efficient oxides, the hydrotelcite route was chosen for the synthesis of the catalysts. The beneficial effect of adding cerium to MgAl-O and CuAl-O oxides towards the oxidation of toluene and/or CO was demonstrated. A relationship between the reducibility and activity of these solids for these reactions has been also identified. For MgAlCe-O catalysts, a beneficial effect on the conversion of toluene in presence of CO was observed. Indeed, the temperature of toluene oxidation was shifted at lower temperatures in presence of CO. In contrary, no effect on toluene conversion was observed for the CuAlCe-O materials. However, a significant effect on the conversion of CO in presence of toluene was revealed. Briefly, a CuAlCe-O type oxide with high activity and stability has been synthesized for the destruction of VOCs and CO mixtures. In addition, the advantage of using the hydrotalcite route to synthesize these CuAlCe-O oxides has been verified by comparison with other synthetic routes. The high activity of the CuAlCe-O catalyst can be attributed to the synergic effect between copper and cerium elements
Piovani, Mônica Regina. "Balanço de carbono em fotobiorreato com cultivo de Chlorella bulgaris em excesso de 'C 'O IND.2'." [s.n.], 2012. http://repositorio.unicamp.br/jspui/handle/REPOSIP/266663.
Повний текст джерелаTese (doutorado) - Universidade Estadual de Campinas, Faculdade de Engenharia Química
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Resumo: As microalgas são microrganismos que vem sendo utilizados na bioconversão de carbono em produtos com interesse comercial como, por exemplo, biocombustíveis, corantes, suplementos alimentares e cosméticos. Elas podem ser cultivadas em sistemas autotróficos e heterotróficas sendo que as fontes de carbono, gasosas ou líquidas, podem ser provenientes de resíduos industriais reduzindo os custos de sua produção. Para identificar quais os possíveis produtos gerados durante o cultivo o objetivo deste trabalho foi avaliar a bioconversão de dióxido de carbono em fotobiorreatores identificando os principais bioprodutos gerados nas fases sólida, líquida e gasosa do sistema. Os experimentos foram conduzidos em fotobiorreatores de coluna de bolhas, alimentados com meio de cultivo sintético, com microalga C. vulgaris em fase exponencial de crescimento. Foi utilizado reator isotérmico, intensidades luminosas de 150?.molm-2.s-1, e injeção de ar com dióxido de carbono na vazão de 1Lmin-1. Além da conversão de carbono foram avaliados métodos de extração de lipídeos baseados no método de Bligh & Dyer e métodos gravimétricos para determinação do teor de umidade. A conversão de CO2 nos sistemas utilizados foi avaliada nas fases sólida, líquida e gasosa e foi expressa em termos de produção de biomassa (6%), em compostos solúveis na fase líquida, e composta orgânicos voláteis (88%) liberados para fase gasosa do sistema. O teor de umidade da biomassa das microalgas foi de 85% para os métodos avaliados e para os métodos para extração de lipídeos foi possível observar a influência do teor de umidade na biomassa na porcentagem de lipídeos que teve variação de 3% a 24%
Abstract: Microalgae are microorganisms that have been used for bioconversion of carbon into products of commercial interest such as, biofuels, pigments, food supplements and cosmetics. They can be grown in autotrophic and heterotrophic systems and the carbon sources, gaseous or liquid, can be derived from industrial wastes, reducing the costs of production. To identify the possible products generated during the culture the objective of this study was to evaluate the bioconversion of carbon dioxide in photobioreactors identifying key byproducts in solid, liquid and gaseous phases the generated in system. The experiments were conducted in bubble column photobioreactors, fed synthetic growth medium, and C. vulgaris cultures in exponential growth phase. The reactor was operated isothermically with 150?molm-2s-1 of light intensities and injection of air with carbon dioxide in the flow 1Lmin-1. Besides the carbon conversion, were evaluated lipid extraction methods based on the Bligh & Dyer's method and gravimetric methods for determination of moisture content. The conversion of CO2 systems will be evaluated in phases solid, liquid and gaseous systems, expressed in terms of biomass (6%), production in soluble compounds in the liquid phase and volatiles organic compounds released into the gaseous phase. The moisture content of microalgae biomass was 85% for the evaluated methods and for the extraction of lipids methods was possible to observe the influence of moisture content in the percentage of lipids that ranged from 3% to 24%
Doutorado
Desenvolvimento de Processos Químicos
Doutora em Engenharia Quimica
Mower, Matthew Bywater. "Competitive desorption of carbon tetrachloride + water from mesoporous silica particles." Online access for everyone, 2005. http://www.dissertations.wsu.edu/Thesis/Summer2005/m%5Fmower%5F081205.pdf.
Повний текст джерелаSalih, Hafiz H. M. "The Implications of Nanoparticles on the Removal of Volatile Organic Compounds from Drinking Water by Activated Carbon." University of Cincinnati / OhioLINK, 2011. http://rave.ohiolink.edu/etdc/view?acc_num=ucin1321366798.
Повний текст джерелаLorne, Jean-Luc. "Etude de l'extraction au dioxyde de carbone supercritique des composes volatils." Paris 7, 1988. http://www.theses.fr/1988PA077108.
Повний текст джерелаOsuagwu, Chiemeriwo Godday. "Investigation of volatile organic compounds from diesel engine emissions using H3O+ chemical ionisation mass spectrometry (H3O+-CIMS)." Thesis, Queensland University of Technology, 2020. https://eprints.qut.edu.au/205507/1/Chiemeriwo_Osuagwu_Thesis.pdf.
Повний текст джерелаKurukundu, Chaitanya Sai Praneeth, and Anvesh Reddy Gajjala. "An Investigation of Market Scalability for Volatile Organic Compounds (VOCs') Filtration Systems : A Case Study within Sweden." Thesis, Uppsala universitet, Industriell teknik, 2020. http://urn.kb.se/resolve?urn=urn:nbn:se:uu:diva-423253.
Повний текст джерелаCamenzuli, Michelle. "The effect of elevated atmospheric carbon dioxide mixing ratios on the emission of Volatile organic compounds from Corymbia citriodora and Tristaniopsis laurina." Master's thesis, Australia : Macquarie University, 2008. http://hdl.handle.net/1959.14/45386.
Повний текст джерелаBibliography: p. 120-124.
Introduction -- Environmental factors affecting the emission of biogenic Volatile organic compounds -- Materials and experimental procedures -- Quantification using sold-phase microextraction in a dynamic system: technique development -- The emission profile of Tristaniopsis laurina -- Study of the effect of elevated atmospheric CO₂ levels on the emission of BVOCS from Australian native plants -- Conclusions and future work.
Biogenic Volatile Organic Compounds (BVOCs) emitted by plants can affect the climate and play important roles in the chemistry of the troposphere. As ambient atmospheric carbon dioxide (CO₂) levels are rapidly increasing knowledge of the effect of elevated atmospheric CO₂ on plant BVOC emissions is necessary for the development of global climate models. -- During this study, the effect of elevated atmospheric CO2 mixing ratios on BVOC emissions from Corymbia citriodora (Lemon Scented Gum) and Tristaniopsis laurina (Water Gum) was determined for the first time through the combination of Solid-Phase Microextraction (SPME), Gas Chromatography-Flame Ionisation Detection (GC-FID), Gas Chromatography-Mass Spectrometry (GC-MS) and an environment chamber. For C. citriodora elevated atmospheric CO₂ led to a decrease in the emission rate of α-pinene, β-pinene, eucalyptol, citronellal and β-caryophyllene, however, elevated CO₂ had no effect on the emission rate of citronellol. The emission profile of T. laurina has been determined for the first time. For T. laurina elevated CO₂ led to a decrease in the emission rate of α-pinene but the emission rates of β-pinene, limonene, eucalyptol and citronellol were unaffected. The results obtained in this work confirm that the effect of elevated atmospheric CO₂ on plant BVOC emissions is species-specific.
Mode of access: World Wide Web.
124 leaves ill. (some col.)
Bahoumina, Prince. "Développement d’une plateforme de détection de gaz, utilisant un capteur différentiel flexible imprimé à transducteurs micro-ondes et matériaux composites carbonés." Thesis, Bordeaux, 2018. http://www.theses.fr/2018BORD0101/document.
Повний текст джерелаSince the Industrial Revolution, the levels of atmospheric concentrations of greenhouse gases have been increasing, causing an acceleration of global warming. Volatile organic compounds (VOCs) contribute not only to this greenhouse effect, but also to environmental pollution, which has a negative impact on all living species on the planet. For example, in the year 2012, air pollution caused 7 million deaths, according to the World Health Organization (WHO) [1]. In addition, a very recent medical study by the Lancet Commission on Pollution and Health found that one in six deaths in 2015 was related to air and water pollution [2]. Also, indoor and outdoor air pollution is linked to 6.5 million deaths worldwide each year. VOCs can indirectly cause cough, chest discomfort, painful discomfort, shortness of breath, as well as nasal, ocular or throat irritation. They can also be directly toxic or explosive or disruptive of the immune response. In addition, some of them are classified as CMR (carcinogenic, mutagenic and reprotoxic). They are very volatile and often used as solvents for example. In these conditions, a better understanding of the health and environmental effects of exposure to VOCs is necessary. Such knowledge also involves the detection and quantification of VOC concentrations in order to propose a better management of the environments and to alert people in real time of the dangers incurred. Most of the existing or commercially available platforms are either too expensive, energy intensive, high temperature functional, unstable for real-time or long-term detection, which limits the proliferation of measurement sites. This thesis is in the field of dedicated gas sensors for the detection of pollution in the air. It deals with the development of a platform for the detection, monitoring and quantification of volatile organic compounds (VOCs) in real time, using a flexible and printed differential gas sensor based on microwave transducers and composite polymeric carbon materials as sensitive layers. The proposed device aims at providing directly exploitable information such as a low-cost embedded platform dedicated to the Internet of things and which offers increasing possibilities for the proliferation of detection and control sites by realizing networks of wireless communicating sensors operating in various environments
Chen, Hui. "Atmospheric chemical processes : reaction of ozone with 2- and 3-carene, evolution of internal mixed combustion particles." Thesis, Orléans, 2014. http://www.theses.fr/2014ORLE2064/document.
Повний текст джерелаIn this thesis, we present a complementary work conducted at ICARE-CNRS (Orléans), Part A and at Fudan University (Shanghai), Part B. Part A: 2-and 3-carene are two important biogenic volatile organic compounds present in the atmosphere. The knowledge on their degradation pathways and the corresponding products are still poor. Using complementary reaction systems-ICARE 7300 L and HELIOS 80000 L simulation chambers, vertical laminar flow reactor, their kinetic rate constants for reaction with ozone were determined. Additionally, important product formation yields, hydroxyl radical (OH), formaldehyde (HCHO) and carbon monoxide (CO) have been determined with indication to their corresponding formation routes from the ozonolysis of carene. To have a better understanding on reactions of Criegee intermediates (CIs) generated through ozonolysis in the atmosphere, a horizontal 2-stage laminar flow reactor was set up to measure the rate constants of CIs with SO2, NO2 and O3. Part B: Radiative forcing of black carbon (BC) in the atmosphere, as well as that of brown carbon (BrC), remains to be a major uncertainty in current climate models. Recent reports indicate that the absorption enhancement of BC and BrC particles is determined by evolution of morphology and mixing state during the atmospheric processing. Laboratory-generated BC-BrC mixture particles (BC-BrC) were exposed to sulfuric acid, ammonia/triethylamine, and water vapor sequentially to investigate the alternation in light absorption, morphology and mixing state during simulated atmospheric processing
Silva, Lênin de Matos. "Avaliação da qualidade ambiental: mercado municipal de São Carlos/SP." Universidade de São Paulo, 2012. http://www.teses.usp.br/teses/disponiveis/18/18138/tde-06062013-160039/.
Повний текст джерелаThe Municipal Market of São Carlos city is a very important commercial center, bringing together different types of shops and services. A large number of people attends the local daily, and it is the work environment of several merchants. A diagnostic of the quality of the indoor environment of the Municipal Market of Sao Carlos/SP was conduct, by monitoring the following parameters: PM10, PM2,5; \'CO IND.2\', CO, VOCs, temperature, humidity and noise. The data collections were performed during the year 2011. For all analyzed parameters were chosen 12 sampling indoor points and an outdoor point, with the exception of noise, which had 9 indoor points. The indoor data of PM10 and PM2,5 showed average concentrations of 44.55 \'mü\'g/m³ and 31.96 \'mü\'g/m³, respectively. The outdoor medium concentrations were 35.60 \'mü\'g/m³ for PM10 and 25.91 \'mü\'g/m³ for PM2,5. The average concentrations of particulate matter observed were below the values recommended by WHO. The reason MP2,5/MP10 was above 70%, indicating the predominance of fine particulate matter at the PM10 fraction. Chemical analysis by X-rays fluorescence was performed in the particulate matter collected and the chemicals identified were: Si, Al, S, Ca, Fe, Ti, Cu, Zn and V. It was observed that the \'CO IND.2\' data were below the limit recommended by ANVISA Resolution 09 which is 800 ppm, the indoor data were also higher than outdoor data. For CO and VOCs, the points with the highest concentrations were the ones near the accesses to the Market by the Episcopal Street, and also higher indoor data that the outdoor. The data of temperature and relative humidity proved generally outside the ranges of the recommendations ANVISA Resolution 09, which indicates that the indoor environment of the market may be uncomfortable considering these two parameters. The indoor noise levels were observed above those recommended by the Technical Standard L11.032 (CETESB), which is 50 dBA. There were some points with averages above 70 dBA, showing that the Market can be a noisy environment, which can cause health problems for their users.
Wenner, Peter. "Measurement of dissolved gas concentrations in natural waters utilizing an in-situ, membrane inlet, linear quadrupole mass spectrometer." [Tampa, Fla] : University of South Florida, 2009. http://purl.fcla.edu/usf/dc/et/SFE0003150.
Повний текст джерелаPortela, Nicole Becker. "Estudo de poluentes atmosféricos no outdoor e indoor de escolas aplicando técnicas de medição em tempo real e de sensoriamento remoto." reponame:Biblioteca Digital de Teses e Dissertações da UFRGS, 2018. http://hdl.handle.net/10183/180973.
Повний текст джерелаAir pollutants as nanoparticles (N), black carbon (BC) and volatile organic compounds (VOCs) may have short and long-term adverse health effects, especially when it comes to children’s health. These pollutants are known to cause cancer and other health effects may include also eye, nose and throat irritation (VOCs and BC), headaches, asthma, pulmonary and cardiovascular diseases (BC). Air-pollution-sized nanoparticles (N) can also affect cerebrovascular system. It can negatively affect students’ learning and children’s cognition. The aim of this study was to verify and compare the indoor (classrooms) and outdoor (access gates) air quality in different schools, where the children remain exposed to air pollutants for long hours per day. Two schools in different areas of Porto Alegre Metropolitan Region (RMPA) were chosen: the first one in an urban area (Canoas) and the second one in a rural area (Nova Santa Rita). Eleven fortnightly samplings were conducted to evaluate N, BC and VOCs levels between July 2016 and December 2016. We also used data of gaseous pollutants (O3, NOx, NO2, and NO) and meteorological data (temperature, relative humidity, solar radiation and wind speed) collected in the same area. Remote sensing techniques and a scanning electron microscope (SEM) were used to obtain images of the black carbon filters. In the outdoor site of the urban school, the maximum levels of BC and N were registered in the rush hours due to a high level of vehicular carbon emissions. The lower levels of BC and N in Nova Santa Rita were attributed to the fact the school is located in a rural area, which assumes a less impacted environment. Nevertheless, this study indicates that these compounds are generated during the classroom activities, since the VOCs levels were higher in the two schools indoor sites. The black carbon particles in the urban area come from vehicle emissions (outdoor) and are easily transferred to the school indoor areas. These emissions can also carry other particles (e.g., Fe) and its dispersion can be hampered in cold days with low wind speed. VOCs and N concentrations are site-independent compounds influenced by several emission sources, reactions of primary pollutants and meteorology. It causes them to reflect with a high sensibility in different atmospheric conditions both in urban and rural areas (indoor and outdoor). We would like to emphasize that both rural and urban schools managers should be aware of the risks involving air pollutants in the classroom (especially VOCs). Urban schools boards should also remain vigilant on the expressive concentrations of N and BC near their access gates, arising from vehicle carbon emissions, which represents a risk for the children’s health.
Venter, Cornelia. "Recovery of petrol vapour at a bulk storage facility." Diss., University of Pretoria, 2004. http://hdl.handle.net/2263/23524.
Повний текст джерелаJiang, Mei. "Mobile Laboratory Measurement of Black Carbon, Particulate Polycyclic Aromatic Hydrocarbons and Other Exhaust Emissions in Mexico City." Thesis, Virginia Tech, 2005. http://hdl.handle.net/10919/41133.
Повний текст джерелаMaster of Science
Xiu, Meng. "Evaluating the emission of air pollutants from different sources." Thesis, Queensland University of Technology, 2022. https://eprints.qut.edu.au/235386/1/Meng%2BXiu%2BThesis%284%29.pdf.
Повний текст джерелаMelnychenko, Andrea Natalie. "Interspecific variation in leaf-level biogenic emissions of the Bambuseae." PDXScholar, 2013. https://pdxscholar.library.pdx.edu/open_access_etds/1031.
Повний текст джерелаAmaral, Gabriela Vieira do. "Whey drink de uva processado por di?xido de carbono supercr?tico: par?metros de qualidade e sensoriais." Universidade Federal Rural do Rio de Janeiro, 2017. https://tede.ufrrj.br/jspui/handle/jspui/2208.
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Coordena??o de Aperfei?oamento de Pessoal de N?vel Superior - CAPES
Emerging supercritical carbon dioxide (SCCD) technology has been studied as a cold pasteurizing agent, however, few studies are available on its efficiency in dairy products. In this study, the effects of SCCD processing by different pressures 14, 16 and 18 MPa (35 ? 2 ?C / 10 min) on whey drink, whey drink and grape juice were investigated in comparison To conventional pasteurization (heat treatment at 72 ?C / 15 s). Physicochemical analyzes of pH, titratable acidity, total soluble solids, phenolic compounds, anthocyanins, antioxidant activity, angiotensin converting enzyme (ACE) inhibitory activity and volatile compounds were performed. The color, particle size, rheology, physical stability, as well as microbiological quality and sensory analysis of beverages were also smoothed. The results of this study evidenced the absence of differences between treatments in pH, titratable acidity, soluble solids, total anthocyanins and DPPH activity (p> 0.05). A direct relationship between SCCD pressure and ACE inhibitory activity was observed, with 34.63, 38.75 and 44.31% (14, 16 and 18 MPa, respectively). Few differences were found in the volatile compounds profile. The beverage processing by SCCD resulted in a product with lower particle diameter, lower consistency index and a reduction in pseudoplastic character compared to the beverage treated by the conventional process. No effect of high pressure CO2 on the sensorial attributes of the drink was observed for the studied levels. Consumers found no difference between CO2 treated beverages and heat-treated beverages. The results confirm the processing of SCCD as a promising technology for the non-thermal treatment of grape whey drink made available a health and wellness promoter beverage. Background: Non-thermal food processing is configured as an interesting alternative for the food industry due to the increased nutrient retention and minimal sensory changes in processed products. Scope and approach: The aim of this review is to address the potential of supercritical carbon dioxide technology, emphasizing milk and dairy processing, including the historical aspects, main advantages, microbial inactivation mechanisms, as well as effects in some quality parameters of dairy products. Key findings and conclusions: The use of supercritical carbon dioxide technology (SC-CO2) presents great potential application in dairy processing, since it is effective to reduce microbial load when compared to the pasteurization process, thus obtaining a product with greater shelf life and better organoleptic properties with minimal and sometimes positive changes in the intrinsic quality parameters The effect of supercritical carbon dioxide technology (SCCD, 140, 160, and 180 bar at 35 ? 2 ?C for 10 min) on whey-grape juice drink characteristics was investigated. Physicochemical characterization (pH, titratable acidity, total soluble solids), bioactive compounds ( phenolic compunds, anthocyanins , DPPH and ACE activity) and the volatile compounds were performed. Absence of differences were found among treatments for pH, titratable acidity, soluble solids, total anthocyanins and DPPH activity (p>0.05). A direct relationship between SCCD pressure and ACE inhibitory activity was observed, with 34.63, 38.75, and 44.31% (140, 160, and 180 bar, respectively). Regards the volatile compounds, it was noted few differences except by the presence of ketones. The findings confirm the SCCD processing as a potential promising technology to the conventional thermal treatment. The use of supercritical technology as a non-thermal pasteurization process of the whey-grape juice drink was investigated in this study. The effects of supercritical carbon dioxide at 14, 16, and 18 MPa (35 ? 2?C/10 min) on the physical and sensory properties of the beverage, when compared to conventional pasteurization (heat treatment at 72?C/15 s) were evaluated. High-pressure CO2 processing of whey-grape juice drink resulted in a product with lower particle diameter, lower consistency index, and a reduction in pseudoplastic character when compared to the beverage treated by the conventional process. No effect of high-pressure CO2 was observed on the sensory attributes of the beverage for the levels studied. Consumers did not find differences between the CO2-treated and heat-treated beverages. Our findings suggest the use of supercritical technology with carbon dioxide as an effective alternative for the production and availability of a health and wellness promoting beverage
A tecnologia emergente de di?xido de carbono supercr?tico (DCSC) vem sendo estudada como agente pasteuriza??o a frio, no entanto, s?o poucos os estudos dispon?veis a cerca da sua efici?ncia em derivados l?cteos. Neste estudo, foram investigados os efeitos do processamento do DCSC por diferentes press?es 14, 16 e 18 MPa (35 ? 2 ?C / 10 min) no whey drink de uva, bebida a base de soro de leite e suco de uva, em compara??o ? pasteuriza??o convencional (tratamento t?rmico a 72 ?C / 15 s). Foram realizadas an?lises f?sico-quimicas de pH, acidez titul?vel, s?lidos sol?veis totais, compostos fen?licos, antocianinas, atividade antioxidante, atividade inibidora da enzima conversora de angiotensina (ECA) e compostos vol?teis. Tamb?m foramam alisados a cor, o tamanho de part?cula, reologia, estabilidade f?sica, assim como a qualidade microbiol?gica e analise sensorial das bebidas. Os resultados deste estudo evidenciaram a aus?ncia de diferen?as entre os tratamentos nas an?lises de pH, acidez titul?vel, s?lidos sol?veis, antocianinas totais e atividade de DPPH (p> 0,05). Foi observada uma rela??o direta entre press?o DCSC e atividade inibit?ria ACE, com 34,63, 38,75 e 44,31% (14, 16 e 18 MPa, respectivamente). Poucas diferen?as foram encontratdas no perfil dos compostos vol?teis. O processamento das bebidas por DCSC resultou em um produto com menor di?metro de part?cula, menor ?ndice de consist?ncia e uma redu??o no car?ter pseudopl?stico em compara??o com a bebida tratada pelo processo convencional. N?o foi observado efeito de CO2 de alta press?o nos atributos sensoriais da bebida para os n?veis estudados. Os consumidores n?o encontraram diferen?as entre as bebidas tratadas com CO2 e as bebidas tratadas termicamente. Os resultados confirmam o processamento do DCSC como uma tecnologia promissora para o tratamento n?o t?rmico de whey drink de uva disponibilizado uma bebida promotora de sa?de e bem-estar Antecedentes: Os processamentos de alimentos n?o t?rmicos s?o configurados como uma alternativa interessante para a ind?stria de alimentos devido ao aumento da reten??o de nutrientes e mudan?as sensoriais m?nimas nos produtos processados. ?mbito e abordagem: o objetivo desta revis?o ? abordar o potencial da tecnologia de di?xido de carbono supercr?tico, enfatizando o processamento de leite e l?cteos, incluindo os aspectos hist?ricos, as principais vantagens, os mecanismos de inativa??o microbiana, bem como os efeitos em alguns par?metros de qualidade dos produtos l?cteos. Principais conclus?es e conclus?es: o uso de tecnologia supercr?tica de di?xido de carbono (SC-CO2) apresenta grande potencial de aplica??o no processamento de l?cteos, uma vez que ? efetivo reduzir a carga microbiana quando comparado ao processo de pasteuriza??o, obtendo-se assim um produto com maior prateleira e melhores propriedades sensoriais com mudan?as m?nimas e ?s vezes positivas nos par?metros de qualidade intr?nseca. O efeito da tecnologia de di?xido de carbono supercr?tico (SCCD, 140, 160 e 180 bar a 35 ? 2 ?C durante 10 min) em caracter?sticas de bebidas de suco de uva foi investigado. Caracteriza??o f?sico-qu?mica (pH, acidez titul?vel, s?lidos sol?veis totais), compostos bioativos (compostos fen?licos, antocianinas, DPPH e atividade ACE) e os compostos vol?teis foram realizados. A aus?ncia de diferen?as foi encontrada entre tratamentos para pH, acidez titul?vel, s?lidos sol?veis, antocianinas totais e atividade de DPPH (p> 0,05). Foi observada uma rela??o direta entre press?o SCCD e atividade inibit?ria ACE, com 34,63, 38,75 e 44,31% (140, 160 e 180 bar, respectivamente). Atende aos compostos vol?teis, observou-se poucas diferen?as, exceto pela presen?a de cetonas. Os resultados confirmam o processamento do SCCD como uma potencial tecnologia promissora para o tratamento t?rmico convencional O uso da tecnologia supercr?tica como processo de pasteuriza??o a frio da bebida de suco de uva e soro de uva foi investigado neste estudo. Os efeitos do di?xido de carbono supercr?tico em 14, 16 e 18 MPa (35 ? 2 ?C / 10 min) nas propriedades f?sicas e sensoriais da bebida, quando comparados ? pasteuriza??o convencional (tratamento t?rmico a 72 ?C / 15 s) Foram avaliados. O processamento de CO2 de alta press?o da bebida de suco de soro de soro de leite resultou em um produto com menor di?metro de part?cula, menor ?ndice de consist?ncia e uma redu??o no car?ter pseudopl?stico em compara??o com a bebida tratada pelo processo convencional. N?o foi observado efeito de CO2 de alta press?o nos atributos sensoriais da bebida para os n?veis estudados. Os consumidores n?o encontraram diferen?as entre as bebidas tratadas com CO2 e as bebidas tratadas termicamente. Nossas descobertas sugerem o uso da tecnologia supercr?tica com di?xido de carbono como uma alternativa efetiva para a produ??o e disponibilidade de uma bebida promotora de sa?de e bem-estar
Clifford, Johanna Marie. "A 2009 mobile source emissions inventory of the University of Central Florida." Master's thesis, University of Central Florida, 2011. http://digital.library.ucf.edu/cdm/ref/collection/ETD/id/4873.
Повний текст джерелаID: 030423247; System requirements: World Wide Web browser and PDF reader.; Mode of access: World Wide Web.; Thesis (M.S.Env.E.)--University of Central Florida, 2011.; Includes bibliographical references (p. 117-120).
M.S.Env.E.
Masters
Civil, Environmental and Construction Engineering
Engineering and Computer Science
Environmental Engineering
Ross, Jessica Leigh. "2008 Emissions Inventory of Central Florida." Master's thesis, University of Central Florida, 2011. http://digital.library.ucf.edu/cdm/ref/collection/ETD/id/5030.
Повний текст джерелаID: 029810421; System requirements: World Wide Web browser and PDF reader.; Mode of access: World Wide Web.; Thesis (M.S.Env.E.)--University of Central Florida, 2011.; Includes bibliographical references (p. 103-107).
M.S.Env.E.
Masters
Civil, Environmental and Construction Engineering
Engineering and Computer Science
Environmental Engineering
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.
Повний текст джерелаГонтаренко, Юрій Олександрович. "Мікроелектронна система моніторингу та аналізу стану забруднення атмосферного повітря". Bachelor's thesis, КПІ ім. Ігоря Сікорського, 2020. https://ela.kpi.ua/handle/123456789/35119.
Повний текст джерелаThe work aim is an air quality system development for temperature, humidity, atmospheric pressure monitoring based on modern microelectronic components, as well as for monitoring and analysis of air pollution in terms of volatile organic compounds (TVOC) and equivalent levels of carbon dioxide and other pollutant gases concentration determination. Thesis is focused on in-depth study of physical methods for determining the the largest air pollutants content, on the electronic sensors current state analysis in this area and controllers choice for monitoring and analysis systems design. The first section of the thesis considers the regulatory framework in the field of obtaining and analyzing information about the atmospheric air current state, analyzes the differences in approaches to air quality indexing in the both Europe and Ukraine, identifies their disadvantages and advantages. The second section considers the methods of the major air pollutants content determining and analyzes the structural schemes of analyzers, considers the features of their key structural elements, compares the design and architecture, provides some basic electronic circuits. The third section considers modern types of atmospheric air physical parameters microelectronic sensors, its chemical composition and mechanical pollutants. The modern sensor technical and metrological parameters are analyzed with regard to compliance with modern requirements, norms, types of interfaces. Based on the results of a detailed study of information in these areas, modern microelectronic sensors with a digital output interface were selected to build microcontroller monitoring systems: - BME280 temperature, humidity and atmospheric pressure sensor; - micromechanical absolute pressure sensor model BMP180 (altitude) with a resolution of 6 kPa (corresponds to a change in altitude 0.5m) in the ultra-low consumption mode and 2 hPa kPa (corresponds to a change in altitude 0.17m) in the mode of precision measurement; - Adafruit CCS811 integrated air quality sensor with the ability to determine the level of volatile organic compounds and effective CO2 level (CCS811 - Adafruit CCS811 Air Quality Sensor Breakout - VOC and eCO2) with an additional built-in unit of precision temperature and humidity sensor HDC1080. The ARDUINO UNO controller was used to design the monitoring system. The structural scheme of the system is offered and the scheme of connection of each of components is resulted in the work. Also the program code in the Arduino IDE software environment for separate components of the monitoring system is developed, its adjustment is carried out.
HANG, YAN-NING, and 黃妍寧. "The Analytical Study of the Carbonyl and Volatile Organic Compounds in the Computer Classrooms of Elementary School in Pingtung Area." Thesis, 2015. http://ndltd.ncl.edu.tw/handle/mdtge7.
Повний текст джерелаYin, Ko-Ghun, and 尹可君. "Simultaneous determination of carbonyl and low-polarity volatile organic compounds in air using on-adsorbent derivatization and thermal desorption-GC/MS." Thesis, 2008. http://ndltd.ncl.edu.tw/handle/50675054199333920016.
Повний текст джерела弘光科技大學
職業安全與防災研究所
96
Measurement of volatile organic chemicals (VOC), including carbonyls, is of interest as these chemicals are ubiquitous, and have environmental and health significance. This study aimed to develop a new analytical method to simultaneously monitor airborne carbonyls compounds and low-polarity VOC. Carbonyls are collected onto an adsorbent (Tenax TA, coated with a derivatization agent (pentafluorophenyl hydrazine, PFPH)) to form thermo-stable derivatives suitable for subsequent analysis by thermal-desorption and GC/MS, whereas VOC are collected onto Tenax TA that is packed in the same sampling tube, and analyzed by the same way as carbonyls. Six carbonyls (formaldehyde, acetaldehyde, benzaldehyde, acetone, methyl ethyl ketone and methyl isobutyl ketone) and five low-polarity VOC (benzene, toluene, ethylbenzene, xylenes and styrene) were evaluated following a standard test protocol. The calibration ranges from 30 to 200 ng per tube for most carbonyls and VOC, and 200 to 1000 ng per tube for formaldehyde. The analytical precisions were within 7%, while the collection efficiency, tested using a static sampling bag, were between 94~98%. PFPH-coated Tenax TA (for collecting carbonyls) needs to be placed in the front section of the tube, and Tenax TA in the back section (for collecting VOC). The method detection limits for the current method range between 0.2~25ng per tube. Samples are stable for at least 10 days under ambient conditions. The current was also tested in field and proved satisfactory. This method is simple, feasible and with satisfactory accuracy and precision, and thus can be used as a reference method to simultaneously monitor environmental carbonyls and low-polarity VOC.
Calejo, Helena Isabel Pinto Cardoso Teixeira. "Development of a GC-MS method for determination of volatile carbonyl compounds in biological matrices: aplication to clinical and post-mortem samples." Master's thesis, 2015. https://repositorio-aberto.up.pt/handle/10216/88980.
Повний текст джерелаCalejo, Helena Isabel Pinto Cardoso Teixeira. "Development of a GC-MS method for determination of volatile carbonyl compounds in biological matrices: aplication to clinical and post-mortem samples." Dissertação, 2015. https://repositorio-aberto.up.pt/handle/10216/88980.
Повний текст джерелаChiou, Jeng Hung, and 邱正宏. "Study on the Thermal Desorption of Volatile Organic Compounds (VOCs) from Activated Carbons." Thesis, 1993. http://ndltd.ncl.edu.tw/handle/34854325984778761843.
Повний текст джерелаChiloane, Kgaugelo Euphinia. "Volatile organic compounds(VOC's) analysis from Cape Town haze ll study." Thesis, 2006. http://hdl.handle.net/10539/1611.
Повний текст джерелаA brown haze which builds-up over Cape Town under calm and cold weather conditions causes public concern. The brown haze is thought to be due to the gaseous and particulate emissions from the city, industries, traffic and townships in the Cape Town region. Volatile organic carbon (VOCs) compounds are an important component of the haze layer particularly because of their reactivity. VOCs play an important role in the carbon budget and radiation balance, regional oxidant balance, and in the distribution of ozone and other reactive gases, both at the regional and global scale. In this study the variation in ambient VOC concentrations during brown and non-brown haze days over Cape Town during July and August 2003 were characterised. Ambient air samples were collected in evacuated stainless steel canistes from the South African Weather Service (SAWS) research aircraft (Aerocommander, ZS-JRB) and later analysed by gas chromotography equipped with a flame ionisation detector (GC-FID). Benzene, toluene, ethylbenzene and xylene (BTEX) were the specific VOCs targeted for this study. Comparable meteorology data was also collected to determine the effects of wind field and atmospheric stability on BTEX concentrations.
Lopes, David Terreiros da Fonseca. "Aerogéis compósitos de nanotubos de carbono/sílica para remediação ambiental." Master's thesis, 2019. http://hdl.handle.net/10316/87920.
Повний текст джерелаO principal objetivo desta dissertação de mestrado foi incorporar nanotubos de carbono (CNTs) em aerogéis de sílica para obtenção de materiais compósitos com boas propriedades de adsorção. Metiltrimetoxissilano (MTMS) e (3-aminopropil) trimetoxissilano (APTMS) foram utilizados como precursores de sílica, os quais, em diferentes proporções molares e utilizando a metodologia sol-gel, levaram à formação de aerogéis compósitos de CNTs-sílica.O surfactante utilizado foi escolhido entre brometo de hexadeciltrimetilamónio (CTAB), dodecil sulfato de sódio (SDS) e polietilenoglicol (PEG). Quando a síntese foi realizada com PEG, não foi obtido um gel, no entanto, o uso dos outros dois surfactantes produziu monólitos que não apresentaram diferenças significativas nos valores da massa volúmica bulk. Em relação ao tempo de gelificação, o CTAB apresentou os melhores resultados, com menor tempo de gelificação, o que é favorável para evitar a sedimentação dos CNTs na suspensão.O próximo parâmetro estudado foi o método de agitação e, embora a agitação mecânica proporcionasse menor massa volúmica bulk, o banho de ultrassom permitiu uma melhor dispersão dos CNTs na solução. Um estudo sobre a necessidade de uma etapa de lavagem para remover o surfactante dos géis foi também realizado. Comparando os resultados para a mesma formulação, com e sem lavagem, foi possível concluir que esta etapa foi fundamental, permitindo uma melhoria significativa na massa volúmica bulk, levando a uma redução de 5 a 10 kg m-3. A análise termogravimétrica confirmou que a etapa de lavagem removeu praticamente todo o surfactante da estrutura dos materiais.Os aerogéis com diferentes proporções de precursores (100% MTMS, 90% MTMS/10% APTMS e 80% MTMS/20% APTMS) foram caracterizados química, física e microestruturalmente. As amostras com 100% de MTMS apresentaram menores valores de massa volúmica bulk. A presença de grupos amina levou a um aumento em termos de tamanho dos poros, mas uma redução da área superficial específica. As técnicas de microscopia permitiram a visualização da microestrutura dos materiais, sendo visíveis grandes partículas secundárias, além de ser possível verificar a matriz de sílica à volta dos CNTs.Os testes de adsorção revelaram que a presença de CNTs levou a uma ligeira melhoria nas propriedades de adsorção dos adsorventes. Em relação aos compostos orgânicos voláteis (VOC), para os melhores materiais, com xileno e benzeno, foram obtidos elevadas percentagens de remoção (para benzeno superior a 80% e para xileno maior que 90%), enquanto para fenol foi removido apenas no máximo 30%. Para os fármacos, os melhores resultados foram obtidos para o naproxeno, com percentagens de remoção de até 96,9%, enquanto para a amoxicilina o melhor resultado de remoção foi em torno de 67%. Num estudo mais aprofundado do processo de adsorção, foi possível concluir que a presença de CNTs melhorou os parâmetros cinéticos (maior velocidade de adsorção), assim como os parâmetros das isotérmicas (maior afinidade entre a fase líquida e a fase sólida).
The main goal of this master’s dissertation was to incorporate carbon nanotubes (CNTs) in silica aerogels with the aim of obtaining composites with good adsorption properties. Methyltrimethoxysilane (MTMS) and (3-aminopropyl) trimethoxysilane (APTMS) were used as silica precursors, which, in different molar proportions and using the sol-gel methodology, led to the formation of CNTs-silica aerogel composites. The used surfactant was chosen among hexadecyltrimethylammonium bromide (CTAB), sodium dodecyl sulfate (SDS) and polyethylene glycol (PEG). When the synthesis was performed with PEG, the gelation did not occur, however, the use of the other two surfactants produced aerogel monoliths that did not show significant differences in the values of bulk densities. Regarding the gelation time, CTAB showed the best results, with lower time, which is favorable to avoid CNTs sedimentation in the suspension. The next studied parameter was the agitation method and, even though the mechanical stirring provided lower bulk density, the ultrasound bath allowed a better CNTs dispersion in the solution. A study concerning the need of a washing step to remove the surfactant was also accomplished. Comparing the results for the same formulation, with and without washing, it was possible to conclude that this step was crucial, and allowed a significant improvement in the bulk density, leading to a decrease of 5 to 10 kg m-3. The thermogravimetric analysis confirmed that the washing step removed practically all the surfactant from the materials structure.The aerogels with different molar ratio of precursors (100% MTMS, 90% MTMS/10% APTMS and 80% MTMS/20% APTMS) were characterized chemical, physical and microstructurally. The samples with 100% MTMS presented lower values of bulk density. The presence of amine groups led to an increase in terms of pore size and a reduction regarding the specific surface area. The microscopy techniques allowed the visualization of the materials microstructure, showing large secondary particles, besides enabling the verification of the silica matrix around the CNTs. The adsorption tests revealed that the presence of CNTs led to a slight improvement in the adsorption properties of the adsorbents. Regarding volatile organic compounds (VOC), for the best materials, with xylene and benzene, high removal percentage rates were obtained (for benzene superior to 80% and for xylene higher than 90%), while for phenol a maximum of 30% was removed. For the pharmaceuticals, the best results were obtained for naproxen, with removal rates of up to 96.9 %, while for amoxicillin the best result was around 67% of removal. In a more in-depth study of the adsorption process, it was possible to conclude that the presence of CNTs improved the kinetic parameters (higher adsorption velocity), as well as the parameters of the adsorption isotherms (higher affinity between liquid phase and solid phase).
Mallya, Ashwini N. "Design and Fabrication of Conjugated Molecule Based Resistive Sensor for Environmental Monitoring Detecting Targeted Analytes." Thesis, 2015. http://etd.iisc.ernet.in/2005/3651.
Повний текст джерела