Atmospheric formaldehyde (H2CO) is an intermediate product common to the degradation of many volatile organic compounds and therefore it is a central component of the tropospheric chemistry. While the global formaldehyde background is due to methane oxidation, emissions of non-methane volatile organic compounds (NMVOCs) from biogenic, biomass burning and anthropogenic continental sources result in important and localised enhancements of the H2CO concentration. Recent spaceborne nadir sensors provide an opportunity to quantify the abundance of tropospheric formaldehyde at the global scale, and thereby to improve our knowledge of NMVOC emissions. This is essential for a better understanding of the processes that control the production and the evolution of tropospheric ozone, a key actor in air quality and climate change, but also of the hydroxyl radical OH, the main cleansing agent of our troposphere. For this reason, H2CO satellite observations are increasingly used in combination with tropospheric chemistry transport models to constrain NMVOC emission inventories in so-called top-down inversion approaches. Such inverse modelling applications require well characterised satellite data products consistently retrieved over long time periods. This work reports on global observations of formaldehyde columns retrieved from the successive solar backscatter nadir sensors GOME, SCIAMACHY and GOME-2, respectively launched in 1995, 2002 and 2006. The retrieval procedure is based on the differential optical absorption spectroscopy technique (DOAS). Formaldehyde concentrations integrated along the mean atmospheric optical path are derived from the recorded spectra in the UV region, and further converted to vertical columns by means of calculated air mass factors. These are obtained from radiative transfer simulations, accounting for cloud coverage, surface properties and best-guess H2CO profiles, the latter being derived from the IMAGES chemistry transport model. A key task of the thesis has consisted in the optimisation of the H2CO retrieval settings from multiple sensors, taking into account the instrumental specificities of each sounder. As a result of these efforts, a homogeneous dataset of formaldehyde columns covering the period from 1996 to 2010 has been created. This comes with a comprehensive error budget that treats errors related to the spectral fit of the columns as well as those associated to the air mass factor evaluation. The time series of the GOME, SCIAMACHY and GOME-2 H2CO observations is shown to be consistent and stable over time. In addition, GOME-2 brings a significant reduction of the noise on spatiotemporally averaged observations, leading to a better identification of the emission sources. Our dataset is used to study the regional formaldehyde distribution, as well as its seasonal and interannual variations, principally related to temperature changes and fire events, but also to anthropogenic activities. Moreover, building on the quality of our 15-year time series, we present the first analysis of long-term changes in the H2CO columns. Positive trends, in the range of 1.5 to 4% yr-1, are found in Asia, more particularly in Eastern China and India, and are related to the known increase of anthropogenic NMVOC emissions in these regions. Finally, our dataset has been extensively used in several studies, in particular by the BIRA-IASB modelling team to constrain NMVOC emission fluxes. The results demonstrate the high potential of satellite data as top-down constraint for biogenic and biomass burning NMVOC emission inventories, especially in Tropical ecosystems, in Southeastern Asia, and in Southeastern US. / Le formaldéhyde (H2CO) joue un rôle central dans la chimie de la troposphère en tant que produit intermédiaire commun à la dégradation chimique de la plupart des composés organiques volatils dans l’atmosphère. L’oxydation du méthane est responsable de plus de la moitié de la concentration moyenne globale du formaldéhyde. Sur les continents en revanche, les hydrocarbures non-méthaniques (NMVOCs) émis par la végétation, les feux de biomasse et les activités humaines, augmentent de façon significative et localisée la concentration de H2CO. Les récents senseurs satellitaires à visée nadir offrent la possibilité de quantifier à l’échelle globale l’abondance du formaldéhyde dans la troposphère et de ce fait, d’améliorer notre connaissance des émissions de NMVOCs. Ceci est essentiel à la compréhension des mécanismes contrôlant la production et l’évolution de l’ozone troposphérique, élément clé pour la qualité de l’air et les changements climatiques, mais aussi du composé hydroxyle OH, le principal agent nettoyant de notre troposphère. C’est pourquoi, une méthode de plus en plus répandue pour améliorer les inventaires d’émissions des NMVOCs consiste en l’utilisation d’observations satellitaires de H2CO en combinaison avec un modèle de chimie et de transport troposphérique, dans une approche appelée modélisation inverse. Ce genre d’application demande des produits satellitaires bien caractérisés et dérivés de façon cohérente sur de longues périodes de temps. Le travail présenté dans ce manuscrit porte sur l’inversion des colonnes de formaldéhyde à partir de spectres de la radiation solaire rétrodiffusée par l’atmosphère terrestre, mesurés par les senseurs GOME, SCIAMACHY et GOME-2, lancés successivement en 1995, 2002 et 2006. La méthode d’inversion est basée sur la spectroscopie d’absorption optique différentielle (DOAS). Les concentrations de formaldéhyde intégrées le long du chemin optique moyen dans l’atmosphère sont dérivées à partir des spectres mesurés, et ensuite transformées en colonnes verticales par le biais de facteurs de conversion appelés facteurs de masse d’air. Ces derniers sont calculés à l’aide d’un modèle de transfert radiatif, en tenant compte de la présence de nuages, des propriétés de la surface terrestre et la distribution verticale supposée du formaldéhyde, fournie par le modèle IMAGES. Un des objectifs principaux de la thèse a été d’optimiser les paramètres d’inversion pour H2CO, et ceci pour les trois senseurs, tout en tenant compte des spécificités de chaque instrument. Ces efforts ont conduit à la création d’un jeu de données homogène, couvrant la période de 1996 à 2010. Les colonnes sont fournies avec un bilan d’erreur complet, incluant les erreurs liées à l’inversion des concentrations dans les spectres, ainsi que celles provenant de l’évaluation des facteurs de masse d’air. La série temporelle des observations de GOME, SCIAMACHY et GOME-2 présente une bonne cohérence et stabilité sur toute la période. Nous montrons aussi que la meilleure couverture terrestre de GOME-2 entraîne une réduction significative du bruit sur les observations moyennées, permettant une meilleure identification des sources d’émission. Notre jeu de données est exploité pour étudier la distribution régionale du formaldéhyde, ainsi que ses variations saisonnières et interannuelles, principalement liées aux variations de température et aux feux de végétation, mais aussi aux activités anthropiques. De plus, en s’appuyant sur la qualité de la série temporelle de 15 ans, nous présentons la première analyse des variations à long terme des concentrations de H2CO. Des tendances positives, de l’ordre de 1.5 à 4% par an, sont observées en Asie, en particulier dans l’est de la Chine et en Inde, liées à l’augmentation des émissions anthropiques d’hydrocarbures dans ces régions. Finalement, nos données ont été largement exploitées par le groupe de modélisation de l’IASB pour faire des études de modélisation inverse des émissions de NMVOCs. Les résultats démontrent le haut potentiel des données satellitaires pour contraindre les inventaires d’émissions dues à la végétation et aux feux de biomasse, particulièrement dans les écosystèmes tropicaux, en Asie du sud-est, et dans le sud-est des Etats-Unis.

A gas-fluidized bed bioreactor was developed in this research as a new method for treating polluted air. The fluidization characteristics of selected packing materials were investigated. Then, bioremediation was tested using two types of packing in a fluidized bioreactor, as well as in a comparable packed bed. Microorganisms on the particles biodegrade contaminants in the polluted air, which flows up through the bed. At high flowrates, the polluted air fluidizes the particles, while at low velocities the operation is in packed bed mode.<p>Initially, sawdust was selected for use as a packing material. Due to the poor fluidization properties of sawdust, glass spheres were added. A mixture of sawdust and glass spheres remained well mixed during fluidization. In the mixture, interparticle forces increased with increasing moisture in the sawdust, eventually causing defluidization of the bed. In the absence of bioremediation, mass transfer was studied between ethanol-contaminated air and sawdust/glass sphere packing, and found to be higher in the fluidized versus packed mode. In bioremediation experiments, ethanol removal efficiencies were as high as 95% in both operating modes. The maximum elimination capacities (EC) of ethanol were 75 and 225 g m^-3 sawdust h^-1 in the fluidized and packed beds respectively.<p>The packing of the fluidized bed bioreactor was optimized in order to boost bioremediation rates. Experiments showed that peat granules fluidized well in a bubbling regime, likely due to their relatively high density and sphericity. In peat bioremediation trials, the fluidized mode outperformed the packed bed; the maximum ECs were 1520 and 530 g m^-3 peat h^-1, respectively. Removal efficiency in the fluidized mode decreased with velocity, because the size and amount of large bubbles increased.<p>A steady-state model of the fluidized bioreactor was developed. By taking account of bubble properties during fluidization, the model helps to explain how bubble size, microbial properties and bioreactor residence time affect removal efficiency and elimination capacity of the bioreactor.<p>A peat gas-fluidized bioreactor shows promise as an efficient, low-cost technology for air treatment. Particle mixing in the fluidized bed may prevent operating problems associated with the packed bed bioreactor. Fluidized bioreactors are ideal for the treatment of high volume, low concentration air emissions.

A versatile method for the reduction of 2-pyrazolines was developed in this research. In every reduction attempt, aluminum trihydride successfully reduced the carbonnitrogen double bond. Since carbon-carbon double bonds were stable to aluminum trihydride, the preparation of 3-vinyl1-pyrazolines by a new synthetic route became possible. Using this method, 3,3-dimethyl-5-(1-isobutenyl)-1-pyrazoline was prepared. This compound was thermalytically decomposed, and the products of the decomposition were determined.In the course of this research, a one-step method for the preparation of cyclopropanes in high yield from 2pyrazolines was uncovered, but not fully developed. A new route to alpha-gamma-diamino compounds was also accomplished with the use of aluminum trihydride.Ball State UniversityMuncie, IN 47306

The synthesis and characterization of the 1-pyrazolines produced from the addition of diazomethane to maleic anhydride, citraconic anhydride, isoprene, norbornene, and norbornadiene was carried out. This was followed by the thermal decomposition of the synthesised 1-pyrazolines. The thermal decomposition of the 1-pyrazolines proceded by the loss of nitrogen to yield both the expected cyclopropanes and olefins, as well as cyclic reversion products in the case of the mono- and disubstituted norbornadiene adducts.Ball State UniversityMuncie, IN 47306

Irradiation of 1,1-dioxo-2-phenyl-4-thiazolidinone resulted in loss of S02 and formation of a carbon-carbon bond. When (2S,5R) cis-3,5-dimethyl-l,l-dioxo-2-phenyl-4thiazolidinone was photolyzed (through a Vycor filter in t-BuOH/CH3CN) (3S,4S) cis-l,3-dimethyl-4-phenyl-2-azetidinone (i.e., optically active cis a-lactam) was obtained as a major product. The synthesis of (2S,5R) cis-3,5-dimethyl1,1-dioxo-2-phenyl-4-thiazolidinone is described. The verification of optical activity was accomplished by the use of Eu(tfc)3.In addition to the earlier data, the above results have helped us to elucidate the mechanistic pathway of S02 photoextrusion to form p-lactam rings. Sensitization experiments by M. R. Johnson and his use of triplet state quencher have shown that the photoextrusion is a singletstate reaction. Johnson's trapping experiments indicated the existence of a radical intermediate. In the work of this thesis, the observation of optical activity of the cis S-lactam product ruled out a planar diradical and a butadiene-like intermediate. Thus, it can be concluded that the S02 photoextrusion process occurs via discrete radical and diradical intermediates. The diradical is probably formed by stepwise loss of S02 and is so shortlived that optical activity along with cis stereochemistry is maintained.Ball State UniversityMuncie, IN 47306

No description available.

A gas-fluidized bed bioreactor was developed in this research as a new method for treating polluted air. The fluidization characteristics of selected packing materials were investigated. Then, bioremediation was tested using two types of packing in a fluidized bioreactor, as well as in a comparable packed bed. Microorganisms on the particles biodegrade contaminants in the polluted air, which flows up through the bed. At high flowrates, the polluted air fluidizes the particles, while at low velocities the operation is in packed bed mode.<p>Initially, sawdust was selected for use as a packing material. Due to the poor fluidization properties of sawdust, glass spheres were added. A mixture of sawdust and glass spheres remained well mixed during fluidization. In the mixture, interparticle forces increased with increasing moisture in the sawdust, eventually causing defluidization of the bed. In the absence of bioremediation, mass transfer was studied between ethanol-contaminated air and sawdust/glass sphere packing, and found to be higher in the fluidized versus packed mode. In bioremediation experiments, ethanol removal efficiencies were as high as 95% in both operating modes. The maximum elimination capacities (EC) of ethanol were 75 and 225 g m^-3 sawdust h^-1 in the fluidized and packed beds respectively.<p>The packing of the fluidized bed bioreactor was optimized in order to boost bioremediation rates. Experiments showed that peat granules fluidized well in a bubbling regime, likely due to their relatively high density and sphericity. In peat bioremediation trials, the fluidized mode outperformed the packed bed; the maximum ECs were 1520 and 530 g m^-3 peat h^-1, respectively. Removal efficiency in the fluidized mode decreased with velocity, because the size and amount of large bubbles increased.<p>A steady-state model of the fluidized bioreactor was developed. By taking account of bubble properties during fluidization, the model helps to explain how bubble size, microbial properties and bioreactor residence time affect removal efficiency and elimination capacity of the bioreactor.<p>A peat gas-fluidized bioreactor shows promise as an efficient, low-cost technology for air treatment. Particle mixing in the fluidized bed may prevent operating problems associated with the packed bed bioreactor. Fluidized bioreactors are ideal for the treatment of high volume, low concentration air emissions.

Biological and physical chemistry treatment methods always are used to remove COD of organic wastewater contains PCB. The effect is not obvious when the compositions of pollutant are too refractory or complicated. The primary treatment method of wastewater containing copper is chemical coagulation/sedimentation and its disadvantage is producing a large of sludge. The objective of this study, using two combinative method of UV/H2O2-Ferrite Process and Fenton-Ferrite Process, is to remove organic compounds and heavy metal in real wastewater. Not only supernatant liquid could meet the standard of discharge wastewater but also produce general(non-hazardous) industrial wastes of heavy metal. The primary operation condition of Fenton and UV/H2O2 process, was ferrous ion and hydrogen peroxide concentration, pH, reaction time, and chemical dosing, searching best operation condition to combine with Ferrite Process. Operation of Fenton and UV/H2O2 process under acid condition (pH=2) and neutral condition (pH=8) showed the best operation condition of Fenton and UV/H2O2. The removal decreased when the dose of hydrogen peroxide was added too more or too less. As Fenton and UV/H2O2 process test finished, Ferrite Process is next used for treatment of heavy metal wastewater; Ferrite Process conducted as three stages and the operation conditions were controlled with temperature, pH and the ratio of Fe/M mole. The results showed that the best removal of treatment of copper containing wastewater by Ferrite Process achieved when the ratio of Fe/M mole was at 10. Treatment of PCB industrial real wastewater by Fenton-Ferrite Process and UV/H2O2-Ferrite Process which combined with Fenton, UV/H2O2 and Ferrite Process. The supernatant liquid containing organic compounds and heavy metal both could meet the standards of discharge wastewater and the sludge was judged with general(non-hazardous) wastes. The characteristic of the sludge were the diameter lattice less 100 nm and with magnetism and to develop recovery and utilization in a further work.

No description available.

In this study, a pilot-scale Regenerative Thermal Oxidizer (RTO) was used to test its performance for volatile organic compound (VOC) destruction and degree of thermal energy conservation. The RTO is electrically heated and contains two 0.5 m ¡Ñ 0.5 m ¡Ñ 2.0 m (L ¡Ñ W ¡Ñ H) columns both packed with gravel particles of 1.0 cm in diameter to a height of 1.4 m. The bed has a void fraction of 0.415. The purpose of this study is to establish the influencing operating conditions and to improve the technique for further applications. Experiments include two phases: (1) energy conservation test with no VOC in the influent air stream , and (2) VOC destruction test with influent air streams containing one of the three VOCs: isopropyl alcohol, acetone, and xylene. Phase 1 experiments were conducted in the maximum gravel temperatures (Tmax) of 402-704 oC, superficial gas velocities (Ug, evaluated at ambient temperatures of 25-30 oC) of 0.15-0.50 m/s, and bed shift times (ts) of 0.5-2.0 min. Results indicate that the temperature raise (