Tesi: "Toluene" – Grafiati

1

Boyle, Sarah Ann. "Oxidation of toluene". Thesis, Queen's University Belfast, 1997. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.387977.

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2

Mar, Therese Frances. "The effects of physical activity and gender on the toxicokinetics of toluene in human volunteers /". Thesis, Connect to this title online; UW restricted, 1998. http://hdl.handle.net/1773/8441.

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3

Simpson, Helen D. "The metabolism of toluene by thermotolerant bacteria". Thesis, University of Warwick, 1987. http://wrap.warwick.ac.uk/98248/.

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Several thermotolerant organisms capable of growth on toluene as the sole carbon and energy source, were isolated from various soil samples and liquid samples from a waste treatment works. Two isolates ware selected for further studies and tentatively characterized as Bacillus species. The isolates were designated strain HTB16 and strain AT50 and had optimum growth temperatures of 45°C and 50°C respectively. An initial aim of the project was to investigate whether thermotolerant organisms could be exploited to produce aromatic cis-dihydrodiols. Both strains HTB16 and AT50 oxidized toluene using a dioxygenase-catalyzed reaction, thereby forming cis-toluene dihydrodiol as an intermediate. Therefore, a mutant of either strain, which lacked functional cis-toluene dihydrodiol dehydrogenase would accumulate cis-toluene dihydrodiol when grown in the presence of toluene and a co-substrate. A mutant of strain AT50 would probably be the most suitable organism for an industrial process since it exhibited a higher optimum growth temperature, which was reflected by a greater thermostability of its enzymes. The enzymes detected in crude extracts of strain AT50 appeared to be more thermostable than those in extracts of HTB16. Cis-Toluene dihydrodiol dehydrogenase from AT5O was particularly stable. This enzyme was purified and partially characterized and amongst its properties, had a half-life of 100 min at 80°C. Strains HTB16 and AT5O were subjected to various mutagenic procedures. NTG mutagenesis appeared to be the best method for obtaining a relatively high percentage of mutants amongst the survivors. Unfortunately, all the mutants obtained appeared to lack toluene dioxygenase. In conclusion, it appears that enzymes from thermotolerant organisms are more thermostable than those from mesophiles. Consequently, it may be advantageous to use strain AT50 to produce cis-toluene dihydrodiol, once a suitable mutant is obtained. However, experiments with continuous cultures of strain AT5O suggested that one possible disadvantage of growing toluene-utilizing bacteria at 50°C is the low solubility of toluene in aqueous medium at this temperature.

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4

Albahar, Mohammed. "Selective toluene disproportionation over ZSM-5 zeolite". Thesis, University of Manchester, 2018. https://www.research.manchester.ac.uk/portal/en/theses/selective-toluene-disproportionation-over-zsm5-zeolite(bcc7a677-3234-470f-be44-fdefa2bd7350).html.

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This research aimed at improving p-xylene selectivity in toluene disproportionation over ZSM-5 zeolite by exploring the effect of crystal size and various post synthetic modification methods. A comprehensive study of the effect of different modifications on the physicochemical properties of ZSM-5 was investigated using X-ray diffraction (XRD), pyridine adsorption, Fourier transform infra-red (FTIR), 29Si magic-angle spinning nuclear magnetic resonance (MAS NMR), BET surface area by N2 adsorption, inductively coupled plasma (ICP) and scanning electron microscopy (SEM). The catalytic performance of each catalyst was studied in a fixed bed reactor at a temperature 475 ÃÂ°C, WHSV 3-83 h-1 and two different pressures (1 and 10 bar). ZSM-5 zeolites with different crystal sizes (5, 50 and 100 ÃÂμm) were synthesized in house and compared with the commercially obtained ZSM-5 having a crystal size of 0.5 ÃÂμm. The increase in crystal size improved p-xylene selectivity which was attributed to the diffusion constraints imposed by the longer diffusion path lengths of large crystals. The highest p-xylene selectivity (58 %) was achieved over ZSM-5 with the largest crystal size 100 ÃÂμm at the highest WHSV 83 h-1. However, it was accompanied by a low conversion (2 wt. %). ZSM-5 with crystal size of 5 ÃÂμm delivered the best results in terms of the combination of para-selectivity (40 %) and toluene conversion (15 wt. %). The p-xylene produced in the channels of ZSM-5 can quickly isomerise to o-xylene and m-xylene on the external unselective acid sites. Different post modification methods were applied in this study in attempt to suppress the fast isomerization reaction by deactivating the external acid sites. This was achieved to some extent by depositing an inert silica layer using different silica agents, amounts and number of modification cycles and as a result p-xylene selectivity was significantly improved (84 %), especially over large crystals 5 ÃÂμm. The decrease in BrÃÂ ̧nsted acidity (FTIR) suggested the success of the silylation method. Furthermore, impregnation of lanthanum and phosphorus on ZSM-5 improved p-xylene selectivity (40 %). FTIR measurements showed a drastic drop in the number of BrÃÂ ̧nsted and Lewis acid sites after loading phosphorus which led to a large reduction in toluene conversion. Lanthanum impregnation had less effect on conversion and increased selectivity with decreased BrÃÂ ̧nsted sites and pore volume reduction showed by N2 adsorption suggesting some pore narrowing. There are several approaches that can be considered in future to further improve p-xylene selectivity. Improving the synthesis of large crystals to balance acidity and crystal size can lead to the enhancement of p-xylene selectivity. Also, performing toluene disproportionation on optimised pre-coked ZSM-5 large crystals at high pressure can help to maintain the conversion while increasing p-xylene selectivity. Another approach would be to apply silylation modification to extruded large crystals ZSM-5.

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Marcelová, Štěpánka. "Toxicita nitroderivátů toluenu a produktů jejich transformací". Master's thesis, Vysoké učení technické v Brně. Fakulta chemická, 2010. http://www.nusl.cz/ntk/nusl-216647.

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This work is focused on verification of p-Nitrotoluenu toxicity and compounds resulting from the aerobic transformation, and methyl group oxidation and reduction of nitro. Some of these products are not commercially available and had to be made soon. Toxicity of the substances was determined by toxicity tests. Were tested root growth inhibition Sinapis alba, which resulted in an inhibitory concentration IC50; test inhibition duckweed Lemna minor , which was also the determination of IC50 inhibitory concentration, and acute toxicity test Artemia salina, which was observed in mortality and immobility organisms and the test result was an efficient concentration EC50 value. Results of tests are compared in the conclusion of the work and is made evaluation of the toxicity of individual substances.

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6

Regan, Lucy. "Metabolic pathway engineering of the toluene degradation pathway". Thesis, University College London (University of London), 1995. http://discovery.ucl.ac.uk/1317891/.

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This thesis addresses the problem of how to examine a metabolic pathway and identify what are the key elements, specifically with respect to rate-limitation. The aim is to be able to analyze a pathway, identify the bottlenecks and implement genetic modifications to remove these bottlenecks. This is done by defining the system of interest and developing a predictive model using kinetic data. The model predictions can then be verified using fermentation data and genetic techniques to make the appropriate changes for improved performance. The test system chosen for this study was the TOL meta-cleavage pathway for the degradation of benzoate. This system was chosen on the basis of the application of pathway engineering principles to other systems. The modelling strategy and software was developed using principles from metabolic control theory and biochemical systems theory. By applying this to the TOL pathway using kinetic data, the control coefficients for the pathway were obtained as well as the system parameters required for the optimization of the pathway. The simulated results obtained from this model must be validated by experiment. Errors can arise both from incorrect assumptions in the model and from the fact that the kinetic data taken from individual in vitro experiments may not be applicable to the in vivo system. The effect of the presence of the TOL pathway on the behaviour of E.coli JM107 during fermentation was investigated and the transient concentration data necessary to identify the bottlenecks in the pathway measured. This data is then used to calculate the flux control coefficients for the TOL pathway. The predictive results were verified by the fermentation data which identified the first two enzymes in the pathway as having significant flux control coefficients. This final chapter also addresses the issue of flux analysis, that is, the calculation of the fluxes in the system to determine where fluxes to unwanted by-products occur and to indicate points of control. A graphical user interface is used to provide a user-friendly and intuitive means of building and customising metabolic pathways which can then be interfaced with instrumentation to provide on-line flux analysis.

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Chalapati, Sachin. "Toluene Mediated FCC of LDPE Using Ionic liquids". Thesis, Högskolan i Borås, Institutionen Ingenjörshögskolan, 2014. http://urn.kb.se/resolve?urn=urn:nbn:se:hb:diva-17973.

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Polyethylene is one of the most widely used synthetic materials produced by mankind and its accumulation in the biosphere is exceeding at an alarming rate. There are several methods to recycle or remediate the waste polyethene apart from land filling and generation of useful products from the waste is on demand for research and development. Ionic liquids are aggressively replacing several organic compounds due to their robust nature and also have novel properties that allow depolymerization of synthetic materials into simpler short chained paraffins. Initial dissolution of polymer using hot toluene followed by agitated depolymerization using EMIM-Cl (AlCl3) ionic liquid for producing fuel grade high calorie organic molecules might be proven successful. This method uses proton sources like sulphuric acid, hydrochloric acid or waters that aid saturation of organic compounds by hydrogen ion exchange. This could be a novel procedure that aims to produce fuel grade products from waste synthetic polymers like polyethene.
Program: Master of Science with a Major in Resource recovery – Industrial biotechnology

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VIEIRA, Kátia Cristina de Melo Tavares. "Efeitos da exposição à mistura comercial de gasolina/etanol sobre a função reprodutiva masculina em modelo experimental". Universidade do Oeste Paulista, 2018. http://bdtd.unoeste.br:8080/jspui/handle/jspui/1083.

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Leaks at gas stations cause major problems for the environment, especially with regard to contamination of groundwater and soils. The major problems of oil derivative contamination are attributed to monoaromatic hydrocarbons (BTEX - benzene, toluene and xylene), which are the most soluble and mobile constituents of the gasoline fraction, being the first to reach the water table. In the most recent survey carried out by the State Company of Environmental Sanitation Technology of the State of São Paulo (CETESB), it was identified that more than 85% of the contamination cases in the region of West Paulista are related to waste from fuel stations. The present study evaluated the toxicological potential of exposure of adult male rats to the commercial gasoline / ethanol blend (75/25 by volume), with emphasis on the possible impacts on reproductive morphophysiology. Adult male Wistar rats were allocated into 4 experimental groups (n = 8 / group). The animals received commercial gasoline diluted in corn oil via gavage at doses of 0 (control group- C), 16 (group A - GA), 160 (group B - GB) or 800 mg / kg / day (group C - GC). The reproductive organs were collected and weighed. The sperm parameters evaluated were motility, plasma membrane integrity and acrosomal, mitochondrial activity and morphology. In addition, the epididymis and right testis were collected for sperm counts. Histopathological analysis of the testis and epididymis, spermatogenesis and cell counts. For the machine learning test, different pattern recognition algorithms were used: Artificial Neural Network (ANN), Bayes Classifier (BAY), K-Nearest Neighbors (KNN), Support Vector Machine (SVM) and Optimum Path Forest OPF). The results were compared by ANOVA with Tukey's posterior test, and the Kruskall-Wallis test with Dunn's a posteriori, considering p <0.05. The sperm parameters were reduced in a dose-dependent manner. Mitochondrial activity and acrosomal integrity were decreased in the GC and GB groups in relation to the control group. There was an increase of isolated heads in the GC and GB groups in relation to the control group. Plasma membrane integrity was reduced in GC in relation to the control group. A decrease in the number of mobile spermatozoa with progressive trajectory was observed in the GC and GB groups, in relation to the control group. The daily sperm production was reduced in GC and GB in relation to the control group. In addition, this parameter was lower in GC than in GB. There was a significant delay in transit time in the tail of the epididymis in the GC and GB groups in relation to the control group. The number of Sertoli cells decreased in the GB and GC groups when compared to the CG and GB groups. Histopathological analysis, spermatogenesis and germ cell counts showed no significant difference between the groups. There was presence of pattern with the subdivision of two classes (control group and exposed groups), with better classification with the SVM test and 90% accuracy for control group. Thus, it was concluded that the exposure of rats to different doses of the commercial gasoline / ethanol mixture can alter spermatogenesis and sperm quality, with a recognizable classification pattern of machine learning algorithms.
Vazamentos em postos de combustíveis provocam grandes problemas ao meio ambiente, principalmente no que diz respeito à contaminação de águas subterrâneas e solos. Os maiores problemas da contaminação por derivados de petróleo são atribuídos aos hidrocarbonetos monoaromáticos (BTEX - benzeno, tolueno e xileno), que são os constituintes mais solúveis e mais móveis da fração da gasolina, sendo os primeiros a atingir o lençol freático. No mais recente levantamento realizado pela Companhia Estadual de Tecnologia de Saneamento Ambiental do Estado de São Paulo (CETESB), identificou-se que mais de 85% dos casos de contaminação na região do Oeste Paulista estão relacionados a resíduos de postos de combustíveis. O presente estudo avaliou o potencial toxicológico da exposição de ratos machos adultos à mistura comercial de gasolina/etanol (75/25 em volume), com ênfase nos possíveis impactos sobre a morfofisiologia reprodutiva. Ratos machos Wistar adultos foram alocados em 4 grupos experimentais (n=8/grupo). Os animais receberam gasolina comercial diluída em óleo de milho, via gavagem, nas doses de 0 (grupo controle - C), 16 (grupo A - GA), 160 (grupo B - GB) ou 800 mg/kg/dia (grupo C - GC). Os órgãos reprodutivos foram coletados e pesados. Os parâmetros espermáticos avaliados foram motilidade, integridade da membrana plasmática e acrossomal, atividade mitocondrial e morfologia. Além disso, o epidídimo e testículo direito foram coletados para contagens espermáticas. Também foram realizadas análise histopatológica do testículo e epidídimo, contagens dos estágios da espermatogênese e de células. Para o teste de aprendizado de máquina foram utilizados diferentes algoritmos de reconhecimento de padrões: Artificial Neural Network (ANN), Bayes Classifier (BAY), K-Nearest Neighbors (K-NN), Support Vector Machine (SVM) e Optimum Path Forest (OPF). Os resultados foram comparados por ANOVA com o teste “a posteriori” de Tukey, e o teste de Kruskall-Wallis, com “a posteriori” de Dunn, considerando p<0,05. Os parâmetros espermáticos foram reduzidos de maneira dose-dependente. A atividade mitocondrial e integridade acrossomal foram diminuídas nos grupos GC e GB em relação ao grupo controle. Houve um aumento de cabeças isoladas nos grupos GC e GB em relação ao grupo controle. A integridade de membrana plasmática foi reduzida em GC em relação ao grupo controle. Foi observada uma redução no número de espermatozoides móveis com trajetória progressiva nos grupos GC e GB, em relação ao grupo controle. A produção diária espermática foi reduzida em GC e GB em relação ao grupo controle. Além disso, este parâmetro foi menor em GC em relação a GB. Houve um atraso significativo no tempo de trânsito na cauda do epidídimo nos grupos GC e GB em relação ao grupo controle. O número de células de Sertoli sofreu redução nos grupos GC e GB quando comparado aos grupos controle e GA. A análise histopatológica, contagem dos estágios da espermatogênese e de celulas germinativas não apresentaram diferença significativa entre os grupos. Houve presença de padrão com a subdivisão de duas classes (grupo controle e grupos expostos), com melhor classificação com o teste SVM e 90% de acurácia para o grupo controle. Assim, concluiu-se que a exposição de ratos a diferentes doses da mistura comercial de gasolina/etanol pode alterar a espermatogênese e a qualidade espermática, com reconhecível padrão de classificação de algoritmos de aprendizado de máquina.

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Sood, Dhiraj S. "The role of strongly acidic media on the formylation of toluene". Diss., Georgia Institute of Technology, 1998. http://hdl.handle.net/1853/10090.

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Burton, Helen Amanda. "Liquid-phase oxidation and coupling of arenes by Pd(II)/HPA". Thesis, University of Liverpool, 2001. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.368630.

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Lee, Sang Hak. "A PVTx study of the mixtures of the first three members of the linear dimethylsiloxane series with toluene /". The Ohio State University, 1987. http://rave.ohiolink.edu/etdc/view?acc_num=osu148732769562334.

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Almulla, Faisal. "Transalkylation of toluene with 1,2,4-trimethylbenzene over zeolite catalysts". Thesis, University of Manchester, 2018. https://www.research.manchester.ac.uk/portal/en/theses/transalkylation-of-toluene-with-124trimethylbenzene-over-zeolite-catalysts(9b1e44b6-0113-4750-865e-72b5e3647e98).html.

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Benzene, toluene, and xylene are three basic raw materials for the production of most aromatic derivatives such as polyesters, plastics and detergents. Xylenes (p-, m- and o-) have the greatest market demand with an increasing annual rate of 6%. Owing to the availability of surplus toluene and low value of C9 aromatics, the transalkylation process is aimed at the production of more valued products, such as xylenes. Catalyst deactivation is a key challenge in transalkylation process. Using industrially relevant operating parameters, the transalkylation of 1,2,4-trimethylbenzene (TMB) with toluene was studied. The effect of zeolite structure and acidity, increased reaction pressure and temperature, and very low levels of platinum (Pt) impregnation has been investigated over both H-form and Pt-loaded zeolites: Beta, Mordenite (MOR), and Y. A fixed bed reactor was used at WHSV of 5 h-1, 400 oC, and a 50:50 wt. % toluene:TMB ratio with the order of activity after 50 h time-on-stream (TOS) of Y > Beta >> MOR at 1 bar. At elevated pressure (10 bar), all catalysts showed better performance with significant improvement in MOR as pore blockage was reduced and the order of activity was Beta > MOR > Y. With varying the Si/Al ratio for zeolites Beta (Si/Al = 12.5, 75 and 150) and Y (Si/Al = 2.6, 6, 15 and 30), the highest stability and xylenes yield were achieved over zeolite Beta with lowest Si/Al ratio at 41 wt. % conversion and 25 wt. % xylenes yield. In contrast, zeolites Y with Si/Al ratio of 2.6 showed the highest deactivation rate, whereas over Y zeolites with Si/Al = 6-30, the conversion was between 25-30 wt. % and xylenes yield around 11 wt. % after 50 h TOS. Incorporation of Pt (0.08 wt. %) further improved the activity of all catalysts with the highest conversion after 50 h TOS over Beta (62 wt. %) where Beta and MOR yielded similar levels of xylenes (40 wt. %). All catalysts were further optimized by reducing Pt levels whilst maintaining the desired stability and highest xylenes yield. In order to further develop a cost-effective and eco-friendly catalyst, the addition of alumina binder to Pt-Beta and the possibility of simplified regeneration of Beta/Pt-Beta catalyst were investigated. Firstly, the alumina binder reduced the conversion and xylenes yield, however, this reduction was small up to 40 wt. % added alumina binder (where xylenes yield only dropped to 35 wt. %). Secondly, the regeneration process was carried out using H2 only and up to four cycles (30 h TOS per cycle). The Pt-Beta catalyst found to be stable and the activity was fully restored by a hydrogenation process at 500 oC. However, the activity of Beta dropped gradually after each cycle suggesting that the H2 alone at 500 oC was insufficient in removing coke precursors. The drop in activity was attributed to the disappearance of BrÃ ̧nsted acid sites over the spent Beta catalyst due to the growth of coke molecules trapped in cavities leading to highly polyaromatic molecules blocking those active sites.

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Rowane, Aaron J. "High-Temperature, High-Pressure Viscosities and Densities of Toluene". VCU Scholars Compass, 2016. http://scholarscompass.vcu.edu/etd/4188.

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High-temperature, high-pressure (HTHP) conditions are exemplified in ultra-deep petroleum reservoirs and can be exhibited within diesel engines. Accurate pure component hydrocarbon data is essential in understanding the overall behavior of petroleum and diesel fuel at these conditions. The present study focuses on the HTHP properties of toluene since this hydrocarbon is frequently used to increase the octane rating of gasoline and toluene occurs naturally in crude oil. In this thesis experimental densities and viscosity are presented to 535 K and 300 MPa extending the database of toluene viscosity data to higher temperature than previous studies. The data is correlated to a Tait-like equation and a Padѐ approximate in conjunction with a single mapping of the isotherms. Free-volume theory and a superposition of the viscosity in relation to the Leonnard-Jones repulsive force are both used to model the toluene viscosity data. It was found that the data are in good agreement with the available literature data.

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Mauro, Mariana [UNESP]. "Influência da exposição ao tolueno por inalação na atividade In Vivo dos transportadores da família Oatp em ratos". Universidade Estadual Paulista (UNESP), 2016. http://hdl.handle.net/11449/143414.

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Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)
Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)
A exposição ocupacional a agentes químicos é potencialmente capaz de modificar a disposição cinética ou o metabolismo de fármacos, principalmente em função da indução ou inibição de enzimas do sistema citocromo P450. Entretanto, estudos que mostram o efeito da exposição ocupacional a agentes químicos na atividade de transportadores de fármacos são escassos. O tolueno está presente no ambiente de trabalho principalmente na forma de vapor. Neste ambiente, o solvente é absorvido principalmente por inalação. O objetivo do estudo é avaliar a influência da exposição inalatória ao tolueno na atividade in vivo do polipeptídeo transportador de ânions orgânicos da família Oatp em ratos, empregando como fármaco marcador a pravastatina. Ratos machos Wistar (n=6 por tempo de coleta, por grupo) foram expostos ao tolueno (85 mg/m3) por inalação ou ao ar em câmara de exposição apenas pelo nariz por 6 horas/dia, 5 dias/semana, 4 semanas. Ao final do período de exposição, os animais receberam dose única de pravastatina (20 mg/kg) por via oral. Amostras seriadas de sangue foram coletadas até 8 horas após a administração de pravastatina. As concentrações plasmáticas do fármaco foram avaliadas por cromatografia líquida de alta eficiência com detecção por espectrometria de massas (LC-MS). O método de análise da pravastatina por LC-MS mostrou detectabilidade, precisão e exatidão compatíveis com a aplicação em estudos de disposição cinética após dose única em ratos. As áreas sob as curvas de concentração plasmática versus tempo (ASC) foram calculadas do tempo zero a infinito com base na Quadratura de Gauss-Laguerre. As concentrações de pravastatina correspondentes aos tempos avaliadas foram estimadas por interpolação polinomial. O clearance total aparente (CL/F) foi calculado a partir da equação: CL/F = dose/ASC0-∞. Na avaliação da disposição cinética da pravastatina, os animais não expostos ao tolueno apresentaram ASC0-∞ de 726 ng h/mL e Cl/F de 49,1 L/h kg. Não houve diferença estatística na ASC0-∞ ao comparar os animais expostos (ASC0-∞: 681,8 ng h/mL) e não expostos ao tolueno. Os resultados do estudo permitem concluir que a atividade de transportadores Oatp, avaliada pelo uso da pravastatina como fármaco marcador, não foi alterada após a exposição ao tolueno por inalação a 85 mg/m3, 6 horas/dia, 5 dias/semana, 4 semanas em ratos.
Occupational exposure to chemical agents is potentially able to modify the kinetic disposition of drug metabolism, mainly due to the induction or inibition of cytochrome P450 enzymes. However, studies investigating the influence of occupational exposure to chemicals on the variability in drug response are rare. Toluene is present in the working environment particularly in vapor form. In this environment, the toluene is mainly absorbed by inhalation. Considering that, the aim of this study was evaluate the influence of inhalation to toluene in the in vivo activity of the polypeptide transporter organic anion (Oatp) family transporters in rats, using pravastatin as a probe drug. Male Wistar rats (n=6, for each sampling time) were exposed to toluene (85 mg / m3) by inhalation or air in a nose only exposure system for 6 hours/day, 5 days/week, during 4 weeks. After 4 weeks of exposure, animals received a single dose of pravastatin (20 mg/kg) orally. Serial blood samples were collected up to 8 hours after administration of pravastatin. Plasma concentrations of pravastatin were measured by high-performance liquid chromatography with detection by mass spectrometry (LC-MS). The analysis method of pravastatin by LC-MS showed detectability, precision and accuracy compatible with the application in kinetic disposition studies after single doses in rats. The areas under the plasma concentration versus time (AUC) were calculated by zero to the infinity by the Gauss-Laguerre Quadrature. The concentrations corresponding to the times were estimated by polynomial interpolation. The total clearance apparent (CL/F) was calculated from the equation: CL/F = dose/AUC0-∞. In assessing the kinetics of pravastatin disposition, animals not exposed to toluene showed AUC0-∞ of 726 ng h/mL and CL/F of 49.1 L/h kg. There was no statistical difference in AUC0-∞ to compare the exposed animals (AUC0-∞: 681.8 ng h/mL) and not exposed to toluene. The results of this study showed that Oatp family transporters activity, assessed by the use of pravastatin as a marker drug, was not altered after exposure to toluene by inhalation at 85 mg/m3 6 hours/day, 5 days/week and for 4 weeks in rats.
CNPq: 448803/2014-3

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Warne, Zoueki Caroline Rose. "Bacterial adhesion to hydrocarbons: role of toluene, asphaltenes and resins". Thesis, McGill University, 2008. http://digitool.Library.McGill.CA:80/R/?func=dbin-jump-full&object_id=21979.

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Bioremediation demands a better understanding of the factors controlling bacterial adhesion to crude oil. In this study, we investigate the effects of asphaltenes and resins on bacterial adhesion to model crude oils using the Microbial Adhesion to Hydrocarbons (MATH) assay. The model crude oils were prepared by adding toluene, asphaltenes or resins to n-hexadecane. After the mixing and phase separation step in the MATH assay, stabilized oil droplets were observed within the aqueous phase, causing an underestimation of the fraction of bacteria partitioned to the hydrocarbons. An improvement to the MATH assay protocol was developed to determine bacterial concentration using counting chambers instead of absorbance measurements. With the new MATH assay, asphaltenes and resins were shown to generally decrease microbial adhesion. This is contrary to what was expected from the extended Derjaguin-Landau-Verwey-Overbeek (XDLVO) interaction energy profiles that were calculated based on physicochemical characterization of the microorganisms and hydrocarbon droplets. The possible role of steric interactions in the observed adhesion behaviour in the presence of asphaltenes and resins is discussed.
Le domaine de la biorestauration exige une compréhension plus complète des facteurs qui influencent l'adhésion des bactéries au pétrole brut. La présente étude évalue l'effet des asphaltènes et résines sur l'adhésion des bactéries aux hydrocarbures. Le protocole « Microbial Adhesion to Hydrocarbons » (MATH) a été utilisé pour déterminer l'adhésion des bactéries aux hydrocarbures composées de cétane, toluène, d'asphaltènes et de résines. Après l'étape de mélange et de séparation des phases dans le protocole MATH, des gouttelettes d'hydrocarbure ont été découvertes dans la suspension bactérienne à l'aide d'un microscope. La présence des gouttelettes avait pour effet de surestimer la concentration bactérienne durant les mesures d'absorption. Une amélioration de la méthode MATH a été développée, où l'analyse des concentrations se fait en comptant les cellules individuelles. Avec la nouvelle méthode nous avons trouvé que les asphaltènes et résines diminuent l'adhésion des bactéries. Ce résultat va à l'encontre de nos prédictions des énergies d'interactions entre les bactéries et les hydrocarbures. Les prédictions ont étés basés sur la théorie des colloïdes « extended Derjaguin-Landau-Verwey-Overbeek » (XDLVO), et calculés à partir de propriétés physico-chimiques que nous avons déterminées pour les bactéries et les gouttelettes d'hydrocarbure. Nous traitons de la possibilité que la diminution de l'adhésion bactérienne aux hydrocarbures contenant des asphaltènes et résines soit due aux interactions stériques.

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16

Heald, Stephen C. "Metabolism of hydrocarbons via the toluene dioxygenase of Pseudomonas putida". Thesis, De Montfort University, 1995. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.391094.

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17

GONCALVES, PRISCILA DOS SANTOS. "BIOSORPTION OF TOLUENE IN THE PRESENCE OF RHODOCOCCUS OPACUS STRAIN". PONTIFÍCIA UNIVERSIDADE CATÓLICA DO RIO DE JANEIRO, 2015. http://www.maxwell.vrac.puc-rio.br/Busca_etds.php?strSecao=resultado&nrSeq=26296@1.

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PONTIFÍCIA UNIVERSIDADE CATÓLICA DO RIO DE JANEIRO
CONSELHO NACIONAL DE DESENVOLVIMENTO CIENTÍFICO E TECNOLÓGICO
Neste estudo foi avaliada a capacidade de adsorção do poluente orgânico tolueno em contato com a cepa Rhodococcus opacus. O tolueno foi selecionando por fazer parte do grupo de compostos BTEX (Benzeno, Tolueno, Etilbenzeno e Xileno), que possui elevada toxicidade, causando impacto ambiental em corpos hídricos, solo e ar, além de possuir características mutagênica e carcinogênica em humanos. A determinação e quantificação do tolueno na solução aquosa foram realizadas em um cromatógrafo a gás, acoplado ao espectrômetro de massas com amostrador automático headspace. A cepa Rhodococcus opacus foi caracterizada por análise de espectrometria no infravermelho e medição de potencial zeta, sendo a última realizada antes e após o contato com o tolueno. Os modelos de isotermas lineares de Langmuir, Freundlich e Temkin foram aplicados aos dados experimentais para descrever o processo de adsorção. Tendo o modelo de Langmuir se adaptado melhor ao processo em análise. As variáveis estudadas para otimizar as condições máximas de adsorção foram: tempo de contato, variação do pH, variação da biomassa. Este estudo mostrou que a cepa bacteriana R. opacus apresentou uma boa capacidade de biossorção, principalmente para concentrações baixas, onde removeu 95,99 porcento e 85,69 porcento das respectivas concentrações de 0,6 e 0,8 mg/L de tolueno, atendendo a resolução do CONAMA 357/2005 para águas salobras de Classe I.
In this study was evaluated the adsorption capacity of the organic pollutant toluene by the Rhodococcus opacus strain. Toluene was chosen by being part of the group of BTEX compounds (benzene, toluene, ethylbenzene and xylene), which has high toxicity, causing environmental impact on water bodies, soil and air, and also are mutagenic and carcinogenic to humans. The determination and quantification of toluene in aqueous solution were performed on a gas chromatograph, coupled with a mass spectrometer with headspace autosampler. The strain Rhodococcus opacus was characterized by infrared spectrometry analysis and zeta potential measurement, the last done before and after the sorption. The isotherm linear models of Langmuir, Freundlich and Temkin were applied to the experimental data to describe the adsorption process. Having the Langmuir model better adapted to process analysed. The variables studied to optimize the maximum adsorption conditions were: contact time, pH variation, biomass variation. This study showed that the bacterial strain R. opacus has good biosorption capabilities, particularly at low concentrations, where it removed 95.99 percent and 85.69 percent of the respective concentrations of 0.6 and 0.8 mg/L of toluene, attending the CONAMA resolution 357/2005 for salt waters of Class I.

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18

Semprini, Elvio, Patrizia Cafarelli, Stefanis Adriana De e Anthony A. G. Tomlinson. "Competitive sorption of toluene and acetone on H-ZSM5 zeolite". Universitätsbibliothek Leipzig, 2016. http://nbn-resolving.de/urn:nbn:de:bsz:15-qucosa-194099.

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19

Moore, Jeffrey W. "Effects of surfactants on the biodegradation of toluene in soil". Thesis, Virginia Tech, 1989. http://hdl.handle.net/10919/43100.

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The objective of this investigation was to observe and evaluate the effects of surfactants on the biodegradation of toluene in the subsurface. Soil microcosms containing gasoline were used to simulate conditions of an aquifer contaminated with hydrocarbons. The surfactants were the nonionics, Surfonic N-40 and N-95. Three volumes of gasoline, 0.005, 0.05, and 0.1 mL, were injected into separate microcosms in order to observe changes in toluene concentration in both adsorbed component conditions and free-phase, interstitial gasoline conditions. The data presented are the results from the microcosms containing 0.005 mL gasoline. -Dissolved toluene was only partially biodegraded in the microcosms containing free-phase hydrocarbons. The lack of complete biodegradation was believed to be due to substrate toxicity.
Master of Science

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20

Detchanamurthy, Swaminathan. "Impact of Different Metabolic Uncouplers on the Specific Degradation Rate of Toluene in a Differential Biofiltration Reactor". Thesis, University of Canterbury. Chemical and Process Engineering, 2013. http://hdl.handle.net/10092/7899.

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In this work, a differential biofiltration reactor was used to explore the potential of metabolic uncouplers to improve pollutant (toluene) degradation rates. Metabolic uncouplers were reported to reduce the cell mass in activated sludge systems, but are untested in biofilters and the current work is the first to report the impact of different metabolic uncouplers in a biofilter. Initially soil was used as a biofilter bed and later experiments were conducted in pure cultures in a biofilm reactor. A simple diffusion system was developed to generate the desired concentration of toluene to the system. Gas chromatography and a carbon dioxide analyzer were connected online to the reactor which improved the precision of the data collected and also the robustness of the measurements. Preliminary experiments including effect of substrate concentration, different nutrients and temperature were done to optimize the conditions before starting the metabolic uncoupler screening studies in soil. Based on the results, inlet toluene concentration between 180 ppm and 250 ppm was used throughout the studies. Also it was found that the toluene degraders were nitrogen limited. Temperature studies showed that the elimination capacity (EC) increased with increasing temperature, from 34 ± 1.4 g.m-3.h-1 to 49.8 ± 2.6 g.m-3.h-1 for temperatures of 20 to 45 oC, respectively. Nine potential metabolic uncouplers were screened in batch serum bottles. The nine uncouplers tested were dinitrophenol (dNP), p-nitrophenol (pNP), benzoic acid (BA), carbonylcyanide p-trifluoromethoxy phenylhydrazone (FCCP), carbonylcyanide m-chloromethoxy phenylhydrazone (CCCP), pentachlorophenol (PCP), malonic acid (MA), m-chlorophenol (mCP) and 2, 4, 6-trichlorophenol (TCP). Other than dNP and pNP (nitrogen containing uncouplers), seven other uncouplers were further tested in the differential biofilter reactor. Only PCP and TCP increased the toluene degradation rate significantly. PCP increased the toluene degradation rate by 35% at 140 µM, whereas 4051 µM TCP increased the rate by 18%. Though FCCP behaved as a classical uncoupler when compared with others, the EC increase was not significant. Five toluene degraders were isolated from soil subjected to toluene and were identified using 16s rDNA/18s rDNA analysis. Out of five, two potential toluene degraders, Stenotrophomonas maltophilia and Pseudomonas putida were used to develop a biofilm reactor. PCP, TCP and CCCP were tested in the biofilm reactors and found that PCP increased the surface elimination capacity (SEC) by 85% at 140 µM in S. maltophilia biofilm reactor and CCCP increased the SEC by 27% at 1 µM in P. putida biofilm reactor. Finally a simple model was developed to calculate the energy uncoupling coefficient for non-growth systems like ours to quantitatively represent the uncoupling mechanism.

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21

Rocha, Ana VÃvian Parente. "Estudo de adsorÃÃo de tiofeno em carbono ativado". Universidade Federal do CearÃ, 2010. http://www.teses.ufc.br/tde_busca/arquivo.php?codArquivo=4966.

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Conselho Nacional de Desenvolvimento CientÃfico e TecnolÃgico
A qualidade do ar e a preocupaÃÃo com o meio ambiente e a saÃde da populaÃÃo tÃm influenciado as regulamentaÃÃes de emissÃes veiculares. A exemplo de ÃrgÃos governamentais em todo o mundo, a AgÃncia Nacional do PetrÃleo, GÃs Natural e BiocombustÃveis (ANP) do Brasil tem estabelecido cronogramas de reduÃÃo drÃstica de sulfurados no diesel e na gasolina nos Ãltimos anos. A hidrodessulfurizaÃÃo (HDS) Ã o processo classicamente utilizado atualmente para reduzir o teor de enxofre em correntes de hidrocarbonetos. No entanto, o processo HDS Ã caro, pois requer elevadas temperaturas e pressÃes e hidrogÃnio, podendo levar Ã saturaÃÃo de compostos olefÃnicos, o que compromete a octanagem da gasolina. Dessa forma, atenÃÃo especial vem sendo dada ao uso da adsorÃÃo para remoÃÃo de compostos sulfurados que poderÃ complementar ou â em alguns casos â substituir os processos existentes de hidrotratamento (HDT). Esse processo de adsorÃÃo pode ser realizado a temperatura e pressÃo ambiente. Neste trabalho foi realizado um estudo de remoÃÃo de enxofre a partir de soluÃÃes tiofeno/n-hexano, tiofeno/n-octano e tiofeno/tolueno/n-octano e um estudo de seletividade tiofeno/tolueno utilizando como adsorvente o carbono ativado 830 W da Norit (Holanda). O material foi caracterizado texturalmente por adsorÃÃo de N2 a 77 K. Os resultados indicaram ser um material microporoso. A adsorÃÃo do tiofeno em n-hexano e a seletividade tiofeno/tolueno foi avaliada usando a tÃcnica experimental de banho finito com cromatografia headspace. A isoterma de adsorÃÃo obtida em headspace apresentou um comportamento desfavorÃvel para o tiofeno e o adsorvente estudado foi seletivo pelo tolueno em relaÃÃo ao tiofeno, sendo observado um ponto de saturaÃÃo em razÃes lÃquido/sÃlido inferiores a 4%. JÃ a adsorÃÃo do tiofeno em n-octano e em n-octano/tolueno foi avaliada atravÃs de um estudo dinÃmico de adsorÃÃo usando uma coluna de leito fixo com uma vazÃo de 0,5 mL/min a duas temperaturas distintas com concentraÃÃo de alimentaÃÃo na faixa de 275 a 1000 ppm. As isotermas de equilÃbrio assim obtidas encontram-se na regiÃo de Henry (linear) com a constante de adsorÃÃo K = 3,7 e 3,0 para temperaturas de 30 ÂC e 45 ÂC, respectivamente. Obteve-se para concentraÃÃo de 1000 ppm sem tolueno uma quantidade adsorvida de 0,035 mmolS/gads, que se reduz para 0,020 mmolS/gads na presenÃa do aromÃtico (20 % vol.). Pode-se observar que â em toda a faixa de concentraÃÃes de sulfurado estudada â a quantidade de tiofeno adsorvida diminuiu consideravelmente na presenÃa do tolueno. Curvas de breakthrough do tiofeno em n-octano foram simuladas segundo um modelo matemÃtico que considera fluxo axialmente disperso e transferÃncia de massa descrita por uma aproximaÃÃo de forÃa motriz linear (LDF). O modelo foi resolvido numericamente por colocaÃÃo ortogonal em elementos finitos, utilizando o software comercial gPROMS. O modelo matemÃtico proposto representou razoavelmente os dados experimentais, especialmente para concentraÃÃo de 1000 ppm. A constante de tempo de transferÃncia de massa foi o parÃmetro de ajuste entre as simulaÃÃes e os dados experimentais, estimando-se valores mÃdios de 3,3 e 2,2 min-1 a 30 e a 45 ÂC, respectivamente.
Concerns with environmental protection and human health have had a remarkable impact on vehicle emissions regulations. Following similar policies of governmental agencies worldwide, Brazilian AgÃncia Nacional do PetrÃleo, GÃs Natural e BiocombustÃveis (ANP) has established a timetable for drastic reduction of sulfur content in diesel and gasoline in the last few years. Hydrodesulfurization (HDS) is the industrial process being currently employed for this matter. However, the HDS process is costly and, to achieve deeper desulfurization levels, it would require higher hydrogen pressure, which may eventually lead to the saturation of olefinic compounds, causing a decrease in gasoline octane number. Therefore, special attention has been given to the use of adsorption for additional removal of sulfur compounds from effluent streams of existing hydrotreatment (HDT) plants. Adsorption processes may operate under mild temperature and pressure conditions. In the present work, desulfurization in thiophene/n-hexane, thiophene/n-octane and thiophene/toluene/n-octane mixtures were conducted, together with a study of thiophene/toluene selectivity, all experiments using activated carbon 830 W by Norit (Netherlands) as sorbent. The adsorbent was characterized texturally by adsorption/desorption of N2 at 77 K and results showed it to be a microporous material. Adsorption of thiophene from n-hexane solutions and thiophene/toluene selectivity were carried out using the experimental technique of headspace chromatography finite bath. Adsorption isotherms thus obtained showed unfavorable behavior and the adsorbent selectively adsorbs toluene as compared to thiophene, reaching maximum selectivity on liquid/solid ratio of less than 4%. Adsorption of thiophene in n-octane and n-octane/toluene (4:1 vol.) was assessed by fixed bed experiments performed under a flow rate of 0.5 mL/min, two different temperatures and sulfur concentration in the feed ranging from 275 to 1000 ppm. Adsorption isotherms thus measured fall within the Henryâs Law region (linear) with dimensionless adsorption constants of 3.7 and 3.0 at 30 ÂC and 45 ÂC, respectively. For the feed concentration of 1000 ppm in n-octane, the measured dynamic adsorption capacity was 0.035 mmolS/gads, which was reduced to 0.020 mmolS/gads when toluene was present. Regardless the inlet sulfur concentration, the amount of adsorbed thiophene decreased considerably in the presence of the aromatic compound. Breakthrough curves of thiophene in n-octane were simulated according to a mathematical model that assumed axially dispersed flow and mass transfer described by a linear driving force approximation (LDF). The model was solved numerically by orthogonal collocation in finite elements, using the commercial solver gPROMS. The proposed model matched experimental data reasonably well, especially for the feed concentration of 1000 ppm. The LDF time constant was the tunable parameter between simulations and experimental data and the best average values were found to be 3.3 and 2.2 min-1 at 30 and 45 ÂC, respectively.

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22

Souza, Ellen Cristina. "Produção e ação de biossurfactante produzido por bactérias em meios salinos contaminados por hidrocarbonetos aromáticos". Universidade de São Paulo, 2013. http://www.teses.usp.br/teses/disponiveis/9/9135/tde-26032014-163942/.

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A contaminação da água e do solo por hidrocarbonetos aromáticos tem aumentado ao longo dos anos, devido ao seu uso nos mais diversos segmentos industriais. Hidrocarbonetos, tais como tolueno, são descritos como extremamente poluentes, tóxicos e potencialmente mutagénicos e carcinogénicos para os seres humanos. Os hidrocarbonetos são compostos lipófilicos difíceis de serem eliminados, contudo, estes aromáticos podem ser removidos de ambientes contaminados por meio de biorremediação utilizando bactérias produtoras de surfactante. Biossurfatantes são surfactantes principalmente produzidos por microrganismos, as quais promovem a quebra das moléculas de hidrocarbonetos, através da formação de micelas, aumentando a sua mobilidade, a biodisponibilidade e sua exposição à bactérias favorecendo a biodegradação do hidrocarboneto. A produção deste tensoativo exige meios de fermentação e oxigênio para o metabolismo microbiano. Por tanto, aeração e agitação são variáveis operacionais importantes para garantir um coeficiente de transferência de massa de oxigénio eficaz (kLa). Para esta finalidade, o kLa foi determinado experimentalmente em diferentes meios de fermentação, especificamente meio salino básico, meio de baixa salinidade, meio Bushnell-Haas e água do mar, por diversas variáveis operacionais. Ensaios foram realizados em agitador rotativo para selecionar, dentre os diferentes tipos de bactérias, nomeadamente Bacillus subtilis, Bacillus licheniformis e Bacillus megatherium, o melhor produtor de biossurfactante na presença de tolueno, nos meios de fermentação descritos acima, formulados com diferentes salinidades. A presença de tolueno inibiu o crescimento de microrganismo deslocando seu metabolismo para a produção de biossurfactante. Assim, B. subtilis foi capaz de reduzir a tensão superficial (TS) em 29,49 ± 0,55 unidades, produzindo cerca de 3,52 ± 0,06 mg/L de biossurfactante. Ao elevar o processo para um fermentador de bancada, a quantidade de tolueno no meio de baixa salinidade foi reduzido drasticamente após 12 horas de crescimento (de 45 ml para 7,43 ml), quando B. subtilis foi utilizado, reduzindo o TS em 22,6 unidades (com concentração de biossurfactante de 3,02 mg/L). Os resultados obtidos mostraram que o B. subtilis pode ser considerado um microrganismo promissor para ser utilizado na biorremediação de locais contaminados por tolueno
Contamination of water and soil by aromatic hydrocarbons has been increasing along the years, due to its use in various industrial segments. Hydrocarbons, such as toluene, are described as extremely polluting, toxic, potentially carcinogenic and mutagenic to humans. Hydrocarbons are lipophilic compounds difficult to be disposed of; however, the aromatic ones can be removed from contaminated environments via bioremediation using surfactant-producing bacteria. Biosurfactants are surfactants produced mainly by microorganisms, which promote the breaking of hydrocarbons molecules, by means of the formation of micelles, increasing their mobility, bioavailability and exposure to bacteria favoring hydrocarbon biodegradation. This tensoactive production requires oxygen and fermentation media for the microorganism metabolism. Thus, aeration and agitation are important operating variables to ensure an effective oxygen mass transfer coefficient (kLa). To this purpose, such a response was experimentally determined in this study in different fermentation media, specifically basal saline medium, low saline medium, Bushnell-Haas medium and sea water, and correlated with the above operating variables. Rotary shaker essays were performed to select, among different bacteria, namely Bacillus subtilis, Bacillus megatherium and Bacillus licheniformis, the best biosurfactant producer in the presence of toluene, in fermentative broths described above, formulated with different salinities. The presence of toluene inhibited the growth of microorganism shifting the metabolism to the production of biosurfactant. Thus, B. subtilis was able to reduce the surface tension (ST) in 29.49 ± 0.55 units producing up to 3.52 ± 0.06 mg/L of biosurfactant. Scaling up the process to a bench fermentor, the quantity of toluene in the low salinity medium was reduced drastically after 12 h of growth (from 45 mL to 7.43 mL), when B. subtilis was used, reducing the ST in 22.6 units (biosurfactant concentration of 3.02 mg/L). The results obtained showed that B. subtilis can be considered a promising microorganism to be used for the bioremediation of sites contaminated by toluene.

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23

Silva, Wender Messiatto da. "Utilização de microrganismos na biorremediação de solo contaminado por derivados de petróleo". Ilha Solteira, 2018. http://hdl.handle.net/11449/154212.

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Orientador: William Deodato Isique
Resumo: Os impactos ambientais decorrentes de vazamentos em postos de combustíveis têm sido preocupantes para órgãos ambientais ao redor do mundo, sobretudo por deteriorarem a qualidade das águas subterrâneas utilizadas como fonte de abastecimento, sendo os compostos benzeno, tolueno e xilenos (BTX) os de maior preocupação à saúde pública. A biorremediação é uma técnica viável do ponto de vista econômico e ecológico quando se utiliza consórcio microbiano de bactérias e fungos aliado a solução de nutrientes. Este trabalho verificou os efeitos da biorremediação sobre microambientes formados em erlenmenyers contendo solo arenoso fino de textura arenosa fina, bastante comum no noroeste paulista, contaminado por soluções sintéticas de BTX por intermédio de consórcio de microrganismos (bactérias ácido láticas, leveduras, bactérias fototróficas e actinomicetes). O desempenho de um consórcio de microrganismos foi verificado por meio de alterações de pH, teor de umidade, teor de carbono e pela de remoção de BTX do microambiente constituído de solo arenoso fino contaminado por solução sintética de BTX mediante a bioestimulação comparando-se os efeitos do ácido esteárico como surfactante. O uso de ácido esteárico como surfactante prejudicou o processo de biorremediação nos microambientes, com isso a remoção de BTX foi menor do que nos microambientes que não possuíam ácido esteárico. De acordo com resultados deste trabalho, um valor adequado para a aplicação da solução de microrganismos em campo... (Resumo completo, clicar acesso eletrônico abaixo)
Abstract: The environmental impacts resulting to leaks at fuel stations has been worrying for environmental agencies around the world mainly for deteriorating the quality of the groundwater used as a water supply whereby the BTX compounds (benzene, toluene and xylene) the most worrisome public health. Bioremediation is a viable technique because the use of bacterial, fungal and yeast microbial consortia is economic and ecological associated with nutrient solutions. The effects of bioremediation verified through a consortium of microrganisms (lactic acid bacteria, yeasts, phototrophic bacteria and actinomycetes) on microenvironment in enlermeyers containing fine sandy texture lateritic soil, very common in São Paulo northwest region, contaminated by synthetic solutions of BTX. The performance of a consortium of microorganisms verified by pH changes, moisture content and organic carbon content of the microenvironments and the rate of BTX removal in fine sandy soil contaminated with BTX synthetics solutions by bioestimulation, comparing the effects of stearic acid as surfactant. The use of stearic acid as a surfactant impaired the bioremediation process in the microenvironments, thus the removal of BTX was lower than in microenvironments that did not possess stearic acid. According to the results of this work, a value of microorganisms per cm³ of microorganisms solution to the soil is 0.02 mL of microorganisms solution 300 cm³ of fine sandy soil in the period of 7, 30 and 58 days of exper... (Complete abstract click electronic access below)
Mestre

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24

Gullic, David Bryan. "Variations in the biodegradation potential of toluene with increasing depth in an unsaturated subsurface environment". Thesis, This resource online, 1990. http://scholar.lib.vt.edu/theses/available/etd-03042009-040343/.

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25

Sihaib, Zakaria. "Oxidation of toluene traces in gas phase in presence of manganese-oxide based catalysts : relationship structure-activity". Thesis, Lyon, 2018. http://www.theses.fr/2018LYSE1029.

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Dans la première partie de mon travail, j'ai préparé quatre catalyseurs différents à base d'oxydes de manganèse: une perovskite (LaMnO3), par voie sol-gel; un oxide simple (Mn2O3), par méthode rapide et un tamis moléculaire octahedrique (OMS-2) par deux méthodes de préparation différentes, via l'état solide (OMS) et la méthode hydrothermale (OMSh). Les propriétés physicochimiques de ces catalyseurs ont été caractérisées par diffraction des rayons X (DRX), adsorption-désorption de N2, analyses thermogravimétriques (ATD/ATG), analyses chimiques (ICP-OES) et réduction en température programmée (H2-RTP). Leurs performances catalytiques ont été évaluées dans la réaction d’oxydation du toluène. Trois cycles catalytiques consécutifs ont été réalisés pour chaque catalyseur afin de confirmer les performances. Afin d'évaluer la stabilité des catalyseurs dans des conditions réactionnelles, les performances catalytiques ont été étudiées sur des expériences de longue durée à température constante, pendant 24 h à 25% de conversion du toluène. Des tests d'oxydation du toluène sur un catalyseur de référence, type Pd/Al2O3 contenant 0,78% en poids de Pd, ont également été effectués à des fins de comparaison. Les caractéristiques cristallines détectées dans les modèles DRX sont bien compatibles avec la formation des structures désirées. Sur la base de leur surface spécifique et de leur réductibilité à basse température, les catalyseurs ont été classés comme suit : OMSs > Mn2O3 > OMS > LaMnO3. Cette tendance est en bon accord avec les performances observées dans l'élimination catalytique du toluène. Un modèle cinétique a été proposé et un bon accord a été obtenu lors de l'ajustement avec les données expérimentales. Dans la seconde partie de mon travail, des catalyseurs LaMnO3 (LM) avec un rapport molaire acide citrique (CA) sur nitrates métalliques (Mn et La) allant de 0,5 à 2 (LM 0,5 à LM 2) ont été synthétisés par méthode sol-gel citrate, afin d'étudier l'effet du rapport de l'acide citrique sur les propriétés physico-chimiques et les performances catalytiques. Les propriétés physicochimiques de ces catalyseurs ont été caractérisées par diffraction des rayons X (DRX), adsorption-désorption de N2 et par spectroscopie d'émission atomique de plasma à couplage inductif (ICP-AES). Sur des échantillons sélectionnés, des caractérisations supplémentaires par analyse thermogravimétrique et thermique différentielle (ATD/ATG), une réduction programmée en température par de l'hydrogène (H2-TPR) et une spectroscopie de photoélectrons X (XPS) ont été réalisées. Les résultats montrent que le rapport molaire acide citrique sur nitrates métalliques influence significativement le profil obtenu en ATD/ATG des solides non calcinés ainsi que les propriétés physico-chimiques des catalyseurs. Les caractéristiques cristallines détectées par DRX sont bien compatibles avec la formation de la phase perovskite LaMnO3. De petites caractéristiques de Mn2O3 ont été détectées dans les diagrammes de diffraction de tous les catalyseurs LM, à l'exception du rapport molaire élevé des nitrates CA / (Mn + La) (1,9 et 2,0). Inversement, des pics La2O3 sont observés pour des valeurs allant de 1,6 à 2, l'intensité la plus élevée étant détectée au rapport molaire égal à 2. Les performances catalytiques ont été évaluées dans l'oxydation du toluène en réalisant trois cycles catalytiques consécutifs pour atteindre des performances stables. Afin d'évaluer la stabilité des catalyseurs dans des conditions de réaction, des expériences à température constante ont été effectuées pendant 24 h à 17% de conversion du toluène. Les catalyseurs LM1.2, LM1.3 et LM1.5 ont montré les meilleures performances catalytiques en oxydation totale du toluène, tandis que LM1 et LM1.7 présentaient un comportement intermédiaire et LM0.8 était peu actif
In the first part of my work, I have prepared four different catalysts based on manganese oxides: a perovskite (LaMnO3), via sol-gel method; a simple oxide (Mn2O3), by rapid method and an Octahedral Molecular Sieve (OMS-2) by two different preparation methods, via solid state (OMSs) and hydrothermal method (OMSh). The physicochemical properties of these catalysts were characterized by X-ray diffraction (XRD), N2 adsorption–desorption, TGA/DTA, ICP-OES and H2-TPR. Their catalytic performances were evaluated in the oxidation of toluene. Three consecutive catalytic cycles were performed for each catalyst in order to reach steady state performances. In order to assess the stability of the catalysts under reaction conditions, the catalytic performances were studied upon long-term experiments running for 24 h at 25% of toluene conversion. Tests of toluene oxidation over a typical industrial catalyst, such as a commercial Pd/Al2O3 catalyst containing 0.78 wt% Pd, were also performed for comparison purposes. The crystalline features detected in the XRD patterns are well consistent with the formation of the desired structures. Based on their specific surface area and their low-temperature reducibility, the catalysts were ranked as follows: OMSs> Mn2O3> OMSh> LaMnO3. This trend was in good agreement with the performances observed in the catalytic removal of toluene. A kinetic model was proposed and a good agreement was obtained upon fitting with the experimental data. In the second part of my work, LaMnO3 (LM) catalysts with molar ratio of citric acid (CA) to metal nitrates (Mn and La) ranging from 0.5 to 2 (LM 0.5 to LM 2) were synthesized by citrate sol–gel method, in order to study effect of citric acid ratio on the physico-chemical properties and the catalytic performances. The physicochemical properties of these catalysts were characterized by X-ray diffraction (XRD), N2 adsorption–desorption and by inductively coupled plasma atomic emission spectroscopy (ICP-AES). Over selected samples, additional characterizations by thermogravimetric and differential thermal analysis (TGA/DTA), temperature-programmed reduction by hydrogen (H2-TPR) and X-ray photoelectron spectroscopy (XPS) were carried out. The results show that the molar ratio of citric acid to metal nitrates significantly influenced the TGA/DTA profile of gels along with the physico-chemical properties of the catalysts. The crystalline features detected by XRD are well consistent with the formation of LaMnO3 perovskite phase. Small features of Mn2O3 were detected in the diffraction patterns of all LM catalysts except for high CA/Mn+La nitrates molar ratio (1.9 and 2.0). Conversely, La2O3 peaks appeared for values ranging from 1.6 to 2, the highest intensity being detected at molar ratio equal to 2. The catalytic performances were evaluated in the oxidation of toluene, performing three consecutive catalytic cycles in order to reach steady-state performances. In order to assess the stability of the catalysts under reaction conditions, long-term experiments running for 24 h at 17 % of toluene conversion were carried out. The catalysts LM1.2, LM1.3 and LM1.5 showed the best catalytic performances in terms of toluene conversion, LM0.8 was poor performing, while LM1 and LM1.7 exhibited an intermediate behaviour

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26

Fink, Samuel Donovan. "A study of the ternary system carbon-dioxide-toluene-1,1,1-trichloroethane /". The Ohio State University, 1987. http://rave.ohiolink.edu/etdc/view?acc_num=osu1487584612164254.

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27

Hicks, Kristin Adair. "Alternative Substrates for Estimating TCE-degrading Capabilities of Toluene-oxidizing Bacteria". NCSU, 2002. http://www.lib.ncsu.edu/theses/available/etd-07172002-182546/.

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One of the primary impediments to the implementation of bioremediation is uncertainty about success in the field. Soils and microbial populations are heterogeneous and it is difficult to extrapolate biodegradation rates from small samples to field scale. While biodegradation rates can be estimated from microcosm studies, in situ methods offer a more meaningful gauge of resident microbial activity. One method used to estimate biodegradation rates in the field is the newly developed Push-Pull technique. While this technique can be conducted on site, it is normally not possible to use target pollutants as the reactive substrates. Consequently, alternative, benign reactive tracers must be used. Ideally, these alternative, reactive tracers interrogate the same enzyme systems that are responsible for the biodegradation of the target pollutant. The objective of this study was to develop a reactive tracer system that could be used to assess toluene-dependent trichloroethylene (TCE) degradation. Our approach has been to determine whether a series of pure strains of toluene-oxidizing bacteria (Burkholderia cepacia G4, Pseudomonas putida F1, Pseudomonas putida mt2, Pseudomonas mendocina KR1), each with different toluene-oxidizing enzymes systems, are capable of cometabolically oxidizing a series of eleven potential alternative substrates. These substrates include simple alkenes, alkanes, and cyclic alkanes. The kinetics (Ks and Vmax) of the biotransformation of these compounds have been determined. While oxidation products were observed for a number of these substrates in connection with one or more of the test organisms, isobutylene was co-oxidized by all test organisms. Oxidation of isobutylene by each organism yielded kinetics constants comparable to the corresponding kinetics of TCE degradation. The enzyme system expressed by Burkholderia cepacia G4 catalyzed the epoxidation of isobutylene while the remaining enzyme systems catalyzed allylic alcohol formation. Isobutylene has potential in field scale Push-Pull studies as a tool for evaluating rates of aerobic toluene-dependent TCE degradation and of differentiating the relative contributions of the TCE-degrading population. A pilot study of this alternative substrate at Edwards Air Force Base will test whether it can be used successfully to estimate in situ degradation of TCE. Analysis of isobutylene oxidation products in toluene-enriched ground water may offer an inexpensive and effective method of measuring the degradation of TCE at contaminated sites nationwide.

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28

Aemprapa, Sirinun. "Toluene/xylene catabolic pathway of Pseudomonas putida strain Oâ†2Câ†2". Thesis, Bangor University, 1996. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.321526.

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29

Byrne, Fergal. "Greener solvents to replace toluene in the polymerisation and coating industry". Thesis, University of York, 2017. http://etheses.whiterose.ac.uk/18988/.

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Toluene is a volatile, non-polar solvent, commonly used throughout the chemical industry, which is facing increasing scrutiny due to its reprotoxicity and production from petroleum. Therefore, replacements which are safe and bio-based are required. A solvent selection method has been developed which involved solubility tests, solvent modelling computer-aided molecular design and chemical intuition to find new, potentially bio-based solvents. Five candidates were identified: 2,2,5,5-tetramethyltetrahydrofuran (TMTHF), methyl butyrate, ethyl isobutyrate, methyl pivalate and pinacolone. TMTHF is one of a new class of ethers, called quaternary ethers, which were identified not to possess the same issues of peroxide formation as traditional ethers due to a key structural difference. In addition, TMTHF has been synthesized from potentially renewable feedstocks where it was found to have similarly non-polar solubility properties (able to dissolve synthetic rubber), and a similar boiling point (112 °C), melting point (< 90 °C) and autoignition temperature (417 °C) to toluene. Application testing showed that TMTHF was able to facilitate radically-initiated polymerisations for the production of vinyl polymers suitable for use as pressure-sensitive adhesives (high Mw), and behaved more like toluene than traditional ethers in esterification, amidation and Grignard reactions. As such, it is an ideal candidate to replace toluene in the polymerisation and coating industry, as well as in many other applications. In addition, four secondary candidates (methyl butyrate, methyl pivalate, ethyl isobutyrate and pinacolone) were also identified to be of low-polarity, like toluene. Methyl pivalate and pinacolone were the best of the four secondary candidates as ethyl isobutyrate could not produce sufficiently high Mw polymers and the odour of methyl butyrate was too unpleasant for large-scale use. Testing in a Menschutkin reaction confirmed that each candidate had similar solubility properties to toluene. Finally, TMTHF, methyl pivalate, pinacolone and methyl butyrate were found to be non-mutagenic in the Ames test (ethyl isobutyrate not tested), but full toxicity testing is required before registration with REACH.

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30

Tsai, Chi-Mo, e 蔡奇謀. "Hydrogenation Of Toluene". Thesis, 1994. http://ndltd.ncl.edu.tw/handle/60473341757625542441.

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31

Liu, Fang-Ting, e 劉芳婷. "Study of toluene disproportionation and toluene methylation reaction on modified ZSM-5 catalysts". Thesis, 2013. http://ndltd.ncl.edu.tw/handle/79379249651650625065.

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碩士
國立勤益科技大學
化工與材料工程系
101
In this study, the commercialization of the ZSM-5 zeolite catalyst as a reaction catalyst to modified around the ZSM-5 zeolite catalyst discuss their physical properties, the characterized with field emission-scanning slectron microscopy, X-ray diffractometer and specific surface determination evaluated for their morphologies, crystal phase structure, BET specific surface, and total pore volume properties, the results showed no change in the surface structure modified and crystalline peak intensity patterns . The CBV2314 modified as toluene disproportionation reaction of the catalyst can be improved the para-xylene selectivity. Toluene methylation inappropriate to carried out under high temperature. However, the reaction temperature is 390℃ under a reaction pressure of 400psi toluene methylation high conversion. CBV2314 and T-4480 and FX55 catalyst under the same reaction temperature, reaction pressure change to CBV2314 catalytic conversion of toluene and para- xylene selectivity is higher. CBV2314 and T-4480 and FX55 catalyst at the same reaction temperature changing the reaction pressure to CBV2314 catalytic conversion of toluene and para - xylene selectivity is higher. CBV2314, T-4480, and FX55 as the reaction catalyst at a reaction temperature of 390℃ and reaction pressure of 14.7 psi and a WHSV of 6.3h-1 under the reaction conditions of toluene methylation, experimental results show that in CBV2314 catalyst in the catalytic reaction on the para - xylene selectivity was higher at 95.7%.

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32

chu, hung-chang, e 朱泓璋. "Effect of toluene and toluene-degrading bacteria amendment on the composition of soil microflora". Thesis, 2006. http://ndltd.ncl.edu.tw/handle/03808734078366382339.

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碩士
東吳大學
微生物學系
94
In order to understand the change of Pseudomonas putida D8 and community in the toluene polluted soil, this experiment use Denaturing Gradient Gel Electrophoresis（DGGE）to analyze the bacteria groups in the soil and use Real-time PCR to track the amount of Pseudomonas putida D8 in the soil. In DGGE experiment, first we extract the bacteria’s DNA which were in the soil and use p63f/p2 as a primer to amplify the V1 to V3 variance of 16S rDNA. Then use perpendicular DGGE to find out that the best analysis condition which is 8% gel; 25-55% gradient; 60℃; volt 80; electrophoresis 12hrs. And then use horizontal DGGE to analyze the bacteria communities which were handled in different ways. Further use Pearson Coefficient and Principal Component Analysis to analyze the similarity of DGGE profiles. The result shows that the control group profile and the toluene group profile were similar, but the profile of toluene is different than the profile of toluene and toluene degradation strain. This proves toluene degradation strain or Pseudomonas putida D8 will effect the bacteria group when they go into the polluted environment. In detecting the amount of Pseudomonas putida D8, used the method of plant count and found the indigenous bacteria has one strain can degrade toluene. It has affected the result of Pseudomonas putida D8 detecting in toluic acid plate. Moreover, the experiment did not see Pseudomonas putida D8 grow in toluic acid plate, so can’t detect the number of Pseudomonas putida D8. In Real-time PCR experiment, we found signal appears even without adding Pseudomonas putida D8 in the soil, and the fluorescence signal is similar to 106CFU/g. Used Real-time PCR to detect the amount change after add Pseudomonas putida D8 into the soil, the number of Pseudomonas putida D8 is 1.5×107CFU/g at day 0 and decrease to the number 6.4×106CFU/g at day 7. I cannot detect after that because the number is same with the background signal. On the other hand, detected the number of the toluene and toluene degradation strain group increase from 1.9×107CFU/g at day 0 to 8.9×107CFU/g at day 3. Yet, the number starts to decrease after day 3. At day 7, the number of Pseudomonas putida D8 decrease to 3.7×107CFU/g, which is same amount with the background, so I cannot keep detecting. Although plant count and Real-time PCR have the same number in counting, but the bacteria in plant count is not Pseudomonas putida D8. It is effect the counting result. So Real-time PCR is more accurate and fast mothed, when detect the bacteria which may become VBNC state. This experiment reveals indigenous community will be affected when toluene degradation strain is added into the polluted environment. According to DGGE and statistic analysis, the community will vary depends on which way we deal with the soil. This experiment also found out Real-time PCR is a better way to detect the number of toluene degradation strain than plant count. Since the change of Pseudomonas putida D8’s number in the soil matches the DGGE profile, reaches the highest amount at day 3. Therefore, this experiment can conclude that use both DGGE and Real-time PCR together can be an effective way to analyze the change of community and toluene degradation strain in the soil.

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33

Hwan, Liou Jhy, e 劉治桓. "Development of toluene passive sampler". Thesis, 1995. http://ndltd.ncl.edu.tw/handle/45233250457173161745.

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34

SULLIVAN, MICHAEL JOSEPH. "OTOTOXICITY OF TOLUENE IN RATS". 1986. http://books.google.com/books?id=BtE9AAAAMAAJ.

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35

Yu, Ming-Che, e 游明哲. "benzene, toluene and 1,2-dichloroethane". Thesis, 2007. http://ndltd.ncl.edu.tw/handle/86814600904950988964.

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碩士
國立中央大學
環境工程研究所碩士在職專班
95
In this study, a site contaminated with benzene, toluene and 1,2-dichloroethane was selected for investigation of the feasibility using the technologies of combining Air Sparging (AS) and Soil Vapor Extraction (SVE) system via the long-term in-situ soil and groundwater sampling. Also, the cost benefit of remediation technology of the combined system was evaluated. Experimental results indicated that both removal of benzene and toluene in the unsaturated soil and groundwater attained 100% after the 11 months operation using the combined system of AS and SVE. Also, 100% of 1,2-dichloroethane in the aquifer was removed. Moreover, the degradation rates of toluene and benzene were fitted pseudo-first-order reaction model. The coefficient of reaction rate constants (k) of benzene and toluene were 0.0576 day-1 and 0.0586 day-1, respectively. In addition, the dissolved oxygen of groundwater was above 1 mg/L; therefore, the condition of groundwater transformed from originally anaerobic to aerobic after treatment. Meanwhile, the total bacterial count of microorganism increased from 40 CFU/mL to 1.7×105 CFU/mL which vastly increased by 4250 times, revealed that the function of biodegradation in situ occurred. On the other hand, the 2,282 kg of VOCs in the soil was drawn using the SVE system. Overall, the AS system would increase the dissolved oxygen of groundwater thus enhanced the degradation of organic contamination using in situ microorganisms. Also, it could strip the VOCs dissolved in the groundwater and vapor to unsaturated soil thus removed by SVE system. Gradually, the concentration of contaminants would decrease and reach the expected goal of the remediation. In terms of the cost of site remediation, it took NT$ 384/m3 of soil of remediation engineering expenses, which is less than that of NT$ 647~5174/m3 of related aboard remediation cases. The reasons of low expenses of remediation engineering in this case were due to the lower cost of treatment equipments, environmental sampling and analysis, man-hour and maintenance compared to other countries.

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36

Shenn-Ping, Chen, e 陳慎平. "Toluene and Propene on ZSM-5". Thesis, 1995. http://ndltd.ncl.edu.tw/handle/16858042147923170903.

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碩士
國立清華大學
化學工程研究所
83
ZSM-5觸媒雖然具有形狀選擇性之催化功能,對於甲苯與丙烯之烷化反應所得的產物p-Cymene,其產物選擇率尤其是對Cymene同分異構物之產物來言仍然不佳,因而會造成後續分離上的困難為了解決此一問題,本研究以矽- 氣相植入法改良ZSM-5觸媒,在只改變觸媒外表結構但不改變觸媒內部活性的情形下，進行甲苯及丙烯合成對異丙基甲苯反應之探討,以期獲得p- Cymene高選擇率,高產量及高產率的最佳操作條件於本文中所探討之矽氣相植入法是在進料液體中添加定量之SiOC25)4為改良劑,探討的操作變數包括：在反應前與反應中觸媒之改良植入改良劑總量溫度WHSV甲苯及丙烯之莫耳比以水蒸氣之加入等由上述使用 Si(OC2H5)4為改良劑經由實驗所獲得之p-Cymene選擇率及產率結果顯示最佳操作條件為溫度275℃於反應中植入改良劑其植入總量是 100uL,WHSV為4.56甲苯及丙烯之莫耳比為7.65,並料中添加水蒸氣

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37

Chen, Shen-Ping, e 陳慎平. "Toluene and Propene on ZSM-5". Thesis, 1995. http://ndltd.ncl.edu.tw/handle/96693501667208839420.

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38

Lin, Hsi-Chen, e 林希貞. "Evaluation of Samplers for Toluene Diisocyanate". Thesis, 2003. http://ndltd.ncl.edu.tw/handle/92222910812711769946.

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碩士
國立交通大學
環境工程所
91
This study was carried-out to compare the performance of five kinds of sampler for toluene diisocyanate (TDI), i.e. triple filter system (TFS), annular denuder system (ADS), dual filter system (DFS), open-face filter cassette (OFFC) and closed-face filter cassette (CFFC). Laboratory tests showed that there was no obvious difference between two relative humidities with different media. Further, it can say that the lon-ger the sampling time, the faster the concentration of 2,4-TDI decreased. The loss rate of TDI during the chamber runs followed first order decay behavior. The field comparison study was carried-out in a polyurethane foam factory situ-ated in Taichung, Taiwan during September to October 2002. Sampling was perform-ed at different time intervals to study the time effect on sampling concentrations. The results show that the concentrations of total TDI estimated by the TFS are comparable to those by the ADS and other filter systems. The comparison with ADS shows that TFS works well with 15-min sampling period, which is the standard duration for TDI sampling. The test data prove the reliability of TFS in the field sampling of TDI. It is a convenient system for the simultaneous sampling of vapor- and aerosol-phase TDI, and derivatives of other isocyanates

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39

林瑞德. "Removal of Trace Toluene from Tetrahydrofuran". Thesis, 2003. http://ndltd.ncl.edu.tw/handle/74915564108507460774.

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碩士
長庚大學
化工與材料工程研究所
91
PTMEG (polytetramethylene ethyl glycol) is the main material of elastic fiber, which is polymerized by THF (tetrahydrofuran) under acidic catalyst. The purity of THF is very important for the quality of PTMEG. THF is made by the process, that is dehydration of 1,4-butylenediol. Because of THF is completely soluble with water, we often use toluene as extractor, and evaporate the concentration of THF to 95% or above. But THF and toluene is partly soluble, hence industrial THF involves trace toluene. My study will focus on the THF solution which including 1000 ppm toluene, and will decrease the concentration of toluene to 300 ppm or below by the adsorption technology. Appling adsorption technology to remove trace impurity, there are some advantages, like saving resources and easy operating. We will use a stirring adsorption tank to screen adsorbent, which has high adsorption capacity and high selectivity from commonly adsorbents like activated carbon, aluminum oxide, silica gel, zeolites and modified zeolites. From the results of dynamic adsorption experiments and mathematical analysis, we can obtain isotherm constant and diffusivity coefficient, and discuss the consistence between experimental results and periodical brakethrough curves.

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40

TSAI, WEI-YUN, e 蔡瑋芸. "Catalyst Development for Toluene Hydroisomerization Reaction". Thesis, 2016. http://ndltd.ncl.edu.tw/handle/81389673080942477581.

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碩士
國立中正大學
化學工程研究所
104
The purpose of this research is to isomerize methylcyclohexane and hydrogenation saturation of toluene at the same time and to produce dimethylcyclopentane and isomers with low aromatic and environmentally friendly characteristic. To study the correlation between structure of catalysts and reaction, toluene is used as feed. Zeolites and platinum metal on catalysts and its surface structure are characterized analyzed by XPRD (X-ray powder diffraction), EXAFS (extend X-ray absorption fine structure) and BET. This research designed bi-functional catalysts which make hydrogenation saturation and isomerization happen at the same time and save process costs. To make catalysts undergo hydrogenation saturation and isomerization and reduce generation of fuel gas (C4-) at the same time, the design of catalysts such as Si/Al ratio, binder and operating conditions of reactions can influence the profit of process directly. From previous researches, catalysts with SiO2 binder have higher isomerization selectivity than catalysts with AlO2 binder is known. Ludox is a better gel than Hi-Sil gel. However Ludox is expensive and mechanical strength of catalysts with Ludox as the binder is low. Therefore, less acidity Hi-Sil gel which has the characteristic of Ludox and doesn’t corrode zeolites is developed. The platinum metal structure and the zeolites Si/Al ratio of the pellets Pt/HY catalysts made by the method described above are directly related. From the results of research, the larger the platinum metal sizes are, the more stable of the catalysts in reactions. Hence, the isomerization yield of the reaction with Pt catalysts made by CBV780 and low sulfur feed is above 50%. ( isomerization selectivity is above 90%). The fuel gas yield is less than 1%.

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41

Tsai, Yi-Ting, e 蔡逸霆. "Toluene oxidation over supported palladium catalysts". Thesis, 2011. http://ndltd.ncl.edu.tw/handle/94608503213467887621.

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Abstract (sommario):

碩士
國立中央大學
化學工程與材料工程研究所
99
Au/CeO2 and Pd/CeO2 were reported to be very active to destruct toluene from this lab. Therefore, combination of gold and palladium is an interesting candidate to achieve a catalyst with higher activity. In this study, a series of Au–Pd/CeO2 and Au–Pd/TiO2 bimetallic catalysts with various Au loadings were prepared. Pd was loaded by incipient-wetness impregnation method and Au was loaded by deposition-precipitation method. The Pd loadings in all samples were fixed at 0.5 wt. %, and the content of gold was between 0.1 and 1 wt. %. High surface area CeO2 with unique microstructure from Nikki Company and TiO2 (P-25) from Evonik Degussa Company were used as the support. The catalysts were characterized by powder X-ray diffraction (XRD), transmission electron microscopy (TEM), high resolution transmission electron microscopy (HRTEM), and X-ray photoelectron spectroscopy (XPS). The catalysts were tested for total oxidation of toluene. The feed concentration of toluene was 8.564 g/m3 (2085 ppm), with GHSV= 10,000 h-1. The TEM and HRTEM images showed that both of Au and Pd particle sizes were 3–5 nm and well-dispersed on the support. This result is consistent with the XRD studies. XPS study indicated that the addition of suitable amount of gold to Pd-based catalyst increased the proportion of metallic palladium and the catalytic activity. However, the overdoes of Au decreased the activity because the Au metal overlapped with the Pd metal and Au was less active than Pd. In activity test, Au–Pd bimetallic catalyst is better than a physically-mixed Au-based and Pd-based catalyst, which indicates there is a good interaction between gold and palladium. In conclusion, Au–Pd bimetallic catalysts were superior to Au and Pd monometallic catalysts due to the synergetic effect between Au and Pd nanocluster. Au–Pd bimetallic catalysts are very promising for toluene destruction.

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42

Bon, David Jean-Yves Denis. "From Toluene to Polyquinane natural products". Phd thesis, 2014. http://hdl.handle.net/1885/155821.

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This thesis is comprised of five scientific articles and is preceded by an overview that contextualises all of the published work. The focus of the work was the development of chemoenzymatic total syntheses of several key members of the hirsutene-class of triquinane natural products from the enantiomerically pure cis-dihydrocatechol A, itself obtained through the whole-cell biotransformation of the simple aromatic compound toluene. Thus, singlehandedly, and using a combination of Diels-Alder cycloaddition and photochemically-promoted oxa-di-pi-methane (ODPM) rearrangement steps, the author has been able to convert metabolite A into the highly oxygenated triquinanes connatusin A and connatusin B. In addition he has been able to devise related methods for the synthesis of compounds D and E, the acquisition of which constitute formal total syntheses of hypnophillin and coriolin. Publication 1 of the thesis is a review article that describes how cis-dihydrocatechols such as A are produced and exploited in chemoenzymatic synthesis while Publication 2, a forthcoming book chapter, provides a survey of the applications of the ODPM and the related di-pi-methane (DPM) rearrangement reactions to the assembly of otherwise inaccessible frameworks, including those associated with polyquinanes. Publications 3, 4 and 5 are journal articles that detail the author's successfully completed total syntheses of triquinanes B, C, D and E. The Appendices to the thesis are comprised of a series reports arising from single-crystal X-ray analyses of certain key compounds synthesised by the Author. These analyses were conducted by Dr Anthony Willis, Dr Ian Cade or Mr Jas Ward, members of the Research School of Chemistry's Crystallographic Analysis Unit.

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43

Chen, Bo Shian, e 陳柏賢. "Toluene oxidation on Pt/SBA15 catalysts". Thesis, 2012. http://ndltd.ncl.edu.tw/handle/58484473267294943940.

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碩士
長庚大學
化工與材料工程學系
100
Our previous study indicated that the mesoporous silica SBA-15 materials containing carboxylic acid groups were used as an effective support to synthesize Cu nanoparticles, the Cu would be trapped in the structure of SBA-15 and can be further transformed to nanosized Cu particles. In this study, we found that the average size of Pt particles in –COOH functionalized SBA-15 is approximately 6 nm and Pt nanoparticles are uniformly distributed inside the SBA-15 channels. In addition, the in situ XRD reveal that Pt particles would switch to reduction state when the calcination temperature increase to 330 ℃. The activity of toluene oxidation has been studied on Pt nanoparticles supported on mesoporous silica SBA-15 using GC. The Pt catalysis supported 10%CES-SBA15 shows better conversion rate than Pt supported SBA15.

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44

Lee, Kun-Jung, e 李堃榮. "Vapor-Liquid Equilibria of Eight Binary Mixtures of Hexane + Heptane, Benzene + Toluene, Benzene + N-Methylformamide, Cyclohexane + Octane, Cyclohexane + Nonane, Heptane + Octane, Toluene + m-Xylene and Toluene + N-Methylformamide". Thesis, 2008. http://ndltd.ncl.edu.tw/handle/37442421100525624376.

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碩士
國立中興大學
化學工程學系所
97
Isothermal vapor-liquid equilibria (VLE) at 333.15 K and 353.15 K for eight binary mixtures of hexane + heptane, benzene + toluene, benzene + N-methylformamide, cyclohexane + octane, cyclohexane + nonane, heptane + octane, toluene + m-xylene and toluene + N-methylformamide have been obtained at pressures ranged from 0.5 to 101.3 kPa. The NRTL, UNIQUAC and the Wilson activity coefficient models have been employed to correlate experimental pressures and liquid mole fractions. The non-ideal behavior of the vapor phase has been considered by using the Soave-Redlich-Kwong equation of state in calculating the vapor mole fraction. Liquid and vapor densities were measured by using two vibrating tube densitometers. Phase behaviors of the P-T-x-y diagrams indicate that five mixtures of hexane + heptane, benzene + toluene, cyclohexane + octane, heptane + octane and toluene + m-xylene were close to the ideal solution. However, cyclohexane + nonane and two mixtures containing N-methylformamide present a large positive deviation from the ideal solution. The benzene + toluene and cyclohexane + octane mixture are negative in the excess Gibbs energy, indicating that they are exothermic systems, but the other six binary mixtures belong to endothermic systems.

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45

Pan, Chien-Yu, e 潘建宇. "Biodegradation of toluene and ethylbenzene by bioreactor". Thesis, 2009. http://ndltd.ncl.edu.tw/handle/00535660158694996644.

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碩士
國立交通大學
生化工程研究所
97
According to the foregoing investigation, the biotechnologies has been proven to be an effective process for treating volatile organic compounds(VOCs). The goals of this study were to extend the previous study to removal toluene and ethylbenzene. We examined the effects of inlet concentration, retention time(RT), pH of the nutrient feed, nutrient feeding frequency, material and nitrogen source on the biofilter performance for treating toluene and ethylbenzene waste gases. When the retention time was 0.5 min, the toluene and ethylbenzene removal efficiency increased as the pH of the nutrient feed increased in the pH range of 5-7 . However, an opposite trend was observed for pH between 7 and 9. The optimum pH range was 7. Nutrient feeding frequency test was three conditions: all day, 15 min/h and 30 min/day.When the nutrient feeding frequency was 15 min/h, the toluene and ethylbenzene removal efficiency was significantly higher than the other. The development of biomass accumulation is related to the bed pressure drop in the biofilter, and it can cause the bed clogging and channelling. As can be observed, the pressure drop increased as gas flow rate was increased. The pressure drop significantly increased after biomass accumulation in the biofilter. The experimental results indicated that toluene and ethylbenzene could be effectively removed when the nitrogen source was (NH4)2SO4. Moreover, when KNO3 was added or not provid nitrogen source, the bacterial growth and pollution degradation became limited. Experiments at various toluene and ethylbenzene inlet loads were carried out. The toluene maximum elimination capacity was 157gm-3h-1 for an inlet loads 192 gm-3h-1. The ethylbenzene maximum elimination capacity was 302 gm-3h-1 for an inlet loads of 419 gm-3h-1.

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46

Kelly, Janya L. "Impact of parameter representation in gas-particle partitioning on aerosol yield model prediction /". 2007. http://gateway.proquest.com/openurl?url_ver=Z39.88-2004&res_dat=xri:pqdiss&rft_val_fmt=info:ofi/fmt:kev:mtx:dissertation&rft_dat=xri:pqdiss:NR29331.

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Thesis (Ph.D.)--York University, 2007. Graduate Programme in Earth and Space Science.
Typescript. Includes bibliographical references (leaves 116-121). Also available on the Internet. MODE OF ACCESS via web browser by entering the following URL: http://gateway.proquest.com/openurl?url_ver=Z39.88-2004&res_dat=xri:pqdiss&rft_val_fmt=info:ofi/fmt:kev:mtx:dissertation&rft_dat=xri:pqdiss:NR29331

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47

Washer, Cheryl E. "Molecular characterization of a methanogenic toluene-degrading consortium". 2004. http://link.library.utoronto.ca/eir/EIRdetail.cfm?Resources__ID=94897&T=F.

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48

洪肇佑. "Photocatalytic Reaction of Toluene in an Airlift Reactor". Thesis, 2000. http://ndltd.ncl.edu.tw/handle/23453384892431731500.

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49

Jian, Chong-Syun, e 簡崇訓. "Complete oxidation of toluene by Cu/Ce1-xZrxO2". Thesis, 2009. http://ndltd.ncl.edu.tw/handle/64229022604587721127.

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碩士
國立中央大學
化學工程與材料工程研究所
97
Cu/CexZr1-xO2 was used as catalyst for toluene total oxidation. Catalyst support was prepared by co-precipitation (CP) or impregnation (IMP), and copper was impregnated on the support with different weight percent. Cu loading amount between 5~7 wt.% show the highest activity, catalytic activity decreased when the copper amount increased. For CP support catalysts, Zr incorporation decreased the activity. For IMP support catalysts, adding ZrO2 on CeO2 (less than 20 molar％) improved catalytic activity. When X<0.2, the trend of decreasing activity was Cu/Ce-Zr(IMP)＞Cu/CeO2＞Cu/Ce-Zr(CP). Calcination temperature effect was studied for Zr free catalysts and Zr＜20 molar%. For catalysts without Zr, lower calcination temperature showed better activity. For catalysts with Zr＜20 molar%, the catalysts calcined at 500℃ showed better activity than those calcined at 300℃. Calcination time effect was also discussed. Catalysts calcined at 500℃, for 4 hours and 8 hours showed different results. For 8 hours calcination, catalysts with Zr＜20 molar% showed better activity than Cu/CeO2. For 4 hours calcination, the catalyst adding Zr did not improve activity. From XPS and H2-TPR results, Zr impregnation on CeO2 surface increased Cu+ amount. Cu+ was the adsorption position of toluene, increasing Cu+ amount improves catalysts activity.

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50

Tsai, Shen-Long, e 蔡伸隆. "Cometabolic Degradation of Trichloroethylene by A Toluene-Oxidizer". Thesis, 2003. http://ndltd.ncl.edu.tw/handle/39227299502273486373.

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