Peroxisome proliferator-activated receptor (PPAR)γ plays a role in tumorigenesis. Previous studies with PPARγ(+/-) mice suggest PPARγ normally suppresses dimethylbenz[a]anthracene (DMBA)-induced breast, and other, tumor progression. Since many cell types associated with the mammary gland express PPARγ, each with unique signaling pathways, the present study aimed to define which tissues are required for PPARγ-dependent anti-tumor effects. Conditional adipocyte and endothelial cell-specific PPARγ knockout mice (PPARγ-A KO and PPARγ-E KO respectively) were used to evaluate whether PPARγ signaling normally acts to prevent DMBA-mediated breast tumour progression in a stromal cell-specific manner. Twelve week old PPARγ KO mice and their congenic wildtype (WT) controls were randomly assigned to one of two treatment groups. All mice were treated by gavage once/week for 6 weeks with 1 mg DMBA and maintained on a normal chow diet. At week 7, mice in each group were divided into those continuing normal chow, and those receiving a PPARγ ligand (ROSI, 4 mg/kg/day) supplemented diet for the duration of the 25 week study, and monitored weekly. Tumour and tissue samples were collected at necropsy, and portions of each were fixed and frozen for future analysis. In both PPARγ-A KOs and PPARγ-E KOs versus PPARγ-WT mice, malignant mammary tumor incidence was significantly higher and mammary tumor latency was decreased. DMBA+ROSI treatment reduced average mammary tumor volumes by 50%. Gene expression analyses of mammary glands by qRT-PCR and immunofluorescence indicated that untreated PPARγ-A KOs had significantly decreased BRCA1 expression in mammary stromal adipocytes. Compared to PPARγ-WT mice, serum leptin levels in PPARγ-A KOs were also significantly higher throughout the study. In the PPARγ-E KO mice, both treatment groups saw a significant increase in thymic tumour incidence, a finding not established before with the study of other stromal cell knockout mice. These studies provide the first direct in vivo evidence that PPARγ signalling in stromal adipocytes and endothelial cells attenuates DMBA-mediated breast tumourigenesis. This study supports a protective effect of activating PPAR gamma as a novel chemopreventive therapy for breast cancer. / Thesis (Master, Pharmacology & Toxicology) -- Queen's University, 2012-12-24 11:28:17.668

The purpose of this thesis is to evaluate the performance and cost effectiveness of a Peroxone Groundwater Treatment Plant (PGTP) designed and operated by Montgomery Watson, in support of the Defense Evaluation Support Agency's independent analysis for the United States Army Environmental Center (USAEC). Many Department of Defense installations have sites that contain groundwater contaminated with explosive materials. Primary methods for the removal of explosive materials involve the use of Granular Activated Carbon (GAC). This process, however, requires additional waste disposal and treatment of explosive laden GAC, thereby incurring additional costs. An alternate method for the treatment of contaminated groundwater involves the use of hydrogen peroxide (H2O2) in conjunction with ozone (03). This method is referred to as the Peroxone oxidation process. A demonstration of the PGTP was conducted from 19 August to 8 November, 1996, at Cornhusker Army Ammunition Plant (CAAP), Grand Island, Nebraska using a small scale version with a maximum flow rate of 25 gallons per minute. The explosive contaminants analyzed during the demonstration include 2,4,6-Trinitrotoluene (TNT), 1,3,5-Trinitrobenzene (TNB), 1,3,5-Triazine (RDX), and Total Nitrobodies. Peroxone cost effectiveness was evaluated using a 30 year life cycle cost comparison to GAC and Ultraviolet/Ozone processes

O principal impacto ambiental do processo de beneficiamento da casca de coco verde é a geração de resíduo líquido com elevada carga orgânica. Este trabalho teve como objetivo aplicar o sistema convencional de lodos ativados para o tratamento biológico do líquido gerado no beneficiamento da casca de coco verde, além de utilizar o teste de taxa de consumo de oxigênio (TCO) para avaliar a toxicidade do efluente ao lodo aeróbio. O reator de escala laboratorial foi inoculado com lodo proveniente de uma estação de tratamento de esgoto em escala plena. Inicialmente o sistema foi alimentado com efluente sintético contendo sacarose e nutrientes para posterior adição progressiva do resíduo líquido proveniente da reciclagem da casca de coco verde. Para o ensaio de respirometria, as composições testadas foram 25, 50, 75 e 100% de resíduo líquido em termos de carga orgânica e o teste se baseou na medição manual da TCO ao longo do tempo. Para cada composição de efluente se verificou o valor máximo de TCO, o nível de toxicidade devido ao líquido da casca de coco verde (LCCV) e a indicação de inibição permanente. O parâmetro usado nos cálculos de toxicidade e de inibição permanente foi a taxa de consumo de oxigênio específica (TCOe) máxima. Para o monitoramento do sistema de fluxo contínuo, foram empregados os parâmetros pH, índice volumétrico de lodo (IVL), oxigênio dissolvido (OD), demanda química de oxigênio (DQO), taninos totais e sólidos suspensos. O reator foi operado com carga orgânica volumétrica (COV) de 0,8 a 2,9 gDQO/L.d e tempo de detenção hidráulica (TDH) de 26,7 d. Devido à presença natural de leveduras no resíduo líquido, os testes de respirometria foram realizados com o efluente tanto esterilizado quanto in natura. Como os resultados preliminares de respirometria não foram conclusivos, optou-se por começar a adaptação do reator de fluxo contínuo com a menor porcentagem testada: 25% de resíduo líquido. Nos testes adicionais de respirometria não houve toxicidade ao lodo e a TCOe foi diretamente proporcional à concentração de resíduo líquido. A remoção média de DQO obtida durante a operação (LCCV a 100%) foi de 81% com amostra filtrada e 82% com amostra bruta. Houve diminuição significativa da concentração de taninos, de 5332 para 1206 mg/L, em média. No início da operação ocorreu o decaimento da concentração de oxigênio dissolvido (OD) no reator para valores menores que 1 mg/L em decorrência do aumento da concentração de biomassa, mas esta situação não afetou a remoção de matéria orgânica e nem a sedimentabilidade do lodo. A remoção de matéria orgânica obtida com o tratamento em escala laboratorial do LCCV mostra que o sistema convencional de lodos ativados pode ser aplicado como alternativa no tratamento biológico dos resíduos líquidos do beneficiamento da casca de coco verde, porém a demanda elevada de oxigênio pode ser um entrave na operação em escala plena. / The main disadvantage of coconut recycling is the highly pollutant wastewater generated during the process. The objectives of this study were to treat the coconut husk liquor (CHL) using a conventional activated sludge system (AS) and to use the oxygen uptake rate (OUR) test for determining the initial effluent composition of reactor feeding and for wastewater toxicity assessment. The laboratory-scale reactor was inoculated with sludge from a full-scale sewage treatment plant. Firtly the system was fed with synthetic effluent containing saccarose and nutrients which was substituted by CHL. For the OUR test the substrate compositions were 25, 50, 75 and 100% of CHL. For each substrate composition, it was verified the maximum OUR value, the toxicity level and permanent inhibition caused by CHL. The maximal specific oxygen uptake rate (SOUR) was the parameter applied for the toxicity assessment and permanent inhibition calculation. The lab-scale reactor was monitored on the basis of pH, sludge volume index, dissolved oxygen, chemical oxygen demand (COD), total tannins and suspended solids. The respirometry assays were carried out with sterilized and natural effluent because of yeast contamination in CRW. Because of the lack of conclusive results in the first respirometry test, it was chosen the lower composition for reactor adaptation beginning: CRW 25%. In the additional OUR tests it was not detected toxicity and the SOUR values were as higher as CRW concentration. After initializing the reactor adaptation with CRW 25%, the percentage changed to 30% and than increased by 10% each 2 or 3 days until the operation beginning. The mean COD removal values were 81% (filtered sample) and 82% (raw sample). The mean tannin concentration decreased from 5332 to 1206 mg/L. The organic removal and sludge settleability were not affected by the DO concentration decrease to less than 1 mg/L due to biomass increase. The organic removal obtained in the lab-scale AS treatment shows that this system can be an alternative for CHL biological treatment, even though the high oxygen demand could be a disadvantage at full-scale treatment.

Chu Kit Man. / Thesis (M.Phil.)--Chinese University of Hong Kong, 2002. / Includes bibliographical references (leaves 142-168). / Abstracts in English and Chinese. / Abstract --- p.i / 摘要 --- p.iii / Acknowledgement --- p.iv / Abbreviations --- p.v / Publications Based on Work in this thesis --- p.viii / Chapter Chapter 1 --- Introduction --- p.1 / Chapter 1.1 --- G protein-coupled receptors --- p.1 / Chapter 1.1.1 --- Introduction --- p.1 / Chapter 1.1.2 --- Heterotrimeric G proteins --- p.3 / Chapter 1.1.3 --- Second messenger systems --- p.4 / Chapter 1.1.4 --- Mechanism of GPCR activation --- p.6 / Chapter 1.2 --- Prostacyclin and its receptors --- p.9 / Chapter 1.2.1 --- General properties of prostacyclin --- p.9 / Chapter 1.2.1.1 --- Synthesis of prostacyclin --- p.9 / Chapter 1.2.1.2 --- Prostacyclin analogues --- p.10 / Chapter 1.2.2 --- Characterization of IP-receptors --- p.12 / Chapter 1.2.2.1 --- Distribution of IP-receptors --- p.12 / Chapter 1.2.2.2 --- Cloning of IP-receptors --- p.14 / Chapter 1.2.2.3 --- Structure of IP-receptors --- p.15 / Chapter 1.2.3 --- Coupling of IP-receptors to G proteins --- p.16 / Chapter 1.2.3.1 --- Interaction with Gs --- p.16 / Chapter 1.2.3.2 --- Interaction with Gq --- p.17 / Chapter 1.2.3.3 --- Interaction with Gi --- p.18 / Chapter 1.2.3.4 --- Interaction with PPARs --- p.20 / Chapter 1.2.4 --- Role of prostacyclin in mitogenesis/anti-mitogenesis --- p.20 / Chapter 1.3 --- Signal transduction network of MAPK family --- p.27 / Chapter 1.3.1 --- MAPK modules in mammalian cells --- p.29 / Chapter 1.3.1.1 --- Extracellular regulated kinase (ERK) cascade --- p.30 / Chapter 1.3.1.2 --- Stress-activated protein kinase (JNK and p38) cascades --- p.33 / Chapter 1.3.2 --- Activation ofERKl/2 through GPCRs --- p.35 / Chapter Chapter 2 --- Materials and solutions --- p.53 / Chapter 2.1 --- Materials --- p.53 / Chapter 2.2 --- "Culture media, buffer and solutions" --- p.58 / Chapter 2.2.1 --- Culture media --- p.58 / Chapter 2.2.2 --- Buffers --- p.59 / Chapter 2.2.3 --- Solutions --- p.62 / Chapter Chapter 3 --- Methods --- p.65 / Chapter 3.1 --- Maintenance of cell lines --- p.65 / Chapter 3.1.1 --- Chinese Hamster ovary (CHO) cells --- p.65 / Chapter 3.1.2 --- Human neuroblastoma (SK-N-SH) cells --- p.66 / Chapter 3.1.3 --- Rat/mouse neuroblastoma/glioma hybrid (NG108-15) cells --- p.66 / Chapter 3.2 --- Transient transfection of mammalian cells --- p.67 / Chapter 3.3 --- Measurement of ERK activity --- p.68 / Chapter 3.3.1 --- PathDetect® Elkl trans-Reporting System --- p.68 / Chapter 3.3.1.1 --- Introduction --- p.68 / Chapter 3.3.1.2 --- β-galactosidase assay --- p.72 / Chapter 3.3.1.3 --- Transient transfection of cells --- p.72 / Chapter 3.3.1.4 --- Cell assay --- p.73 / Chapter 3.3.1.5 --- Luciferase assay --- p.74 / Chapter 3.3.1.6 --- Micro β-gal assay --- p.74 / Chapter 3.3.1.7 --- Data analysis --- p.75 / Chapter 3.3.2 --- Western Blotting --- p.79 / Chapter 3.3.2.1 --- Introduction --- p.79 / Chapter 3.3.2.2 --- Transient transfection of cells --- p.79 / Chapter 3.3.2.3 --- Cell assay --- p.79 / Chapter 3.3.2.4 --- Protein electrophoresis and transfer --- p.80 / Chapter 3.3.2.5 --- Immunodetection --- p.80 / Chapter 3.4.1 --- Measurement of adenylyl cyclase activity --- p.83 / Chapter 3.4.1 --- wyo-[3H]-inositol labelling method --- p.83 / Chapter 3.4.1.1 --- Preparation of columns --- p.83 / Chapter 3.4.1.2 --- Incubation of cells --- p.84 / Chapter 3.4.1.3 --- Measurement of [3H]-cyclic AMP production --- p.84 / Chapter 3.4.1.4 --- Data analysis --- p.85 / Chapter 3.5 --- Measurement of phospholipase C activity --- p.85 / Chapter 3.5.1 --- wyo-[3H]-inositol labelling method --- p.85 / Chapter 3.5.1.1 --- Preparation of columns --- p.86 / Chapter 3.5.1.2 --- Incubation of cells --- p.86 / Chapter 3.5.1.3 --- Measurement of [3H]-inositol phosphate production --- p.87 / Chapter 3.5.1.4 --- Data analysis --- p.88 / Chapter Chapter 4 --- Results --- p.89 / Chapter 4.1 --- Validation of PathDetect® Elkl Trans-Reporting System --- p.89 / Chapter 4.1.1 --- Introduction --- p.89 / Chapter 4.1.2 --- Internal control --- p.89 / Chapter 4.1.3 --- Response to cicaprost and ATP --- p.91 / Chapter 4.1.4 --- Normalisation of ERK1/2 activity with transfection efficiency --- p.92 / Chapter 4.1.5 --- Cicaprost response in CHO cells in the absence of mIP- receptor --- p.93 / Chapter 4.1.6 --- Normalised luciferase activity reflecting ERK1/2 activation --- p.93 / Chapter 4.1.7 --- Conclusion --- p.95 / Chapter 4.2 --- Characterization of IP-receptors --- p.101 / Chapter 4.2.1 --- IP-receptor activation of adenylyl cyclase and phospholipase C --- p.101 / Chapter 4.2.2 --- IP-receptor activation ofERKl/2 in mIP-CHO cells --- p.102 / Chapter 4.2.2.1 --- PathDetect System --- p.102 / Chapter 4.2.2.2 --- Western Blotting --- p.103 / Chapter 4.2.2.3 --- Conclusion --- p.104 / Chapter 4.2.3 --- Role of the Gs-mediated pathway in cicaprost-stimulated ERK1/2 activation --- p.104 / Chapter 4.2.3.1 --- Role of cyclic AMP --- p.105 / Chapter 4.2.3.2 --- Role of protein kinase A --- p.106 / Chapter 4.2.4 --- Role of the Gq-mediated pathway in cicaprost-stimulated ERK1/2 activation --- p.106 / Chapter 4.2.4.1 --- Role of IP3 --- p.107 / Chapter 4.2.4.2 --- Role of protein kinase C --- p.108 / Chapter 4.2.4.3 --- Conclusion --- p.108 / Chapter 4.2.5 --- IP-receptor activation of ERKl/2 in hIP-CHO cells --- p.109 / Chapter 4.2.5.1 --- Activation ofERKl/2 in hIP-CHO cells --- p.109 / Chapter 4.2.5.2 --- Role of the Gq-mediated pathway in cicaprost- stimulated ERK 1/2 activation --- p.110 / Chapter 4.2.5.3 --- Role of the Gs-mediated pathway in cicaprost- stimulated ERK 1/2 activation --- p.111 / Chapter 4.2.5.4 --- Conclusions --- p.113 / Chapter 4.2.6 --- IP-receptor activation of ERX1/2 in neuroblastoma cells --- p.114 / Chapter 4.2.6.1 --- Rat/mouse neuroblastoma/glioma (NG108-15) cells --- p.114 / Chapter 4.2.6.2 --- Human neuroblastoma (SK-N-SH) cells --- p.115 / Chapter Chapter 5 --- General Discussion and Conclusions --- p.137 / References --- p.142

Typescript, etc. / Digitized by Kansas Correctional Industries

Digitized by Kansas Correctional Industries

This work concerns the functionalisation of a variety of carbon materials for the selective adsorption of carbon dioxide. A key challenge in post-combustion capture from gas fired power plants is related to the low CO2 concentration in the flue gas (4- 8%). Therefore highly selective adsorbents have the potential to improve the efficiency of the separation of carbon dioxide from gas mixtures. The study was performed in conjunction with the EPSRC funded project ‘Adsorption Materials and Processes for Carbon Capture from Gas-Fired Power Plants – AMPGas’. The carbon materials investigated included multi-walled carbon nanotubes, a microporous activated carbon, two types of mesoporous activated carbon and multi-walled carbon nanotube/polyvinyl alcohol composite aerogels. The uptake of carbon dioxide by these materials was enhanced through the addition of basic amine groups to the materials. The adsorption properties of the samples were tested by the zero-length column technique, thermal gravimetric analysis and breakthrough experiments. The materials were generally tested at conditions representative of those found in the flue gas of a fossil fuel power plant: 0.1 bar partial pressure of CO2. Two approaches were adopted for the chemical functionalization of the solid carbon supports. First, amine groups were covalently grafted directly to the surface and secondly amine molecules were physically adsorbed within the porous structure of the material by wet impregnation. It was seen that wet impregnation enabled the incorporation of a greater number of amine groups and the CO2 capacity of the materials was investigated with respect to the carbon support structure, the type of amine and the amount of amine loading. Larger pore volume mesoporous carbon materials were seen to provide a more efficient support for the amine to interact with the CO2. A greater than 12-fold increase in the CO2 capacity was observed when the amine impregnated carbon material was compared to the raw starting material. The extended zero-length column was introduced and fully characterized as a novel breakthrough experiment. It requires a small sample mass (~50 mg) and it allows binary selectivities to be calculated. It was shown, through multiple experiments and simulations that the breakthrough experiments were conducted under close to isothermal conditions which greatly simplifies the analysis of the breakthrough curves. In addition, a new zero-length column model was proposed to account for the reaction between the amine and the CO2 in the adsorbed phase and fitted to experimental data. An interesting double curvature was observed in the concentration profile during the desorption step which was attributed to the kinetics of the amine-CO2 reaction. A brief investigation was carried out into the binary separation of biogas (45% CO2: 55% CH4) by zeolite 13X, activated carbon and an amine impregnated activated carbon. Finally, initial investigations into the properties of low density carbon nanotube aerogels which have a large accessible pore volume, were carried out. Their potential as highly efficient supports for amine impregnation was investigated. It was found that amine functionalized carbons strongly interact with carbon dioxide and have the potential to be integrated as an adsorbent in a rapid temperature swing process that separates carbon dioxide from dilute gas streams.

O principal impacto ambiental do processo de beneficiamento da casca de coco verde é a geração de resíduo líquido com elevada carga orgânica. Este trabalho teve como objetivo aplicar o sistema convencional de lodos ativados para o tratamento biológico do líquido gerado no beneficiamento da casca de coco verde, além de utilizar o teste de taxa de consumo de oxigênio (TCO) para avaliar a toxicidade do efluente ao lodo aeróbio. O reator de escala laboratorial foi inoculado com lodo proveniente de uma estação de tratamento de esgoto em escala plena. Inicialmente o sistema foi alimentado com efluente sintético contendo sacarose e nutrientes para posterior adição progressiva do resíduo líquido proveniente da reciclagem da casca de coco verde. Para o ensaio de respirometria, as composições testadas foram 25, 50, 75 e 100% de resíduo líquido em termos de carga orgânica e o teste se baseou na medição manual da TCO ao longo do tempo. Para cada composição de efluente se verificou o valor máximo de TCO, o nível de toxicidade devido ao líquido da casca de coco verde (LCCV) e a indicação de inibição permanente. O parâmetro usado nos cálculos de toxicidade e de inibição permanente foi a taxa de consumo de oxigênio específica (TCOe) máxima. Para o monitoramento do sistema de fluxo contínuo, foram empregados os parâmetros pH, índice volumétrico de lodo (IVL), oxigênio dissolvido (OD), demanda química de oxigênio (DQO), taninos totais e sólidos suspensos. O reator foi operado com carga orgânica volumétrica (COV) de 0,8 a 2,9 gDQO/L.d e tempo de detenção hidráulica (TDH) de 26,7 d. Devido à presença natural de leveduras no resíduo líquido, os testes de respirometria foram realizados com o efluente tanto esterilizado quanto in natura. Como os resultados preliminares de respirometria não foram conclusivos, optou-se por começar a adaptação do reator de fluxo contínuo com a menor porcentagem testada: 25% de resíduo líquido. Nos testes adicionais de respirometria não houve toxicidade ao lodo e a TCOe foi diretamente proporcional à concentração de resíduo líquido. A remoção média de DQO obtida durante a operação (LCCV a 100%) foi de 81% com amostra filtrada e 82% com amostra bruta. Houve diminuição significativa da concentração de taninos, de 5332 para 1206 mg/L, em média. No início da operação ocorreu o decaimento da concentração de oxigênio dissolvido (OD) no reator para valores menores que 1 mg/L em decorrência do aumento da concentração de biomassa, mas esta situação não afetou a remoção de matéria orgânica e nem a sedimentabilidade do lodo. A remoção de matéria orgânica obtida com o tratamento em escala laboratorial do LCCV mostra que o sistema convencional de lodos ativados pode ser aplicado como alternativa no tratamento biológico dos resíduos líquidos do beneficiamento da casca de coco verde, porém a demanda elevada de oxigênio pode ser um entrave na operação em escala plena. / The main disadvantage of coconut recycling is the highly pollutant wastewater generated during the process. The objectives of this study were to treat the coconut husk liquor (CHL) using a conventional activated sludge system (AS) and to use the oxygen uptake rate (OUR) test for determining the initial effluent composition of reactor feeding and for wastewater toxicity assessment. The laboratory-scale reactor was inoculated with sludge from a full-scale sewage treatment plant. Firtly the system was fed with synthetic effluent containing saccarose and nutrients which was substituted by CHL. For the OUR test the substrate compositions were 25, 50, 75 and 100% of CHL. For each substrate composition, it was verified the maximum OUR value, the toxicity level and permanent inhibition caused by CHL. The maximal specific oxygen uptake rate (SOUR) was the parameter applied for the toxicity assessment and permanent inhibition calculation. The lab-scale reactor was monitored on the basis of pH, sludge volume index, dissolved oxygen, chemical oxygen demand (COD), total tannins and suspended solids. The respirometry assays were carried out with sterilized and natural effluent because of yeast contamination in CRW. Because of the lack of conclusive results in the first respirometry test, it was chosen the lower composition for reactor adaptation beginning: CRW 25%. In the additional OUR tests it was not detected toxicity and the SOUR values were as higher as CRW concentration. After initializing the reactor adaptation with CRW 25%, the percentage changed to 30% and than increased by 10% each 2 or 3 days until the operation beginning. The mean COD removal values were 81% (filtered sample) and 82% (raw sample). The mean tannin concentration decreased from 5332 to 1206 mg/L. The organic removal and sludge settleability were not affected by the DO concentration decrease to less than 1 mg/L due to biomass increase. The organic removal obtained in the lab-scale AS treatment shows that this system can be an alternative for CHL biological treatment, even though the high oxygen demand could be a disadvantage at full-scale treatment.

Hydrogen sulphide is an environmentally hazardous gas which is present in many gas streams associated with oil and gas industry. Oxidation of H2S to sulphur in air produces no bulky or waste material and requires no further purification. Activated carbon is known as a catalyst for this reaction.<p> In this research, a coal-based precursor (luscar char) and a biomass-based precursor (biochar) were used for production of activated carbons by two common methods of activation: physical and chemical activation in which steam and potassium hydroxide (KOH), respectively, were used. Experiments were designed by the statistical central composite design method. Two models were developed for the BET surface area and reaction yield of each activation process. These models showed the effects of operating conditions, such as activation temperature, mass ratio of activating agent to precursor, activation time, and nitrogen flowrate on the BET surface area and reaction yield for each activation method for each precursor. The optimum operating conditions were calculated using these models to produce activated carbons with relatively large BET surface area (> 500 m2/g) and high reaction yield (> 50 wt %). The BET surface area and reaction yield for activated carbons produced at optimum operating conditions showed maximum 7 and 7.4 % difference, respectively, comparing to the values predicted by models.<p> The activated carbons produced at optimum operating conditions were used as the base catalysts for the direct oxidation of 1 mol % hydrogen sulphide in nitrogen to sulphur at the temperature range of 160-205 oC and pressure of 700 kPa. Originally activated carbons showed a good potential for oxidation of hydrogen sulphide by their selectivity for sulphur product and low amount of sulphur dioxide production. To improve the performance of steam-activated carbons, the catalysts were modified by acid-treatment followed by thermal desorption. This method increased the break-through times for coal-based and biomass-based catalysts to 115 and 141 minutes, respectively. The average amounts of sulphur dioxide produced during the reaction time were 0.14 and 0.03 % (as % of hydrogen sulphide fed to the reactor) for modified activated carbons prepared from biochar and luscar char, respectively. The effects of porous structure, surface chemistry, and ash content on the performances of these activated carbon catalysts were investigated for the direct oxidation reaction of hydrogen sulphide.<p> The acid-treatment followed by thermal desorption of activated carbons developed the porosity which produced more surface area for active sites and in addition, provided more space for sulphur product storage resulting in higher life time for catalyst. Boehm titration and temperature program desorption showed that the modification method increased basic character of carbon surface after thermal desorption in comparison to acid-treated sample. In addition, the effects of impregnating agents (potassium iodide and manganese nitrate) and two solvents for impregnation process were studied on the performance of the activated carbon catalysts for the direct oxidation of H2S to sulphur.<p> Sulphur L-edge X-ray near edge structure (XANES) showed that the elemental sulphur was the dominant sulphur species in the product. The kinetic study for oxidation reaction of H2S over LusAC-O-D(650) was performed for temperature range of 160-190 oC, oxygen to hydrogen sulphide molar ratio of 1-3, and H2S concentration of 6000-10000 ppm at 200 kPa. The values of activation energy were 26.6 and 29.3 kJ.gmol-1 for Eley-Rideal and Langmuir-Hinshelwood mechanisms, respectively.

Activated Carbon (AC) is an amorphous carbon-based material characterized with a large surface area (~ 1,000 m2/g) and consists primarily of graphitic (sp2 hybrid) layers. Its amphoteric chemical property results because of the chemical treatment of the surface of AC with oxidizing agents, reducing agents, and grafting agents. β-cyclodextrin (β-CD) is a very interesting carbohydrate oligomer that provides very strong binding ability for small organic guest molecules in its inner cavity (6.0 ~ 6.5 Å) by van der Waals interactions and hydrogen bond formation between the guest molecules and the host. <p>Surface modification of AC with β-CD was synthesized by chemical methods: oxidation with HNO3, reduction with LiAlH4, and grafting β-CD onto the surface of AC via organic linkers such as glutaraldehyde and 1,4-phenylene diisocyanate. This surface grafted AC with β-CD, then, was evaluated for its surface area and sorption performance by using a solution dye sorption method using dye adsorbates. <p>Surface functional groups produced from oxidation (carboxylic acid, lactone, quinine, phenol, and nitro groups), reduction (alcohol and amine groups), and grafting (imine, hemiacetal, and urethane bonds) methods including microscopy of untreated, surface modified, and grafted ACs were characterized by various surface characterization methods: Diffuse Reflectance Infra-red Fourier Transform Spectroscopy (DRIFTS), Scanning Electron Microscopy (SEM), Raman spectroscopy, X-ray photoelectron spectroscopy (XPS), Thermogravimetric analysis (TGA), Differential thermogravimetry (DTG), Matrix Assisted Laser Desorption Ionization Time of Flight mass spectrometry (MALDI TOF MS), and Electron spin resonance (ESR) spectroscopy. A chemical method, the Boehm method, was used for identifying surface bound acidic and basic functional groups. Nitrogen porosimetry was used to analyze the surface area and pore structure characteristics of AC, surface modified ACs, and grafted ACs. <p>p-nitrophenol (PNP) and methylene blue (MB) were used as adsorbates for the dye sorption method. PNP and MB were used to measure the sorption performance of grafted ACs at equilibrium using UV-vis spectrophotometry in aqueous solution. Sorption capacity (Qe), surface area (m2/g), and binding affinity characteristics [KF (L/g), KL (g/mol), and KBET (L/g)] were determined at equilibrium conditions using fundamental sorption models such as Langmuir, Freundlich, and BET isotherms. The sorption performance of grafted ACs and granular AC were different according to the difference in surface area and pore structure characteristics of each material.