Per- and polyfluoroalkylated substances (PFASs) are a large group of organic chemicals that have gained an increased attention during recent years. Many of the compounds have shown to be persistent, toxic and bioaccumulating and they are found in water, soils, sediments, biota, animals and humans across the globe. The effects of PFASs to humans and animals are still being debated. It is suspected that the compounds can be carcinogenic, disrupt different hormone systems and have other severe effects. The main transport pathways of PFASs to soil are applied PFAS based firefighting foam, soil improvers and waste from industries producing PFASs or PFAS based products. Once the PFASs find their way to the soil the risk for leaching to drinking water supplies and aquatic ecosystems becomes some of the issues of great concern. In order to be able to evaluate the potential leakage of PFASs from different contaminated soils it is important to know how the PFASs interact with the soil matrix and what parameters that affects these interactions. The objective of this study was to investigate the influence of organic carbon (OC), Ca2+ ions and active carbon (AC) on the n of PFCAs and PFSAs to soil. The PFCAs examined were PFHxA, PFOA, PFNA, PFDA, PFUnDA, PFOcDA, PFHxDA and PFOcDA and the PFSAs examined were PFBS, PFHxS, PFOS and PFDS. Batch experiments were performed on soils with varying concentrations of TOC, Ca2+ and AC. The samples were spiked with PFAS native standard solution containing the 12 target PFASs. All studied parameters showed a positive influence on the sorption of PFASs to soil. The AC was found to have the highest influence on the sorption. The OC was however found to be the most important soil parameter influencing the sorption of PFASs to soil. In order to investigate the influence of aging on the sorption of PFASs, batch experiments were also conducted on soils from four different PFAS contaminated sites. The results showed that the aging positively influenced the strength of the interactions between PFASs and soil. The organic carbon normalized distribution coefficients (Koc) showed a positive correlation with the carbon chain length of the PFAS molecules and also with the substitution of a carboxylic group with a sulfonic group. The log Koc values calculated in this study decreased in the following order PFDS (log Koc3.8 0.3) > PFOS > (log Koc2.8 0.3) > PFUnDA (log Koc 3.2 0.2) > PFDA (log Koc2.7 0.1) > PFNA (log Koc2.0 0.1) > PFHxS (log Koc1.9 0.1) > PFOA (log Koc1.8 0.3) > PFHxA (log Koc1.6 0.3) > PFBS (log Koc 1.5 0.2). The log Koc values found in this study were within the range of previously reported log Kocvalues.

<p>Cover crop use, especially in no-till systems, is an evolving practice to maintain or improve soil health. There are many possible indicators of soil health, but this study focuses on the analysis of soil aggregate stability, soil active carbon, and soil organic matter. Soil aggregate stability is related to water infiltration and potential for soil erosion, while active carbon serves as an indicator of a readily-available food source for microbial activity, and soil organic matter serves as a mediator for the soil physical, chemical, and biological processes. The sites include: three Purdue Agricultural Centers, two soil and water conservation district sites, 12 farmer sites with conservation cropping systems, and seven conventional comparison sites. The treatments consisted of cover crop versus no cover crop use, or cover crop use with different tillage systems or nitrogen rates. In 2016 and 2017, soil samples were collected at a depth of 0-5 cm, air-dried, and separated into two soil size fractions: 0-2 mm and 2-8 mm. The wet sieve method was used to measure the mean weight diameter of the water stable soil aggregates from the 2-8 mm size fraction in both years. The potassium permanganate method was used to measure the soil active carbon from both size fractions in both years. The dry combustion method was used to measure the soil organic matter from both soil size fractions in 2017 only. Results showed relatively small improvements in soil active carbon and aggregate stability with the addition of three to four years of cover crops to the long-term no-till systems. However, these improvements were greater when comparing the cover crops plus no-till treatments to the conventional-till without cover crops. More work is needed to understand the dynamics of soil aggregate stability, soil active carbon, and soil organic matter in relation to soil health and cover crop use. Cover crops will likely have more impact on soil aggregate stability, active carbon, and organic matter with a longer duration of use.</p><p></p>

O processo de adsorção por carvão ativado é uma técnica muito aplicada para tratamento de efluentes. Porém o tratamento que envolve adsorção não é um sistema completo, pois há a necessidade da destruição dos compostos que foram imobilizados na superfície do carvão. Frente a esse problema, métodos alternativos de regeneração de carvão ativado são investigados. Os processos Fenton e foto-Fenton são considerados tecnologias promissoras de tratamento de efluentes, e foram testados para regenerar o carvão ativado. Este trabalho objetiva estudar a adsorção de fenol em carvões ativados (CAs) e a consecutiva regeneração in-situ do carvão pela oxidação de (foto-) Fenton. Duas operações diferentes foram realizadas: 1) sistema de batelada, a fim de investigar a influência das concentrações de Fe2+ e H2O2; 2) adsorção contínua em leito fixo, seguido de circulação em batelada dos reagentes de Fenton pelo leito de CA saturado, para examinar a eficiência do processo real. Foram estudados dois tipos de carvão ativado: CA L27 (meso e microporoso) e CA S23 (somente microporoso). No reator de batelada as melhores condições encontradas para a mineralização do poluente no sistema Fenton homogêneo não são as melhores para a regeneração do CA: foi observada uma redução contínua da capacidade de adsorção do L27 após 3 oxidações, devido à redução tanto da massa do CA quanto da área superficial. Uma maior concentração de Fe2+ e menor concentração de H2O2 (2 vezes a estequiometria) levou a uma recuperação de 50% da capacidade de adsorção inicial em pelo menos 4 ciclos consecutivos para o L27, enquanto que cerca de 20% para o S23. No processo consecutivo de adsorção contínua/oxidação de Fenton em batelada, a eficiência de regeneração atinge de 30% a 40% para o L27 após dois ciclos independente da concentração da alimentação e menos de 10% para o S23. O processo foto-Fenton realizado para o L27 levou à quase completa mineralização e aumentou a recuperação da capacidade de adsorção do CA (56% após dois ciclos). / The adsorption process by active carbon is a technique applied extensively for wastewater treatment. However the tertiary treatment involving adsorption is not a complete system, since there is a need of destruction of the compounds that were immobilized on the carbon surface. In face of this problem, some alternative regeneration methods of active carbon are investigated. Fenton and photo-Fenton processes have been considered promising technologies for wastewater treatment and have been tested to regenerate the AC. The purposes of this study are the adsorption of phenol on activated carbons (ACs) and the consecutive in-situ regeneration of carbon by (photo-) Fenton oxidation. Two different operations have been carried out: 1) batch procedure in order to investigate the influence of Fe2+ and H2O2 concentrations; 2) continuous fixed bed adsorption, followed by a batch circulation of the Fentons reagent through the saturated AC bed, to examine the efficiency of the real process. Two different activated carbons have been also studied: a both micro- and mesoporous AC (L27) and an only microporous one (S23). In the batch reactor the best conditions found for pollutant mineralization in the homogeneous Fenton system are not the best for AC regeneration: a continuous reduction of adsorption capacity of L27 is observed after 3 oxidations, due to the decrease of both AC weight and surface area. Higher concentration of Fe2+ and lower concentration of H2O2 (2 times the stoechiometry) lead to a 50% recovery of the initial adsorption capacity during at least 4 consecutive cycles for L27, while about 20% for S23. In the consecutive continuous adsorption/batch Fenton oxidation process, the regeneration efficiency reaches 30% to 40% for L27 after two cycles whatever the feed concentration and less than 10% for S23. A photo- Fenton test performed on L27 shows almost complete mineralization (contrary to dark Fenton) and further improves recovery of AC adsorption capacity although not complete (56% after two cycles).

Pyrolysis of biomass consists of heating solid biomass inthe absence of air to produce solid, liquid and gaseous fuels.In the first part of this thesis rapid pyrolysis of wood(birch) and some agricultural residues (olive waste, sugarcanebagasse and wheat straw in untreated and in pelletized form) athigh temperature (800ºC–1000ºC) is studied ina free fall reactor at pilot scale. These conditions are ofinterest for gasification in fluidized beds. Of main interestare the gas and char yields and compositions as well as thereactivity of the produced char in gasification. A higher temperature and smaller particles increase theheating rate resulting in a decreased char yield. The crackingof the hydrocarbons with an increase of the hydrogen content inthe gaseous product is favoured by a higher temperature and byusing smaller particles. Wood gives more volatiles and lesschar than straw and olive waste. The higher ash content inagricultural residues favours the charring reactions. Charsfrom olive waste and straw are more reactive in gasificationthan chars from birch because of the higher ash content. Thecomposition of the biomass influences the product distribution.Birch and bagasse give more volatiles and less char thanquebracho, straw and olive waste. Longer residence time inrapid pyrolysis increase the time for contact between tar andchar which makes the char less reactive. The secondary charproduced from tar not only covers the primary char but alsoprobably encapsulates the ash and hinders the catalytic effectof the ash. High char reactivity is favoured by conditionswherethe volatiles are rapidly removed from the particle, i.e.high heating rate, high temperature and small particles. The second part of this thesis deals with slow pyrolysis inpresence of steam for preparation of active carbon. Theinfluence of the type of biomass, the type of reactor and thetreatment conditions, mainly temperature and activation time,on the properties and the yield of active carbons are studied.The precursors used in the experiments are birch (wood) anddifferent types of agricultural residues such as sugarcanebagasse, olive waste, miscanthus pellets and straw in untreatedand pelletized form. The results from the pyrolysis of biomass in presence ofsteam are compared with those obtained in inert atmosphere ofnitrogen. The steam contributes to the formation of solidresidues with high surface area and good adsorption capacity.The yield of liquid products increases significantly at theexpense of the gaseous and solid products. Large amount ofsteam result in liquid products consisting predominantly ofwater-soluble polar compounds. In comparison to the stationary fixed bed reactor, therotary reactor increases the production of energy-rich gases atthe expense of liquid products. The raw materials have strong effect on the yields and theproperties of the pyrolysis products. At equal time oftreatment an increase of the temperature results in a decreaseof the yield of solid residue and improvement of the adsorptioncapacity until the highest surface area is reached. Furtherincrease of the temperature decreases the yield of solidproduct without any improvement in the adsorption capacity. Therate of steam flow influences the product distribution. Theyield of liquid products increases while the gas yielddecreases when the steam flow is increased. <b>Keywords</b>: rapid pyrolysis, pyrolysis, wood, agriculturalresidues,biomass, char, tar, gas, char reactivity,gasification, steam, active carbon

Growth of bacteria in drinking water distribution and storage systems can lead to the deterioration of water quality, violation of water standards, and increased operating costs. Growth or Regrowth results from viable bacteria surviving the disinfection process and utilizing nutrient in the water and biofilm to sustain growth. Factors other than nutrients that influence regrowth include temperature, residence time in mains and storage units, and the efficacy of disinfection. Tests to determine the potential for bacterial regrowth focus on the concentration of nutrients. Not all organic compounds are equally susceptible to microbial decomposition; the fraction that provides energy and carbon for bacterial growth has been called labile dissolved organic carbon, biodegradable organic carbon (BDOC), or Assimilable Organic Carbon (AOC). Easily measured chemical surrogates for AOC are not available now. As alternative to chemical methods, bioassays have been proposed. Assimilable Organic Carbon (AOC) is that portion of the biodegradable organic carbon that can be converted to cell mass and expressed as a carbon concentration by means of a conversion factor. In this study, two organisms, namely Psuedomonas fluorescens strain P17 and Spirillum species NOX were selected for the AOC determination. The growth of the bacteria was determined by periodic colony counts with spread plate technique on LLA (Lab-Lemco nutrient agar) cultivation medium until the growth reached maximum (maximum colony count, Nmax). Results showed that AOC follows a trend based on the climatic and seasonal changes (local climate) with peaks in summer and low during winter season and vice versa in term of AOC removing capability. In addition to confirm AOC removal rate in biofiltration bed was evaluated with a test column containing the same filling materials, Granular Activated Carbon (GAC). Long term test showed that GAC would last for forty weeks without any special treatment. Other result showed that biofiltration bed has a better removal efficiency rate 72% (average based on four year), than the test column 49% since it experience frequent back-washing, thus maintaining a healthy removal rate. In the test column change in total organic carbon was quite abnormal. AOC yearly distribution was also studied and differentiated into four stages. AOC removal of each stage was 48%, 70%, 83% and 77%. Total organic carbon concentration was much higher in the effluent 384 than influent 334 £gg C/L; later methionine was found in water sample (effluent) which strongly suggests that the indigenous microbes had been reducing organic material such as cystein to methionine thus increasing the organic carbon content of the effluent. The microbial growths inside the GAC test column is entirely based on the long term feed of water at the treatment plant. Several other parameters such as Scanning Electron Microscope (SEM), Excitation Emissions Fluorescence Matrix (EEFM), Molecular Weight and Amino acids detection were selected and coupled with the AOC to shed light on the working mechanisms of both GAC as filtration material and characteristics of indigenous microbes towards the removal of organic contaminants and changes they can bring about to the quality of clear water.

<p>Pyrolysis of biomass consists of heating solid biomass inthe absence of air to produce solid, liquid and gaseous fuels.In the first part of this thesis rapid pyrolysis of wood(birch) and some agricultural residues (olive waste, sugarcanebagasse and wheat straw in untreated and in pelletized form) athigh temperature (800ºC–1000ºC) is studied ina free fall reactor at pilot scale. These conditions are ofinterest for gasification in fluidized beds. Of main interestare the gas and char yields and compositions as well as thereactivity of the produced char in gasification.</p><p>A higher temperature and smaller particles increase theheating rate resulting in a decreased char yield. The crackingof the hydrocarbons with an increase of the hydrogen content inthe gaseous product is favoured by a higher temperature and byusing smaller particles. Wood gives more volatiles and lesschar than straw and olive waste. The higher ash content inagricultural residues favours the charring reactions. Charsfrom olive waste and straw are more reactive in gasificationthan chars from birch because of the higher ash content. Thecomposition of the biomass influences the product distribution.Birch and bagasse give more volatiles and less char thanquebracho, straw and olive waste. Longer residence time inrapid pyrolysis increase the time for contact between tar andchar which makes the char less reactive. The secondary charproduced from tar not only covers the primary char but alsoprobably encapsulates the ash and hinders the catalytic effectof the ash. High char reactivity is favoured by conditionswherethe volatiles are rapidly removed from the particle, i.e.high heating rate, high temperature and small particles.</p><p>The second part of this thesis deals with slow pyrolysis inpresence of steam for preparation of active carbon. Theinfluence of the type of biomass, the type of reactor and thetreatment conditions, mainly temperature and activation time,on the properties and the yield of active carbons are studied.The precursors used in the experiments are birch (wood) anddifferent types of agricultural residues such as sugarcanebagasse, olive waste, miscanthus pellets and straw in untreatedand pelletized form.</p><p>The results from the pyrolysis of biomass in presence ofsteam are compared with those obtained in inert atmosphere ofnitrogen. The steam contributes to the formation of solidresidues with high surface area and good adsorption capacity.The yield of liquid products increases significantly at theexpense of the gaseous and solid products. Large amount ofsteam result in liquid products consisting predominantly ofwater-soluble polar compounds.</p><p>In comparison to the stationary fixed bed reactor, therotary reactor increases the production of energy-rich gases atthe expense of liquid products.</p><p>The raw materials have strong effect on the yields and theproperties of the pyrolysis products. At equal time oftreatment an increase of the temperature results in a decreaseof the yield of solid residue and improvement of the adsorptioncapacity until the highest surface area is reached. Furtherincrease of the temperature decreases the yield of solidproduct without any improvement in the adsorption capacity. Therate of steam flow influences the product distribution. Theyield of liquid products increases while the gas yielddecreases when the steam flow is increased.</p><p><b>Keywords</b>: rapid pyrolysis, pyrolysis, wood, agriculturalresidues,biomass, char, tar, gas, char reactivity,gasification, steam, active carbon</p>

La rápida industrialización y urbanización mundial ha creado un sin número de contaminantes para los medios acuosos tóxicos y peligrosos, los cuales en su gran mayoría son difícil de degradar de forma natural. Los fenoles son algunos de estos compuestos tóxicos que se encuentran con frecuencia en muchos efluentes industriales. Revisión literaria específica que la oxidación catalítica en aire húmedo utilizando carbón activado podría ser una solución prometedora para la destrucción de estos contaminantes fenólicos. Sin embargo, parece difícil lograr la estabilidad del catalizador dentro del reactor de lecho fijo, en estado estacionario, debido a la combustión lenta de carbón activado. Dentro de este contexto, el presente trabajo se centró en tres aspectos principales para extender los conocimientos actuales sobre la oxidación catalítica del aire húmedo, los cuales son: el establecimiento de las condiciones de arranque del reactor, el estudio de la cinética de reacción y la evaluación de la operación periódica de reactores de lecho fijo. Se ha demostrado que la cinética de la reacción puede llevarse a cabo en un reactor por goteo de lecho fijo sin limitaciones de transferencia de masa y calor. Y más importante aún, el catalizador pudo mantenerse estable durante la oxidación catalítica del aire húmedo de fenol sobre carbón activo en un reactor de lecho fijo, a través de la operación de un reactor dinámico mediante la optimización de los parámetros periódicos. / The fast world industrialization and urbanization creates a large number of water pollutants that are toxic and hazardous and in most cases too hard to amend naturally. Phenols are amongst those toxic compounds frequently found in many industrial effluents. A review of the specific literature points out that catalytic wet air oxidation using activated carbon can be a promising solution for the destruction of phenolic pollutants. However, it seems unlikely to achieve stable catalyst in fixed bed reactor under steady state operation due to the slow combustion of activated carbon. Within this context, the present work focus on three main aspects to extend the current state of art of catalytic wet air oxidation: establishing reactor start-up, kinetic measurements and periodic operation of fixed bed reactors. It has been shown that kinetic measurement can be conducted in trickle bed reactor without mass and heat transfer limitations. Most importantly, stable catalyst during catalytic wet air oxidation of phenol over active carbon was achieved in fixed bed reactor through dynamic reactor operation by optimizing periodic parameters.

O processo de adsorção por carvão ativado é uma técnica muito aplicada para tratamento de efluentes. Porém o tratamento que envolve adsorção não é um sistema completo, pois há a necessidade da destruição dos compostos que foram imobilizados na superfície do carvão. Frente a esse problema, métodos alternativos de regeneração de carvão ativado são investigados. Os processos Fenton e foto-Fenton são considerados tecnologias promissoras de tratamento de efluentes, e foram testados para regenerar o carvão ativado. Este trabalho objetiva estudar a adsorção de fenol em carvões ativados (CAs) e a consecutiva regeneração in-situ do carvão pela oxidação de (foto-) Fenton. Duas operações diferentes foram realizadas: 1) sistema de batelada, a fim de investigar a influência das concentrações de Fe2+ e H2O2; 2) adsorção contínua em leito fixo, seguido de circulação em batelada dos reagentes de Fenton pelo leito de CA saturado, para examinar a eficiência do processo real. Foram estudados dois tipos de carvão ativado: CA L27 (meso e microporoso) e CA S23 (somente microporoso). No reator de batelada as melhores condições encontradas para a mineralização do poluente no sistema Fenton homogêneo não são as melhores para a regeneração do CA: foi observada uma redução contínua da capacidade de adsorção do L27 após 3 oxidações, devido à redução tanto da massa do CA quanto da área superficial. Uma maior concentração de Fe2+ e menor concentração de H2O2 (2 vezes a estequiometria) levou a uma recuperação de 50% da capacidade de adsorção inicial em pelo menos 4 ciclos consecutivos para o L27, enquanto que cerca de 20% para o S23. No processo consecutivo de adsorção contínua/oxidação de Fenton em batelada, a eficiência de regeneração atinge de 30% a 40% para o L27 após dois ciclos independente da concentração da alimentação e menos de 10% para o S23. O processo foto-Fenton realizado para o L27 levou à quase completa mineralização e aumentou a recuperação da capacidade de adsorção do CA (56% após dois ciclos). / The adsorption process by active carbon is a technique applied extensively for wastewater treatment. However the tertiary treatment involving adsorption is not a complete system, since there is a need of destruction of the compounds that were immobilized on the carbon surface. In face of this problem, some alternative regeneration methods of active carbon are investigated. Fenton and photo-Fenton processes have been considered promising technologies for wastewater treatment and have been tested to regenerate the AC. The purposes of this study are the adsorption of phenol on activated carbons (ACs) and the consecutive in-situ regeneration of carbon by (photo-) Fenton oxidation. Two different operations have been carried out: 1) batch procedure in order to investigate the influence of Fe2+ and H2O2 concentrations; 2) continuous fixed bed adsorption, followed by a batch circulation of the Fentons reagent through the saturated AC bed, to examine the efficiency of the real process. Two different activated carbons have been also studied: a both micro- and mesoporous AC (L27) and an only microporous one (S23). In the batch reactor the best conditions found for pollutant mineralization in the homogeneous Fenton system are not the best for AC regeneration: a continuous reduction of adsorption capacity of L27 is observed after 3 oxidations, due to the decrease of both AC weight and surface area. Higher concentration of Fe2+ and lower concentration of H2O2 (2 times the stoechiometry) lead to a 50% recovery of the initial adsorption capacity during at least 4 consecutive cycles for L27, while about 20% for S23. In the consecutive continuous adsorption/batch Fenton oxidation process, the regeneration efficiency reaches 30% to 40% for L27 after two cycles whatever the feed concentration and less than 10% for S23. A photo- Fenton test performed on L27 shows almost complete mineralization (contrary to dark Fenton) and further improves recovery of AC adsorption capacity although not complete (56% after two cycles).

Orientadores: Antonio Carlos Luz Lisbôa, Aparecido dos Reis Coutinho / Tese (doutorado) - Universidade Estadual de Campinas, Faculdade de Engenharia Química / Made available in DSpace on 2018-08-25T22:28:23Z (GMT). No. of bitstreams: 1 Mendez_ManoelOrlandoAlvarez_D.pdf: 8886603 bytes, checksum: 23381b4592620a30fa07c0e7366d50c1 (MD5) Previous issue date: 2014 / Resumo: Gás natural (GN) é uma fonte de energia de origem fóssil, encontrado em formações rochosas subterrâneas ou associados em reservatórios de petróleo. O consumo anual de gás natural no Brasil em 2013 foi de 36,8 bilhões de metros cúbicos, equivalente a 1,1% do consumo mundial de 3,35 trilhões de metros cúbicos. Segundo o Ministério de Minas e Energia do Brasil, em 2013 o GN apresentou aproximadamente 12% da oferta interna de energia, com aumento em torno de 16% de 2012 para 2013. Porém o aumento nesta oferta enfrenta problemas devido aos elevados custos de transporte e armazenamento do GN, devido sua baixa densidade energética em condições de temperatura e pressão padrão, quando comparado com combustíveis líquidos derivados do petróleo. Os dois métodos convencionais de armazenamento e transporte de GN é a liquefação (GN Liquefeito ¿ GNL) e compressão (GN Comprimido ¿ GNC). O GN Adsorvido (GNA) é uma alternativa promissora aos métodos convencionais, pois em pressões moderadas, em torno de 4,0 MPa, um tanque com adsorvente possui capacidade de armazenamento superior a de um tanque vazio, devido à adsorção do gás natural nos microporos no adsorvente, que permite utilização de reservatórios mais leves e seguros. No presente trabalho foi realizado a produção de carvões ativados (CA) à partir de resíduos ou subprodutos de baixo valor agregado de setores industriais, com objetivo de avaliar a aplicabilidade destes CA em sistemas GNA, e de avaliar a influência de suas características na transferência de calor do leito adorvente. Coque de petróleo e biomassa foram ativadas física e/ou quimicamente, resultando em materiais adsorvente. Estes materiais foram caracterizados por meio de adsorção de nitrogênio gasoso a 77 K para identificar quais materiais e condições de produção são mais adequadas para o uso em sistemas GNA. Medidas de armazenamento de metano foram realizadas para avaliar a capacidade dos CA em função da pressão e temperatura. Os resultados de armazenamento foram analisados por meio de relações viriais, modelo de adsorção de Toth, potencial de adsorção e modelo de Dubinin-Stoeckli, permitindo obter parâmetros de adsorção, tais como, distribuição de poros e energias de adsorção. Modelo de transferência de calor em leito de armazenamento de gás natural foi desenvolvido considerando simultaneamente a transferência de calor e equilíbrio de adsorção. A resolução deste modelo permitiu avaliar parâmetros relativos aos efeitos da evolução térmica do leito e como esta afeta a operação de armazenamento. Perfis de temperatura no interior do leito de armazenamento em função da posição radial e tempo de armazenamento foram obtidos considerando diferentes cenários de troca térmica pela parede do tanque / Abstract: Natural gas (NG) is a energy source found in underground rock formations or associated with petroleum reservoirs. Brazil's annual natural gas consumption in 2013 was 36.8 billion cubic meters, equivalent to 1.1% of world consumption of 3.35 trillion cubic meters. According to the Ministry of Mines and Energy of Brazil, in 2013 the NG was approximately 12% of the domestic energy supply, an increase of around 16% from 2012 to 2013. However this offer is facing increasing problems due to high cost of transportation and storage, and because of its low energy density in standard conditions of temperature and pressure when compared to petroleum-derived liquid fuels. The two conventional methods of storage and transportation of natural gas is the liquefied natural gas (LNG) and compressed natural gas (CNG). The Adsorbed NG (ANG) is a promising alternative to conventional methods because at moderate pressures around 4.0 MPa, the adsorbent has a higher storage capacity than an empty storage tank, due to the adsorption of natural gas in the micropores of the adsorbent, which allows the use of lighter and safer tanks. In the present work production of activated carbon (AC) was made from waste or by-products of low cost from industries, in order to evaluate the applicability of these AC in ANG systems, and to evaluate the influence of their characteristics on the heat transfer of the asdorbent bed. Petroleum coke and biomass were activated physically and/or chemically. These materials were characterized by nitrogen gas adsorption at 77 K in order to identify wich materials and wich production conditions are better suited for use in ANG systems. Measurements of methane storage were carried out to evaluate the methane adsorption capacity of the AC as a function of pressure and temperature. The methane storage results were analyzed by adsorption virial relations, Toth adsorption model, potential adsorption model and Dubinin-Stoeckli model, allowing to obtain adsorption parameters such as pore distribution and adsorption energies. A heat transfer model in the adsorbent bed was developed considering heat transfer and adsorption equilibrium. The data obtained ny this model allow evaluate parameters related to the termal effects of the adsorbent bed and how this parameters affects the storage operation. Temperature profiles within the bed storage as function of the radial position and time of storage were obtained considering different scenarios by heat exchange through tank wall / Doutorado / Engenharia de Processos / Doutor em Engenharia Química

L’adsorption solide-liquide des PCB et des DDT constitue un moyen efficace pour leur récupération des eaux polluées à condition d’avoir une meilleure connaissance du mécanisme impliqué. Les cinétiques d’adsorption statique ont été principalement réalisées à 25 °C avec le2-PCB, un mélange de tétra-, penta- et hexa-CB et le 4,4’-DDT sur 3 charbons actifs (CA) en poudre différents par le précurseur (houille, bois) et le mode d’activation (H2O, H3PO4) dans l’eau, en présence ou non d’éthanol. Les résultats marquants ont été les suivants : L’adsorption du polluant sur le CA est d’autant plus favorisée que sa solubilité dans la phase liquide est plus faible. Ainsi, l’adsorption du polluant hydrophobe est très augmentée dans l’eau pure. L’adsorption des polluants favorisée par la microporosité développée est essentiellement un phénomène de surface où interviennent les forces de Van der Waals. Une bonne adéquation entre la taille des molécules et la largeur moyenne des pores en forme de fentes montre un confinement maximum des molécules dans la microporosité. L’interaction π−π entre adsorbat et adsorbant, favorisée par le nombre de Cl n’est pas à exclure. Enfin, nous avons montré par la cinétique dans les conditions initiales que l’adsorption y est limitée par le transfert de masse externe. Les modélisations par diffusion superficielle homogène (HSDM), conduisant aux coefficients de diffusion superficielle interne, ont montré que la cinétiqued’adsorption est presque complètement gouvernée par la diffusion intraparticulaire. / The solid-liquid adsorption of PCBs and DDT is an effective process for the recuperation of wastewaters but a better understanding of the involved mechanism is required. In this study, the static adsorption kinetics were mainly carried out at 25 ° C for 2-PCB, a mixture of tetra-, penta-and hexa-CB, and 4,4 '-DDT onto three different powdered activated carbons (AC) of the precursor (coal, wood) and the activation mode (H2O, H3PO4) in water, with or without ethanol. The prominent results were as follows: The adsorption of the pollutant on the AC is favored if its solubility in the liquid phase is lower. As a result, the adsorption of the hydrophobic pollutant is significantly increased in pure water. Moreover, the adsorption of pollutants favored by the developed microporosity is a surface phenomenon which involved the Van der Waals forces. A good fit between the size of molecules and the average width of the slit-shape pores gave a maximum confinement of molecules in the micropores. The π−π interaction between adsorbate and adsorbent, favored by the number of Cl, is not excluded. Finally, by studying the kinetics of the initial conditions, we found that the adsorption is limited by the external mass transfer. The internal surface diffusion coefficients estimated from applying the homogeneous surface diffusion models (HSDM) showed that the adsorption kinetics are almost completely governed by the intra-particle diffusion.