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Control of NOâ†x and SOâ†2 emission by plasma treatmentVasanthakumar, Adaikalamuthu Louis Savio January 1995 (has links)
No description available.
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Avaliação da utilização de diferentes materiais suporte na biofiltração de sulfeto de hidrogênio / Utilization of different packing materials in the hydrogen sulfide biofiltrationPantoja Filho, Jorge Luis Rodrigues 25 April 2008 (has links)
O sulfeto de hidrogênio é um gás que pode causar os mais diversos danos se lançado ao meio ambiente devido, principalmente, à sua elevada toxicidade, corrosividade, odores indesejáveis e alta demanda de oxigênio. Atualmente existem diferentes processos físico-químicos estabelecidos para o tratamento desse composto, entretanto são consideradas técnicas onerosas do ponto de vista econômico e ambiental. Os processos biológicos constituem-se como uma alternativa bastante interessante quando comparados aos processos físico-químicos, sendo que a biofiltração é o processo mais amplamente utilizado. Neste trabalho, foram avaliados três tipos diferentes de materiais suporte, sendo um sintético - espuma de poliuretano - e dois orgânicos - fibra de côco e bagaço de cana -, para a biofiltração de uma mistura gasosa contendo \'H IND.2\'S\'. Como inóculo, optou-se pela utilização de cultura mista originária de duas fontes: a) unidade de biofiltro aerado submerso pertencente ao Serviço Autônomo de Água e Esgoto da Cidade de São Carlos, b) unidade de lodos ativados pertencente a São Carlos S/A - Indústria de Papel e Celulose. A adaptação do inóculo foi realizada em meio nutriente específico. Foi observado um período de partida de somente 2 dias nos três sistemas. Com o intuito de avaliar o impacto do aumento progressivo das taxas de carregamento mássico no desempenho dos três biofiltros, os mesmos foram submetidos a taxas de 19, 32, 54 e 70 g/m³.h (concentrações afluentes médias de 184, 328, 526 e 644 ppm para tempo de retenção do gás de, aproximadamente, 50 segundos). As eficiências remoção média em todos os sistemas mantiveram-se sempre acima dos 99,3%. A capacidade eliminação máxima alcançada pelos biofiltros oscilou entre 74 e 80 g/m³.h. As perdas de carga verificadas no ensaio hidrodinâmico foram baixas, variando entre 0,59.\'10 POT.-2\' a 0,68 \'10 POT.-2\' mca, para a velocidade superficial utilizada durante o estudo. O modelo matemático empregado na previsão do desempenho dos sistemas ajustou-se bem aos dados experimentais. Portanto, pode-se concluir que os materiais suportes testados são adequados para a biofiltração de sulfeto de hidrogênio. / Hydrogen sulfide is a gas which has high restrictions regarding to its disposal in the environment, mainly, because of its high toxicity, malodors, high oxygen demand, etc. Currently, there are many different physical-chemical processes established in order to treat this compound, nevertheless they are considered expensive techniques by the point of economical and environmental views. Biological processes are very interesting alternatives when they are compared to the physical-chemical ones, and biofiltration is the most used process. In this work, three different materials as support media were evaluated, - a synthetic one - represented by the polyurethane foam, - two organic ones - represented by coconut fiber and sugar bagasse -, for a biofiltration of a gaseous mixture containing \'H IND.2\'S\'. Microorganisms were obtained from two sources: a) submerged aerated biofilter unit, b) activated sludge unit. Inoculum\'s adaptation was realized in specific nutrient media. It was observed a 2 days start-up period in the three systems. In order to evaluate some impact caused by the progressive increasing of mass loading rate on the biofilters performance, were applied rates of 19, 32, 54 e 70 g/m³.h (average influent concentrations of 184, 328, 526 e 644 ppm to the empty bed retention time of, approximately, 50 seconds). Average removal efficiencies in the systems were always above 99,3%. Maximum elimination capacities reached by the biofilters were in the range of 74 e 80 g/m³.h. Loss pressure verified by the hands of hydrodynamic essays varied between 0,59.\'10 POT.-2\' a 0,68.\'10 POT.-2\' mca, to a superficial velocity utilized during the work. Mathematical model used to predict the performance of the systems fitted reasonably the experimental data. Then, it can be concluded that the three packing materials are appropriated for the hydrogen sulfide biofiltration.
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Avaliação da utilização de diferentes materiais suporte na biofiltração de sulfeto de hidrogênio / Utilization of different packing materials in the hydrogen sulfide biofiltrationJorge Luis Rodrigues Pantoja Filho 25 April 2008 (has links)
O sulfeto de hidrogênio é um gás que pode causar os mais diversos danos se lançado ao meio ambiente devido, principalmente, à sua elevada toxicidade, corrosividade, odores indesejáveis e alta demanda de oxigênio. Atualmente existem diferentes processos físico-químicos estabelecidos para o tratamento desse composto, entretanto são consideradas técnicas onerosas do ponto de vista econômico e ambiental. Os processos biológicos constituem-se como uma alternativa bastante interessante quando comparados aos processos físico-químicos, sendo que a biofiltração é o processo mais amplamente utilizado. Neste trabalho, foram avaliados três tipos diferentes de materiais suporte, sendo um sintético - espuma de poliuretano - e dois orgânicos - fibra de côco e bagaço de cana -, para a biofiltração de uma mistura gasosa contendo \'H IND.2\'S\'. Como inóculo, optou-se pela utilização de cultura mista originária de duas fontes: a) unidade de biofiltro aerado submerso pertencente ao Serviço Autônomo de Água e Esgoto da Cidade de São Carlos, b) unidade de lodos ativados pertencente a São Carlos S/A - Indústria de Papel e Celulose. A adaptação do inóculo foi realizada em meio nutriente específico. Foi observado um período de partida de somente 2 dias nos três sistemas. Com o intuito de avaliar o impacto do aumento progressivo das taxas de carregamento mássico no desempenho dos três biofiltros, os mesmos foram submetidos a taxas de 19, 32, 54 e 70 g/m³.h (concentrações afluentes médias de 184, 328, 526 e 644 ppm para tempo de retenção do gás de, aproximadamente, 50 segundos). As eficiências remoção média em todos os sistemas mantiveram-se sempre acima dos 99,3%. A capacidade eliminação máxima alcançada pelos biofiltros oscilou entre 74 e 80 g/m³.h. As perdas de carga verificadas no ensaio hidrodinâmico foram baixas, variando entre 0,59.\'10 POT.-2\' a 0,68 \'10 POT.-2\' mca, para a velocidade superficial utilizada durante o estudo. O modelo matemático empregado na previsão do desempenho dos sistemas ajustou-se bem aos dados experimentais. Portanto, pode-se concluir que os materiais suportes testados são adequados para a biofiltração de sulfeto de hidrogênio. / Hydrogen sulfide is a gas which has high restrictions regarding to its disposal in the environment, mainly, because of its high toxicity, malodors, high oxygen demand, etc. Currently, there are many different physical-chemical processes established in order to treat this compound, nevertheless they are considered expensive techniques by the point of economical and environmental views. Biological processes are very interesting alternatives when they are compared to the physical-chemical ones, and biofiltration is the most used process. In this work, three different materials as support media were evaluated, - a synthetic one - represented by the polyurethane foam, - two organic ones - represented by coconut fiber and sugar bagasse -, for a biofiltration of a gaseous mixture containing \'H IND.2\'S\'. Microorganisms were obtained from two sources: a) submerged aerated biofilter unit, b) activated sludge unit. Inoculum\'s adaptation was realized in specific nutrient media. It was observed a 2 days start-up period in the three systems. In order to evaluate some impact caused by the progressive increasing of mass loading rate on the biofilters performance, were applied rates of 19, 32, 54 e 70 g/m³.h (average influent concentrations of 184, 328, 526 e 644 ppm to the empty bed retention time of, approximately, 50 seconds). Average removal efficiencies in the systems were always above 99,3%. Maximum elimination capacities reached by the biofilters were in the range of 74 e 80 g/m³.h. Loss pressure verified by the hands of hydrodynamic essays varied between 0,59.\'10 POT.-2\' a 0,68.\'10 POT.-2\' mca, to a superficial velocity utilized during the work. Mathematical model used to predict the performance of the systems fitted reasonably the experimental data. Then, it can be concluded that the three packing materials are appropriated for the hydrogen sulfide biofiltration.
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Rökgasrening för småskalig avfallsförbränning i länder under utveckling : En kartläggning över föroreningar i rökgaser, deras uppkomst och hur de kan reduceras / Flue Gas Treatment for Small-Scale Waste Incineration in Developing CountriesJohansson, Anton, Jonasson, Axel January 2017 (has links)
Företaget Againity AB har planer på att driftsätta avfallsförbränningsanläggningar i områden av världen där avfallsförbränning inte är särskilt vanlig. Againity står därför inför utmaningen att rena rökgaserna till godkända nivåer. För att göra detta krävs först och främst en kartläggning över förbränningstekniker, föroreningsemissioner och de olika utsläppskrav som finns. Vidare utvärderas vilka rökgasreningstekniker som är bäst lämpade för avfallsförbränningsanläggningar i de områden som Againity vill vara verksamt i. Genom att förbränna avfall i en förbränningsanläggning finns förutsättningar att rent förbränningstekniskt minska utsläppen av föroreningar. I en eldstad där förbränningen sker i kontrollerade former kan en önskad temperatur uppnås med hjälp av optimal lufttillförsel. Med kombinationen av en temperatur kring 800 – 1100 ºC och en uppehållstid på minst 2 sekunder kan fullständig förbränning av bränslet uppnås och utsläppen av miljöbelastande ämnen kan reduceras kraftigt. Föroreningar har undersökts baserat på de lagstiftningar som finns för utsläppsbegränsningar. En av dessa är svaveldioxid, som bidrar till försurning av vatten och mark. En annan är dioxiner, som genom biomagnifikation är skadliga för människor och djur. För att uppnå maximal reduktion av föroreningar används kombinationer av olika rökgasreningstekniker. Stoftbundna partiklar kan avskiljas ur rökgaserna med hjälp av olika slags filter, medan sura gaser måste reagera med ett annat ämne för att kunna fångas upp eller avskiljas på annat sätt. Kväveoxider avskiljs inte på samma sätt som de tidigare nämnda föroreningarna, utan reduceras istället med en reaktant som bildar en harmlös gas. Tack vare att data finns angående avfallsfraktioner, har teoretiska halter av vissa ämnen i rökgaserna beräknats. Företaget Testos mätningar vid avfallsförbränningsanläggningar har använts för andra föroreningar. Efter jämförelse med utsläppskrav för olika regioner har rekommendationer av lämpliga röksgasreningstekniker presenterats. Dessa förslag på rökgasreningsanläggningar har tagits fram ur ett miljö- och ekonomiperspektiv. Vi har kommit fram till att fullständig förbränning är en grundläggande princip som verksamhetsutövare behöver lägga stort fokus på. Gemensamt för alla våra anläggningsförslag har varit det elektrostatiska filtret, som vi tycker bör implementeras vid alla förbränningsanläggningar. Vi rekommenderar också andra reningstekniker som skrubber och SNCR, men dessa metoder bör sättas i relation till den miljömässiga kravbild, de ekonomiska resurser som finns och infrastrukturens funktionalitet. / The company Againity AB has plans to apply waste incineration systems in regions where waste management is a major issue. To manage this Againity must take flue gas treatment in consideration. As flue gas treatment isn’t their area of expertise, a disquisition of combustion techniques, pollution and emission standards will be necessary. Henceforth can an evaluation of which flue gas treatment techniques that would be suitable for waste incineration plants in the regions where the plants are intended to be. By incinerate waste in an incineration plant there is good conditions to obtain a less polluted flue gas just by using good combustion techniques. In a plant where you can control the combustion, a certain desired temperature can be achieved by injecting the right amount of air. The combination of a temperature around 800 – 1100 °C and a residence time of at least two seconds, result in complete combustion of the waste and emissions of environmental pollutants will be reduced. Based on emission standards, certain pollutants have been evaluated. One of those pollutants is sulphur dioxide, which contribute to acidification of earth and water. Another relevant pollutant is dioxins, which is harmful for humans and animals due to its capability of biomagnification. To acquire as clean flue gas as possible several flue gas treatment techniques should be applied in combination. By using filters in general, dust and particles bound in dust can be separated from the flue gas. As for acidic gases, these must react with another substance first to be separated. Nitrogen oxides however cannot be separated from the flue gas as the recently mentioned pollutants can, they can only be reduced by reacting with a reducing agent to form harmless gases. Thanks to available data concerning waste fractions, theoretical values of some pollutants in flue gases has been calculated. Emission measurements at waste incineration plants made by the company Testo, has been used for other pollutants. Calculated and measured values has been compared to the emission standards of Vietnam and the European Union and depending on the outcome of the comparison, suggestions of flue-gas techniques has been presented. Different suggestions of flue-gas systems have been presented depending of economic resources and to what extent the emissions should be reduced. Our conclusion is that complete combustion is a fundamental factor that operators must focus on. Electrostatic precipitator is a flue-gas technique that all our suggestions have in common and is a technique that we strongly recommend. We also recommend other flue-gas techniques such as scrubber and SNCR, but these methods are not always necessary. Planning of advanced flue-gas treatment needs consideration of the environmental requirements, the economic resources available and the functionality of the infrastructure.
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Účinnost separace škodlivých par a plynů na poloprovozní pračce vzduchu / The separation efficiency of air pollutants on pilot air scrubberMagera, Lukáš January 2021 (has links)
This diploma thesis deals with the separation process of air polutant on air scrubber. Absorption of carbon dioxide was carried out into 1 % solution of sodium hydroxide. Theoretical part is aimed at mass transportation, theory of absorption and examples of scrubbers. Experimental part focuses on some operating characteristics of scrubber and on optimisation of two-phase flow. The influence of hydrodynamic conditions on the absorption efficiency was found.
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Particules imprégnées : mise en œuvre et application aux procédés de séparation de mélanges gazeux en lit fixe / Impregnated particles : preparation and use in gas separation process in fixed bedMadariaga Calles, Luis Fernando 06 July 2009 (has links)
Ce travail de thèse repose sur l'étude d’un objet original : des particules solides poreuses imprégnées de liquide non volatil. L'objectif principal de cette thèse est de démontrer le potentiel d’un tel système pour des applications innovantes dans le domaine du traitement de gaz en lit fixe en particulier. Le premier axe de recherche de notre travail concerne l’étude détaillée des processus d’imprégnation de particules de silice par un liquide. Une partie importante du travail est dédiée à la caractérisation des particules imprégnées par une méthode innovante basée sur la rhéologie des poudres très sensible aux changements de surface qui permet de décrire de façon précise l’état d’une particule imprégnée et de comprendre la dynamique du processus d'imprégnation. Une évolution en trois étapes est proposée : adsorption du polymère, infiltration dans les pores et enrobage de la particule. Une seconde partie concerne une étude des propriétés thermodynamiques de plusieurs systèmes liquide – gaz pour identifier le type d’application et le type de composés pour lesquels ce système pourrait s'avérer intéressant. Le système N2-CO2 avec une amine polymère a été choisi pour l’étude expérimentale. Dans la dernière partie, un modèle du procédé est présenté pour simuler les performances de nos particules imprégnées en lit fixe. Ce modèle est validé avec nos résultats expérimentaux. L'objectif de ces simulations est d'identifier les conditions opératoires optimales des différents cycles d'absorption-désorption pour lesquelles les pourcentages de récupération et de concentration du CO2, pour notre application expérimentale, sont maximaux / This work is about an original object: porous particles impregnated with a non volatile liquid. The aim of this work is to show the potential of such a system for applications in the area of gas treatment on fixed beds. The first part of our work is dedicated to the impregnation process and the characterization of such particles by an innovative technique based on powder rheology. This technique is very sensitive to changes on the surface of the particles and helps to understand the impregnation process. Three stages of impregnation are proposed: adsorption of the polymer, filling of the pores and coating of the outer surface. The second part is focused on a thermodynamic study of the properties of some gas-absorbent systems in order to identify the systems for which the retention capacity would be important. The absorbents are compared to activated carbon. A system N2-CO2 with a polymer amine was selected to impregnate the particles and carry out the experimental tests. A model of the process is presented in order to simulate and anticipate the performance of the particles for different operating conditions. The goal of this simulation is to identify the optimal conditions for the absorption-desorption cycles in which the values of recuperation and concentration of CO2 would be maximal
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Desempenho de filtro biológico na depuração e desodorização de emissões de sulfeto de hidrogênio / Biofilter efficiencies in the purification and deodorization of hydrogen sulfide emissionsRocha, Alexandre Prado 17 April 2007 (has links)
Os efluentes gasosos industriais têm sido tradicionalmente tratados por processos físico-químicos, como lavadores, adsorção, condensação e oxidação. Embora essas técnicas tenham altas eficiências, a necessidade de adição de produtos químicos e a substituição do adsorvente resulta em custo de operação relativamente alto quando comparados com técnicas de tratamento biológico. O objetivo deste trabalho foi: aprimorar uma unidade experimental de biofiltração para depuração de uma corrente gasosa contendo \'H IND.2\'S\' utilizando como material suporte a espuma de poliuretano, analisar a fluidodinâmica do leito através de ensaios de perda de carga em função da vazão de ar e da umidade do leito e analisar o desempenho do biofiltro na depuração do \'H IND.2\'S\' com o aumento progressivo da concentração de entrada. O biofiltro foi construído com uma coluna de acrílico, dividida em 3 módulos, 2 com 13 cm de altura e um central com 50 cm, totalizando uma altura do leito de 76 cm e o diâmetro interno era de 5,2 cm. Nas extremidades superiores e inferiores do biofiltro foram acoplados módulos para a distribuição e captação da corrente gasosa e também para a recirculação da fase líquida. O inóculo utilizado foi lodo de uma unidade de lodos ativados, que trabalha como pós-tratamento de um reator UASB tratando esgotos domésticos. A adaptação do inóculo foi realizada por 7 dias com tiossulfato e 7 dias com o \'H IND.2\'S\'. As concentrações médias de sulfeto estudadas foram subdivididas em sete fases com concentrações médias de 141, 271, 514, 532, 581, 878 e 1303 ppm. A vazão utilizada foi de 100 L/h resultando em um tempo de detenção de aproximadamente 58 segundos. As perdas de carga obtidas no sistema foram inferiores a 0,8.\'10 POT.-2\' mca. A espuma de poliuretano se apresentou um bom meio suporte para a fixação dos microrganismos. O lodo ativado se apresentou um bom inóculo para o tratamento de \'H IND.2\'S\' por necessitar de um curto período de tempo para sua adaptação. A eficiência média do biofiltro se manteve acima dos 96%. A umidade do leito se manteve acima de 92%, atingindo uma capacidade de eliminação máxima (ECmáx) de aproximadamente 155 g/\'M POT.3\'.h e uma capacidade de eliminação ótima (ECótimo) de aproximadamente 139 g/\'M POT.3\'.h. O principal produto da degradação do \'H IND.2\'S\' encontrado foi o enxofre elementar. / Traditionally the industrial waste gases have been treated by physical-chemical processes, such as scrubbers, absorption, condensation and oxidation. Although these techniques presented great efficiency, the need to add chemical products and the replacement of adsorbent results in relatively high operational costs compared to biological treatment techniques. The objective of this study is to improve an experimental biofiltration unit to remove air steam containing \'H IND.2\'S\', using polyurethane foam as filter bed, to analyze the bed dynamic flow through pressure drop and the bed moisture, and to analyze the biofilter behavior during the \'H IND.2\'S\' depuration with the progressive increase of input concentration. The bio-filter has an acrylic column, divided into 3 parts, from which two are 13 cm high and the central one is 50 cm high, adding up to a 76 cm high column with an inner diameter of 5.2 cm. Modules were attached on the top and bottom biofilter extremities to distribute and collect the air stream and also to recirculate the liquid phase. The inoculum used was a sludge from a activated sludge unit, which works as post-treatment for domestic sewer treated by a UASB reactor. The inoculum acclimatizing was done for 7 days with thiosulphate and 7 days with \'H IND.2\'S\'. The studied measured hydrogen sulphide concentrations were divided into seven average concentration levels, which are 141, 271, 514, 532, 581, 878 e 1303 ppm. The used ratio was 100 L/h resulting in hydraulic retention time of approximately 58 seconds. The head losses obtained in the system were below 0.8 \'10 POT.-2\' mca. The polyurethane foam presented to be a good support manner to the microorganisms attach. The activated sludge presented to be a good inoculum for the treatment of \'H IND.2\'S\' because it required a short time to adapt. The average efficiency of the biofilter kept above 96% and the bed humidity above 92%, reaching the maximum elimination capacity (ECmáx) of approximately 155 g/\'M POT.3\'.h and a optimum elimination capacity of approximately 139 g/\'M POT.3\'.h. The main \'H IND.2\'S\' degradation product found was the elemental sulfur.
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A LCA Study of Activated Carbon Adsorption and Incineration in Air Pollution ControlSaffarian, Saman January 2010 (has links)
The main purpose of this thesis was to compare GAC adsorption method, VOCs incinerationmethod and Non-treatment alternative by using LCA to find which method or alternative isenvironmentally preferable. The LCA framework proposed by ISO 14040 (1997) has beenconsidered in this research. The comparison was made by considering a flue gas contaminatedby toluene (with three different concentration 100, 1000, 2000 mg/m3). The plant locationwhere the polluted flue gas is emitted has been assumed to be located in Borås, Sweden. Theflow rate of emitted flue gas was 10000m3/hr. The present thesis report contains two mainparts.The results of LCA showed that when the toluene concentration is low (< 100 mg/m3), GACadsorption method, Non-treatment alternative and VOCs incineration method are respectivelypreferable from environmental point of view. On the other side, when the tolueneconcentration of inlet stream is high (>1000 mg/m3), the order of GAC adsorption method,incineration and Non-treatment alternative is more desirable. Furthermore, the resultsillustrated that as toluene plays the role of fuel as a hydrocarbon, VOCs incineration methodis much more suitable when toluene concentration is high due to lower demand on additionalfuel. In the other words, high toluene concentration of influent leads to less environmentalimpact when VOCs incineration method is exploited. Conversely, the environmental impactof GAC adsorption method is increased when the inlet concentration of toluene is escalated.In overall, the weighted result showed that GAC adsorption method is the most preferablemethod while Non-treatment alternative is the worst.
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Desempenho de filtro biológico na depuração e desodorização de emissões de sulfeto de hidrogênio / Biofilter efficiencies in the purification and deodorization of hydrogen sulfide emissionsAlexandre Prado Rocha 17 April 2007 (has links)
Os efluentes gasosos industriais têm sido tradicionalmente tratados por processos físico-químicos, como lavadores, adsorção, condensação e oxidação. Embora essas técnicas tenham altas eficiências, a necessidade de adição de produtos químicos e a substituição do adsorvente resulta em custo de operação relativamente alto quando comparados com técnicas de tratamento biológico. O objetivo deste trabalho foi: aprimorar uma unidade experimental de biofiltração para depuração de uma corrente gasosa contendo \'H IND.2\'S\' utilizando como material suporte a espuma de poliuretano, analisar a fluidodinâmica do leito através de ensaios de perda de carga em função da vazão de ar e da umidade do leito e analisar o desempenho do biofiltro na depuração do \'H IND.2\'S\' com o aumento progressivo da concentração de entrada. O biofiltro foi construído com uma coluna de acrílico, dividida em 3 módulos, 2 com 13 cm de altura e um central com 50 cm, totalizando uma altura do leito de 76 cm e o diâmetro interno era de 5,2 cm. Nas extremidades superiores e inferiores do biofiltro foram acoplados módulos para a distribuição e captação da corrente gasosa e também para a recirculação da fase líquida. O inóculo utilizado foi lodo de uma unidade de lodos ativados, que trabalha como pós-tratamento de um reator UASB tratando esgotos domésticos. A adaptação do inóculo foi realizada por 7 dias com tiossulfato e 7 dias com o \'H IND.2\'S\'. As concentrações médias de sulfeto estudadas foram subdivididas em sete fases com concentrações médias de 141, 271, 514, 532, 581, 878 e 1303 ppm. A vazão utilizada foi de 100 L/h resultando em um tempo de detenção de aproximadamente 58 segundos. As perdas de carga obtidas no sistema foram inferiores a 0,8.\'10 POT.-2\' mca. A espuma de poliuretano se apresentou um bom meio suporte para a fixação dos microrganismos. O lodo ativado se apresentou um bom inóculo para o tratamento de \'H IND.2\'S\' por necessitar de um curto período de tempo para sua adaptação. A eficiência média do biofiltro se manteve acima dos 96%. A umidade do leito se manteve acima de 92%, atingindo uma capacidade de eliminação máxima (ECmáx) de aproximadamente 155 g/\'M POT.3\'.h e uma capacidade de eliminação ótima (ECótimo) de aproximadamente 139 g/\'M POT.3\'.h. O principal produto da degradação do \'H IND.2\'S\' encontrado foi o enxofre elementar. / Traditionally the industrial waste gases have been treated by physical-chemical processes, such as scrubbers, absorption, condensation and oxidation. Although these techniques presented great efficiency, the need to add chemical products and the replacement of adsorbent results in relatively high operational costs compared to biological treatment techniques. The objective of this study is to improve an experimental biofiltration unit to remove air steam containing \'H IND.2\'S\', using polyurethane foam as filter bed, to analyze the bed dynamic flow through pressure drop and the bed moisture, and to analyze the biofilter behavior during the \'H IND.2\'S\' depuration with the progressive increase of input concentration. The bio-filter has an acrylic column, divided into 3 parts, from which two are 13 cm high and the central one is 50 cm high, adding up to a 76 cm high column with an inner diameter of 5.2 cm. Modules were attached on the top and bottom biofilter extremities to distribute and collect the air stream and also to recirculate the liquid phase. The inoculum used was a sludge from a activated sludge unit, which works as post-treatment for domestic sewer treated by a UASB reactor. The inoculum acclimatizing was done for 7 days with thiosulphate and 7 days with \'H IND.2\'S\'. The studied measured hydrogen sulphide concentrations were divided into seven average concentration levels, which are 141, 271, 514, 532, 581, 878 e 1303 ppm. The used ratio was 100 L/h resulting in hydraulic retention time of approximately 58 seconds. The head losses obtained in the system were below 0.8 \'10 POT.-2\' mca. The polyurethane foam presented to be a good support manner to the microorganisms attach. The activated sludge presented to be a good inoculum for the treatment of \'H IND.2\'S\' because it required a short time to adapt. The average efficiency of the biofilter kept above 96% and the bed humidity above 92%, reaching the maximum elimination capacity (ECmáx) of approximately 155 g/\'M POT.3\'.h and a optimum elimination capacity of approximately 139 g/\'M POT.3\'.h. The main \'H IND.2\'S\' degradation product found was the elemental sulfur.
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Valorisation des résidus carbonatés industriels pour le traitement de sulfure d'hydrogène dans les effluents gazeux / Valorization of calcium carbonate-based solid wastes for the removal of hydrogen sulfide from gasGalera Martinez, Marta 04 November 2015 (has links)
Cette thèse explore la possibilité d'utiliser des déchets solides carbonatés issus du procédé Solvay de fabrication de carbonate de sodium (Na2CO3) comme réactifs pour le traitement de l'H2S à des concentrations trouvées typiquement dans des stations d'épuration des eaux usées. Dans un premier temps, la réactivité de deux résidus issus du procédé Solvay ont été évalués en termes d'efficacité d'abattement d'H2S dans un réacteur gaz-liquide-solide à l'échelle laboratoire (250 ml). Ce réacteur fonctionne en mode semi-continu (passage continu du gaz à travers un volume fixe de suspension). L'influence des paramètres opératoires comme la teneur en solide de la suspension, la concentration en H2S, la vitesse d'agitation et le volume de suspension a été examinée. Les processus cinétiques et physico-chimiques mis en jeu ont été identifiés et expliqués malgré le milieu réactionnel complexe. Dans un deuxième temps, l'étude du traitement d'H2S a été réalisée à l'échelle pilote sur un site industriel de Solvay en utilisant une colonne à bulles avec passettes (170 L) qui fonctionne également en mode semi-continu. Les résultats de l'étude paramétrique à l'échelle laboratoire ont été confirmés à l'échelle pilote. Finalement, la colonne a été évaluée avec un effluent gazeux réel issu d'une station d'épuration d'eaux usées à Graulhet (81) qui contient jusqu'à 200 ppmv d'H2S. En présence d'autres gaz comme le méthane (0,4 % vol.), le dioxyde de carbone (2,5 % vol.), le système s'est révélé efficace pour l'abattement sélectif d'H2S. Un abattement quasi-total (100 %) a pu être maintenu pendant au moins deux semaines avec un batch de la suspension à base de résidu. Cette étude démontre la compétitivité du procédé en termes d'efficacité et de coût pour le traitement d'H2S dans des conditions ambiantes. Les résultats obtenus démontrent également la possibilité de transposition du procédé à l'échelle industrielle. / The purpose of this study to valorize solid wastes from the Solvay process for the production of sodium carbonate as reagents for the treatment of H2S in air at concentrations typically found in wastewater treatment plants (tens to hundreds of ppmv of H2S). Firstly, the reactivity of two residues was evaluated in a gas-liquid-solid reactor at laboratory scale (250 ml). This reactor operates semi-continuously (continuous passage of gas through a fixed volume of slurry). The influence of operating parameters including the solid content of the suspension, the concentration of H2S, the stirring speed and the volume of suspension was discussed. The kinetics, physicochemical processes as well as mechanism involved have been identified despite the complex reaction medium. Secondly, the H2S treatment was investigated at pilot scale using a bubble column with trays (170 L) which also operates in semi-continuous mode. The results of the parametric study obtained at laboratory scale were checked at pilot scale. Finally, the column was evaluated with a real gaseous effluent from a wastewater plant in Graulhet (Tarn, France) which contains up to 200 ppmv of H2S. In the presence of other gases as methane (0.4% vol.) and carbon dioxide (2.5% vol.), the system has proven to be effective for the selective elimination of H2S. A near total abatement (100%) was maintained for at least two weeks with only one batch of suspension. Stable and non-volatile sulfur compounds (sulfates, sulfites, thiosulfates) were formed as products of the process. This study demonstrates the competitiveness of the process in terms of cost-effectiveness for the treatment of H2S in ambient conditions. The results obtained also demonstrate the possibility of scaling-up the method to an industrial scale.
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