Spelling suggestions: "subject:"incineration""
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A proposed walkway system constructed from selected combustion residuesHillabrand, James L 02 May 2009 (has links)
This thesis studies a new more affordable way to build sidewalks in the U.S. Typical sidewalks are often impractical on many roads because of a steep runoff slope and/or close proximity to the drainage ditch. Also, if future road widening is required, the sidewalk must be removed. This thesis proposes a structure called a Lanwalk which is an elevated sidewalk made of precast units. A Lanwalk could simultaneously serve as a sidewalk and potentially as a guardrail. It can be placed over drainage areas if necessary without obstructing the flow of water. Lanwalks can be easily installed and relocated if necessary. This thesis examines the possibility of using high amounts of waste ash as an admixture during the construction of Lanwalks or sidewalks to lower cost and save landfill space. The two waste products examined are municipal solid waste incinerator bottom ash (IBA) and coal fly ash (CFA).
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SAKO Brno - vyvedení tepelného výkonu do CZT / SAKO Brno - heat output in CHPMazák, Tomáš January 2014 (has links)
The purpose of this thesis is to design a solution thermal power outlet of incinerator in hot water for the supply this town of heat. First and foremost are described problems landfill society and their implications on the environment. Next some alternatives of the waste and the burning in incinerators are described too. The thesis describes the history of the first incineration plant in the Czech Republic and its subsequent upgrading of the economical and environmentally friendly waste recovery and modernization of flue gas cleaning. Contribution of the work is then proposed as amendments to equipment and wiring for use of steam for the conversion heat output into hot water. This is essentially a calculation of steam water heaters at the end of the expansion of the steam and the related adjustments to the turbine blading. At the conclusion outlines the basic economic calculation and comparison of profits and investment associated with this implementation compared to implementation, which is now projected. It is a calculation of investment efficiency and its possible repayment due to higher profits from the sale of energy. This work serves only as a basis work for future technical realization and it outlines the appropriateness of this alteration.
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Melting Treatment of Municipal Incinerator Fly Ashes by an Electric Arc Furnace in a Steel MillChuang, Tsun-Nan 08 July 2003 (has links)
In this work, feasibility of utilizing municipal incinerator fly ash (MIFA) of different sources as a substitute of raw materials for steel-making in a mini-mill was studied. Also studied included the efficacy of this mode of melting treatment and recycling. Under the condition of adding 1 wt% MIFA to scrap iron/scrap steel for partial replacement of lime, the L9 orthogonal arrays of Taguchi methods were utilized to investigate the effects of MIFA melting treatment of different sources by an electric arc furnace (EAF). Four experimental factors (i.e., scrap iron mass, lime mass, coke mass, and MIFA mass) were selected to study their effects on Pb leaching of EAF dust and slag. Test results for MIFA obtained from Plants K1, K2, and K3 show that EAF dust remains hazardous as it is originally a listed waste. On the other hand, slag so generated remains nonhazardous based on the TCLP results.
The experimental results of EAF dust and slag were further subjected to the analysis of variance (ANOVA) and regular analysis. Using this process, the optimal operating conditions with respect to the leached Pb concentration would be as follows: (1) Plant K1(injection mode operation)--87 tons of scrap iron, 1.4 tons of lime, 0.4 ton of coke, and 0.9 ton of MIFA; (2) Plant K2(injection mode operation)--90 tons of scrap iron, 1.4 tons of lime, 0.7 ton of coke, and 1.1 tons of MIFA; (3) Plant K2(one-time-charge mode operation)--90 tons of scrap iron, 1.4 tons of lime, 0.9 ton of coke, and 0.7 ton of MIFA; (4) Plant K3(injection mode operation)--85 tons of scrap iron, 1.4 tons of lime, 0.7 ton of coke, and 0.9 ton of MIFA; and (5) Plant K3(one-time-charge mode operation)--87 tons of scrap iron, 1.5 tons of lime, 0.4 ton of coke, and 0.7 ton of MIFA.
In this study, using MIFA from Plant K2 as an example, it was found that it required 29-35 kg of lime per ton of steel billets produced when MIFA was added. Under a normal operation of EAF steel-making, however, it required 35-45 kg of lime per ton of steel billets produced based on the past experience. In average, when MIFA is added, it needs only 32 kg of lime per ton of steel billets produced as compared to 40 kg of lime for regular steel-making. In other words, it would result in a reduction of 8 kg of lime per ton of steel billets produced by using this novel process. Based on an average monthly production of 20,973 tons of steel billets and a unit cost of 2,200 NT$ per ton of lime, a monthly saving of lime cost would be 369,125 NT$. Namely, about 4.4 million NT$ per year.
In addition, it was also found that using this novel process to melt MIFA would not deteriorate the quality of steel billets and bars produced.
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Captage du dioxyde de carbone en postcombustion : Application à un incinérateur de déchets industriels : Etude expérimentale à l’échelle pilote / Carbon dioxide capture in post-combustion : Application to an industrial waste incinerator : Experimental study on a pilot scaleAouini, Ismaël 02 April 2012 (has links)
Les recherches s’inscrivent dans une prospection qui étudie la viabilité de la valorisation du CO2 d’un incinérateur de déchets industriels. Plusieurs licences commerciales existent pour le captage du CO2 dans des gaz de combustion mais il n’existe pas de référence pour le traitement de fumées d’incinérateur de déchets. Les travaux évaluent, à l’aide d’une installation pilote, la viabilité du captage du CO2 en postcombustion par absorption/désorption avec un solvant à 30 % massique en monoéthanolamine (MEA). Tout d’abord, une synthèse bibliographique identifie les verrous technologiques. Puis, le fonctionnement de l’installation est détaillé. Ensuite, une étude paramétrique a évalué les performances de captage du CO2 et la consommation énergétique du pilote. Enfin, des expériences sur une période de 5 jours ont étudié la résistance chimique du solvant face des gaz de combustion. Les travaux de recherche ont permis une première validation du procédé pour un incinérateur de déchets. / This research is part of a survey designed to establish the viability of the CO2 recovery as a raw material from an industrial waste incinerator.. Several commercial licenses are available to capture CO2 in flue gas, but there are no references for incinerators. This work studies with a pilot the post-combustion CO2 capture from incinerator flue gas using absorption/desorption process with 30 %wt monoethanolamine (MEA). A literature review identifies the technology gaps. Then, the pilot setup was described. A parametric study has evaluated the pilot performance for CO2 capture and energy consumption. Finally, Long runs (5 days) have studied the solvent chemical stability in front of incinerator flue gas. The laboratory experiments show that CO2 capture form incinerator flue gas is possible.
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Horizont odpadu / Waste horizonOchotná, Barbora Unknown Date (has links)
The city is a place of accumulation, production and reproduction of production resources and consumption of goods, but waste typically accumulates outside it. It falls out of our horizon physically and mentally. The waste we produce changes the landscape and transforms the processes on earth without most of us visiting the "places of transformation". The project works with the idea of redirecting the final phase of the production chain back to the place of consumption by producing elements of public space from municipal waste. The presentation of waste leads to an awareness of its amount and degree of consumption. At the same time, waste becomes something much more ambivalent, possibly useful or even beautiful.
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"Impacto ambiental na área do aterro sanitário e incinerador de resíduos sólidos de Ribeirão Preto, SP: avaliação dos níveis de metais pesados" / Environmental impact in the Municipal Landfill Site and Medical Waste Incinerator area in Ribeirao Preto, São Paulo: Evaluation of heavy metals levels.Muñoz, Susana Inés Segura 02 December 2002 (has links)
Os resíduos sólidos podem conter substâncias químicas com características tóxicas, dentre elas os metais pesados presentes em diversos materiais provenientes de indústrias, funilarias, atividades agrícolas, laboratórios, hospitais e residências. A contaminação por metais pesados apresenta um amplo espectro de toxicidade que inclui efeitos neurotóxicos, hepatotóxicos, nefrotóxicos, teratogênicos, carcinogênicos ou mutagênicos. Em Ribeirão Preto SP há em funcionamento desde 1989, um aterro sanitário (AS) para resíduos domiciliares e um incinerador de resíduos de serviços de saúde (IRSS). Este estudo teve como objetivo fazer um diagnóstico dos níveis de metais pesados na área do AS e IRSS de Ribeirão Preto, entre 2000 e 2001. Foram realizadas análises de amostras de solo, água, chorume e vegetais, em pontos previamente demarcados na área, tendo sido avaliada a presença de mercúrio (Hg), cobre (Cu), chumbo (Pb), cádmio (Cd), manganês (Mn), zinco (Zn) e cromo (Cr) por Espectrofotometria de Absorção Atômica. Visando a obtenção de parâmetros locais, foram também analisadas amostras coletadas na Estação Ecológica na mata Santa Teresa, zona de preservação permanente do município, para comparação de valores. Pela análise dos resultados verificou-se, de um modo geral, que os níveis de metais pesados presentes nas amostras de solo e vegetais na área apresentaram concentrações significativamente superiores às detectadas nas amostras coletadas na mata Santa Teresa, evidenciando-se uma tendência de maiores concentrações no sentido Norte, fato que pode estar associado com a declividade geográfica da área, com a direção dos ventos e com a localização do incinerador. Destacam-se neste estudo os níveis de Cd, Mn e Cu presentes em amostras de solo em níveis que superaram os valores máximos estabelecidos para solos de uso agrícola no Estado de São Paulo pela CETESB, órgão estadual ambiental. O chorume também apresentou níveis de Cd, Pb, Mn, Cu em concentrações superiores às normatizadas para efluentes líquidos, segundo o Decreto 8486/76 do estado de São Paulo. A água subterrânea da área estudada não apresentou níveis de metais acima dos valores máximos permitidos, de acordo com a Portaria 1469/2000 do Ministério da Saúde. Considerando a carência de pesquisas dessa natureza no Brasil, este estudo tem gerado informações que podem constituir-se em ferramenta para a tomada de decisões político-administrativas pelas autoridades responsáveis pelo gerenciamento de resíduos sólidos, não apenas do Município de Ribeirão Preto e região, mas, também, podendo servir de parâmetro para realidades similares no país. / Solid waste may content toxic chemical substances such as heavy metals that are present in materials generated by industries, agricultural activities, laboratories, hospitals and houses. The contamination with heavy metals has a wide spectrum of toxicity that includes neurotoxic, hepatotoxic, nephrotoxic, teratogenic, carcinogenic or mutagenic effects. Since 1989, a municipal landfill site (MLS) for urban waste disposal has been in operation in Ribeirao Preto (Sao Paulo, Brazil) integrated with a medical waste incinerator plant (MWIP). This study aimed to do a diagnostic of the heavy metal levels in MLS and MWIP area, in 2000 and 2001. The total cadmiun (Cd), chromium (Cr), lead (Pb), manganese (Mn), zinc (Zn), cooper (Cu) and mercury (Hg) levels were analysed by Atomic Absortion Spectrophotometry in soil, water, percolated liquid and vegetables, in previously delimitated points. Samples from Santa Teresa Forest Ecological Station of Ribeirao Preto were collected as control samples. The results showed that, in general terms, the heavy metals detected in soil and vegetal samples in that area showed significant higher concentrations when compared with Santa Teresa Forest samples. The highest concentrations were detected to the North direction, these results can be associated with the topographic gradient in the area, the prevailing winds and the Incinerator localization. Special atention should be given to Cd, Mn and Cu levels detected in soil samples, that showed higher concentrations that those recomended for agricultural soil in Sao Paulo State by the Environmental Sanitation Company (CETESB). The percolated liquid also showed Cd, Pb, Mn and Cu levels higher than the maximum recomended levels according to the Sao Paulo State Law (Decreto 8486/76). The water samples showed levels according to the Brasilian Health Ministry Law (Portaria 1469/2000). Taking into account that few researches had been developed on this thematic in Brasil, the obtained results constituted an instrument for the decision makers and public managers, not only for Ribeirao Preto and region but for other cities around the country.
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Análise de ecoeficiência de técnicas para tratamento e disposição de resíduos sólidos urbanos / Eco-efficiency analysis of techniques for disposal of urban solid wasteCibele Dmitrijevas 30 April 2010 (has links)
Os resíduos sólidos urbanos são um dos grandes problemas da sociedade atual. Nesse sentido é necessário discutir soluções para o destino dos resíduos gerados diariamente, cada vez mais em maior quantidade, sendo imperativo avançar na busca de alternativas, não só na busca de novas tecnologias e soluções, como também o aprimoramento das metodologias hoje empregadas para resolver este relevante problema, especialmente nos grande centros urbanos. Esta dissertação expõe o resultado de uma avaliação econômico-ambiental comparativa realizada por meio de uma metodologia desenvolvida pela BASF, entre duas potenciais tecnologias: aterro sanitário e a incineração com recuperação de energia. Para viabilizar o trabalho, as informações utilizadas foram tanto de dados reais aterro sanitário e incinerador Essencis Soluções Ambientais S.A., (assumindo algumas premissas) quanto a utilização de dados secundários, utilizando o estudo de Arena et al., 2003. Esta ferramenta de Análise de Ecoeficiência abrange a metodologia de Avaliação do Ciclo de Vida (ACV), que é uma técnica para avaliar as entradas e saídas de matéria e energia e os impactos ambientais potenciais associados a todas as etapas de extração de recursos e suas transformações, além do uso e disposição final do produto. Os dados obtidos na avaliação ambiental são apresentados segundo as categorias principais, usando um método de ponderação desenvolvido pela BASF e compreendem o consumo de recursos naturais, consumo de recursos energéticos, emissões para o ar, água e solo, potencial de toxicidade humana, acidentes do trabalho, doenças ocupacionais e uso da terra. A avaliação econômica, neste trabalho, levou em consideração os custos envolvidos na operação e manutenção das técnicas de disposição ou tratamento dos resíduos sólidos urbanos. O estudo comparativo considerou a disposição ou tratamento de 7.324.109.000 quilogramas de resíduos sólidos urbanos. Como resultado, a matriz de ecoeficiência aponta que o incinerador é a alternativa que mais se destaca, considerando o perfil ambiental e econômico, dentro das premissas adotadas neste estudo e levando-se em consideração que é uma técnica com aproveitamento de energia. / Municipal solid waste is one of the major problems of modern society. In this sense it is necessary to discuss solutions to the fate of waste generated daily, increasingly in larger amounts, being imperative to advance the search for alternatives, not only in search of new technologies and solutions, as well as the improvement of methodologies currently employed to solve this relevant issue, especially in large urban centers. This paper presents the results of a comparative economic-environmental assessment performed by a method developed by BASF, two potential technologies: landfill and incineration with energy recovery. To facilitate the work, the information used were both real data - landfill and incinerator - Essencis Soluções Ambientais S.A., (assuming some assumptions) and the use of secondary data, using the study of Arena et al., 2003. This Ecoefficiency Analysis tool covers the methodology of Life Cycle Assessment (LCA), which is a technique to evaluate the inputs and outputs of matter and energy and the potential environmental impacts associated with all stages of resource extraction and their transformations , and the use and final disposal of the product. The data in the environmental assessment are presented according to major categories, using a weighting method developed by BASF and understand the consumption of natural resources, consumption of energy resources, air emissions, water and soil, potential for human toxicity, accidents work, occupational diseases and land use. Economic evaluation in this work took into account the costs involved in operation and maintenance of disposal techniques or treatment of waste. The comparative study found the treatment or disposal of 7.324109 billion kilograms of waste. As a result, the array of eco-efficiency indicates that the incinerator is the alternative that stands out, considering the environmental and economic profile, within the assumptions made in this study and taking into account which is a technique with energy recovery.
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Análise de ecoeficiência de técnicas para tratamento e disposição de resíduos sólidos urbanos / Eco-efficiency analysis of techniques for disposal of urban solid wasteDmitrijevas, Cibele 30 April 2010 (has links)
Os resíduos sólidos urbanos são um dos grandes problemas da sociedade atual. Nesse sentido é necessário discutir soluções para o destino dos resíduos gerados diariamente, cada vez mais em maior quantidade, sendo imperativo avançar na busca de alternativas, não só na busca de novas tecnologias e soluções, como também o aprimoramento das metodologias hoje empregadas para resolver este relevante problema, especialmente nos grande centros urbanos. Esta dissertação expõe o resultado de uma avaliação econômico-ambiental comparativa realizada por meio de uma metodologia desenvolvida pela BASF, entre duas potenciais tecnologias: aterro sanitário e a incineração com recuperação de energia. Para viabilizar o trabalho, as informações utilizadas foram tanto de dados reais aterro sanitário e incinerador Essencis Soluções Ambientais S.A., (assumindo algumas premissas) quanto a utilização de dados secundários, utilizando o estudo de Arena et al., 2003. Esta ferramenta de Análise de Ecoeficiência abrange a metodologia de Avaliação do Ciclo de Vida (ACV), que é uma técnica para avaliar as entradas e saídas de matéria e energia e os impactos ambientais potenciais associados a todas as etapas de extração de recursos e suas transformações, além do uso e disposição final do produto. Os dados obtidos na avaliação ambiental são apresentados segundo as categorias principais, usando um método de ponderação desenvolvido pela BASF e compreendem o consumo de recursos naturais, consumo de recursos energéticos, emissões para o ar, água e solo, potencial de toxicidade humana, acidentes do trabalho, doenças ocupacionais e uso da terra. A avaliação econômica, neste trabalho, levou em consideração os custos envolvidos na operação e manutenção das técnicas de disposição ou tratamento dos resíduos sólidos urbanos. O estudo comparativo considerou a disposição ou tratamento de 7.324.109.000 quilogramas de resíduos sólidos urbanos. Como resultado, a matriz de ecoeficiência aponta que o incinerador é a alternativa que mais se destaca, considerando o perfil ambiental e econômico, dentro das premissas adotadas neste estudo e levando-se em consideração que é uma técnica com aproveitamento de energia. / Municipal solid waste is one of the major problems of modern society. In this sense it is necessary to discuss solutions to the fate of waste generated daily, increasingly in larger amounts, being imperative to advance the search for alternatives, not only in search of new technologies and solutions, as well as the improvement of methodologies currently employed to solve this relevant issue, especially in large urban centers. This paper presents the results of a comparative economic-environmental assessment performed by a method developed by BASF, two potential technologies: landfill and incineration with energy recovery. To facilitate the work, the information used were both real data - landfill and incinerator - Essencis Soluções Ambientais S.A., (assuming some assumptions) and the use of secondary data, using the study of Arena et al., 2003. This Ecoefficiency Analysis tool covers the methodology of Life Cycle Assessment (LCA), which is a technique to evaluate the inputs and outputs of matter and energy and the potential environmental impacts associated with all stages of resource extraction and their transformations , and the use and final disposal of the product. The data in the environmental assessment are presented according to major categories, using a weighting method developed by BASF and understand the consumption of natural resources, consumption of energy resources, air emissions, water and soil, potential for human toxicity, accidents work, occupational diseases and land use. Economic evaluation in this work took into account the costs involved in operation and maintenance of disposal techniques or treatment of waste. The comparative study found the treatment or disposal of 7.324109 billion kilograms of waste. As a result, the array of eco-efficiency indicates that the incinerator is the alternative that stands out, considering the environmental and economic profile, within the assumptions made in this study and taking into account which is a technique with energy recovery.
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"Impacto ambiental na área do aterro sanitário e incinerador de resíduos sólidos de Ribeirão Preto, SP: avaliação dos níveis de metais pesados" / Environmental impact in the Municipal Landfill Site and Medical Waste Incinerator area in Ribeirao Preto, São Paulo: Evaluation of heavy metals levels.Susana Inés Segura Muñoz 02 December 2002 (has links)
Os resíduos sólidos podem conter substâncias químicas com características tóxicas, dentre elas os metais pesados presentes em diversos materiais provenientes de indústrias, funilarias, atividades agrícolas, laboratórios, hospitais e residências. A contaminação por metais pesados apresenta um amplo espectro de toxicidade que inclui efeitos neurotóxicos, hepatotóxicos, nefrotóxicos, teratogênicos, carcinogênicos ou mutagênicos. Em Ribeirão Preto SP há em funcionamento desde 1989, um aterro sanitário (AS) para resíduos domiciliares e um incinerador de resíduos de serviços de saúde (IRSS). Este estudo teve como objetivo fazer um diagnóstico dos níveis de metais pesados na área do AS e IRSS de Ribeirão Preto, entre 2000 e 2001. Foram realizadas análises de amostras de solo, água, chorume e vegetais, em pontos previamente demarcados na área, tendo sido avaliada a presença de mercúrio (Hg), cobre (Cu), chumbo (Pb), cádmio (Cd), manganês (Mn), zinco (Zn) e cromo (Cr) por Espectrofotometria de Absorção Atômica. Visando a obtenção de parâmetros locais, foram também analisadas amostras coletadas na Estação Ecológica na mata Santa Teresa, zona de preservação permanente do município, para comparação de valores. Pela análise dos resultados verificou-se, de um modo geral, que os níveis de metais pesados presentes nas amostras de solo e vegetais na área apresentaram concentrações significativamente superiores às detectadas nas amostras coletadas na mata Santa Teresa, evidenciando-se uma tendência de maiores concentrações no sentido Norte, fato que pode estar associado com a declividade geográfica da área, com a direção dos ventos e com a localização do incinerador. Destacam-se neste estudo os níveis de Cd, Mn e Cu presentes em amostras de solo em níveis que superaram os valores máximos estabelecidos para solos de uso agrícola no Estado de São Paulo pela CETESB, órgão estadual ambiental. O chorume também apresentou níveis de Cd, Pb, Mn, Cu em concentrações superiores às normatizadas para efluentes líquidos, segundo o Decreto 8486/76 do estado de São Paulo. A água subterrânea da área estudada não apresentou níveis de metais acima dos valores máximos permitidos, de acordo com a Portaria 1469/2000 do Ministério da Saúde. Considerando a carência de pesquisas dessa natureza no Brasil, este estudo tem gerado informações que podem constituir-se em ferramenta para a tomada de decisões político-administrativas pelas autoridades responsáveis pelo gerenciamento de resíduos sólidos, não apenas do Município de Ribeirão Preto e região, mas, também, podendo servir de parâmetro para realidades similares no país. / Solid waste may content toxic chemical substances such as heavy metals that are present in materials generated by industries, agricultural activities, laboratories, hospitals and houses. The contamination with heavy metals has a wide spectrum of toxicity that includes neurotoxic, hepatotoxic, nephrotoxic, teratogenic, carcinogenic or mutagenic effects. Since 1989, a municipal landfill site (MLS) for urban waste disposal has been in operation in Ribeirao Preto (Sao Paulo, Brazil) integrated with a medical waste incinerator plant (MWIP). This study aimed to do a diagnostic of the heavy metal levels in MLS and MWIP area, in 2000 and 2001. The total cadmiun (Cd), chromium (Cr), lead (Pb), manganese (Mn), zinc (Zn), cooper (Cu) and mercury (Hg) levels were analysed by Atomic Absortion Spectrophotometry in soil, water, percolated liquid and vegetables, in previously delimitated points. Samples from Santa Teresa Forest Ecological Station of Ribeirao Preto were collected as control samples. The results showed that, in general terms, the heavy metals detected in soil and vegetal samples in that area showed significant higher concentrations when compared with Santa Teresa Forest samples. The highest concentrations were detected to the North direction, these results can be associated with the topographic gradient in the area, the prevailing winds and the Incinerator localization. Special atention should be given to Cd, Mn and Cu levels detected in soil samples, that showed higher concentrations that those recomended for agricultural soil in Sao Paulo State by the Environmental Sanitation Company (CETESB). The percolated liquid also showed Cd, Pb, Mn and Cu levels higher than the maximum recomended levels according to the Sao Paulo State Law (Decreto 8486/76). The water samples showed levels according to the Brasilian Health Ministry Law (Portaria 1469/2000). Taking into account that few researches had been developed on this thematic in Brasil, the obtained results constituted an instrument for the decision makers and public managers, not only for Ribeirao Preto and region but for other cities around the country.
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Kloridutlakning från flygaska : möjligheten till en lokal hantering / Chloride leaching from fly ash : The possibility of a local managementBröms Axelsson, Emilia January 2014 (has links)
In Sweden, there are limits to how much leachable substances waste must contain in order to be deposited as hazardous waste. Fly ash from waste incineration often end up over the limit, mainly due to the chloride content. Fly ash is therefore often deposited abroad. The purpose of this study was to investigate the possibility to handle fly ash locally. To clarify how the law is applied, environmental reports and permit documents from ten waste sites with permission to deposit fly ash were studied. In addition, a literature study was made to review the state of knowledge regarding the treatments of fly ash. The treatment methods are numerous, but are at different levels of commerciality. Among the treatments available there are both physical, chemical, biological, electrical and thermal variants. Many of the treatments (except for carbonation and microbial bioleaching) results in chloride levels below the limits. Several are however unrealistically expensive or generate wastewater with high levels of chloride that would need further treatment. Three plants out of the ten holding permits to deposit fly ash, have exemptions from the limit for chlorides. It's however difficult to see a common reasoning for allowing exemptions. In several cases there are sensitive receiving waters downstream from the landfill. One reason to be dispensed despite this sensitivity, may be the guidance that EPA issued. It is not formulated any specific concerns relating to chlorides. One handles therefore often high levels of chloride in the leachate as a dilution problem, not a leaching problem. / I Sverige finns det gränsvärden för hur mycket utlakningsbara ämnen avfall får innehålla för att kunna deponeras som farligt avfall. Flygaska från avfallsförbränning hamnar ofta över gränsen för vad som får deponeras, främst p.g.a. kloridinnehållet, och askan deponeras därför bl.a. i Norge och Tyskland. Syftet med denna studie var att utreda möjligheten att hantera flygaska lokalt. För att klargöra hur lagstiftningen tillämpas har miljörapporter och tillståndsbeslut från tio avfallsanläggningar med tillstånd att deponera flygaska studerats. Dessutom har en litteraturstudie gjorts av kunskapsläget när det gäller behandling av flygaska för att motverka lakning av klorider. Behandlingsmetoderna är många, men har kommit olika långt i att anses som kommersiella. Bland behandlingarna finns både fysiska, kemiska, biologiska, elektriska och termiska varianter. Många av behandlingarna (med undantag för karbonatisering och mikrobiell bioutlakning) gör att gränsvärden för utlakning av klorider klaras. Många av behandlingarna är dock orealistiskt dyra eller genererar avloppsvatten med höga kloridhalter. Av de tio anläggningar som innehar tillstånd till att deponera flygaska, så har tre även dispens för gränsvärdet för klorider. Utifrån den information som finns i tillståndsbesluten är det mycket svårt att se ett mönster vad gäller bedömningen av de enskilda fallen. I flera fall finns känsliga recipienter nedströms deponin. En anledning till att dispens ges trots denna känslighet kan vara den vägledning som Naturvårdsverket gett ut. Där formuleras inte någon specifik problematik kring klorider, utan andra ämnen är i fokus. Man behandlar därför ofta höga kloridhalter i lakvatten som ett utspädningsproblem, istället för ett utlakningsproblem.
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