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Cobertura para oxidação biológica do metano em aterros de resíduos sólidos urbanos. / Biocover for methane oxidation in solid waste landfills.Maldaner, Lia de Sousa 25 August 2011 (has links)
A decomposição de resíduos sólidos urbanos em aterros sanitários é uma fonte importante de metano para a atmosfera. Este gás tem uma contribuição significativamente maior que o dióxido de carbono na retenção do calor na atmosfera e no consequente aquecimento global (efeito estufa). A oxidação biológica do metano nos sistemas de cobertura de aterros é uma alternativa para a diminuição das emissões fugitivas deste gás. Esse processo ocorre pela atividade microbiana em ambientes nos quais estão disponíveis metano, oxigênio e bactérias metanotróficas. O potencial de oxidação de metano nas camadas de cobertura de aterros de resíduos sólidos urbanos (RSU) pode ser favorecido pela criação de condições ambientais propícias. Este trabalho propõe uma metodologia para monitoramento e quantificação da oxidação do metano, a fim de avaliar o desempenho de diferentes materiais para coberturas oxidativas, levando-se em conta os aspectos climáticos. Foram avaliados dois sistemas de coberturas por meio de biofiltros. Estes biofiltros foram instalados no aterro DELTA A da cidade de Campinas, utilizando como fonte de metano um poço de captação de biogás do aterro. Foram utilizados dois tipos de materiais, um com resíduo de construção e demolição (RCD) e outro com areia natural, os dois misturados a composto orgânico maduro. Foram monitorados ao longo de 20 meses os perfis de concentração dos gases (metano, dióxido de carbono e oxigênio) e os fatores meteorológicos (pressão atmosférica, temperatura e precipitação). O estudo demonstrou que as duas misturas utilizadas podem oxidar o metano e que o fluxo de metano é controlado pela permeabilidade ao gás e este fluxo condiciona o percentual de oxidação. O valor máximo de oxidação obtido foi de cerca de 10 kg de CH4/m²dia. O estudo propõe, ainda, uma metodologia para quantificação da oxidação do metano que toma como base as medições de concentração ao longo do perfil da camada e a vazão oxidada. / The decomposition of solid waste in landfills is a major source of methane to the atmosphere. This gas contributes more than carbon dioxide to heat trapping in the atmosphere and to the consequent global warming (greenhouse effect). The biological oxidation of methane in landfill cover systems is an alternative to reduce fugitive gas emissions. This process occurs by microbial activity in environments where methane, oxygen and methanotrophic bacteria are available. The methane oxidation in urban landfill cover systems can be improved by the creation of favorable environment conditions. A methodology for monitoring and quantification of methane oxidation is proposed, to evaluate the performance of different materials for oxidative cover, taking into account the climatic aspects. We evaluated two biofilter cover systems installed at Delta A landfill located in the city of Campinas (SP). The gas collection system well was used as methane source. Two different materials were tested: (1) construction and demolition waste and (2) natural quartz sand, both mixed with organic mature compost. The methane, carbon dioxide and oxygen concentration profiles and meteorological factors (atmospheric pressure, temperature and precipitation) were monitored over 20 months. The two materials were capable of oxidizing methane. Methane oxidation was affected by flow rate through the cover system, and therefore by the material gas permeability. The maximum methane oxidation rate was approximately 10 kg CH4/m².day. A methodology is proposed for quantifying methane oxidation based on measurements of methane concentration and flow rate in the upper part of the biofilter.
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Biochemical characterisation of landfill leachate toxicity in fishLinderoth, Maria January 2006 (has links)
<p>Deposition remains the most common form of waste disposal in many parts of the world. As a terminus of the products consumed in our society a landfill may contain virtually all sorts of man-made chemicals. Despite this, the harmfulness of landfill leachate has not been extensively evaluated in feral organisms in the environment. In a leachate-contaminated lake, Molnbyggen, in Sweden, our studies reported a low percent of sexually mature (SM) female perch (<i>Perca fluviatilis</i>) that had decreased plasma androgen levels, decreased brain aromatase activity, distinctive sores and fin erosion. The impairments were attributed to unidentified compound(s) present in the leachate. In one out of four other investigated leachate-contaminated lakes, the low percent of SM female perch had reduced plasma sex steroid levels and similar sores as perch in Molnbyggen. The biochemical mechanism causing the disorders was investigated in order to establish a connection between the impairments and possible causative compound(s). Plasma levels of progesterone and 17α-hydroxyprogesterone were unaffected. Ovarian 17,20-lyase activity was decreased while levels of biliary steroid conjugates and hepatic testosterone UDP-glucuronosyltransferase activity did not differ between exposed and reference SM fish. Furthermore, the decreased brain aromatase activity seems to be a secondary effect; possibly a result of low substrate availability. Altogether, this suggests a possible disruption in the synthesis of androgens, knowledge that could be used as a tool in biomarker-directed fractionation studies to pinpoint compound(s). Molnbyggen sediment extracts decreased the testosterone and estradiol concentrations in whole-body homogenates of zebrafish (<i>Danio rerio</i>) after a three week exposure period. This suggests that compound(s) with the potency to alter endocrine function are present in the sediment. Although the first steps have been taken towards identifying compound(s) responsible for this kind of reproductive impairments, they still remain unidentified. Measures have to be taken to identify harmful chemicals in our society, to reduce their number, and to minimise their uncontrolled dispersal.</p>
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Identifiering av deponerat material i en deponi samt metodikförslag för upprättande av vattenbalans.vienola, sari January 2008 (has links)
<p>Högbytorp is Ragn-Sells’ largest waste facility and it is located north of Stockholm. There is an old landfill still in use, but at the end of this year it will be closed. The waste deposited on the landfill can, through decomposition, give rise to a large amount of methane gas, which is an energy rich gas that can be used for heat and electricity production. To receive a relatively large amount of gas, the decomposition requires a high moisture content in the waste. Therefore the landfill is dependent on precipitation input, although when the landfill is covered, rainfall can no longer infiltrate the landfill and hence irrigation might be necessary to sustain gas production. To know where to irrigate, knowledge about the material content in the landfill is necessary. Thus the purpose of this report is to identify and describe what kind and amount of waste that has been deposited on the landfill and also where the waste has been placed. The purpose is also to investigate the availability of methods and that are used in Sweden for establishing a water balance for a landfill. The identification work showed that the landfill consists mainly of household-, construction- and industrial waste, retted sludge from sewage treatment plants and soil, which all can produce large quantities of methane gas. The investigation about the different methods for conducting a water balance resulted in the presentation of two methods. One of the methods is called Hydrologic Evaluation of Landfill Performance (HELP) and is a computer simulation. The other method is an equation established by the Swedish Environmental Protection Agency (Naturvårdsverket). Both of the methods works well for obtaining a water balance, however modification is needed for each of them in order to be well suited for the studied landfill, so that realistic and site specific results can be obtained.</p>
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Waste Management with Focus on Waste incineration with energyrecovery in Chisinau Municipality, MoldovaGunnarsson, Martin, Johannesson, Rickard January 2010 (has links)
<p>The amount of waste in the world increases every year due to an improved living standard andgrowing population. The problem is especially large in poor countries where the ability tohandle the waste is limited due to financial and management problems. If instead wastematerial is seen as a resource it can help reduce the amount of waste on landfill. Byincinerating waste and recover the energy it would also help reducing greenhouse gasemissions from landfill and give electric and thermal energy.Chisinau Municipality in the Republic of Moldova today lacks several important parts fora satisfying waste management. Today most of the waste generated in Chisinau municipalityends up at the municipality landfill. The current contract to use the landfill expires on the 31December 2010, if the municipality won’t be able to renew the contract they have to look forother ways to deal with the waste problem. As the dominating source for energy in Chisinau isimported natural gas, an effective way to reduce the use of gas for electricity and thermalenergy production would be to use waste material for incineration with energy recovery.Therefore, the goal with this thesis is to evaluate the possibility to extract energy from coincinerationof sewage sludge and waste material generated in Chisinau. To reach this goal thesituation in Chisinau where studied on site for two months, quantities and composition of thewaste material was investigated. Based on the data gathered on the waste, a suitabletechnology for the waste-to-energy (WTE) plant is proposed. The proposal is made based onthe assumption that a WTE plant would not be established until 2025.The result shows that the waste material in Chisinau can be used for co-incineration ofwaste and sludge. The calorific value of the waste material was determined to 7.87 MJ per kg.The suggested WTE plant has the total power of 138 MW, the result based on that all wastematerial available 2025 are incinerated. Annually this makes it possible to recover 1152 TJ(320 GWh) electric power and 2650 TJ (736 GWh) heat, based on 8000 operating hoursannually.Even if a WTE plant sounds like a good investment it is a long time before a plant couldoperational. Much is to be made in the waste management to have well-functioninginfrastructure that will work together with an incineration plant. Furthermore, the data used inthis study regarding the quantities is very uncertain and further studies in affected areas arenecessary before a WTE plant can be established.</p> / <p>Den totala mängden avfall i världen ökar varje år som följd av ökad folkmängd ochlevnadsstandard. Problemet är extra påtagligt i fattiga länder med begränsade ekonomiskaresurser för att ta hantera avfallet. Om avfallet istället skulle ses som en resurs skulle detkunna reducera andelen avfall som läggs på deponi. Genom att förbränna avfallet medenergiåtervinning skulle också växthusgaserna från deponering minska och samtidigt geelektrisk och termisk energi.Chisinau kommun i Republiken Moldavien saknar idag flera vitala delar iavfallshanteringen. Idag slutar den största delen av avfallet som produceras i Chisinaukommun på den kommunala deponin. Kontraktet för att använda deponin löper ut den sistadecember 2010, om Chisinau kommun inte tillåts förnya kontraktet är det nödvändigt att sesig om efter nya lösningar för avfallshanteringen. Eftersom den dominerande källan för energii Chisinau är importerad gas, skulle ett effektivt sätt att reducera gasanvändningen vid el ochtermisk energiproduktion att förbränna avfall med energiåtervinning.Av den orsaken är målet med studien att utvärdera möjligheterna att utnyttjasamförbränning med energiåtervinning av avfall och avloppsslam från Chisinau kommun. Föratt nå detta mål har den nuvarande situationen i Chisinau kommun studerats på plats under tvåmånaders tid, detta för att undersöka vilka mängder avfall som årligen produceras och huravfallets fraktionsfördelning ser ut. Baserat på de data som samlats in föreslogs en lämpligavfallsförbränningsanläggning. Förslaget är baserat på antagandet att enavfallsförbränningsanläggning inte är etablerad förrän tidigast 2025.Resultatet visar att det är möjligt att samförbränna avloppsslam och avfall i Chisinau. Detkalorimetriska värmevärdet för avfallet och slammet har bestämts till 7.87 MJ per kg. Det irapporten presenterade förslag på kraftvärmeverk för avfallsförbränning kommer att ha entotal effekt av 138 MW, resultatet är baserat på att allt tillgängligt kommunalt avfall 2025förbränns. Kraftvärmeverket beräknas årligen utvinna TJ (320 GWh) elektrisk energi och2650 TJ (736 GWh) termisk energi, beräknad på 8000 drifttimmar årligen.Även om en avfallsförbränningsanläggning låter som en god investering så ligger detlångt fram i tiden innan en sådan anläggning är möjlig att etablera. Först måste en brafungerande infrastruktur som fungerar tillsammans med avfallsförbränningsanläggningenupprättas. Vidare bör poängteras att de data som använts i denna studie gällandeavfallsmängder är ytterst osäkra och ytterligare studier inom området krävs innan enavfallsförbränningsanläggning kan etableras.</p>
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Biochemical characterisation of landfill leachate toxicity in fishLinderoth, Maria January 2006 (has links)
Deposition remains the most common form of waste disposal in many parts of the world. As a terminus of the products consumed in our society a landfill may contain virtually all sorts of man-made chemicals. Despite this, the harmfulness of landfill leachate has not been extensively evaluated in feral organisms in the environment. In a leachate-contaminated lake, Molnbyggen, in Sweden, our studies reported a low percent of sexually mature (SM) female perch (Perca fluviatilis) that had decreased plasma androgen levels, decreased brain aromatase activity, distinctive sores and fin erosion. The impairments were attributed to unidentified compound(s) present in the leachate. In one out of four other investigated leachate-contaminated lakes, the low percent of SM female perch had reduced plasma sex steroid levels and similar sores as perch in Molnbyggen. The biochemical mechanism causing the disorders was investigated in order to establish a connection between the impairments and possible causative compound(s). Plasma levels of progesterone and 17α-hydroxyprogesterone were unaffected. Ovarian 17,20-lyase activity was decreased while levels of biliary steroid conjugates and hepatic testosterone UDP-glucuronosyltransferase activity did not differ between exposed and reference SM fish. Furthermore, the decreased brain aromatase activity seems to be a secondary effect; possibly a result of low substrate availability. Altogether, this suggests a possible disruption in the synthesis of androgens, knowledge that could be used as a tool in biomarker-directed fractionation studies to pinpoint compound(s). Molnbyggen sediment extracts decreased the testosterone and estradiol concentrations in whole-body homogenates of zebrafish (Danio rerio) after a three week exposure period. This suggests that compound(s) with the potency to alter endocrine function are present in the sediment. Although the first steps have been taken towards identifying compound(s) responsible for this kind of reproductive impairments, they still remain unidentified. Measures have to be taken to identify harmful chemicals in our society, to reduce their number, and to minimise their uncontrolled dispersal.
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The toxicity of Harmony Landfill Leachate to Green Hydra (Hydra viridiisma)Ginou, Carrie 01 August 2010 (has links)
Harmony Landfill is a former industrial waste disposal site located adjacent to Harmony Creek in Oshawa, Ontario, Canada. During active disposal, from 1957 until 1980, approximately 1 million tonnes of waste were land-filled at the site. Although past environmental monitoring had indicated localized contamination of ground and surface waters, the current level of impact remained unclear. In order to determine the potential of Harmony Landfill leachate to affect aquatic organisms in Harmony Creek, chemical analysis of field samples and laboratory toxicity testing were performed. Chemical analysis was completed on water samples from Harmony Creek and surface leachate samples collected seasonally at Harmony Landfill. Toxicity tests were conducted using the model freshwater invertebrate Green Hydra (Hydra viridissima). Hydra were pulse-exposed for 24 hours to varying concentrations (0%, 3.2%, 10%, 32%, 100%) of monthly field-collected leachate samples diluted with laboratory water. Population growth, Hydra morphology and survival were recorded daily for 7 days. Results showed that creek waters generally had comparable analyte levels upstream and downstream of Harmony Landfill. Leachate samples contained iron, manganese and zinc at levels which may be toxic to aquatic invertebrates. Population growth was significantly inhibited compared to lab water (0%) controls at the 100% leachate concentration in December 2008 and July 2009. Hydra morphology (32% and 100%) and survival (100%) were also affected by the December 2008 leachate. Findings indicate that leaching is occurring at Harmony Landfill and that the leachate sampled and tested during this research program had the potential to negatively affect Green Hydra (Hydra viridissima). / UOIT
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Characterization of stress-deformation behaviour of municipal solid wasteSingh, Manoj Kumar 05 September 2008
Several catastrophic failures have occurred during the past two decades, both in engineered as well as non-engineered landfills. In addition, there are numerous instances of significant deformations, although not failure in the sense of significant and rapid downslope mass movement, which may cause sufficient damage to buried gas and leachate collection infrastructure. One such instance was observed in 1999 near the toe of a 75 m high 4H:1V slope at the Brock West Landfill in Ontario, Canada. Significant distortion of gas collection laterals was observed at this site. The present research is an in-depth study intended to examine deformation in landfills based on a detailed study of the mechanical properties of municipal solid waste. Four research objectives were defined based on identified shortcomings and knowledge gaps in the existing literature pertaining to mechanical properties of MSW viz; (a) to develop a method for obtaining intact samples of MSW and to examine the significance of using intact and recompacted samples in characterizing the stress-deformation behaviour of MSW; (b) to characterize MSW shear strength and Youngs modulus of elasticity from interpretation of triaxial test results and to determine the parameters of a non-linear elastic constitutive model as applied to MSW; (c) to measure the evolution of compressibility behaviour of MSW with degradation and verify the mechanism of secondary compression in waste; (d) to develop a simple design chart for predicting lateral deformations in landfills. A comprehensive research program was carried out to address various research objectives - field monitoring of deformations at the Brock West site; triaxial compression tests on large intact and recompacted samples of waste; simulating waste degradation in a large laboratory compression cell; analyzing stress-strain data from various published studies and a numerical modelling study. Interpretation of the effective stress paths followed during shearing in triaxial compression tests suggested that while recompacted samples may be sufficient to characterize shear strength parameters for use in stability analysis of landfill slopes, there might be a benefit in obtaining intact samples to evaluate the deformation characteristics of MSW. A hyperbolic model is proposed to describe the stress-deformation response of waste. The required parameters for this model were determined from evaluation of the results of numerous triaxial tests, both from this study and from the published literature. Observations from the long-term degradation test suggested that degradation has a significant effect on the compressibility of waste and further verifies the mechanism of secondary compression in waste. The coefficient of at-rest lateral pressure was observed to maintain an essentially constant value during combined compression and degradation.<p>The results obtained from the experimental work were combined with the findings of a stochastic numerical modelling study and a statistical evaluation of published data and used to propose a simple design chart for estimating the maximum lateral displacement in a landfill slope. The design chart was developed using results of a finite element parametric study in which the behaviour of the municipal solid waste was modeled using a non-linear elastic hyperbolic model. The design chart incorporates nonlinear variation in unit weight as well as Youngs modulus with depth. The predictions from the design chart were compared with the results of field monitoring of lateral displacement in the instrumented slope at the Brock West landfill and were found to be in good agreement.
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Identifiering av deponerat material i en deponi samt metodikförslag för upprättande av vattenbalans.vienola, sari January 2008 (has links)
Högbytorp is Ragn-Sells’ largest waste facility and it is located north of Stockholm. There is an old landfill still in use, but at the end of this year it will be closed. The waste deposited on the landfill can, through decomposition, give rise to a large amount of methane gas, which is an energy rich gas that can be used for heat and electricity production. To receive a relatively large amount of gas, the decomposition requires a high moisture content in the waste. Therefore the landfill is dependent on precipitation input, although when the landfill is covered, rainfall can no longer infiltrate the landfill and hence irrigation might be necessary to sustain gas production. To know where to irrigate, knowledge about the material content in the landfill is necessary. Thus the purpose of this report is to identify and describe what kind and amount of waste that has been deposited on the landfill and also where the waste has been placed. The purpose is also to investigate the availability of methods and that are used in Sweden for establishing a water balance for a landfill. The identification work showed that the landfill consists mainly of household-, construction- and industrial waste, retted sludge from sewage treatment plants and soil, which all can produce large quantities of methane gas. The investigation about the different methods for conducting a water balance resulted in the presentation of two methods. One of the methods is called Hydrologic Evaluation of Landfill Performance (HELP) and is a computer simulation. The other method is an equation established by the Swedish Environmental Protection Agency (Naturvårdsverket). Both of the methods works well for obtaining a water balance, however modification is needed for each of them in order to be well suited for the studied landfill, so that realistic and site specific results can be obtained.
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Waste Management with Focus on Waste incineration with energyrecovery in Chisinau Municipality, MoldovaGunnarsson, Martin, Johannesson, Rickard January 2010 (has links)
The amount of waste in the world increases every year due to an improved living standard andgrowing population. The problem is especially large in poor countries where the ability tohandle the waste is limited due to financial and management problems. If instead wastematerial is seen as a resource it can help reduce the amount of waste on landfill. Byincinerating waste and recover the energy it would also help reducing greenhouse gasemissions from landfill and give electric and thermal energy.Chisinau Municipality in the Republic of Moldova today lacks several important parts fora satisfying waste management. Today most of the waste generated in Chisinau municipalityends up at the municipality landfill. The current contract to use the landfill expires on the 31December 2010, if the municipality won’t be able to renew the contract they have to look forother ways to deal with the waste problem. As the dominating source for energy in Chisinau isimported natural gas, an effective way to reduce the use of gas for electricity and thermalenergy production would be to use waste material for incineration with energy recovery.Therefore, the goal with this thesis is to evaluate the possibility to extract energy from coincinerationof sewage sludge and waste material generated in Chisinau. To reach this goal thesituation in Chisinau where studied on site for two months, quantities and composition of thewaste material was investigated. Based on the data gathered on the waste, a suitabletechnology for the waste-to-energy (WTE) plant is proposed. The proposal is made based onthe assumption that a WTE plant would not be established until 2025.The result shows that the waste material in Chisinau can be used for co-incineration ofwaste and sludge. The calorific value of the waste material was determined to 7.87 MJ per kg.The suggested WTE plant has the total power of 138 MW, the result based on that all wastematerial available 2025 are incinerated. Annually this makes it possible to recover 1152 TJ(320 GWh) electric power and 2650 TJ (736 GWh) heat, based on 8000 operating hoursannually.Even if a WTE plant sounds like a good investment it is a long time before a plant couldoperational. Much is to be made in the waste management to have well-functioninginfrastructure that will work together with an incineration plant. Furthermore, the data used inthis study regarding the quantities is very uncertain and further studies in affected areas arenecessary before a WTE plant can be established. / Den totala mängden avfall i världen ökar varje år som följd av ökad folkmängd ochlevnadsstandard. Problemet är extra påtagligt i fattiga länder med begränsade ekonomiskaresurser för att ta hantera avfallet. Om avfallet istället skulle ses som en resurs skulle detkunna reducera andelen avfall som läggs på deponi. Genom att förbränna avfallet medenergiåtervinning skulle också växthusgaserna från deponering minska och samtidigt geelektrisk och termisk energi.Chisinau kommun i Republiken Moldavien saknar idag flera vitala delar iavfallshanteringen. Idag slutar den största delen av avfallet som produceras i Chisinaukommun på den kommunala deponin. Kontraktet för att använda deponin löper ut den sistadecember 2010, om Chisinau kommun inte tillåts förnya kontraktet är det nödvändigt att sesig om efter nya lösningar för avfallshanteringen. Eftersom den dominerande källan för energii Chisinau är importerad gas, skulle ett effektivt sätt att reducera gasanvändningen vid el ochtermisk energiproduktion att förbränna avfall med energiåtervinning.Av den orsaken är målet med studien att utvärdera möjligheterna att utnyttjasamförbränning med energiåtervinning av avfall och avloppsslam från Chisinau kommun. Föratt nå detta mål har den nuvarande situationen i Chisinau kommun studerats på plats under tvåmånaders tid, detta för att undersöka vilka mängder avfall som årligen produceras och huravfallets fraktionsfördelning ser ut. Baserat på de data som samlats in föreslogs en lämpligavfallsförbränningsanläggning. Förslaget är baserat på antagandet att enavfallsförbränningsanläggning inte är etablerad förrän tidigast 2025.Resultatet visar att det är möjligt att samförbränna avloppsslam och avfall i Chisinau. Detkalorimetriska värmevärdet för avfallet och slammet har bestämts till 7.87 MJ per kg. Det irapporten presenterade förslag på kraftvärmeverk för avfallsförbränning kommer att ha entotal effekt av 138 MW, resultatet är baserat på att allt tillgängligt kommunalt avfall 2025förbränns. Kraftvärmeverket beräknas årligen utvinna TJ (320 GWh) elektrisk energi och2650 TJ (736 GWh) termisk energi, beräknad på 8000 drifttimmar årligen.Även om en avfallsförbränningsanläggning låter som en god investering så ligger detlångt fram i tiden innan en sådan anläggning är möjlig att etablera. Först måste en brafungerande infrastruktur som fungerar tillsammans med avfallsförbränningsanläggningenupprättas. Vidare bör poängteras att de data som använts i denna studie gällandeavfallsmängder är ytterst osäkra och ytterligare studier inom området krävs innan enavfallsförbränningsanläggning kan etableras.
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Characterization of stress-deformation behaviour of municipal solid wasteSingh, Manoj Kumar 05 September 2008 (has links)
Several catastrophic failures have occurred during the past two decades, both in engineered as well as non-engineered landfills. In addition, there are numerous instances of significant deformations, although not failure in the sense of significant and rapid downslope mass movement, which may cause sufficient damage to buried gas and leachate collection infrastructure. One such instance was observed in 1999 near the toe of a 75 m high 4H:1V slope at the Brock West Landfill in Ontario, Canada. Significant distortion of gas collection laterals was observed at this site. The present research is an in-depth study intended to examine deformation in landfills based on a detailed study of the mechanical properties of municipal solid waste. Four research objectives were defined based on identified shortcomings and knowledge gaps in the existing literature pertaining to mechanical properties of MSW viz; (a) to develop a method for obtaining intact samples of MSW and to examine the significance of using intact and recompacted samples in characterizing the stress-deformation behaviour of MSW; (b) to characterize MSW shear strength and Youngs modulus of elasticity from interpretation of triaxial test results and to determine the parameters of a non-linear elastic constitutive model as applied to MSW; (c) to measure the evolution of compressibility behaviour of MSW with degradation and verify the mechanism of secondary compression in waste; (d) to develop a simple design chart for predicting lateral deformations in landfills. A comprehensive research program was carried out to address various research objectives - field monitoring of deformations at the Brock West site; triaxial compression tests on large intact and recompacted samples of waste; simulating waste degradation in a large laboratory compression cell; analyzing stress-strain data from various published studies and a numerical modelling study. Interpretation of the effective stress paths followed during shearing in triaxial compression tests suggested that while recompacted samples may be sufficient to characterize shear strength parameters for use in stability analysis of landfill slopes, there might be a benefit in obtaining intact samples to evaluate the deformation characteristics of MSW. A hyperbolic model is proposed to describe the stress-deformation response of waste. The required parameters for this model were determined from evaluation of the results of numerous triaxial tests, both from this study and from the published literature. Observations from the long-term degradation test suggested that degradation has a significant effect on the compressibility of waste and further verifies the mechanism of secondary compression in waste. The coefficient of at-rest lateral pressure was observed to maintain an essentially constant value during combined compression and degradation.<p>The results obtained from the experimental work were combined with the findings of a stochastic numerical modelling study and a statistical evaluation of published data and used to propose a simple design chart for estimating the maximum lateral displacement in a landfill slope. The design chart was developed using results of a finite element parametric study in which the behaviour of the municipal solid waste was modeled using a non-linear elastic hyperbolic model. The design chart incorporates nonlinear variation in unit weight as well as Youngs modulus with depth. The predictions from the design chart were compared with the results of field monitoring of lateral displacement in the instrumented slope at the Brock West landfill and were found to be in good agreement.
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