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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
11

Waste Management with Focus on Waste incineration with energyrecovery in Chisinau Municipality, Moldova

Gunnarsson, 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.
12

Evaluation of capacitance moisture sensors for use in municipal solid waste

Schmidt, Patrick 03 March 2010 (has links)
Current municipal solid waste (MSW) practices have encouraged rapid waste degradation (stabilization) as an alternative to past methods of isolating the waste from the surrounding environment. There are challenges to rapid-stabilization technology, in particular, the management of the in-situ MSW moisture content.<p> The primary objective of this study was to evaluate the use of capacitance moisture probes for the purpose of measuring the moisture content within MSW. Capacitance moisture probes have not previously been used in MSW, however their use in agriculture is extensive and knowledge of their potential for monitoring MSW is limited.<p> The specific objectives of this research were to: i) establish a laboratory based correlation between sensor data and volumetric moisture content in MSW, ii) establish a correlation between field-installed capacitance sensors and moisture content derived from continuous-depth in-situ sampling of MSW, and iii) demonstrate the ability of capturing advancing/receding moisture fronts with the field-installed capacitance sensors.<p> Laboratory trials were conducted using hand-compacted MSW at volumetric moisture contents ranging from 15%-55% and a manual type of capacitance sensor. This series of laboratory trials successfully produced a correlation between sensor output and volumetric moisture content.<p> To evaluate the sensors in a real-world application, two configurations of capacitance moisture probes were installed in the field: i) an in-place, continuous-time capacitance probe, and ii) a portable, continuous-depth at discrete time, capacitance probe.<p> Field results indicated that capacitance moisture probes were able to capture the passing of both an artificially and naturally induced moisture front, though quantitative correlation between the in-situ moisture content of the sampled MSW and the readings of the sensors could not be achieved.<p> The reasons for this were a combination of three factors:<p> 1. The introduction of void-space during sensor installation significantly reduced sensor output;<p> 2. Poor MSW sampling technique resulted in 57% recovery (causing the exact origin of samples to be unknown); and<p> 3. The sampling technique disturbed the MSW samples, resulting in incorrect volumetric moisture contents in the samples.
13

An evaluation of potential benefits from the redevelopment of landfills into parks in Houston, Texas

Taylor, Michael Lawrence 21 November 2013 (has links)
This report examines the potential benefits from the redevelopment of landfills into parks in Houston, Texas. Many Park and Recreation (P&R) Departments are unable to acquire and develop parkland at a rate on par with new residential construction. Parks provide economic, environmental, public health and aesthetic benefits. Despite these benefits, P&R Departments are often the target of budget cuts when city governments grapple with funding shortfalls. P&R Departments must pursue low value lands to meet parkland needs. Closed Municipal Solid Waste (MSW) landfills are a source of low value land in, and surrounding urban areas. New regulatory framework in the form of the U.S. EPA’s Municipal Solid Waste Landfill Criteria ensures closed landfills may be safely and cost effectively redeveloped for recreational use with limited liability concerns for the P&R Department. This regulatory framework is discussed and Best Management Practices (BMPs) are outlined. These BMPs focus on accommodating the dynamic nature of landfills to minimize park development and Operation and Maintenance (O&M) costs. The substantial parkland deficit in the City of Houston is quantified. The findings of the needs assessment in the City’s Parks Master Plan are presented. A multi-tiered Geographic Information Systems (GIS) based analysis is utilized to evaluate the potential benefits from the redevelopment of existing landfills in the City into parks. The GIS analysis identified 8 landfills that, if redeveloped, will increase the distributional equity of City parkland holdings. Of these 8, the 4 landfills with the lowest expected total development costs and the highest expected savings over traditional greenfield development were identified. It is recommended the City adopt a thorough site characterization and planning process and pursue landfill redevelopment as a cost effective and beneficial way to increase parkland holdings. / text
14

Prefeasibility Study for a Waste-to-EnergyApplication in Gauteng Province, South Africa

Subasinghe, Gayan January 2013 (has links)
Waste-to-Energy concept becomes increasingly popular from the perspectives of the waste management and alternative energy. South Africa, which is a country heavily dependent on the fossil fuel, can explore the opportunities of Waste-to-Energy in order to deal with increasing amount of waste generated while reducing what is deposited at non-engineered landfills, thereby increase the renewable energy share. This prefeasibility study attempts to identify Waste-to-Energy potentials in Gauteng provinceso as to develop a Waste-to-Energy facility under the new renewable Independent Power Producer procurement programme of South Africa. The analysis identifies abundant Wasteto-Energy incineration and landfill gas opportunities linked with municipal solid waste in twomunicipalities. The prefeasibility study further evaluates environmental, socio-economic aspects of Waste-to-Energy initiative. The financial viability of a Waste-to-Energy incineration facility with the Feed-in-Tariff proposed by the government of South Africa isalso detailed analysed.
15

Sustainable municipal solid waste management: A qualitative study on possibilities and solutions in Mutomo, Kenya

Selin, Emma January 2013 (has links)
This report investigates the possibilities and solutions for a sustainable municipal solid waste management in the community of Mutomo, situated in Kitui County, Kenya. The aim was to formulate an action plan to start reaching for a sustainable development in the waste sector, with citizen participation. Specific research questions were to find requests and ideas from the community members. Also, how the Swedish solid waste management system is built up in order to find potential good examples. Qualitative methods for data collection were used both in-depth interviews and focus group discussions conducted. Data collection was done with the help of an interpreter; interviewing guides and a recording device were used. The data was transcribed and thematic analysis done using NVivo. The interviews and discussions resulted in many requests and ideas regarding solid waste management. In brief; a legal dumping site, health education of the advantages of managing waste and the disadvantages if not, increase of public dustbins, increase of people employed for waste collection, an organized system for trade of waste and improved future planning of the town by the local authorities. To conclude, if a sustainable development within the waste sector is to be initiated, the local authorities have to take action and shoulder their responsibility. Improved collaboration between them and the public health office, community members and private stakeholders is essential. The proposed action plan is a good tool to use when initiating this work and would be created through co-operation with residents in Mutomo.
16

Mathematical modeling of municipal solid waste plasma gasification in a fixed-bed melting reactor

Zhang, Qinglin January 2011 (has links)
The increasing yield of municipal solid waste (MSW) is one of the main by-products of modern society. Among various MSW treatment methods, plasma gasification in a fixed-bed melting reactor (PGM) is a new technology, which may provide an efficient and environmental friendly solution for problems related to MSW disposals. General objectives of this work are to develop mathematical models for the PGM process, and using these models to analyze the characteristics of this new technology. In this thesis, both experimental measurement and numerical analysis are carried out to evaluate the performance of both air gasification and air&amp;steam gasification in a PGM reactor. Furthermore, parameter studies were launched to investigate the effect of three main operation parameters: equivalence ratio (ER), steam feedstock mass ratio(S/F) and plasma energy ratio (PER). Based on the above analysis, the optimal suggestions aiming at providing highest syngas calorific value, as well as system energy efficiency, are given. Six experimental tests were conducted in a demonstration reactor. These tests are classified into two groups: air gasification (case 1 and 2) and air&amp;steam gasification (case 3 to 6). In all these cases, the plasma gasification and melting of MSW produced a   syngas with a lower heating value of 6.0-7.0 MJ/Nm3. By comparing the syngas yield and calorific value, the study found out that the steam and air mixture is a better gasification agent than pure air. It is also discovered that the operation parameters seriously influence the operation of the PGM process. A zero-dimensional kinetic free model was built up to investigate the influence of operation parameters. The model was developed using the popular process simulation software Aspen Plus. In this model, the whole plasma gasification and melting process was divided into four layers: drying, pyrolysis, char combustion&amp;gasificaiton, and plasma melting. Mass and energy balances were considered in all layers. It was proved that the model is able to give good agreement of the syngas yield and composition. This model was used to study the influence of ER, S/F and PER on average gasification temperature, syngas composition and syngas yield. It is pointed out that a common problem for the PGM air gasification is the incomplete char conversion due to low ER value. Both increasing plasma power and feeding steam is helpful for solving this problem. The syngas quality can also be improved by reasonably feeding high temperature steam into the reactor.   In order to provide detailed information inside the reactor, a two-dimensional steady model was developed for the PGM process. The model used the Euler-Euler multiphase approach. The mass, momentum and energy balances of both gas and solid phases are considered in this model. The model described the complex chemical and physical processes such as drying, pyrolysis, homogeneous reactions, heterogeneous char reactions and melting of the inorganic components of MSW. The rates of chemical reactions are controlled by kinetic rates and physical transport theories. The model is capable of simulating the pressure fields, temperature fields, and velocity fields of both phase, as well as variations of gas and solid composition insider the reactor. This model was used to simulate both air gasification and air&amp;steam gasification of MSW in the PGM reactor. For PGM air gasification, simulated results showed that when ER varies from 0.043 to 0.077, both the syngas yield and cold gas efficiency demonstrated a trend of increasing. This is explained mainly by the increase of char conversion rate with ER. However, the increase of ER was restricted by peak temperature inside the fixed-bed reactor. Therefore, it is not suggested to use only air as gasification in the PGM process. The influence of plasma power is not obvious when PER varies from 0.098 to 0.138.  The positive influences of steam addition on cold gas efficiency and syngas lower-heating-value are confirmed by the simulation results of PGM air&amp;steam gasification. The main effect of steam addition is the rouse of water shift reaction, which largely accelerates the char conversion and final yields of hydrogen and carbon dioxide. The effect of steam injection is affected by steam feeding rate, air feeding rate and plasma power. Based on the above modeling work, Interactions between operation parameters were discussed. Possible operation extents of operation parameters are delimitated. The optimal points aiming at obtaining maximum syngas LHV and system CGE are suggested.
17

Municipal Solid Waste in Bioreactor Landfills: A Large Scale Study

El Khatib, Dounia January 2010 (has links)
No description available.
18

Economic perspectives on the siting of a municipal solid waste facility

Kim, Hyuncheol 12 1900 (has links)
LULU (Locally Unwanted Land Use) and NIMBY (Never In My Back Yard) are often cited as two major hurdles to overcome for successful siting of a noxious facility. Among various types of waste in Korea, food waste has been posing a serious problem for its high rate of moisture and salt component (MOE 2001). This has necessitated siting of large scale composting facilities around the country. Although there has been an increasing number of studies on NIMBY towards siting of noxious facilities, one can hardly find a study on NIMBY attitudes toward a composting facility from an economic perspective. To analyze NIMBY attitude of residents in Cheju City, Korea toward hosting a composting facility, we base our theoretical analysis on the expected utility theory and subsequently use a MNLM (muitinomial logit model) for empirical analysis. This study consists of four major parts: theoretical analysis, data management, MNLM estimations, and interpretation. A theoretical model is constructed by maximizing expected utility: first, a two-choice model, then extending it to a three-choice model to incorporate residents' uncertain attitudes toward a composting facility, providing a theoretical basis for using MNLM model. Our empirical results show with statistical significance that the higher the income, the stronger the NIMBY attitude towards siting a composting facility. Further, it shows that the negative effect of economic benefits on NIMBY attitude is (marginally) stronger than the positive effect of environmental concern, which contrast with what is usually observed in US where the effect of environmental concern dominates over that of economic benefits. Socio-demographic variables included to have the economic variables controlled for are mostly insignificant. Further, from our empirical results is deduced that the residents gave uncertain responses are tilted towards accepting the composting facility.
19

Avaliação do potencial de integração da gestão de resí­duos sólidos urbanos na Região Metropolitana de São Paulo. Estudo de caso: sub-região sudeste. / Evaluation of the integration of the urban solid waste management in the metropolitan region of São Paulo. Case study: southeast sub-region.

Penna Dallora, Renato Augusto 14 March 2019 (has links)
A Região Metropolitana de São Paulo (RMSP) é uma das dez maiores regiões metropolitanas do mundo e a maior do Brasil. Cerca de vinte mil toneladas de Resíduos Sólidos Urbanos (RSU) são gerados diariamente na região, sendo dispostos em aterros distantes dos centros urbanos. Nesse contexto, o planejamento intermunicipal tornou-se essencial para integrar os sistemas de gestão de RSU e fomentar iniciativas regionais de valorização dos resíduos. O objetivo dessa pesquisa foi realizar o diagnóstico da gestão de RSU dos municípios que constituem a RSMP e avaliar potenciais formas de integração da gestão de RSU no âmbito da sub-região Sudeste da RMSP, constituída pelos municípios Diadema, Mauá, Ribeirão Pires, Rio Grande da Serra, Santo André, São Bernardo do Campo e São Caetano do Sul. Como método, realizou-se pesquisa bibliográfica sobre planejamento e gestão de RSU, Regiões Metropolitanas, governança metropolitana, RMSP, assim como a investigação de modelos e seleção de um modelo matemático (System Dynamics), aplicado na avaliação técnica e econômica de potenciais formas de integração da gestão de RSU na sub-região Sudeste da RMSP. Como resultado, mostrou-se, de forma quantificada, que não beneficiar os RSU gerados na sub-região e manter a reciclagem incipiente dos municípios, em longo prazo, perpetua a lógica de encontrar novos locais para a disposição dos resíduos em aterros. Por outro lado, a cooperação intermunicipal para a viabilização de usinas de tratamento de RSU mostrou-se eficaz na redução dos resíduos que vão para disposição final. Já a reciclagem não se configurou uma solução eficaz no âmbito regional segundo as condições de contorno consideradas, pois depende da coleta seletiva eficiente, que, por sua vez, prescinde de maior conscientização ambiental e adesão por parte da população. Verificou-se, ainda, que municípios com geração similar de RSU possuem melhor potencial de integração e podem viabilizar novas infraestruturas regionais em consórcios exclusivos para a gestão dos RSU. / The Metropolitan Region of São Paulo (MRSP) is one of the ten largest metropolitan regions in the world and the largest in Brazil. Around 20,000 tons of Municipal Solid Waste (MSW) are generated daily in the region, being disposed in landfills far from urban centers. In this context, inter-municipal planning has become essential for integrating MSW management systems and promoting regional valorization initiatives. The objective of this research was to perform a diagnosis of the management of MSW in the municipalities which are included in the Metropolitan Region of São Paulo and evaluate potential forms of integrating MSW management in the Southeast sub-region of MRSP, constituted by the municipalities of Diadema, Mauá, Ribeirão Pires, Rio Grande da Serra, Santo André, São Bernardo do Campo and São Caetano do Sul. As method, a bibliographic research was carried out on planning and management of municipal solid waste, metropolitan regions, metropolitan governance, MRSP, as well as the investigation of models and selection of a mathematical model (System Dynamics), applied in the technical and economic evaluation of potential ways of integrating MSW management in the Southeast sub-region of MRSP. Results showed, in a quantified way, that not benefiting the MSW generated in the sub-region and maintaining the incipient recycling of the municipalities, in the long term, perpetuates the logic of finding new places for waste disposal in landfills. On the other hand, the inter-municipal cooperation for the feasibility of MSW treatment plants proved to be effective in reducing waste that goes to final disposal. Recycling did not provide an effective solution at the regional level according to the boundary conditions considered, because it depends much on efficient selective collection, which, in turn, depends on environmental awareness and population adherence. It was also verified that municipalities with a similar generation of MSW have a better integration potential and can make possible new regional infrastructures in exclusive consortia for the MSW management.
20

Analytical Models For Stress-Strain Response Of Fiber-Reinforced Soil And Municipal Solid Waste

Chouksey, Sandeep Kumar 07 1900 (has links)
The present thesis proposes model for the analyses of stress-strain response of fiber reinforced soil and municipal solid waste (MSW). The concept of reinforcing soils by introducing tension resisting elements such as fibers is becoming widely accepted. Fiber inclusions are found to improve the post-peak behavior of the soil. Evaluation of the stress-strain response of the fiber-reinforced soil indicates that mobilization of the fiber tension generally requires a strain level higher than that corresponding to the peak strength of unreinforced soil. Further, geotechnical engineering properties of MSW such as compressibility, shear strength and stiffness are of prime importance in design and maintenance of landfills. It is also referred in literature that MSW tends to behave as fiber-reinforced soil due to the presence of various types of wastes in its matrix. However, it is not well understood how the stress-strain and strength characteristics vary with time as the biodegradation of waste continues in the landfill. Based on the experimental observations, in this thesis, an attempt is made for developing generalized constitutive models based on the critical state soil mechanics frame work for fiber reinforced soils and municipal solid waste. The proposed models consider the fiber effect in fiber reinforced soil and, time dependent mechanical and biodegradation effects in case of municipal solid waste, respectively. The proposed models are able to capture the stress-strain and pore water pressure response in both the cases. For better understanding, the present thesis is divided into following seven chapters. Chapter 1 is an introductory chapter, in which the need for use of the constitutive models is presented. Further, the organization of thesis is also presented. Chapter 2 presents a brief description of the available studies in the literature on fiber-reinforced soils and municipal solid waste. Various studies on fiber-reinforced soil included experimental results (both laboratory and field) and modeling methods. Experiments on fiber-reinforced soils were mainly carried out with triaxial compression tests, unconfined compression tests, direct shear tests, one dimensional consolidation tests, etc. Force equilibrium model, limit equilibrium model, statistical theory, regression based models are some of the models available in the literature for quantifying the strength of the fiber-reinforced soil. Further, various studies with regard to the engineering properties of municipal solid waste and their characteristic properties available in the literature are presented. They include different models proposed by various researchers for the prediction of stress-strain response, time dependent behavior and load settlement analysis of the municipal solid waste. Finally, based on the literature review, the scope and objectives of the thesis are presented at the end. Chapter 3 describes various types of soils, properties of soils and fibers used in the present study. A detailed description of the sample preparation and methods adopted in the experimental program are presented in this chapter. Chapter 4 presents the experimental results of triaxial compression tests and one dimensional consolidation test carried out on fiber-reinforced soils. Based on the experimental observations, a constitutive model for fiber-reinforced soil in the frame work of modified cam clay model is proposed. Further, the detailed derivation of proposed model and the discussion on evaluation of the input model parameters from triaxial and consolidation tests are presented. The predictions from the proposed models are validated with the experimental data. From the comparison of the results from the proposed model and experiments, it is evident that the proposed model is able to capture stress-strain behavior of fiber-reinforced soils. Chapter 5 presents the experimental studies on the behavior of municipal solid waste based on the triaxial compression and consolidation tests. Based on the experimental observations, a constitutive model for municipal solid waste in the frame work of modified cam clay model is proposed which considers the mechanisms such as mechanical creep and biodegradation. It also provides detailed description of the selection of the input parameters required for the proposed model. The experimental results in the form of stress-strain and pore water pressure response are compared with the prediction from the proposed model. In addition, the applicability of the proposed model is illustrated using detailed parametric studies of parameters of the model for various ranges. Chapter 6 presents a brief study of load settlement response on municipal solid waste using a case example. The constitutive model for municipal solid waste proposed in chapter 5 is used to study the time-settlement response of municipal solid waste and to compare the results with available published models considering different mechanisms. The major conclusions from the study are presented at the end. Chapter 7 presents a brief summary and conclusions from the various studies reported in the present thesis. vi

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