• Refine Query
  • Source
  • Publication year
  • to
  • Language
  • 866
  • 220
  • 24
  • 18
  • 17
  • 8
  • 5
  • 4
  • 4
  • 4
  • 3
  • 3
  • 2
  • 2
  • 2
  • Tagged with
  • 1277
  • 1277
  • 765
  • 752
  • 447
  • 288
  • 275
  • 232
  • 230
  • 188
  • 154
  • 145
  • 141
  • 139
  • 130
  • 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.
111

A Systematic Comparison of Municipal Solid Waste Management Systems: Case Studies of Dalian City, China and the Region of Waterloo, Canada

Chen, Xudong 06 1900 (has links)
Since the 1990s, Municipal Solid Waste Management (MSWM) has shifted to a more comprehensive approach with an emphasis on managing Municipal Solid Waste (MSW) through the whole process from generation to disposal. Meanwhile, developing countries started to alter their ways of managing wastes and engage in more efforts on waste diversion. Due to their shortage of both resources and expertise, developing countries usually refer to and learn from developed countries’ experiences in MSWM to improve their own practices. How and to what extent these experiences are helpful for developing countries remains inconclusive because significant differences are present among MSWM systems in different countries. These differences do not simply reflect the variations in regulations and resource allocation; more importantly, they reflect the variations in the underlying connections between MSWM and other social, economic, demographic, and technological conditions. Therefore, a systematic examination is needed to enhance the understanding of these differences, the reasons for these differences, and the priorities that need to be stressed in order to improve waste diversion in a particular case. A systematic model, as the framework for the comparison in this thesis, is proposed to illustrate MSMW systems. Based on the model, this thesis compares and contrasts two cases, the Regional Municipality of Waterloo (RMOW) in Canada and Dalian City in China, at multiple levels: overall stage, system components, system structures, and interactions. The results show that Dalian, compared with the RMOW, has less sufficient capacities for waste planning and implementation. Challenges in MSWM are associated with higher density of residences, difficulties in managing informal profit-driven recycling activities, insufficient and unreliable treatment capacity, insufficient multi-agent dialogues and cooperation both within the government and between the public and private sectors, and less specific, program-based public education. The majority of participants in the RMOW are more self-motivated as opposed to the majority in Dalian who are motivated more by compensations. Based on the comparison, implications and suggestions in several aspects concerning waste planning are discussed. From the systematic perspective, to improve waste diversion in Dalian requires collaborative efforts of multiple agents. The key aspect is to strengthen the relatively incompetent component in the system to improve the capacities for waste service and treatment, which are contingent on the development of waste industries. In Dalian, waste diversion should begin with limited types of wastes and gradually expand the scope, and new programs should be designed based on the existing system with cooperation of the informal sector. Meanwhile, cooperation among governmental divisions and between public and private sectors need to be promoted by encouraging multi-agent dialogues and improving information transparency. Program promotion also needs to be more specific in instructions and to address both pro- environmental attitudes and service quality and convenience. Finally, scavenging at landfill sites should be discouraged in order to protect scavengers from the detrimental working environment.
112

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.
113

E-waste management in Botswana

Taye, Mesfin, Kanda, Wisdom January 2011 (has links)
Electr(on)ic equipments possess parts and components with high economic value and environmental peril which prompts a potential need to assess the EEE’s management at EoL. E-waste management in developing countries is one of the least revised environmental topics. In recent times however the subject is getting research limelight from scholars. This study aims at enhancing the existing e-waste management practice in Gaborone, Botswana through systematic investigation of the current circulation, usage, handling and management of W(EEEs). Several stakeholders in the solid waste management system were interviewed and also an in situ (on the landfill) waste composition study was conducted in line with the aims and objectives of the research. The study finds that WEEEs do not have exclusively designed management structure in Gaborone and they rather flow source to sink usually blended with the general waste derived from the entire socio-economic activity. Waste composition study conducted on the landfill indicates a very low percentage composition (less than 1%) of WEEEs in the junk corresponding to 1.9 kg/capita/year. Substantial amount of obsolete EEEs rather seem to linger in the socio-economic system until a capable tapping mechanism is installed. An integrated e-waste management system cored around public sensitisation and the novel phenomenon of Enhanced landfill mining which simultaneously offers time to consult developed countries for expertise on sustainable WEEE management is proposed. The impetus to close the linear flow of electr(on)ic materials remain with the government and a range of stakeholders/interest groups who seek to gain economic advantages and also trim down environmental implications from the circulating and landfilled W(EEEs).
114

The Environmental Sanitation Policy of Ghana (2010) and Stakeholder Capacity : A Case Study of Solid Waste Management in Accra and Koforidua

Appiah Boamah, Linda January 2011 (has links)
Managing solid waste effectively has become a burden for many countries especially thedeveloping and the least developed ones. Policies are made as guidelines for various actorsin the waste management sector to implement, but implementation also comes withresource availability and the capacity of the actors to ensure their roles in the policy areachieved. This research focuses on the actors in the solid waste management in twoassemblies of Ghana: the New Juaben Municipal Assembly and the Accra MetropolitanAssembly. The study explores the capacity of the stakeholders in these two study areas inrelation to their roles in the Environmental Sanitation Policy of Ghana, looking at theircurrent practices in solid waste management. A seven weeks field research in Ghanainvolving the use of semi‐structured interviews, informal interviews, snow‐ball sampling,participant observation and focus group discussion with actors within the solid wastemanagement sector, provided for the data of the study. The study identifies somechallenges of these actors and gives recommendation of some issues which would requirefurther research.
115

The Role of Local Knowledge in planning and managing urban solid waste: the tale of two (2) West African Cities, Accra and Kumasi, Ghana

Demanya, Benoit Klenam 28 January 2007 (has links)
Ongoing and potential developments with regards to solid waste management have raised concerns about well being in African cities. There is also growing concern among environmental managers, scientists, and the public that the pace and scale of human activities may lead to adverse environmental and health impacts. These concerns have been worsened by two factors: (1.) That all attempts so far made at dealing with the present situation of solid waste handling in African cities have either failed or only met with moderate success; and, (2.) There is significant economic, spiritual and cultural value placed on the city's development in Africa, therefore, a deterioration in its environment spells further difficulties for improving conditions of development. To date however, very little research has been conducted on the role local knowledge has to play in managing urban solid waste in the context of African cities. This study is a contribution on this topic, using case study cities of Accra and Kumasi in Ghana, West Africa where it was found that local knowledge plays a role not only in the day-to-day decision making of the actors involved, but also in the management of solid waste activities through, the employment of appropriate technology, the creation of awareness around local waste practices, education, adherence to norms and beliefs, and also in stopping littering and encouraging proper waste practices.
116

A Systematic Comparison of Municipal Solid Waste Management Systems: Case Studies of Dalian City, China and the Region of Waterloo, Canada

Chen, Xudong 06 1900 (has links)
Since the 1990s, Municipal Solid Waste Management (MSWM) has shifted to a more comprehensive approach with an emphasis on managing Municipal Solid Waste (MSW) through the whole process from generation to disposal. Meanwhile, developing countries started to alter their ways of managing wastes and engage in more efforts on waste diversion. Due to their shortage of both resources and expertise, developing countries usually refer to and learn from developed countries’ experiences in MSWM to improve their own practices. How and to what extent these experiences are helpful for developing countries remains inconclusive because significant differences are present among MSWM systems in different countries. These differences do not simply reflect the variations in regulations and resource allocation; more importantly, they reflect the variations in the underlying connections between MSWM and other social, economic, demographic, and technological conditions. Therefore, a systematic examination is needed to enhance the understanding of these differences, the reasons for these differences, and the priorities that need to be stressed in order to improve waste diversion in a particular case. A systematic model, as the framework for the comparison in this thesis, is proposed to illustrate MSMW systems. Based on the model, this thesis compares and contrasts two cases, the Regional Municipality of Waterloo (RMOW) in Canada and Dalian City in China, at multiple levels: overall stage, system components, system structures, and interactions. The results show that Dalian, compared with the RMOW, has less sufficient capacities for waste planning and implementation. Challenges in MSWM are associated with higher density of residences, difficulties in managing informal profit-driven recycling activities, insufficient and unreliable treatment capacity, insufficient multi-agent dialogues and cooperation both within the government and between the public and private sectors, and less specific, program-based public education. The majority of participants in the RMOW are more self-motivated as opposed to the majority in Dalian who are motivated more by compensations. Based on the comparison, implications and suggestions in several aspects concerning waste planning are discussed. From the systematic perspective, to improve waste diversion in Dalian requires collaborative efforts of multiple agents. The key aspect is to strengthen the relatively incompetent component in the system to improve the capacities for waste service and treatment, which are contingent on the development of waste industries. In Dalian, waste diversion should begin with limited types of wastes and gradually expand the scope, and new programs should be designed based on the existing system with cooperation of the informal sector. Meanwhile, cooperation among governmental divisions and between public and private sectors need to be promoted by encouraging multi-agent dialogues and improving information transparency. Program promotion also needs to be more specific in instructions and to address both pro- environmental attitudes and service quality and convenience. Finally, scavenging at landfill sites should be discouraged in order to protect scavengers from the detrimental working environment.
117

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.
118

Municipal Solid Waste Management in an urban area of China: Case studies of Shanghai, China and Linköping, Sweden.

Yang, Cha January 2011 (has links)
With the rapid and large increase of waste quantities, China, surpassed the USA as the world’s largest municipal solid waste (MSW) generator since 2004. The phenomena and critical issues of MSWM in China inspired this paper to investigate and analyse the MSWM in an urban area of China. Comparing with the increasing rates of MSW generation, little has been done concerning the municipal solid waste management (MSWM). Not only the local government and authorities are responsible for the MSWM, but also the individuals are playing a significant role in MSWM. An integrated waste management system should be built in order to improve the holistic MSW system and reduce the waste production. The aim of the study is to investigate and analyse the current status and problems of MSWM in an urban area of China and to analyse to what extent a viable reduction of the MSW can be implemented and management systems to be improved in the near future. In this study, two case studies of Shanghai and Linköping are employed and compared to explore the challenges and potentials for improving the MSWM system in China. The result indicated that inadequate facilities and infrastructure, less advanced technology, insufficient public participation, low awareness of environmental protection, problems in policy and laws are the major barriers for the improvement of MSWM. Involving international environmental cooperation activities, planning a sustainable and comprehensive policy and framework for MSWM, introducing economic incentive approaches, promoting the capacities of waste management technologies, raising public environmental awareness are believed to be viable solutions to improve the MSWM system in China.
119

Examining solid waste management issues in the City of Bryan

Arekere, Dhananjaya Marigowda 12 April 2006 (has links)
Economic aspects of household recycling behavior and attitudes in City of Bryan are examined to improve solid waste management policies in the city. Using survey data collected by mail and personal interviews, residents’ attitudes towards solid waste management are analyzed, in general, and specifically, the factors influencing recycling behavior examined using logistic regression. In addition, three alternative policies are presented to respondents. First, support for an additional drop-off recycling center (Policy I) is examined. Second, WTP for two different recycling programs, curbside recycling service (Policy II), and curbside recycling with a drop-off recycling center (Policy III), as a function of socio-economic factors thought to influence WTP are computed using contingent valuation method, an indirect valuation tool. Finally, preference for a particular policy among the three alternatives presented to the residents of Bryan is explored. Because of the different data collection modes and assumptions on the bid prices two logit models are estimated to examine recycling behavior, and Policy I and two multinomial logit models for the most preferred policy, whereas four logit models are estimated for Policy II and III. The estimated models are similar both within the Policies and between the Policies in terms of the affects of variables, significance of coefficients, and consistency with previous studies indicating a potential set of factors that can be used to explain WTP for recycling services. Bryan residents that are female, white, employed, have higher incomes, have children, own a house, and are self-perceived environmentalists tend to recycle more. Similarly, males, nonwhites, older respondents, students, non-environmentalists and non-recyclers are more likely to support an additional drop-off center. WTP for Policy II is positively influenced by males, whites, respondents who are employed, low-income respondents, environmentalists, non-recyclers, and those who support Policy I. In comparison, WTP for Policy III is positively influenced by females, whites, respondents who are employed, younger respondents, environmentalists, non-recyclers, and those who support Policy I. In the case of both Policies I and II, the bid price negatively influences WTP as expected. While the WTP for Policy II is slightly higher than the estimated cost of a curbside recycling service ($2.50), the WTP for Policy III is lower than the estimated cost. No consistent pattern emerges across most of the coefficients and the four possible alternatives, three proposed policies and the current situation. However, probabilities computed using the multinomial logit results is the highest for Policy II, followed by either Policy III or no change to the existing solid waste management policy.
120

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

Page generated in 0.1359 seconds