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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.
281

A Novel Computational Approach for the Management of Bioreactor Landfills

Abdallah, Mohamed E. S. M. 13 October 2011 (has links)
The bioreactor landfill is an emerging concept for solid waste management that has gained significant attention in the last decade. This technology employs specific operational practices to enhance the microbial decomposition processes in landfills. However, the unsupervised management and lack of operational guidelines for the bioreactor landfill, specifically leachate manipulation and recirculation processes, usually results in less than optimal system performance. Therefore, these limitations have led to the development of SMART (Sensor-based Monitoring and Remote-control Technology), an expert control system that utilizes real-time monitoring of key system parameters in the management of bioreactor landfills. SMART replaces conventional open-loop control with a feedback control system that aids the human operator in making decisions and managing complex control issues. The target from this control system is to provide optimum conditions for the biodegradation of the refuse, and also, to enhance the performance of the bioreactor in terms of biogas generation. SMART includes multiple cascading logic controllers and mathematical calculations through which the quantity and quality of the recirculated solution are determined. The expert system computes the required quantities of leachate, buffer, supplemental water, and nutritional amendments in order to provide the bioreactor landfill microbial consortia with their optimum growth requirements. Soft computational methods, particularly fuzzy logic, were incorporated in the logic controllers of SMART so as to accommodate the uncertainty, complexity, and nonlinearity of the bioreactor landfill processes. Fuzzy logic was used to solve complex operational issues in the control program of SMART including: (1) identify the current operational phase of the bioreactor landfill based on quantifiable parameters of the leachate generated and biogas produced, (2) evaluate the toxicological status of the leachate based on certain parameters that directly contribute to or indirectly indicates bacterial inhibition, and (3) predict biogas generation rates based on the operational phase, leachate recirculation, and sludge addition. The later fuzzy logic model was upgraded to a hybrid model that employed the learning algorithm of artificial neural networks to optimize the model parameters. SMART was applied to a pilot-scale bioreactor landfill prototype that incorporated the hardware components (sensors, communication devices, and control elements) and the software components (user interface and control program) of the system. During a one-year monitoring period, the feasibility and effectiveness of the SMART system were evaluated in terms of multiple leachate, biogas, and waste parameters. In addition, leachate heating was evaluated as a potential temperature control tool in bioreactor landfills. The pilot-scale implementation of SMART demonstrated the applicability of the system. SMART led to a significant improvement in the overall performance of the BL in terms of methane production and leachate stabilization. Temperature control via recirculation of heated leachate achieved high degradation rates of organic matter and improved the methanogenic activity.
282

Sustainability of Municipal Solid Waste Management in Nigeria : A Case Study of Lagos

Agbesola, Yetunde January 2013 (has links)
Waste generation is an unavoidable product of man’s activities, however, sustainable management of such waste is a challenge faced in many countries today. Nigeria, a developing country in Africa, has been in a quandary of how to efficiently manage the municipal solid waste its population generates. Many states in the country lack adequate plans and infrastructure required for efficient and sustainable management of municipal solid waste. For Lagos, the most populous and popular state in Nigeria, the problem is further compounded by its rather large and still increasing population. In this research, Lagos is taken as a case study; the extant trend for solid waste handling in households, trends in the formal and informal sector as regards solid waste management from household collection to final disposal are focused upon. Many countries, particularly the developed ones, have employed options in the waste management hierarchy for sustainable management of their municipal solid waste and the blend of options employed is usually highly dependent on local factors. Following the waste management hierarchy, possible options for sustainable municipal solid waste management in Lagos are discussed. It is concluded that waste reduction, reuse, recycling and composting are potential management options for the state. Landfilling will remain an important option for final disposal but reliance on this method could be significantly reduced if management options are exploited to the maximum in a sustainable solid waste management structure.
283

Developing Standardized Work in Casting Department : Case Study of Luvata Sweden AB Finspång

Kurilova, Jelena January 2010 (has links)
This thesis is one part of a lean project initiated by Luvata Sweden AB in Finspang casting department. The primary goal of that project is to increase the production efficiency, reduce costs and improve the quality of the copper coil. The aim of this thesis is to develop standardized work in casting department at Luvata Sweden AB Finspang. The research is based on lean thinking and organized in three steps. FIRST STEP: This step implies value stream mapping (VSM) of the current manufacturing process. VSM technique is applied in order to create an overview of the entirety production flow in a casting department, to visualize non-value added activities and to identify process wastes. SECOND STEP: By using lean tools as: Waste Management, SMED and Visual Management, thesis work intends to clean the production process. 7 Wastes or seven forms of Muda were studied at Luvata Finspang. The source of 5 wastes were identified and reduced/eliminated. SMED (single minute exchange of dies) analysis was carried out for a changeover during a casting montage in order to reduce the changeover time and streamline the montage process. Spaghetti diagram was applied particularly to inspect the best location for all montage materials, equipments and tools in a casting floor. Ensuring the efficient implementation of Waste Management and SMED practices Visual Management technique was used. This mean expresses the information about production process, its real-time status and results in a way that could be understood by operators in a shop floor. It is important to clean a production process before the standardized work can be developed, since the purpose of standardized work is to represent the best practice: method and sequence for each process. THIRD STEP: The last thesis step focuses on developing standardized work sheets as a steering tool for operators to follow the best practice while executing their tasks in each work center (melting, casting, rolling) and during the casting montage. The standardized work sheets are designed to show the approved way to perform the specific procedures and are expected to motivate operators to perform theirs job in the common way. That would consequently reduce high variation in operators performance. It would probably take several years before any reasonable improvements could be observed. However the developed standardized work sheets are already placed in the shop floor and successfully used by operators this is my small contribution to a big improvement project!
284

A Study on the Implementation of Green Supply Chain- A Comparative Analysis between Small Scale Industries in India and Developed Nations

Selvaraj, Ranjith Karthick January 2011 (has links)
Environmental pollution is the major problem that mankind faces in present state, the major emission of toxic gases is from vehicles and manufacturing industries. The thesis study focuses on three different types of Small Scale Industries (SSI) in India that are bumper manufacturing industry, dyeing industry and food processing industry. The product life cycles of the process for each industry are identified and their final green waste disposal methods are investigated. The industries are identified with more lean wastes within their product life cycle process. The major green wastes from their disposal methods have high influence on environment. These wastes have to be reduced or eliminated by practicing a suitable supply chain. In present the companies doesn’t practice any supply chain in their organization. The implement of supply chain could reduce the environmental pressures and wastes of the companies to some extent. The lean wastes identified in the process could be eliminated by practicing suitable lean tools and methods. The final disposal wastes are considered to be the green wastes. The method of disposal practiced by the SSIs in India shows an evidence of how much they concern towards the environment. The research tries to explain some suitable waste management techniques for the industries and discusses about importance of government role on making this techniques possible. The small scale industries experiences both wastes, so it has to integrate lean for practicing green supply chain, the implementation of lean would pay a way for green supply chain management. As a result of it a comprehensive lean and green model is suggested for the industries because the model is composed of both lean and green waste reduction techniques and it also helps in achieving both lean and green business results.
285

Waste Management - CSR Engagement within the Construction Industry in Sweden

Nordlander, Anna, Tararyko, Jelena January 2011 (has links)
Introduction: Over the last few decades there has been a great increase in the attention to Corporate Social Responsibility. Organizations that up until recently have had profit maximization and shareholder value as their only concerns have found themselves in a position where stakeholder demands have created pressure to produce and act on sustainability agendas. Concepts like intergenerational equity, wealth distribution, equality and macroeconomic stability became a part of everyday business language and these days the majority of firms communicate a variety of CSR related issues through annual or separate sustainability reports. Up until recently the construction industry has managed to avoid such demands, however lately, the pressure from various stakeholders such as society, activist groups, governments and external competition, has put the industry among the more environmentally sensitive sectors. Although industry wide CSR involvement has increased within environmental construction management, much is still left to be done. Problem: One area which has received little attention is recycling after demolition. Most companies focus on making new building projects as environmentally friendly as possible, however hardly any attention is geared towards what happens to old buildings being torn down and the lifecycle of the old material. Although construction companies have the legal obligation to recycle hazardous material, much can be improved within the other areas especially regarding the reusing of materials from the demolishing sites which means both environmental and economical aspects are so far being overlooked.  Purpose: The authors aim to examine the complexities and challenges facing the construction industry in environmental management of demolition projects, and more specifically the effect this has on the recycling and reusing of materials. Methodology: In order to research the waste management practices on demolition sites the research employs interview studies conducted through qualitative mostly face-to-face and a few telephone interviews. Complementary cases were selected within different categories of the construction industry sectors related to demolition projects: client, construction, demolition and waste management companies’ employees were interviewed. Conclusion: The results show that companies within the construction industry realize the potential negative effects their line of business has on the environment. Sustainability agendas in all cases focus extensively on environmental management, which includes proper disposal of demolition waste. The main benefits for recycling and reusing (in some cases reselling) the material were financial incentives and generated competitive advantage, which resulted in better competitiveness concerning procurement. The main challenges identified are time and monetary constraints. Lack of regulation, common standard that would enable firms to compete equally, and lack of common effort and cooperation towards more efficient waste management practices on demolition sites were identified as main hindering factors for industry wide improvement.
286

Wast Management System for Western Africa : Analysis of systemssuccessfully applied in the world that may fit the reality faced in Western Africa

Adamoski, Michele January 2011 (has links)
Health and safety have been the most important concerns in waste management formany years. However, nowadays society demands that as well as being safe, waste managementmust also be sustainable. The management of a sustainable Municipal Solid Waste is anecessary but not-prioritized aspect of environmental management in most countries with lowand middle income.This study purposes an analysis of technologies, in order to select the best and mostsuitable practices in Sustainable Waste Management Systems already applied or in advancedlevel of research in developed and developing countries. The target countries for receiving thisstudy of waste system are located in Western Africa: Ghana, Côte d‟Ivoire, Senegal andNigeria.The analysis of collection, transportation, treatment and disposal of waste, with focus onorganic matter, was presented in two groups. The first group, “collection and transportation”was analysed with attention to aspects and stakeholders presented in the Integrated SustainableWaste Management framework. In the second group, “treatment and disposal”, each technologywas analysed based on aspects of sustainable development. The decision-support software Web-HIPRE was also used to frame the final rank of solutions for the African scenario.The conclusions for those analyses were that the creation of micro and small enterprisesand community based organizations for collection and transportation should strongly beencouraged. They generate not just new employment but awareness among the population aswell. As for the treatment and disposal of organic household waste, two promising technologiesare decentralized composting and home composting with plastic bins.
287

A GIS-based study of sites for decentralized composting and waste sorting stations in Kumasi, Ghana

Öberg, Hanna January 2011 (has links)
Developing countries are facing a great challenge to collect, treat and dispose their waste in a more sustainable way. Today, most of the produced waste ends up on landfills, where they pose a great threat to the environment and human health. Kumasi, the second largest city in Ghana, faces the same issues as other cities in developing countries; waste management is run poorly and most waste ends up on the cities largest landfill, Dompoase, which will be full in a few years time. Issues such as low financial resources, bad urban planning and a growing population aggravate the implementation of a more sustainable development. Since most solid waste in developing countries is organic, composting is a good option towards a more sustainable waste management. There are numerous amounts of articles stating that decentralized composting is the best option for developed countries. Decentralized compost facilities are less costly to install and maintain, they require less technology and decrease the cost of waste transportation. Transportation poses a large expense when it comes  to waste management in developing countries. There is an advantage in integrating a more sustainable waste management in to the existing waste infrastructure since cities often are densely built up and there is a shortage of land. Therefore this thesis has investigated the possibilities of having waste sorting stations and decentralized compost facilities at public dumping sites in the Bantama area, one of ten sub--‐metros in Kumasi. Based on literature and observations during field visits in the Bantama area, a classification scheme was developed. The classification scheme was designed to simplify identification and differentiation of the sites. It contains thirteen criteria to consider when planning for organic waste sorting stations and decentralized compost facilities. Suitable sites for sorting stations and decentralized compost facilities were selected by a SQL analyzes in a Geographic Information System (GIS). The analyzes was based on the classification scheme. The result shows that of twenty--‐one public dumpingsites, seven were suitable as sorting stations and two sites were suitable for a decentralized compost facility. The expectation is that in due time and with infrastructure improvements, more than only seven communal sites can become sorting stations. When it comes to sites for composting the result reveals an issue in many cities  there is just not enough land to build as many decentralized facilities as would be necessary to recycle all organic waste. However, due to the advantages of having decentralized facilities, the recommendation is that Kumasi should start with a decentralized approach and as finance and technological skills exists the organic waste management can extend to also include larger facilities. Further this thesis shows the advantage of having decentralized composting when it comes totransportation costs. A transport analyzes was done in a GIS,  which showed the difference intransportation distances between having decentralized and centralized composting. The result showed that waste recycled close to its source, i.e. having decentralized waste management, is transported shorter distance compared to having centralized composting and  thus saving on cost for transportation.
288

An analysis of the social relations inwaste management : Two case studies on Somanya and Agormanya in Ghana

Kadfak, Alin January 2011 (has links)
This thesis presents the analysis of how the social relations shape the situation ofwaste management in developing countries. The towns of Somanya and Agormanya,which are both located in the Eastern Region of Ghana, have been selected as casestudies for this thesis. Qualitative research methods were applied to collect theinformation during the fieldwork. The thesis applies different social science concepts,such as the concept of community, gender relations, corruption and space, to analyzethe social relations among the actors within waste management in the two study areas.The thesis aims to look at waste management from a new perspective and seeks tofind better solutions to deal with the waste situation in developing countries.The results obtained from the empirical work presents the relationships of differentactors in the private space and in the public domain. Relationships between membersof the family are analyzed through concepts of gender and cultural structure withinthe private space. Social relations in the public space involve several actors, such astraditional leaders, local officers, the church community and private companies. Theconcepts of state, community and decentralization are applied to explain how theactors relate to each other in waste management.
289

Small-scale anaerobic digesters in Vietnam - development and challenges / Hầm ủ khí sinh học quy mô nhỏ ở Việt Nam - quá trình phát triển và các thách thức

Nguyen, Vo Chau Ngan 06 August 2012 (has links) (PDF)
Small-scale anaerobic digesters, known as biogas plants, were applied as an optimal livestock waste treatment as well as biogas supply for cooking and lighting demand for small-scale farmers in Vietnam. Although the biogas technology was introduced for nearly 30 years, the number of the constructed biogas plants is still limited. The current development of biogas plants is far below the real demand on livestock waste treatment that has increased significantly. This paper gives a comprehensive overview on the biogas plant development in Vietnam and attempts to address the challenges and discuss appropriate solutions for the further biogas development. / Mô hình lên men yếm khí quy mô nhỏ (được biết với tên hầm ủ khí sinh học) đã được ứng dụng hiệu quả trong xử lý chất thải chăn nuôi cũng như cung cấp nguồn nhiên liệu phục vụ nhu cầu nấu ăn và thắp sáng cho các hộ chăn nuôi nhỏ ở Việt Nam. Mặc dù đã hiện diện gần 30 năm, nhưng số lượng hầm ủ khí sinh học vẫn còn hạn chế. Sự gia tăng số lượng hầm ủ khí sinh học chưa theo kịp với nhu cầu về xử lý chất thải chăn nuôi đang ngày càng gia tăng. Bài báo trình bày các chặng đường phát triển của hầm ủ khí sinh học tại Việt Nam, ghi nhận các thách thức trong việc nhân rộng hầm ủ khí sinh học trong thực tế và thảo luận một số giải pháp để phát triển công nghệ khí sinh học.
290

Solid waste management in Mekong Delta / Quản lý chất thải rắn ở Đồng bằng Sông Cửu Long

Nguyen, Xuan Hoang, Le, Hoang Viet 07 August 2012 (has links) (PDF)
Municipal solid waste (MSW) in Vietnam has been increasing quickly and became one of the most considered environmental problems in Mekong Delta (MD) region covering 13 provinces and municipalities in the south of Vietnam. With a considerably large amount of MSW, the region produces about 5% of the total amount of MSW of the country. The collection rate of solid waste is about quite high (65 - 72%) in the cities and rather low (about 40 - 55%) in the rural areas, with a high content in organic matter (about 60 - 85%). The climate of MD can be characterized as tropical and monsoonal with a high rate of humidity and a strong impact of flooding. Like other regions too, the MSW collection and treatment system is still underdeveloped and rudimentary, with disposal sites being the sole dumping method of the unsorted MSW remaining untreated by any mechanical and biological pre-treatment steps. Within this paper, the current treatment, management and operation of MSW systems are introduced, as well as the identification of advantages and disadvantages, environmental impacts, potential risks of the MSW system within the impact of global climate change. The situation of MSW treatment and management is correlated with the climate change impact and the integrated solid waste management is introduced as a new approach for adapting the environmental protection awareness by considering the climate change for the longterm sustainable development orientation. / Sự gia tăng chất thải rắn ở các đô thị Việt Nam ngày càng nhanh và chất thải rắn đang là một trong những vấn đề môi trường được quan tâm hàng đầu. Đồng bằng Sông Cửu Long (ĐBSCL) nơi có đến 13 tỉnh và thành phố nằm ở phía Nam Việt Nam. Với lượng chất thải không nhỏ, chiếm khoảng 5 % tổng lượng chất thải rắn sinh hoạt của quốc gia. Tỷ lệ thu gom chất thải rắn thấp, chiếm khoảng 65 - 72 % ở thành thị, tỷ lệ này ở nông thôn thấp 40 - 55%, chất thải có hàm lượng hữu cơ cao chiếm khoảng 60 - 85%. Khí hậu nhiệt đới gió mùa với độ ẩm không khí cao và chịu ảnh hưởng lớn của lũ lụt hàng năm. Cũng như các khu vực khác, hệ thống thu gom và xử lý rác thải ở khu vực ĐBSCL còn rất thô sơ và lạc hậu, bãi rác là nơi duy nhất tiếp nhận trực tiếp hổnhợp rác thải không phân loại và qua bất kỳ công đoạn tiền xử lý nào. Trong phạm vi bài viết này, chúng tôi giới thiệu hoạt động vận hành hệ thống quản lý và xử lý rác đô thị trong khu vực đồng thời phân tích các thuận lợi và bất lợi, cũng như các tác động môi trường, những rủi ro tiềm ẩn trong điều kiện ảnh hưởng của biến đổi khí hậu toàn cầu - khu vực ĐBSCL là nơi chịu ảnh hưởng nặng nề nhất. Tình hình quản lý và xử lý rác được cân nhắc trong điều kiện tác động của biến đổi khí hậu, đồng thời quản lý tổng hợp rác thải cũng được đề xuất như một các tiếp cận mới nhằm đáp ứng nhiệm vụ bảo vệ môi trường trong điều kiện biến đổi khí hậu theo định hướng phát triển bền vững lâu dài.

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