• Refine Query
  • Source
  • Publication year
  • to
  • Language
  • 432
  • 331
  • 71
  • 64
  • 20
  • 20
  • 13
  • 9
  • 8
  • 7
  • 6
  • 3
  • 3
  • 2
  • 2
  • Tagged with
  • 1123
  • 1123
  • 304
  • 291
  • 277
  • 179
  • 168
  • 154
  • 144
  • 129
  • 129
  • 124
  • 105
  • 91
  • 87
  • 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.
291

Management of organic solid waste from rail operation by the Vietnam railways: the current situation and possible solutions / Hiện trạng và giải pháp quản lý rác thải hữu cơ trên đường sắt Việt nam

Nguyen, Thi Hoai An 15 November 2012 (has links) (PDF)
The quick social economic development of Vietnam stimulates great demand of quality as well as quantity on transport service by the increasingly growing needs of customer for transportation. The railway passenger transport is currently still an important branch of a country’s transport system because it is safer, more eco-friendly and much more efficient in comparison to another means. However, the increasing of the number of passengers is the main causes of fast increasing waste amount from the rail service. The aim of this paper is to study how the organic waste from rail service is managed and treated today by the Vietnam railways. The paper ends with some proposal solutions for treating and disposing of organic waste by applying renewable energy technologies for climate change mitigation to protect human health and the environment. / Sự phát triển nhanh chóng của nền kinh tế Việt nam dẫn đến nhu cầu vận chuyển hành khách ngày càng tăng mạnh về số lượng cũng như chất lượng dịch vụ. Vận chuyển hành khách bằng đường sắt hiện tại ở Việt nam vẫn đóng vai trò quan trọng trong hệ thống vận tải quốc gia do lợi thế an toàn cao, thân thiện với môi trường và lợi ích cao của nó so với các phương tiện khác. Tuy nhiên sự biến động lớn của lượng hành khách đi tàu là nguyên nhân làm cho lượng rác thải từ các dịch vụ đường sắt cũng tăng mạnh. Bài báo tập trung vào nghiên cứu và làm rõ hiện trạng quản lý chất thải hữu cơ trên đường sắt Việt nam hiện nay cũng như các chiến lược nhằm xử lý chất thải hữu cơ, sử dụng công nghệ năng lượng tái tạo nhằm bảo vệ môi trường, giảm thiểu biến đổi khí hậu.
292

Degradation Of Epdm Via Gamma Irradiation And Possible Use Of Epdm In Radioactive Waste Management

Hacioglu, Firat 01 September 2010 (has links) (PDF)
In this study, degradation of ethylene propylene diene terpolymer (EPDM) via gamma radiation and possible use of EPDM in radioactive waste management were investigated. In estimation of radiation stability and possible use of EPDM in radioactive waste management, dose rate (both high and low), irradiation environment (in water and in air), additives (carbon black, zinc oxide, plasticizer) used in formulation, peroxide type (either aliphatic or aromatic) and content were parameters which were analyzed. Three EPDM samples having different peroxides were irradiated in water and in air with two different dose rates (993 Gy/h, 54 Gy/h) to 2163 kGy (for high dose rate) and 1178 kGy (for low dose rate). Irradiation periods for low dose rate were 2.5 years (last sample) which have not been observed in literature. Characterization of irradiated EPDM samples were done by mechanical (tensile, hardness, compression), dynamic mechanical (DMA), thermal (TGA-FTIR) and morphological (ATR-FTIR, XRD, SEM) tests. High dose rate irradiations were done in predicting how far EPDM resist to radiation and which dose rate emitted waste can be immobilized and stored in EPDM for 300 years. Low dose rate irradiations were carried out in determining morphological changes in structure, thermal stability, oxygen effect and types of reactions (crosslinking, chain scisson) which were dominant in irradiated samples. According to the test results, improvement in thermal properties and decrease in elasticity on EPDM via radiation were recorded from thermal and mechanical tests respectively. Moreover, structural changes were monitored from ATR-FTIR, SEM and XRD analysis. Mechanical tests showed that irradiated EPDM samples, which were differentiated with respect to peroxide type (aliphatic, aromatic), could resist up to total absorbed doses of 3750 kGy and 3955 kGy respectively. Up to 1178 kGy in low dose irradiation, there were not much structural changes, which were observed in ATR-FTIR analysis, in EPDM chain. It was concluded that EPDM rubber used in this study were radiation stable polymer so that they could possibly be used in conditioning of radioactive waste.
293

Environmental assessment of municipal solid waste incinerator bottom ash in road constructions

Olsson, Susanna January 2005 (has links)
<p>There are several incentives for using bottom ash from municipal solid waste incineration (MSWI bottom ash) as a construction material, such as for road construction. These incentives include decreased disposal of material on landfills and a reduced amount of raw material extracted for road building purposes. However, one of the main obstacles to utilising the material is uncertainties regarding its environmental properties. The overall objective of this thesis is to describe the potential environmental impacts of utilising MSWI bottom ash in constructions and to improve the tools for environmental assessments.</p><p>An environmental systems analysis (ESA) approach based on a life cycle perspective was outlined and used in a case study, with the aim of describing the differences in resource use and emissions that can be expected if crushed rock in the sub-base of a road in the Stockholm region in Sweden were to be substituted by MSWI bottom ash. The whole life cycle of the road was taken into account and the alternative disposal of the bottom ash was included. It was found that the studied alternatives would cause different types of potential environmental impact; whereas the conventional alternative with only crushed rock in the road’s sub-base would lead to larger use of energy and natural resources, the alternative with MSWI bottom ash in the sub-base would lead to larger contaminant leaching. It was concluded that a life cycle approach is needed in order to include both resource use and emissions in the comparison between the two alternative scenarios. The leaching of metals turned out to be the most important environmental aspect for the comparison and in particular the difference in copper (Cu) leaching was shown to be large.</p><p>However, a large amount of Cu may not pose an environmental threat if the Cu is strongly bound to dissolved organic carbon (DOC). In order to improve the basis for toxicity estimates and environmental risk assessments, and thereby provide better input values for ESAs, the speciation of Cu to DOC in MSWI bottom ash leachate was studied. It was found that Cu to a large extent was bound to DOC, which is consistent with previous research. The results also suggest that the hydrophilic fraction of the MSWI bottom ash DOC is important for Cu complexation and that the pH-dependence for Cu complexation to MSWI bottom ash DOC is smaller than for natural DOC. This implies that models calibrated for natural DOC may give inconsistent simulations of Cu-DOC complexation in MSWI bottom ash leachate.</p>
294

Avfallsförebyggande arbete i Norrbottens läns kommuner : En studie om kommunal avfallshantering och avfallsdirektivets påverkan

Kevnell, Stefan January 2015 (has links)
This study aims to evaluate the waste management in Norrbottens municipalities in key areas such as possibilities to reach the two national waste goals, information to the public, the effect of legislation, future of waste management and differences in geographic- and demographic areas. The Waste Framework Directive (WFD) issued by the EU and incorporated into Swedish law plays a major part in waste management by defining a hierarchy in five steps how waste should be treated. Interviews conducted with each of the fourteen municipalities aimed to find out what step in the hierarchy they are at and what effect the implementation of EU-legislature into Swedish law has had. Based on the interviews a diverse range of answers was found in relation to the questions asked, generally the more populated municipalities saw a more positive future of waste management, mainly because more developed infrastructure to handle waste is already in place. However the smaller the municipality is the harder it is to allocate resources for waste management and problems arise in the form of expensive transports of waste. A few municipalities think that the WFD has had a positive effect in the form of clearer responsibility for all parties involved in waste management but in general the answers point to a greater effect on a national level rather than a local. Regarding the national waste goals 7 of 14 municipalities believe they will reach the food waste goal but only 1 of 14 believe they will reach the construction waste goal.
295

The Present and Future Role of Energy Recovery in Waste Management - A Case Study of Linköping and Norrköping

Molin, Johan January 2015 (has links)
In the European Union 500 million tonnes of waste are either incinerated without energy recovery,or deposited in landfills, which could have been recycled instead. The European Union initiated theCircular Economy Package in order to decrease the amount of waste being generated, lost inlandfills, and to increase the recycling and usage of recycled material. However, the CircularEconomy Package did not contain any targets focusing on energy recovery, and only mentionedenergy recovery as having a role in decreasing the amount of waste deposited in landfills. TheCircular Economy Package was in the end of 2014 withdrawn but will come back with moreambitious targets. In Sweden energy recovery is treating more than 50% of the municipal waste andwould then be affected by the targets of the Circular Economy Package when it comes back.This thesis focuses on Linköping and Norrköping to identify the what role energy recovery have inthese municipalities, both present and future, as well as asking the questions of how waste is valuedas a resource.The results were that both municipalities thought that it was important to have separate sorting ofmunicipal waste, to separate organic waste from the rest, in order to use it in material recycling andthe rest in energy recovery. In both municipalities the energy recovery had the role of treating themunicipal waste which was found to be not recyclable, as well as to deliver heat and electricity. Allof the organisations were identified to have a high environmental value on waste, but the economicvalue of waste were low or negative. The municipalities also knew little of the Circular EconomyPackage, but were aware of it, while the energy companies knew a little more of it, but still littlecompared to their national interest organisations Avfall Sverige and Svensk Fjärrvärme. All of theorganisations had identified similar challenges such as increased focus on recycling, minimisationof waste, but also a focus on decreasing amount of hazardous substances in products in order todecrease the amount of waste which needed to be deposited in landfills.
296

Food waste in Hong Kong : a study on source reduction

Woo, Pak-keung, 鄔柏強 January 2014 (has links)
Hong Kong is a densely populated area located in the south-eastern coast of China. The volume of food waste generated surges with the substantial economic and population growth. In Hong Kong, there are currently 3,584 tonnes of food waste produced daily which are mainly disposed at landfills. The existing landfills, however, are expected to be full in the coming 5 years. The food waste problem is therefore urgent and significant. As a response, the Policy Address 2014 puts forward a package of waste management measures and calls for the implementation of “reduction first” approach. This study reviews the past efforts of food waste management and looks specifically at source reduction. Consumerism promotes the progressive purchasing of food products without the consideration of the adverse environmental impacts. The consumer behaviors driven by consumerist lifestyles boosted the food waste quantity. The meanings and relationships of food waste, source reduction, sustainable waste management, consumerism and consumer behaviors are therefore analyzed to illustrate the sustainable food waste management. The principles affecting consumer behavior, household behavior and C&I sector behavior on both supply and demand sides are especially studied to understand the situation. Making reference to overseas experience and a best practice framework, this research study focuses on the attitudes, difficulties and decision making of the Hong Kong residents, foodservice suppliers, the Government and NGOs on food waste issues. Literature review, questionnaire survey, in-depth interviews and site visits were conducted to understand consumer behavior. A collection of government policies and other stakeholders’ initiatives was reviewed and analyzed. These include: A food waste & yard waste plan for Hong Kong, Food Wise Hong Kong Campaign, volume-based waste charging scheme, voluntary garbage sorting, OWTF infrastructure, Green lunch charter and Community Green Stations. The green groups have organized food waste reduction programs, food donation activities and light banquet campaigns to promote right-size food purchase and sustainable lifestyles in Hong Kong. Food waste-to-energy approach is more preferred than composting and animal feed production in Hong Kong. Other relevant measures learned from Taiwan can be the environmental awards, food waste recycling industry, financial funding and university researches. The study found that there are insufficient environmental policies and laws, inadequate financial incentives and low level of environmental CSR to promote food waste reduction. Limited collaboration among stakeholders, weak environmental education in the formal curriculum and consumerist lifestyles are also the reasons of the food waste problem. The study concludes that the food waste source reduction is achievable. The Government should improve the existing environmental policies and laws to promote sustainable lifestyles. A combination of measures should be implemented. Waste charging, Food Wise Hong Kong Campaign, food donation, social mobilization, OWTF infrastructure, environmental education and publicity, community green stations and right-size food purchase should work together to solve the problem. / published_or_final_version / Environmental Management / Master / Master of Science in Environmental Management
297

Textile waste is only matter out of place : Antecedents of value creation in reverse textile value chains

Nyström, Matilda, Johansson, Emelie January 2015 (has links)
The current waste management system of Post Consumer Textile Waste (PCTW) in Sweden leads to vast amounts of incinerated or exported textiles. The amount of PCTW reused or repurposed within the country is small in comparison to the amounts of textile products consumed every year. Hence, there is an observed problem in terms of low value creation from textile waste. A system that allows for more textiles to be kept and reused in Sweden could create more economic value in a resource-efficient way. Hence, the purpose of this thesis is to investigate value creation from PCTW for reuse and redesign in Sweden, and to establish a framework for the antecedents of value creation in reverse textile value chains. A pre-study was conducted to map the PCTW industry structure, and served as the basis for sampling cases. Data collection consisted of multiple case studies from 4 charity organisations, 3 clothing brands and 3 redesign brands. The interviews were performed in a semi-structured manner in order to discover the state-of-art in value creation and to identify the key enabling attributes. The findings were analysed to adjust the deductive framework to the textile industry context. Results and findings shows that the state-of-art for value creation among the selected cases varies depending on its mission. Charity organisations are facing a new competition of resources from clothing brands, who have realised a potential of new differentiation by engaging in value creation from PCTW. This has led to a new mind-set among the charity organisations to work more strategically in all their activities. Redesign brands are a relatively new actor and want to work symbolically with redesign to communicate the values in textile materials. Enablers and disablers to value creation from PCTW were found in the interviews and led to the development of an empirical framework. As a whole, this thesis provides rich descriptions of the current preconditions and challenges within the field. Furthermore, it presents a framework for the antecedents of value creation along the recovery processes involved in reuse and redesign value chain. The empirical framework confirms the themes in the theoretical framework, and concludes that there is a set of generic antecedents for value creation in reverse textile value chains. However, there are also category specific antecedents, which need to be considered. The specific experiences of one actor category might as well be valuable knowledge to another, which is why increased collaboration is suggested to enhance value creation from PCTW.
298

Nutrient Availability and Dynamics of Compost Bedded Pack Dairy Barn Waste

Hammond, Leslie 01 January 2015 (has links)
Increased adoption of compost bedded pack dairy barns (CBP), a relatively new housing and manure handling strategy, warrants study to facilitate proper use of CBP waste as a soil amendment. This study: 1) characterized in situ nutrient content and availability of CBP waste in terms of nitrogen (N) and phosphorus (P); 2) examined the decomposition of surface-applied CBP waste compared to an alternative processed solid waste amendment; 3) examined nutrient dynamics of incorporated CBP waste in high and low soil test phosphorus (STP) environments. Quick anaerobic mineralization assays revealed that bed management affects nutrient content and availability of CBP waste. A Fall surface-applied litter bag study showed that different particle sizes of CBP waste and a biosolid decomposed at similar rates. The biosolid had greater nutrient density and availability, but the decomposition was similar to CBP waste in terms of mineralization dynamics. Aerobic mineralization of CBP waste in high and low STP soils amended on a uniform P basis was compared with fresh manure. In general, CBP increased STP more and yielded more plant available P than fresh manure. These studies provide recommendations for CBP management and further study to ensure the proper land application of CBP waste.
299

Visuomenės informavimo atliekų tvarkymo klausimais Lietuvoje analizė / Analysis of public awareness of waste management issues in Lithuania

Pečkys, Artūras 14 June 2010 (has links)
Šio darbo tikslas - išanalizuoti visuomenės informavimo ir švietimo atliekų tvarkymo klausimais reglamentavimą teisės aktuose ir įvertinti regioninių atliekų tvarkymo centrų (RATC), savivaldybių tinklalapių išsamumą ir kokybę bei sukurti internetinę svetainę apie atliekų tvarkymą. Naudotas aprašomasis teisės aktų metodas. Palygintas regioninių atliekų tvarkymo centrų ir savivaldybių tinklalapių išsamumas. Magistro baigiamąjame darbe aprašomas magistro darbo autoriaus sukurtas tinklalapis apie atliekų tvarkymą. www.atliekos.visiems.lt . Alytaus, Šiaulių, Tauragės, Telšių, Kauno regioniniai atliekų tvarkymo centrai privalo rengti ir įgyvendinti visuomenės informavimo programas. Pagal pateikiamos informacijos išsamumą, Lietuvos regioninių atliekų tvarkymo centrų tinklalapiai buvo suskirstyti į 4 kategorijas. Šiaulių ir Telšių regiono atliekų tvarkymo centrų tinklalapiai yra išsamiausi tarp visų regioninių centrų tinklalapių. Neissamūs yra Marijampolės, Panevėžio, Tauragės, Utenos regioninių atliekų tvarkymo centrų tinklalapiai. Atliktas tyrimas parodė, kad dažnai savivaldybių tinklalapiuose nėra atskiros skilties apie savivaldybės atliekų tvarkymo sistemą arba tokiose skiltyje informacija neišsami. Suformuluotos 9 rekomendacijos esamai visuomenės informavimo situacijai pagerinti. / The aim of the paper is to analyze the legal aspects of public environmental education and awareness rising on waste management issues, to evaluate the completeness and quality of the websites of regional waste management centers and municipalities and to develop a web site for waste management issues. Methods of the work: descriptive analysis of the legislation, comparative analysis of educational material on the websites of regional waste management centers in Lithuania. Master's thesis describes the website (www.atliekos.visiems.lt) for waste management developed by the author. Alytus, Šiauliai, Tauragė, Telšiai, Kaunas regional waste management centers according to legislation must develop and implement public awareness programs on waste issues. According to the information provided, Lithuanian regional waste management centers, were grouped into four categories. Websites of Siauliai and Telsiai regional waste management centers are the most developed and complete among of all regional centers. The websites of the waste management centers of Marijampolė, Panevėžys, Tauragė, Utena were among those that mostly lacked comprehensiveness. The research revealed that in the websites of municipalities’ there is no a separate column on municipal waste management system or information in such column is not complete. It was formulated 9 recommendations for the improvement of public environmental education and awareness rising on waste management issues.
300

Urban poverty reduction through municipal solid waste management (MSWM) : a case study of Maseru and Maputsoe in Lesotho.

Mvuma, Godfrey Ganizani Kwantha. January 2002 (has links)
The study was designed to generate data and information necessary for designing an appropriate sustainable solid waste management system, and examining the socio-economic benefits of urban municipal so lid waste management through job creation opportunities (albeit mainly informal) in Lesotho. The review of literature on the integrated solid waste management systems at international, regional and local levels in relation to job creation was carried out with a view to establish the necessity of carrying out this research. In addition, specific solid waste management experiences and practices in other countries have been cited. In Lesotho, investors and donors have, for long expressed the need for formulation of solid waste management policy and guidelines formulated in the country in order to create an enabling environment for investment. However, the process of preparing policy and guidelines requires substantial data and information. This study supplemented this effort by gathering data and information. The data and information gathered were on the existing policies and regulatory framework concerning waste management; waste generation rates, types and quantity from domestic, industrial and commercial establishments; recycling activities; and the waste harvesting (scavenging) activities. The study was undertaken in Maseru and Maputsoe, being the hub of commercial and industrial activities in the country. The data and information may also be useful to other SADC countries From the results of the study, it has been concluded that in Lesotho, paper was the most commonly generated waste in all the categories: domestic, industrial and commercial establishments. Plastic was the second category of the most commonly generated waste, which was followed by organic waste, and then, beverage cans. The study established that the weighted average household generation rate for the surveyed areas was: 0.13 Kg per capita day-I. In the same findings, it occurred that overall, households contribution to waste generation in the surveyed areas ranked second to commercial establishments despite their low per capita, in comparison with industrial establishments. The study has further concluded that out of an estimated total quantity of 157552 tonnes per annum of waste generated in Maseru, commercial establishments contributed 82%, while households contribute 15% and industrial establishments 3%. Households generated more waste than industries because they were in large numbers and hence contributed more than fewer industries. It has also been established that the household waste generation is dependent on incomes ofthese households, but had poor relationship with regard to the number of persons per household. To this effect, it was seen that high-income households generated more waste than low-income. The study further showed that where the municipal council offered waste collection service, not all recipients paid for this service. However, there was a general willingness- to- pay for the waste collection service by all sectors, on condition that there was an improvement in the offering of this service; and if made available where currently not offered. Furthermore, there was a general indication of affordability for these services up to a certain amount (albeit minimal) per different sectors. On the other hand, the information collected strongly indicated the need to invest more in solid waste management if this would be a means of employment creation and improvement of the environment. On the overall, the study revealed that there was a low level of awareness on waste related policy and regulatory instruments, and fragmented legal framework on waste management in Lesotho. The study also established that currently, solid waste as an informal sector generated an estimated profit of MO.7rnillion per annum from waste recycling related activities and that this informal sector generated about 282 jobs. In addition to these benefits, the question of solid waste as a source of biomass energy was another beneficial route in Lesotho. It has been established that the combustible organic waste was highly sought after as a source of energy for cooking and heating. However, besides the benefits, these activities also gave rise to some adverse impacts. The waste harvesters expressed that their health had been negatively impacted upon by the waste scavenging activities. Needless to suggest that there would be a need by the government to intervene in this problem by formalising these waste harvesting activities. It is hoped that this study would serve as a reservoiur for the source of data and information and for Lesotho and that other countries in the SADC Region shall fmd this document a useful tool. / Theses (Ph.D.)-University of Westville, 2002.

Page generated in 0.0877 seconds