• Refine Query
  • Source
  • Publication year
  • to
  • Language
  • 338
  • 23
  • 18
  • 16
  • 2
  • 2
  • 2
  • 2
  • 2
  • 2
  • 2
  • 2
  • 2
  • 1
  • 1
  • Tagged with
  • 456
  • 456
  • 236
  • 120
  • 109
  • 106
  • 99
  • 96
  • 96
  • 69
  • 51
  • 50
  • 50
  • 50
  • 43
  • 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

Coal fly ash waste management challenges in the South African power generation sector and possible recycling opportunities: a case study of Hendrina and Kendal power stations

Ramagoma, Mbavhalelo Justice January 2018 (has links)
A dissertation submitted to the Faculty of Science, University of the Witwatersrand, Johannesburg In fulfillment of the requirements for the degree of Master of Science in Geography and Environmental Studies 31 May 2018 / South Africa will be dependent on coal for power generation for many decades to come, before a complete transition is achieved where more energy will be generated from non-fossil fuel sources. Through case studies of Hendrina and Kendal Power Stations, this study explored how the management of fly ash (FA) waste in South Africa can be improved to minimise its impact on the environment and human health and examined the potential recycling applications that can benefit local communities. The study drew insights from an environmental justice framework to examine the pollution impacts that FA is exposing to the local community. The environmental justice theory is based on the principle that all people have a right to live in an environment that enhances their wellbeing. Empirical evidence obtained from local community’s in-depth interviews revealed that FA is impacting on the health of communities by exposing them to respiratory and other illnesses and it is also affecting their livelihoods which primarily involves farming. A just transition theory was employed to examine potential socio economic opportunities that can be derived from FA recycling to fulfil redistributive measures that can reduce inequality and eradicate poverty in local communities. Some of Eskom’s power stations like Hendrina are nearing the end of their lifespan since their commissioning in the 1960’s and 1970’s. To aid a just transition, ash recycling was found to have the potential to address the socio economic situation of the power station’s employees and the local communities. The study found that local communities generally lack knowledge about coal ash recycling and need to be empowered and supported to partake in ash recycling ventures. The study argues that a shift in the ash recycling regime is needed in order to benefit local communities and facilitate a just transition to a clean energy production. / MT 2018
292

A survey of solid wastes and their current and potential uses in building construction/

Hanna, Makram A. M. January 1974 (has links)
No description available.
293

La participation dans un projet local de gestion des déchets : étude de cas à Curitiba, la capitale écologique du Brésil

Doucet Donida, Andrea. January 1997 (has links)
No description available.
294

Evaluation of municipal solid waste composts for growing greenhouse crops /

Lin, Fei-Wen 01 January 1995 (has links) (PDF)
No description available.
295

A geochemical analysis of municipal solid waste ash

Kirby, Carl Scott 07 June 2006 (has links)
Bulk chemical analysis of a combined municipal solid waste (MSW) bottom and fly ash from one facility showed most elements enriched over average soil abundances. Eleven minerals were identified using powder X-ray diffraction (XRD). Standard additions using XRD gave the following weight % minerals (±2σ): gypsum, 1.8 ± 1.9; hematite, 3.7 ± 1.7; quartz, 2.3 ± 1.0; spinel, approximately 3.5; halite, 0.5 ± 0.4; calcite 3.5 ± 1.9; rutile, 1.1 ± 1.3. Mullite, sylvite, anhydrite, and wüstite were also identified. The ash contained 18% minerals, 9% structural and adsorbed water, and 72% glass. Chemical sequential extraction showed that most Cr is present in phases resistant to chemical weathering, while significant Cd and Pb are sequestered in acid soluble (carbonate) phases. Little of these toxic trace metals are water soluble or in exchangeable surface sites. Batch reactors experiments showed that ash-water solutions were dominated by ions released by soluble salts. Three types of reactions are identified. 1) After rapid exhaustion of soluble salts, sodium and potassium exhibited nearly steady state behavior due to slow release of ions from less-soluble minerals and glasses. 2) Calcium and sulfate concentrations are controlled by either gypsum or anhydrite equilibrium after a few hours. Iron, aluminum, and manganese concentrations rapidly equilibrate with respect to hydroxide or oxide solid phases. 3) Silicon clearly shows temperature dependent kinetic behavior, but its rate of release into solution is slowed by back-reaction of a secondary silicate phase. Calculation of the CIPW normative minerals for MSW ash showed it to be analogous to a tholeiitic basalt. Over the long term, the concentrations of elements in MSW ash will continue to change and can be predicted by Goldschmidt's concept of ionic potential, and mineralogical changes can be predicted based on weathering of basalts. Comparisons of literature values showed that field MSW ash leachates contained higher concentrations of soluble salts and lower concentrations of magnesium, iron, zinc, copper, and nickel than uncombusted refuse leachates. Comparison of chromium, cadmium, lead, and arsenic concentrations did not clearly delineate which leachate contains more of these elements. / Ph. D.
296

Collecting recyclables at corporate sites: attempts to increase employee participation

Randall, Kim D. 24 October 2009 (has links)
The primary purpose of this study was to determine the efficacy of corporate-based recycling for communities without access to curb-side pick up of recyclable material. The secondary purpose was to use the taxonomy of behavior change strategies as devised by Geller et al. (1990a, b). The hypotheses of the study were as follows: 1) corporate-based recycling is an effective means of dealing with residential waste management in a rural community, 2) the effectiveness of one behavior change technique with a score of three (as proposed in the Taxonomy of Behavior Change Techniques) will be the same as an intervention package comprised of several techniques with a score of three, 3) the smaller the company, the more effective the intervention package and, 4) salaried employees will deposit more recyclable materials per person at the drop-off site than wage employees. Recycling drop off sites were established at the work place of rural residents as an alternative to curb-side pick up of recyclable material. Three sites chosen were located in a rural community in Southwestern Virginia. Two of the companies produced machine parts (n= 220, n=300). The third company produced printed material (n=32). Each company had both male and female wage and salaried employees with varying ages and levels of income. Recyclable materials (clear glass, green glass, brown glass and aluminum cans) were collected in four 33 gallon barrels in the parking lot of each company every Friday and weighed at the county collection center. In an attempt to motivate participation in the recycling program, the employees were informed of the availability of the barrels, given written prompts in the form of paycheck inserts and posters, and given group feedback in the form of a poster showing the weekly amount of each material collected at an individual company. One company also received a group meeting to promote consensus and to determine the weakness of the project. All prompts and feedback were given as a package at discrete periods of time in a multiple baseline design by groups. The intervention package was given twice at one site to determine the impact of repeated exposure to the intervention materials. Findings of the study indicated an erratic pattern of participation across the three sites. One site had such low participation that it was dropped from the study. The intervention packages did not significantly increase participation and the differences between wage and salaried employees were insignificant. It must be concluded that while some employees did participate in the recycling program refinements to both the interventions and the measurement techniques are needed. Directions for future research on the feasibility of corporate-based are discussed. / Master of Science
297

Geoenvironmental aspects of coal refuse-fly ash blends

Albuquerque, Allwyn J. 04 December 2009 (has links)
The separate land disposal of coal refuse and fly ash presents difficulties throughout the Appalachian region, both in terms of disposal costs per acre and in terms of its potential environmental impacts on soil, ground water, revegetation, and slope stability. The purpose of this study was to determine how fly ash addition to coal refuse would impact on certain geotechnical properties of the refuse disposal piles, and whether the refuse-fly ash blends would be suitable as co-disposed materials. Accordingly, the compaction, permeability and shear strength characteristics of the refuse-fly ash blends were experimentally determined for varying fly ash percentages. The compaction test results indicated that, with increasing fly ash, the maximum dry density of these blends marginally decreased. The permeability test results showed that the permeability of the test specimens progressively decreased with the increase in fly ash. The shear strength results demonstrated that the addition of fly ash did not significantly influence the shear strength of the refuse. The critical factor of safety determined during slope stability analysis revealed that the tested slope geometries were stable for long term, drained conditions (using the STABGM computer program). The volume change analysis determined that there was a minimal expansion in the volume of refuse when it was blended with fly ash. However, it may be noted that all the stated results depend on a number offactors, including the nature of the refuse and fly ash used. Therefore, these findings would be specific to bulk blends of coal refuse and fly ash only. In general, this study indicates that fly ash can be beneficially reused with respect to the geotechnical properties evaluated. Co-disposal of fly ash and coal refuse may be a reasonable alternative to present disposal methods. / Master of Science
298

Values and concerns in decision-making about a waste-reduction incinerator at Stormsriver, Tsitsikamma : a case study in applied ethics

Maharajh, Rajinder Jain 12 1900 (has links)
Thesis (MPhil)--Stellenbosch University, 2003. / Full text to be digitised and attached to bibliographic record. / ENGLISH ABSTRACT: The Tsitsikamma Forest, in the most southern part of the Eastern Cape, is part of the Cape Floral Kingdom, one of six such Kingdoms in the world. It has the richest area of plant bio-diversity and fauna in the world which are rare and endemic to the area. The deep gorges, temperate forests, un spoilt oceans and various other features such as the famous Bloukrantz River Bridge, where the world's highest bungi jumps take place are factors that have become the main source of job-creation and income for tourism and its inter-related activities. However, this ecosystem is also home to about 480 families who live in low-income housing at Stormsriver. This settlement which was relocated from the shack area of Coesa, nearby, has an unemployment index of 67% and a similar poverty index. In addition, the Stormsriver Village nearby has a population of about 300 families, mainly older retired white folks. The area is administered by the Koukamma Municipality which is an amalgam of several smaller municipalities viz., Clarkeson, Kareedouw, Stormsriver, Woodlands, Eerste River, ]oubertina and Bloukrantz. Waste reduction and the disposal thereof has always been a major concern to local authorities and the Koukamma Municipality is obviously faced with the same challenge. The authorities have resorted to the concept of landfill sites, which has proven to be the cheapest solution to date. But, with this option comes the problems of health risks to the poorer people who converge on the dump sites in search of food, the harm to children searching through rubbish heaps and the various legal repercussions emanating out of this practice. The option of open-burning and its related effects on human life and forest fires rules it out as an option. Transporting waste out of the area is also very costly. It was then resolved by the Koukamma Municipalities that the possibility of installing an incinerator at Stormsriver would be an option to be investigated. The reasoning behind the selection of this site was the concern of high unemployment in the Stormsriver area and extreme poverty and this venture would in some small measure create jobs, put food on the table and break the poverty cycle. The process of incineration gives rise to emissions such as dioxins and furans which is known to cause cancer, asthma and tuberculosis, if subjected in high doses over a long period of time. It is also regulated by the Atmospheric Pollution Act 45 of 1965. The important moral debate at the core of this problem is the whole question of humans rights and should these be violated solely because the subjects do not belong to an affluent class and should be shown less respect and have their health jeopardised by the toxic air from incineration. Or, should the people's poverty index rise further due to lack of employment. The question that also begs here is whether the well-being of the entire ecosystem, especially the rare and endangered plants and animals take preference over the well-being of the people of Stormsriver, given that the emissions from the incinerator will impact on the animal, bird and plant life, including that of water, soil and air. This would also put into jeopardy the income generated by Tourism and the jobs inherent in it for the locals and would threaten the area's sustainability. The various moral views of philosophers have been canvassed in order to come to a holistic understanding. I have in this vein looked at the views of ethicists such as Tibor Machan, who believes that animals and other organisms do not have any rights and are there purely for human consumption. Then the views of Peter Singer and Tom Regan have also been included, in which consideration is shown to animals. Others such as AIda Leopold, J. Baird Callicott and Paul Taylor whose thinking extends to that of not just showing respect for a single entity but allows for equal respect for all members of the biotic community, have also been. considered. Various solutions have thereafter been considered and amongst those are the relocation of the incinerator out of the Stormsriver, moving the plant to the industrial zone at Kareedouw, transporting the waste out to Port Elizabeth, dumping and finally the 'Do Nothing' option. Using Paul Taylor's "respect for nature" ethics as a guide, I have come to the conclusion that the installation of a waste-reduction incinerator at Stormsriver, Tsitsikamma, may be supported subject to a set of serious riders and conditions in that firstly, the health of the immediate and surrounding inhabitants should not be affected in any way whatsoever. Secondly, the well-being of the non-human environment which must include air, soil, water and plant life, including the animal and bird life must not be harmed in any way. In this way all members of the biotic community will be shown equal respect, thus creating a viable and sustainable community / AFRIKAANSE OPSOMMING: Die Tsitsikamma Woude, in die mees suidelike deel van the Oos-Kaap, is deel van die "Cape Floral Kingdom", een van ses sulke woudgebiede in die wêreld. Dit beskerm die rykste area van plant bio-verskeidenheid asook fauna wat skaars is in die wêreld en slegs daar gevind word. Die diep bergpasse. gemagtigde woude en ongerepte oseaan, tesame met die beroemde Bloukransrivier brug waar die wêreld se hoogste bungi spronge plaasvind is faktore wat bygedra het dat werkskepping en inkomste hoofsaaklik uit toerisme en verwante bedrywe afkomstig is. Hierdie eko-sisteem is ook die tuiste vir ongeveer 480 gesinne wat in sub-ekonomiese huise in Stormsrivier woon. Hierdie gemeenskappie wat vanaf die naby geleë Coesa hervesig is, het 'n werkloosheid sowel as armoede syfer van 67%. Bykomend is daar die Stormsriver nedersetting daar naby met 'n bevolking van 300 families, hoofsaaklik ouer, afgetrede blankes. Die gebied word bestuur deur die Koukamma Munisipaliteit wat in 'n samesmelting van 'n hele paar kleiner munisipaliteite is o.a Clarkson, Kareedouw, Stormsrivier, Woodlands, Eerste Rivier, ]oubertina en Bloukrans. Die vermindering van afvalstowwe asook die verwydering daarvan was maar altyd 'n groet kopseer vir die plaaslike owerhede en dit geld nou ook vir die Koukamma Munisipaliteit. Die owerhede het besluit op die konsep van afvalstortings areas omdat dit die goedkoopste oplossing tot nou toe is. Met hierdie opsie kom egter die probleem van gesondheids risiko's vir die armer gemeenskappe (mense) wat op hierdie stortings terreine toesak op soek na kos, die beserings wat kinders opdoen wat die gemors deursoek asook die wettige terugslag wat hierdie praktyk totgevolg het. Die gevaar van oop vure en die effek wat dit sou hê op mense en die woud self maak dat hierdie opsie nie oorweeg word nie. Ook is dit te duur om afvalstowwe uit die gebied uit te vervoer. Die Koukamma Munisipaliteit het toe besluit om die instállering van 'n verbrandingsoond by Stormsrivier te ondersoek. Die rede om hierdie gebied te kies was die hoë werkloosheid syfer en armoede in Stormsrivier. Hierdie besluit sou werkskepping, kos op die tafel en die verbreking van die armoede-siklus tot gevolg hê. Die proses van verbranding het aanleiding gegee tot die nuwe gevare van skadelike afval produkte van dioksiede en furane wat kanker, asma en tuberkulose tot gevolg het as mense vir lang periodes aan hoë dosisse blootgestel word. Hierdie uitstraling word ook deur die "Atmosferiese Besoedelingswet 45 van 1965" gereguleer. Die belangrike morele debat wat die kern van hierdie probleem vorm is die vraag na menseregte en of die menseregte geskend kan word bloot omdat die mense in die gebied nie aan 'n gegoede klas behoort nie moet daar minder respek aan hulle getoon word en moet hul gesondheid in die weeg skaal geplaas word deur die giftige lug as gevolg van die verbrandering van afvalstowwe, of moet werkloosheid verder styg as gevolg van die gebrek aan werk? Die ander vraag wat gevra moet word is of die welvaart van die hele ekosisteem, veral die van skaars en bedreigde plante en diere voorkeur moet geniet bo die welvaart van die mense van Stormsrivier gegee die feit dat die uitstraling van die verbrandingsoond ook 'n inpak gaan hê op die diere, voëls en plant lewe inkluisend op water, grond en lug. Dit sal ook die inkomste wat uit Toerisme voort gebring word, en die werksgeleenthede vir die plaaslike mense wat daarmee gepaard gaan, in die weegskaal plaas asook die gebied se standhoudendheid bedreig. Die verskeie standpunte van filosowe is na gekyk ten einde tot 'n holistiese verstaan van die situasie te kom. Langs hierdie weg het ek dan na die etiese standpunt van Tibor Machan gekyk. Tibor Machan glo dat diere en ander organismes geen regte het nie en dat hulle daar is vir die uitsluitlike gebruik deur mense. Die standpunte van Peter Singer en Tom Regan, wat 'n mate van sorgsaamheid teenoor diere toon, is ook in ag geneem. Andere wie se standpunte in ag geneem is, is Aldo Leipold,J. Baird Callicot and Paul Taylor. Hulle denkrigting maak voorsiening daarvoor dat respek nie net aan 'n enkele entiteit getoon moet word nie, maar aan almal wat in 'n biotiese gemeenskap saamwoon. Verskeie oplossings is hierna oorweeg onder andere die verskuiwing van die verbrandingsoond buite Stormsrivier na die industriële gebied in Kareedouw, die vervoer van die afval na Port Elizabeth, storting asook die "Doen Niks" opsie. Ek het as etiese riglyn Paul Tayor se "respekteer vir natuur" gebruik en het tot die slotsoom gekom dat die iristallering van 'n afval verminderings verbrandingsoond te Stormsrivier ondersteun kan word met ernstige voorbehoude en voorwaardes deurdat, eerstens, die gesondheid van die onmiddelike en omliggende inwoners op geen manier hoegenaamd aangetas moet word nie. Tweedens, die welvaart van die nie-lewende omgewing met inagneming van lug, grond, water en plantlewe, insluitende die diere en voëls moet op geen manier geskaad word nie. Op hieride maruer sal almal wat deel uitmaak van die biotiese gemeenskap gelyke respek betoon word wat die daarstelling van 'n lewensvatbare en standhoudende gemeenskap tot gevolg sal hê.
299

Municipal solid waste management and recycling: a comparison of Hong Kong and Beijing

鄭彩如, Cheng, Choi-yu. January 2003 (has links)
published_or_final_version / abstract / toc / China Area Studies / Master / Master of Arts
300

澳門政府管理城市固體廢物之政策執行及評估

楊艷紅 January 2018 (has links)
University of Macau / Faculty of Social Sciences. / Department of Government and Public Administration

Page generated in 0.0824 seconds