• Refine Query
  • Source
  • Publication year
  • to
  • Language
  • 47
  • 28
  • 7
  • 3
  • 3
  • 2
  • 2
  • 2
  • 2
  • 2
  • 2
  • 1
  • 1
  • 1
  • 1
  • Tagged with
  • 105
  • 105
  • 36
  • 24
  • 21
  • 21
  • 20
  • 19
  • 18
  • 18
  • 14
  • 14
  • 12
  • 11
  • 10
  • 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.
91

Biosurveillance des retardateurs de flamme organophosphorés chez les travailleurs du recyclage électronique au Québec

Traore, Inna Tata 05 1900 (has links)
No description available.
92

Plýtvání potravinami v USA jako otázka tvorby federální politiky / Food Waste in the United States as an Issue of Federal Public Policy Making

Hlaváčková, Anna January 2020 (has links)
The Master's thesis "Food Waste in the United States as an Issue of Federal Public Policy Making" analyzes the role of the federal government in dealing with food waste. It mainly focuses on federal legislation, but it also examines actions on the state level to illustrate the contrast between the two. In the thesis, the author examines the causes and sources of food waste, federal jurisdiction for intervention, and the history of passed legislation, as well as proposed legislation, and solutions. The main goal of the thesis is to demonstrate that federal involvement is fundamental in achieving any significant change, but so far has failed to do so. Primary literature consisting largely of bills, materials published by federal agencies, and reports by non-profit organizations were used to uncover the character of passed legislation. Academic secondary literature in the form of articles, reports, and factsheets offered context to understand the scope and impacts of the legislation. Analysis of those sources revealed federal authority to deal with the issue, as well as possible obstacles standing in the way of an extensive federal intervention. Research also showed that in the absence of federal action, some states have stepped up to introduce legislation to reduce food waste, but this legislation is...
93

Formulation de mélanges de polyoléfines à l’aide d’une extrudeuse à très haute vitesse : Application à la dispersion de particules de traceurs, détectables par fluorescence X ou UV, en vue du tri de déchets polymères post-consommation / Formulation of polyolefin blends using high shear extruder : Application of this technique to the dispersion of particles of tracers detectable by X or UV fluorescence for sorting polymers from post-consumer waste

Louizi, Molka 04 December 2013 (has links)
Cette thèse, qui s’inscrit dans le cadre du projet ANR Eco-Tech TRIPTIC, a eu comme objectif de contribuer au tri industriel en cadence de polymères contenant des traceurs détectables grâce à leurs propriétés en fluorescence X ou UV. Dans un premier temps, étant donné que le coût des traceurs choisis pour l’étude TRIPTIC est assez élevé, nous avons réalisé une étude préliminaire, avec des particules modèles de silice, visant à optimiser la dispersion de charges dans une matrice polypropylène/éthylène propylène rubber (PP/EPR). Nous avons montré que l’extrusion à taux de cisaillement élevé est une technologie efficace permettant une dispersion homogène de charges de tailles micro ou nanométriques. Dans un deuxième temps, après optimisation des conditions de dispersion, nous avons extrapolé nos résultats à la dispersion de particules de traceurs UV dans différentes matrices thermoplastiques. Nous avons montré que la dispersion de 1000 ppm de particules de traceurs, de tailles micrométriques, dans des matrices polypropylènes, en extrusion à haute vitesse (N= 800 rpm), n’a pas d’impact sur les propriétés mécaniques et physico-chimiques des mélanges tracés, ainsi que sur la photo-dégradation sous rayonnement UV. Cette fine dispersion a non seulement permis la conservation des propriétés des polymères tracés mais aussi une bonne détection dynamique, tant en fluorescence X qu’UV, sur un prototype conçu par des partenaires du projet (Pellenc Selective Technologies, CEA-LITT et ENSAM- LCPI). Enfin, nous avons validé l’extrusion à haute vitesse pour compatibiliser des mélanges de polymères ternaires (PP/EPR)/PE (polyéthylène) pouvant correspondre à la valorisation de polymères post-consommation, par exemple dans l’hypothèse où on souhaite recycler (PP/EPR) et PE ensembles. Les propriétés prometteuses des mélanges obtenus doivent leur permettre de trouver des applications dans l’industrie automobile, par exemple. Cette voie est d’un grand intérêt pour les applications industrielles, car elle permet d’envisager des propriétés mécaniques élevées pour les polymères recyclés. Elle ouvre aussi de nouvelles perspectives pour l’élaboration de matériaux allégés, obtenus à partir de matières vierges ou recyclées. / This thesis, which is part of the ANR Eco-Tech TRIPTIC project, had the objective of contributing to industrial sorting rate of polymers containing tracers detectable by their fluorescence X or UV properties. At first, given that the cost of tracers selected for TRIPTIC study is quite high, a preliminary study is conducted with models of silica particles to optimize the dispersion of fillers in polypropylene / ethylene-propylene rubber (PP / EPR) matrix. It was found that processing under high shear rate is an effective technology for accomplishing a homogeneous dispersion of micro or nanoscale fillers. In a second step, after optimization of dispersion conditions, our results are extrapolated to the dispersion of UV tracer in different thermoplastic matrices. It was shown that the dispersion of 1000 ppm of micrometer tracer particles, in polypropylene matrices, extruded at high shear rates (N = 800 rpm), has no impact on the mechanical and physico-chemical properties as well as in the photo-degradation of the polymer after UV irradiation exposure. This fine dispersion was beneficial not only for the conservation of the properties of traced polymers but also for achieving a good dynamic detection of UV or X tracers using a prototype developed by the project partners ( Pellenc Selective Technologies , CEA- LITT and ENSAM - RPI ). Finally, high shear processing has successfully used to the compatibilization of ternary blends ( PP / EPR ) / PE (polyethylene) which may correspond to the post-consumer polymers. This technique has proved to be an effective method to produce polymer blends with unique mechanical properties. This novel strategy of compatibilization is of a particular interest, especially for industrial application prospects. It also opens new perspectives for materials lightening as well as “high shear recycling” of immiscible polymers.
94

Эколого-экономическая эффективность переработки бытовых пластиковых отходов : магистерская диссертация / Environmental and economic efficiency of household plastic waste recycling

Паситов, В. И., Pasitov, V. I. January 2019 (has links)
Пластиковые отходы занимают первое место по стоимости и скорости накопления среди твердых коммунальных отходов. Вторичное использование отходов пластика способствует существенному сокращению использования первичных ресурсов, снижению вредного воздействия на окружающую среду. Цель исследования заключается в разработке практических рекомендаций по оптимизации схем переработки бытовых пластиковых отходов на основе оценки их эколого-экономической эффективности исходя из анализа существующей ситуации в системе обращения с отходами в Свердловской области. В работе проведен анализ региональной политики по обращению с отходами и опыта переработки твердых коммунальных отходов. Предложен проект по созданию производства по переработке ПЭТ-пластика с оценкой его эколого-экономической эффективности. Впервые количественно оценен дополнительный экологический эффект от замены первичного сырья на вторичное при реализации проекта. / Plastic waste takes first place in terms of cost and rate of accumulation among municipal solid waste. Recycling of plastic waste contributes to a significant reduction in the use of primary resources, reducing the harmful effects on the environment. The purpose of the study is to develop practical recommendations for optimizing recycling schemes for household plastic waste based on an assessment of their environmental and economic efficiency based on an analysis of the current situation in the waste management system in the Sverdlovsk region. The work analyzes the regional policy on waste management and the experience of processing municipal solid waste. A project is proposed to create a production for processing PET plastic with an assessment of its environmental and economic efficiency. For the first time, the additional environmental effect of replacing primary raw materials with secondary ones during project implementation was presented.
95

Household participation in domestic waste disposal and recycling in the Tshwane Metropolitan Area : an environmental education perspective

Kamara, Agnes Jonton 02 1900 (has links)
The aim of this study was to investigate the factors influencing household awareness and participation in domestic waste disposal and recycling, focusing on environmental educational (EE), wealth and location of suburb. The study was carried out in four suburbs in the Tshwane Metropolitan Area (TMA), namely Waterkloof, Lynnwood, Sunnyside and Mamelodi. A literature review was conducted, covering concepts of domestic waste management - waste prevention, collection, recycling and reuse, followed by household analysis using empirical data. The analysis shows that there is a low level of household awareness about the environmental implications of domestic waste management in TMA, and hence low level of participation in domestic waste sorting, disposal and recycling. Among relevant factors are the level of EE and income of the households across all suburbs. This calls attention to the need for strengthening EE not only in schools, but also in suburbs using both formal and informal outreach programmes. / Educational Studies / M. Ed. (Environmental Education)
96

An evaluation of electronic waste management in Ba-Phalaborwa local municipality, Limpopo Province, South Africa

Tshimbana, Tsakani Permlar 30 May 2014 (has links)
An evaluation of electronic waste (e-waste) management in Ba-Phalaborwa Local Municipality was undertaken in this study. The aim of the study was to evaluate the electronic waste management practices such as generation, storage, collection, transportation and disposal in Ba-Phalaborwa Local Municipality. This was achieved through questionnaires distributed to residents in Namakgale and Phalaborwa residential areas, structured interviews with municipal workers under the Environmental Health Division and observation in the landfill site and collection points were also used in gathering information on the electronic waste management. In the study it was found that a wide range of electronic waste is generated and lighting equipment, small household equipment and ICT equipment are disposed of in large numbers in the study area. The municipality is responsible for waste management in the study area. Electronic waste generated is stored, collected and disposed together with all other domestic waste in the area. No segregation or recycling at household level was evident. It was also found that the municipality does not have a formal relationship with electronic waste recycling companies to eliminate the flow of electronic waste from households to the landfill site. A lack of own regulatory and by-laws on electronic waste was noted and seemed to be one of the challenges the municipality is facing. The findings highlighted the low level of community awareness regarding electronic waste. The study concluded that there is a lack or absence of good management of electronic waste storage, collection, transportation in the Ba-Phalaborwa Local Municipality. From the study, it is recommended that there is a need for meaningful community awareness, environmental education, formulation of by-laws and formal recycling projects for effective electronic waste in Ba-Phalaborwa Local Municipality. / Environmental Sciences / M. Sc. (Environmental Management)
97

Waste electrical and electronic equipment (e-waste) management and disposal methods in the city of Addis Ababa, Ethiopia

Abenezer Wakuma Kitila January 2018 (has links)
E-waste is a world-wide, interregional, and domestic problem. E-waste management is a challenging task not only due to its speedily increasing volume but more outstandingly because of its hazardous nature. This study examined the e-waste management and disposal methods in the city of Addis Ababa to propose appropriate e-waste management model. Further, it attempted to comprehend the existing policy gap by identifying the different obstructions to the adoption of e-waste management policy. To this end, the study employs both descriptive and explanatory research designs. It selected 100 household heads from Bole and NSL sub-cities, 72 GSD personnel from the educational institutions and governmental sector offices, and 6 higher government officials. The quantitative data were analysed using IBM SPSS 21. Thus, the frequencies, the chi-square tests, t-tests, a one-way ANOVA, the partial and product-moment correlations, the ordinal, multiple and Poisson regression models were computed. The qualitative data were analysed using ATLAS ti 7. The findings of the study revealed that most of the respondents were not aware of e-waste and its management. The households generated about 4,010 number of non-functional, 2,077 obsolete, and 1,856 broken e-waste. Besides, the educational institutions and governmental sector offices generated about 11,153 non-functional, 15,911 obsolete, and 11,360 broken e-waste. The monthly income was statistically significant in the e-waste management whereas family sizes, gender, and educational qualifications were insignificant. The major e-waste causes encompass rapid obsolescence rate, breakage, and the demands for extra and innovative models or designs of electronic gadgets. The most common e-waste disposal method was storing. The recycling, reusing, donation, and refurbishing of e-waste had hardly been practiced. The study found the absence of good disposal methods and recyclers as the root causes for the prolonged storage and improper disposal of e-waste. E-waste laws, legislation, projects, activities, and recycling centres were non-existent. What is more, the administrative, economic, and socio-cultural challenges triggered the poor e-waste management of the city. Based on the findings, the study proposed a workable e-waste management model, which would most likely result in efficient and sustainable e-waste management in the city. Further, it calls for the stakeholders to work jointly to ensure proper e-waste management. / Geography / D. Lit. et Phil. (Geography)
98

Household participation in domestic waste disposal and recycling in the Tshwane Metropolitan Area : an environmental education perspective

Kamara, Agnes Jonton 02 1900 (has links)
The aim of this study was to investigate the factors influencing household awareness and participation in domestic waste disposal and recycling, focusing on environmental educational (EE), wealth and location of suburb. The study was carried out in four suburbs in the Tshwane Metropolitan Area (TMA), namely Waterkloof, Lynnwood, Sunnyside and Mamelodi. A literature review was conducted, covering concepts of domestic waste management - waste prevention, collection, recycling and reuse, followed by household analysis using empirical data. The analysis shows that there is a low level of household awareness about the environmental implications of domestic waste management in TMA, and hence low level of participation in domestic waste sorting, disposal and recycling. Among relevant factors are the level of EE and income of the households across all suburbs. This calls attention to the need for strengthening EE not only in schools, but also in suburbs using both formal and informal outreach programmes. / Educational Studies / M. Ed. (Environmental Education)
99

An evaluation of electronic waste management in Ba-Phalaborwa local municipality, Limpopo Province, South Africa

Tshimbana, Tsakani Permlar 30 May 2014 (has links)
An evaluation of electronic waste (e-waste) management in Ba-Phalaborwa Local Municipality was undertaken in this study. The aim of the study was to evaluate the electronic waste management practices such as generation, storage, collection, transportation and disposal in Ba-Phalaborwa Local Municipality. This was achieved through questionnaires distributed to residents in Namakgale and Phalaborwa residential areas, structured interviews with municipal workers under the Environmental Health Division and observation in the landfill site and collection points were also used in gathering information on the electronic waste management. In the study it was found that a wide range of electronic waste is generated and lighting equipment, small household equipment and ICT equipment are disposed of in large numbers in the study area. The municipality is responsible for waste management in the study area. Electronic waste generated is stored, collected and disposed together with all other domestic waste in the area. No segregation or recycling at household level was evident. It was also found that the municipality does not have a formal relationship with electronic waste recycling companies to eliminate the flow of electronic waste from households to the landfill site. A lack of own regulatory and by-laws on electronic waste was noted and seemed to be one of the challenges the municipality is facing. The findings highlighted the low level of community awareness regarding electronic waste. The study concluded that there is a lack or absence of good management of electronic waste storage, collection, transportation in the Ba-Phalaborwa Local Municipality. From the study, it is recommended that there is a need for meaningful community awareness, environmental education, formulation of by-laws and formal recycling projects for effective electronic waste in Ba-Phalaborwa Local Municipality. / Environmental Sciences / M. Sc. (Environmental Management)
100

Remoção de matéria orgânica e cor de efluente kraft por adsorção usando carvão ativado e argila

Hinojosa, Eduardo Alberto Lazo 17 October 2014 (has links)
CAPES / Atualmente há preocupação da sociedade em relação aos impactos gerados pelas indústrias ao meio ambiente. Para produção de celulose e de papel é usada grande quantidade de água, madeira e produtos químicos, sendo gerado efluente nos diferentes processos produtivos da indústria. A matéria orgânica e a cor do efluente do processo Kraft se devem à presença de moléculas derivadas da lignina que são difíceis de serem removidas ou biodegradadas. Com vistas à remedição deste efluente, o presente trabalho busca avaliar a remoção de cor e matéria orgânica residual de efluente de celulose Kraft pré-tratado biologicamente, usando carvão ativado de casca de coco e argila montmorilonita pelo método de adsorção através de delineamentos experimentais. Para remoção de cor e matéria orgânica foram avaliados os fatores: a) pH do efluente; b) massa do material adsorvente no processo de adsorção e c) temperatura. A capacidade de adsorção de matéria orgânica e cor no carvão ativado e argila montmorilonita foram determinados pelo modelo matemático de Langmuir e Freundlich, por meio de ensaios de construção de isotermas de adsorção em efluente Kraft. O efluente foi caracterizado quanto a DQO, DBO5,20, COT e cor verdadeira antes e depois do tratamento terciário. Para o tratamento do efluente foram empregadas duas temperaturas: 25 e 40°C, seguiu-se planejamento fatorial completo 32 em triplicata com ponto central tendo como variáveis pH (5,0; 6,0 e 7,0) e massa de material adsorvente (0,5; 1,0 e 1,5 g). O planejamento experimental utilizado permitiu obter os melhores resultados com carvão ativado em 40 °C, pH 7,0 e 1,5 g de adsorvente com remoção de: 98% de COT, 83% de DQO, 97% de DBO5,20 e 95% de cor verdadeira e para argila em temperatura de 40 oC, pH 7, e 1,5 g de adsorvente com remoção de: 55% de COT, 50% de DQO, 90% de DBO5,20, e 56% de cor verdadeira. A principal variável responsável pela remoção de cor e matéria orgânica foi a massa de adsorvente seguida do pH. Também foi avaliada a possibilidade de aproveitamento do resíduo obtido a partir do processo de adsorção na incorporação de cinzas de carvão na produção de argamassas com teores de 0,4%, 1,0% e 1,2%; em cimento portland, areia e água com tempos de cura de 7 e 28 dias fazendo testes de resistência à compressão. Para a reutilização da argila foram utilizados 15% de argila do processo de adsorção, 25% de vidro e 60% de argila vermelha, para a confecção de corpos de prova cerâmico à temperatura de 1100 oC a 1150 oC. De modo geral, o processo de tratamento proposto neste trabalho utilizando carvão ativado, demostrou ser boa alternativa comparado com argila montmorilonita para redução de cor e matéria orgânica residual do efluente de processo Kraft, tendo-se em vista a utilização da cinza do carvão utilizado no processo de adsorção como um agregado para formação de argamassas na construção civil e argila utilizada na adsorção como material cerâmico. / Nowadays, there is a concern of society regarding the impacts caused by the industries on the environment. Large amounts of water, wood and chemichal are used to produce cellulose and paper, and contaminated effluents are generated through the various industrial processes associated. The organic matter and the color of the Kraft effluent are due to the presence of lignin-derived molecules that are difficult to be removed or biodegraded. With intent to remediate this effluent, this study aim to evaluate the removal of color and residual organic matter from biologically pretreated Kraft effluent, using activated carbon from coconut shell and montmorillonite clay by adsorption method through experimental designs. For the color and organic matter removal, the following factors were evaluated: a) pH of the effluent; b) the mass of the adsorbent material in the adsorption process and c) temperature. The adsorption capacity of organic matter and color in the activated carbon and in the montmorillonite clay were determined by the mathematical model of Langmuir and Freundlich, by means of isotherm adsorption construction in Kraft effluent.The effluent was characterized by COD, DBO5,20, COT and true color before and after the tertiary treatment. For it treatment two temperatures were employed: 25 °C and 40 °C, followed by a 32 full factorial design with center point in triplicate, using pH (5.0, 6.0 and 7.0) and masses of adsorbent material (0.5, 1.0 and 1.5 g) as variables. The experimental design used showed that the best results with activated carbon are obtained at 40 ° C, pH 7.0 and 1.5 g of adsorbent with removals of 98% of TOC, 83% of COD, 97% of BOD5,25 and 95% of true color. With clay, the best results occurred at temperature of 40 ° C, pH 7, and 1.5 g of adsorbent to remove 55% of COT, 50% of COD, 90% of BOD5,20 and 56% of true color. The main responsible for the removal of color and organic matter was the mass of adsorbent, followed by the pH. It was also evaluated the possibility of using the residue obtained from the adsorption process in the incorporation of carbon ash to produce mortars with levels of 0.4%, 1.0% and 1.2% in Portland cement, sand and water, with curing times of 7 and 28 days, for which compressive strength tests were performed. To reuse the clay, 15% of the clay from the adsorption process was used, together with 25% of glass and 60% of red clay, in order to construct ceramics bodies specimen generated at temperatures from 1100 °C to 1150 °C. The treatment process proposed in this work using activated carbon demonstrated to be, in general, a good alternative compared to montmorillonite clay for the color reduction and residual organic matter removal from Kraft process effluent, while residues from both process can be used as aggregates for mortars and ceramic body production.

Page generated in 0.1976 seconds