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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.
1

Identifying the prospects of job creation along the value chain of plastic recycling

Bala, Siwapiwe January 2021 (has links)
Magister Commercii - MCom / South Africa is faced with a triple threat of poor economic growth, poverty and unemployment. Concurrently, the production of waste is increasing predominantly among urban areas. If catered for, the informal recycling sector has the potential to create a notable amount of opportunities for improving livelihoods and generating jobs. Street Waste Pickers (SWPs) are identified as individuals who collect recyclable waste material from households or industrial firms with the aim of selling them to recycling firms. This study aims to identify the barriers and challenges for job creation along the value chain of plastic recycling that SWPs face in the urban regions of Cape Town. In the absence of national database on the informal recycling sector, this study utilises primary data collection methods in the form of semi-structured interviews and questionnaires. The findings in this study indicate that the informal recycling economy is predominantly male-dominated. This is particularly due to the labour-intensive nature of the activities in this sector. Furthermore, the informal recycling economy possesses little to no barriers of entry. This is substantiated by the slight difference found in the comparison of earnings by race, age and educational attainment. These results reveal that initiatives to absorb these individuals could potentially curb the large amount of unskilled unemployed citizens of South Africa and simultaneously help decrease the level of unemployment in the country.
2

TRATAMENTO DO EFLUENTE DE UMA RECICLADORA DE PLÁSTICOS UTILIZANDO COAGULANTE NÃO METÁLICO E COMPOSTAGEM / EFFLUENT TREATMENT FROM THE PLASTIC RECYCLING INDUSTRY USING NON-METALLIC COAGULANT AND COMPOSTING

Casali, Dionisio Junior 27 May 2011 (has links)
Plastic is the most consumed raw material in the modern world and recycling is vitally important, both in society and the environment, however this activity generates a liquid effluent with high organic values which must be properly treated. The traditional physical chemical treatment method using coagulation generally features aluminum or iron based coagulants, however the slurry generated in this process contains heavy metals, resulting in improper slurry that is not suitable for any other application and must be directed to an industrial landfill. This study details an environmentally friendly process for effluent treatment, with organic tannin using as a flocculant agent on waste water from the polypropylene plastic recycling industry. Results show a 78.4% COD reduction and more than 90% of some heavy metal contamination had been removed. With the resulting slurry composting was carried out, utilizing conic windrows with native grass and rice hull as organic substrates, obtaining a compound that can be used as organic fertilizer. The organic tannin application proved to be a perfectly suitable coagulant opposite traditional metallicbased coagulants, and had the advantage that the slurry can be used as a composting raw material to produce a natural fertilizer liable for agricultural applications. / O plástico é considerado a matéria prima mais utilizada no mundo moderno, sua reciclagem é de vital importância para a sociedade e ambiente, contudo esta atividade gera um efluente líquido, com alta carga orgânica, a qual deve ser corretamente tratada. Os métodos tradicionais de tratamento físico-químico, via floculação comumente utilizam coagulantes a base de alumínio ou ferro, porém o lodo gerado nesse processo acaba por conter metais pesados, podendo resultar num lodo impróprio para outro fim a não ser a destinação para aterros industriais. Neste trabalho foi desenvolvido um tratamento ambientalmente adequado de efluente de uma indústria de reciclagem de resíduo plástico de polietileno, utilizando tanino vegetal como agente floculante. Obteve-se reduções na DQO de 78,4%, e de alguns metais pesados acima de 90%. Com o lodo resultante foi feita a compostagem com emprego de leiras cônicas utilizando campo nativo e casca de arroz como substratos vegetais resultando em um composto que pode ser utilizado como adubo orgânico. O emprego de taninos vegetais mostrou-se perfeitamente adequado em frente aos coagulantes metálicos tradicionais, com a vantagem de seu lodo poder servir de insumo para compostagem gerando adubo orgânico passível de aplicação agrícola.
3

Livsmedelsföretags problematik i omställningen till återvinningsbar plastanvändning / Food companies’ problems in the transition to recyclable plastic use

Tveiten, Kristoffer January 2020 (has links)
This study aims to identify problems that food companies may encounter during the transition from un-recyclable plastic packaging, to recyclable plastic packaging. The study is based on a survey and a case study. The survey was answered by 16 food companies who, with their signature of the Plastinitiativet 2022, have taken responsibility for increasing the recyclability of their plastic packaging. The case study focuses on a food company that may want to sign Plastinitiativet 2022, but first need to know more about their current plastic usage and what possibilities they have to increase the recyclability of their plastic package. Both studies show that food companies may experience some problems in the transition to a more recyclable plastic usage. A change in the plastics material and color may result in unexpected problems. Multilaminates and barrier materials have special functions but lower the recyclability. Laser marking and/or minimal printing, labels, shrink labels and adhesives on the packaging do not appear to be problematic for most of the companies. Signing Plastinitiativet 2022 seems to motivate the food companies to take measures, to increase the recyclability of their plastic packaging. All food companies will probably encounter problems of varying severity. The severity varies depending on the type of plastic used at present and the type of food that is packaged. The transition is also likely to contribute to higher materials- and staff costs for food companies.
4

Åtgärder för minskade utsläppskostnader : En förstudie till försorteringsanläggning för utsortering av plast

Assaf, Carlo, Röstedal, Simon January 2023 (has links)
Undersökningen syftar till att ge en bild av vilka förutsättningar och möjligheter det finns för uppförande av en försorteringsanläggning där plasten i avfallet kan sorteras ut. Detta sker genom att undersöka ekonomiska besparingar genom minskat behov av utsläppsrätter, identifiera lämplig utsorteringsteknik, utreda hur avsättningen för utsorterad plast kan se ut genom att identifiera potentiella mottagare samt kostnader för avsättning och transport. Undersökningen tyder på att NIR-teknik är den mest lämpliga för en försorteringsanläggning. Med Svensk Plaståtervinning som mottagare beräknas en framtida försorteringsanläggning kunna minska mängden plast som går till förbränning med 48%. Detta motsvarar en kostnadsbesparing i utsläppsrätter på 7 670 000 kr per år med dagens utsläppsrättspriser och 9 850 000 kronor per år med estimerade värden för framtidens utsläppsrättspriser. En medförd årlig transportkostnad av den utsorterade plasten till mottagare beräknas uppgå på 632 000 kronor per år. Det finns idag ett flertal potentiella mottagare av den utsorterade plasten men ett pris för denna hantering är svårt att få och kräver vidare utredning och diskussion. Ett ungefärligt europeiskt marknadspris för hantering av utsorterad förpackningsplast är givet till cirka 250 €/ton.
5

An experimental study on recycling plastic waste from E-waste into filament for additive manufacturing

Freigard, Patricia, Nilsson, Liza January 2024 (has links)
This thesis seeks to establish whether recycled E-waste rABS from Stena Recycling AB in Halmstad, Sweden, can be effectively utilized in additive manufacturing processes and if it can be applied similarly to virgin ABS. Results show that it is possible to apply the rABS granules on 3D-printing but with mechanical property losses and cosmetic losses. The result shows a loss in tensile strength between rABS and virgin ABS.The difference of the best performing rABS versus the best performing virgin ABS results in a mean loss of 32% and best performing loss of 25%. The research is confined to filament extrusion and experiments were conducted in FabLab Halmstad utilizing 3Devo Composer with 15 different temperature settings. The filament was then used in Prusa MK4 where three tensile tests in 0, 45 and 90 degrees with 5 iterations per test and per setting. The 3D-printed recycled tensile tests results are compared to tensile tests made from virgin ABS. The conclusion is that there are significant mechanical property losses  and with poor printability compared to store bought ABS filament.
6

Direct Force Measurement between Surfaces Coated with Hydrophobic Polymers in Aqueous Solutions and the Separation of Mixed Plastics by Flotation

Ma, Nini 09 January 2009 (has links)
Froth floatation is an important process used in the mining industry for separating minerals from each other. The separation process is based on rendering a selected mineral hydrophobic using an appropriate hydrophobizing reagent (collector), so that it can selectively attach onto the surfaces of a rising stream of air bubbles. Thus, controlling the hydrophobicity of the minerals to be separated from each other is of critical importance in flotation. If one wishes to separate plastics from each other by flotation, however, it would be necessary to render a selected plastic hydrophilic and leave the others hydrophobic. In the present work, the possibility of separating common plastics from each other by flotation has been explored. While water contact angle is the most widely used measure of the hydrophobicity of a solid, it does not give the information on the kinetics of flotation. Therefore, the forces acting between the surfaces coated with different hydrophobic polymers (or plastics) in water were measured using the Atomic Force Microscope (AFM). The results obtained with polystyrene, polymethylmethacryrate (PMMA), polypropylene (PP), and Teflon showed the existence of long-range attractive forces (or hydrophobic force) that cannot be explained by the classical DLVO theory. The surface force measurements were conducted in pure water and in solutions of surfactant (alkyltrimethylammonium chloride) and a salt (NaCl). In pure water, the attractive forces were much stronger than van der Waals force. In the presence of the surfactant and NaCl, the long-range attraction decreased with increasing concentration and the alkyl chain length. A series of contact angle measurements were conducted to determine the hydrophobicity of polystyrene (PS), polyvinyl chlorite (PVC), and polymethylmethacrylate (PMMA) in the presence of different wetting agents (surfactants). The results show the possibility of separating plastics from each other by flotation, and a series of microflotation tests conducted on PS and PVC showed promising results. / Master of Science
7

Targeting Plastic Recycling Intentions : Insights from a Community-Based Social Marketing Approach

Dagarp, Veronica, Svensson, Johanna January 2023 (has links)
Mitigating the negative environmental impact of plastics is an important part of achieving the Sustainable Development Goals. Despite plastics having great recycling potential, it is the waste fraction with the lowest recycling rate in Sweden (with 33% being recycled). Hence, efforts must be made to promote households' engagement in plastic recycling. Therefore, an informational campaign with the aim of increasing residents’ plastic recycling intentions was designed, using Community-Based Social Marketing. The campaign was made in collaboration with the real estate company Ikano Bostad, and was implemented in their residential area in Danderyd, Sweden. The campaign was running for 5 weeks and was designed and distributed as two posters, which addressed the context-specific barriers and enablers to plastic recycling among residents. To aid the design and evaluation of the campaign, the Theory of Planned Behaviour (TPB) was applied for a deeper understanding of the underlying constructs of plastic recycling intentions. To measure the campaign's effectiveness, two questionnaires (one pre-campaign and one post-campaign) were distributed to the residents, consisting of 294 individuals, to obtain quantitative data about their intentions towards plastic recycling. The results did not show any empirical support for the campaign's effectiveness in increasing residents’ plastic recycling intentions. However, this study contributes important insights and recommendations for increasing future campaign effectiveness, such as highlighting the importance of empowering and motivating individuals and the benefits of conducting a profound pre-study before designing the campaign.
8

Plastic recycling is a team sport / Plaståtervinning är en lagsport

Golding, Alice January 2023 (has links)
As the impact sport, its consumers and performers have on the environment increases, the Earth continues to suffer. Amongst others, the plastic consumption is exploiting natural resources and the lack of recycling causes even further damage. Previous research shows that there is a rising demand for increased plastic recycling both on a small-scale and large-scale level. This study therefore investigated the possibilities football clubs in Malmö have when recycling the plastic they generate. With the help of semi-structured interviews, in-depth answers which were analysed thematically and an understanding of what actions need to be taken in order to increase plastic recycling was provided. By using theory of planned behaviour as well as institutional theory the study showed how the actions of individuals and norms of an organisation affects the efforts put into recycling. It became evident that the clubs are aware of the environmental obstacles we are facing but to a large extent feel as if it is not their responsibility. On the other hand, those administering the football clubs expect the clubs to take more responsibility. Instead, this study shows the need for increased efforts put in by everyone in order to increase plastic recycling and help the environment.
9

Conflitos socioambientais no contexto da Política Nacional de Resíduos Sólidos: implantação da logística reversa do plástico / Socio-environmental conflicts within the national policy for solid residurs: na implementation of reverse logistics in plastic industrie

Morais, Karine Tavares 14 May 2015 (has links)
This research aims to identify the challenges present in the implementation of shared esponsibility among the principal actors of the National Solid Waste Policy (PNRS), with emphasis on the industrial sector of plastic, because this large waste generator. The goal is to restore the historical processing of PNRS the Federal Congress to understand how the plastics industry is responding to legal requirements on the importance of managing one of the most abundant waste on the environment. The aim is to identify and characterize environmental conflicts embedded in the legal obligation of PNRS, given the economic interests of the industry and, in particular, such as streamline conflicts or hamper sectoral agreements between government and business representative bodies. The research is based on desk research, in which it was possible to identify the plastics sector companies resist the responsibility to bear the weight of the Reverse Logistics without the consideration of the public sector. It appears from the central role of the Ministry of Environment in mediating between economic agents and the representative institutions of the segments involved with the effective implementation of selective collection system which depends on the recycling industry in Brazil and Reverse Logistics in the country. / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior / Esta pesquisa pretende identificar os desafios presentes na implantação da responsabilidade compartilhada entre os atores principais da Política Nacional de Resíduos Sólidos (PNRS), com ênfase no Setor Industrial do Plástico, por ser este grande gerador de resíduos. O objetivo é o de recompor o histórico da tramitação da PNRS no Congresso Federal para entender como o setor industrial do plástico está respondendo às determinações legais diante da importância da gestão de um dos resíduos mais abundantes no meio ambiente. Busca-se identificar e caracterizar os conflitos socioambientais embutidos na obrigatoriedade legal da PNRS, em face dos interesses econômicos do setor industrial e, notadamente, como tais conflitos dinamizam ou dificultam os acordos setoriais entre o Poder Público e as entidades de representação empresarial. A investigação se apoia em pesquisa documental, mediante a qual foi possível identificar que as empresas do setor do plástico resistem à responsabilidade de arcar com o peso da Logística Reversa sem a contrapartida do setor público. Depreende-se o papel central do Ministério do Meio Ambiente na mediação entre os agentes econômicos e as instituições representantes dos segmentos envolvidos com a implantação efetiva de sistema de coleta seletiva da qual depende a indústria da reciclagem no Brasil e a Logística Reversa no país.
10

Estudo de processo de reciclagem do composto de polietileno e alumínio proveniente de embalagens cartonadas assépticas através de simulação computacional usando o método dos elementos discretos (DEM) / Study of recycling process for polyethylene / aluminum compound by computer simulation using discrete element method (DEM)

Merendino, Edy Maicon 12 June 2011 (has links)
Orientador: José Roberto Nunhez / Dissertação (mestrado) - Universidade Estadual de Campinas, Faculdade de Engenharia Química / Made available in DSpace on 2018-08-19T14:59:08Z (GMT). No. of bitstreams: 1 Merendino_EdyMaicon_M.pdf: 4244405 bytes, checksum: c56623b83b7e229872966885f5e9eca5 (MD5) Previous issue date: 2011 / Resumo: As embalagens cartonadas assépticas para alimentos são comuns em nosso dia-a-dia. Tais embalagens são compostas por três materiais: papel, polietileno de baixa densidade e alumínio. Seu processo de reciclagem se dá em duas etapas sucessivas: a reciclagem do papel e a posterior reciclagem do composto de polietileno e alumínio. Durante a primeira etapa de reciclagem, um percentual das fibras de papel não é retirado do composto de polietileno e alumínio o que pode comprometer a qualidade de produtos feitos a partir da reciclagem deste composto. Para a extração do papel residual foi desenvolvido de maneira empírica um equipamento centrífugo em escala industrial. Visando o estudo do funcionamento deste equipamento fez-se a simulação deste usando o método dos elementos discretos (DEM). O primeiro passo foi a determinação de parâmetros físicos e de interação através de experimentos práticos e respectivas simulações computacionais para a calibração de um modelo, o qual foi conseguido de maneira satisfatória. Uma vez tendo o modelo calibrado, foram realizadas simulações com diferentes geometrias para o rotor e parte estática deste equipamento buscando levantar hipóteses para o entendimento do funcionamento do equipamento. Os resultados para diferentes especificações foram comparados e discutidos / Abstract: Milk and beverages carton packages are very common in our lives. These packages are made of three different materials: paper, low density polyethylene and aluminium. The recycling process of these packages takes place in two successive stages: the recycling of paper and the subsequent recycling of polyethylene and aluminium composite. During the first stage of recycling a percentage of the paper is not removed from the composite of polyethylene and aluminium which can compromise the quality of products made from recycling of this composite. An industrial-scale centrifuge equipment was developed empirically for extraction of residual paper. In order to study the operation of this equipment, it was made its simulation using the discrete element method (DEM). The first step was set-up of physical and interaction parameters through practical experiments and computer simulations to calibrate a model, which was achieved satisfactorily. Once the model was calibrated, simulations were performed with different geometries for rotor and static body of this equipment seeking hypotheses in order to understand equipment operation. The results for different specifications were compared and discussed / Mestrado / Processos em Tecnologia Química / Mestre em Engenharia Química

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