Thesis (M.Sc.)--University of Hong Kong, 1994. / Includes bibliographical references (leaf 63-64). Also available in print.

This study and design concept explores the need for a change of the behaviour and recycling knowledge in Nybro Municipality, situated in Eastern Sweden.  The main aim of this study is to provide support for discussion and act as an inspiration for the future development of projects with participatory citizenship. Additionally, to invigorate the need for a sustainable and circular waste management to reach sustainable development.  The theoretical framework set up for this study focus on sustainable development, citizens’ behaviour and knowledge of recycling. The explorative research stage of the project is performed through several methods, including interviews with current waste management companies and Nybro Municipality’s Sustainability Department. Furthermore, a survey of the citizens of Nybro municipality, to investigate the behaviour and knowledge about recycling. Correspondingly, relevant secondary research and compulsory review of the context, waste management and circular economy in Sweden, but also the behaviour within recycling of the system users - citizens, is being examined. The project focuses on sorting and analysing the data and findings by using methods of several different visual thinking tools.  The outcome of the project is a proposal of a design concept to facilitate the recycling of waste for the citizens as the users. Moreover, to emphasize the need and importance of recycling our everyday waste materials. This project is not a solution-based project, but more widely to provide a basis for discussion and inspire.  The goal is to find a way that encourages citizens to recycle waste from products purchased in their daily living. A social design workshop, focusing on circular waste management and recycling behaviour, together with the citizens living in Nybro municipality, will be proposed and co-designed with the municipality’s sustainability department of Nybro Municipality.

Thesis (MTech (Chemical Engineering))--Cape Peninsula University of Technology, 2017. / Coal fly ash waste produced from the coal combustion process is becoming an ever increasing concern. It is produced in such abundance due to not only South Africa, but the whole of the world relying mainly on coal combustion for the main source of energy production. With the growing rate of the human population this energy production is ever increasing. The current methods of disposal of this fly ash is not sustainable, it is being dumped in ash dumps, and poses a risk to the surrounding environment and human population. Therefore, processes need to be developed to take this waste and turn it into useful materials. This would not only solve the problem of its disposal but also create useful products that can be applied to further protect the environment. It was discovered that one of the useful materials that can be synthesised from fly ash are zeolites. These nano-porous structures have a wide variety of uses. Therefore, many studies have been conducted around optimising the synthesis of various zeolites from coal fly ash. More recently these studies have focused on the scale-up conditions needed to synthesise these zeolites on the large industrial scale, regarding the sheer volume of fly ash produced annually. The most robust and widely used technique for zeolite synthesis involves a pre-synthesis fusion of the fly ash with sodium hydroxide at a temperature of 550 0C. This would not be feasible to scale-up to industrial scale because of the energy intensity. Therefore, alternative pre-synthesis techniques have been proposed. One of those techniques involves using a sonochemical treatment as a pre-synthesis. It can be argued that this technique may not be able to be easily scaled. To solve this problem, another alternative technique was investigated within this study. It involves the use of a jet loop pilot plant mixing system, which can be scaled-up very readily to industrial scale.

In today’s World, sustainability is not just a buzz word but should be the new quality. In order to live in a pollution free environment, there is an urgent need to move towards a circular economy. The rapidly increasing demand of textiles results in high amount of textile waste leading to pollution. Textile to textile recycling is the most feasible solution to minimize textile waste while meeting the fashion demand. Mechanical recycling by shredding is one way of recycling textiles where, fabrics are broken down into their constituent fibres. The problem with this method is that, after shredding, there is huge reduction in fibre length due to the harsh process. This makes it difficult to use a high percentage of these reclaimed fibres in formation of new textile garments. The main focus of this thesis was to reduce the fibre length drop that occurs during shredding through lubricant pretreatment. It was anticipated that, inter-fibre friction would be the reason for the huge fibre length drop during shredding. Therefore, a method was developed to measure the inter-fibre friction of cotton and polyester staple fibres using a tensile tester. The effect of blending on inter-fibre friction was investigated. Different types of lubricants were used to alter the inter fibre friction. The lubricants were sprayed on the fibres and dried prior to carding. Two lubricants were chosen for pretreatment of fibres for yarn formation. The effect of the lubricant on the inter-fibre friction of carded fibre webs as well as yarn strength and spinnability were investigated. The results showed that, the method developed can be used to measure inter-fibre friction of staple fibres. It was also found that, inter-fibre friction in carded webs depends on the crimp and mechanical interlocking in the web. Inter-fibre friction in blended fibres depends on the percentage amount of each fibre in the blend. Addition of a small amount of lubricant significantly lowers the inter-fibre friction. The effect depends on the type of lubricant and type of fibre. Lubricant amount above 1.43% on weight of fibre lead to poor carding of fibres. Lubricant amounts between 0.29 % and 1% on weight of fibre lead to good carding of cotton and polyester fibres but the cotton fibre webs may not be spun. PEG4000 lubricant was found to significantly lower the inter-fibre friction compared to other lubricants. It was also found that, lubricants significantly affect the tensile strength of the yarn as well as their spinnability. Basing on the results, it was concluded that, lubricant pretreatment of fabrics prior to shredding will most likely provide a more gentle process. This was based on the fact that, the lubricants reduce the inter-fibre friction. This enables easier slippage of fibres within the yarns which facilitates easier deformation of the yarns during the shredding process. Thus reduce the fibre length drop. PEG 4000 is more likely to provide better results when used in amounts ranging from 0.1 to 0.71% on weight of fabric. Besides that, PEG is safe for the environment.

Due to concern about diminishing landfill space, the City of Denton contracted a municipal solid waste characterization study in 1999 that would identify materials for diversion. This paper describes the results of 5 1-week waste sorting events, a scale-house analysis, a recycling participation study, a recycler profile and a similar city study. The results of the characterization studies suggest that at least 50% of each waste stream is recyclable or divertible though paper products accounted for no more than 45% by weight of any waste stream. Curbside recycling participation rate was 71% during the 6-week study period though the average weekly set-out rate was 37%. Recycling participation rates varied significantly by zip code and by home value categories but not by gender. Denton is fairly progressive in its waste management approach when compared to demographically similar cities on a 15-question assessment though recommendations for improvement have been identified.

Algal biofuels present a promising future alternative to petroleum based fuels. Water nutrient recycling is a key step to increase the sustainability of algae biofuel production facilities. This thesis discusses the process of nutrient and water recycling in high rate algae raceway ponds (HRAP) fed primary treated municipal wastewater. Research was conducted primarily at the San Luis Obispo Water Resource Reclamation Facility (SLOWRRF). Nine 30 m2, 0.3 m deep HRAP’s were operated continuously from June 1, 2013 to April 17, 2014. The ponds were arranged in three sets of triplicate ponds, with two pond sets run on 3-day hydraulic residence time (HRT), and the third on a 2-day HRT. The biomass productivity of the 2-day HRT and 3-day HRT were compared. The two sets of 3-day HRT ponds were run in series to determine the effect on productivity associated with recycling growth media without supplemental nutrient addition. The first pond in series was referred to as round 1 and the second as round 2. Due to solids accumulation in the 2-day HRT ponds in summer proper biomass productivity values could not be determined. 4-inch standpipes were determined to cause the solids accumulation when large flocs were present in ponds. As a possible solution to the solids accumulation issue, a ramped standpipe was designed and installed in one pond per triplicate set. In winter the 2-day HRT pond was roughly 37% more productive than the 3-day HRT. In summer the round 1 (3-day HRT) ponds were roughly 33% more productive than the round 2 (3-day HRT) ponds. In winter the round 1 (3-day HRT) ponds were roughly 19% more productive than the round 2 (3-day HRT) ponds. The type of standpipe (ramped or 4-inch) did not cause a significant amount of solids accumulation in either of the 3-day HRT ponds. The type of standpipe did make a difference in the 2-day HRT ponds. On average the 4-inch standpipe pond had 35% higher TSS than the ramped standpipe ponds. In addition to these field experiments, laboratory aerobic degradation experiments were conducted to determine the nutrient release of previously digested sludge in aerobic ponds. Pretreatment of algae sludge did not have a significant effect on nutrient release of previously anaerobically digested algae sludge in aerobic conditions. The maximum soluble nitrogen generated in the aeration reactors was between 56% for the treated sludge, and 66% for the untreated sludge.

The first part of this master’s thesis contain the history of photovoltaic technology and types of PV cells. Gave a consideration to advantages and disadvantages of solar cells. Compared their effectiveness and important parameters. In the next part described the recycling technology of modules at the end of their lifetime. Described certain recycled materials. At the end of the work described possible improvements to existing technologies used for encapsulating of cell. And wich would improve the recycling process.

Recycling and recovery of materials and energy from waste is a key factor to mitigate virgin material demands and reduce resource consumption by utilising waste as a resource for new products. However, some critical materials, such as neodymium, are barely recycled because of missing information on amount and disposition of these critical materials within the waste streams. The goal of the study is to quantify recycling potentials from small and electric motors originating from end-of-life vehicles (ELV), electric bicycles and industrial machinery in Germany and the EU with focus on currently lost rare earth elements. Furthermore, innovative approaches to improve recycling of these motors shall be investigated. Therefore, a calculation model to predict current and future waste streams and the incorporated recycling potentials has been developed. The results show an increasing trend of recycling potentials from small and electric motors for all waste streams. The recycling potential of neodymium is estimated at a range of 150 t to 240 t in 2020 in Germany. However, data inaccuracy and the calculation model are likely to cause overestimation of actually available recycling potential and have to be interpreted carefully. In conclusion, disassembly of small and electric motors from ELV and electric bicycles in combination with a subsequent specific recycling process has been identified as promising to improve utilisation of the recycling potentials of rare earth elements from small and electric motors. However, in case recycling quotas are the prior goal of improvement, the application and further optimisation of post shredder technology is more relevant.

Plast är ett kostnadseffektivt och användbart material i dagens samhälle. Baksidan med plasten är dock hur den produceras och slutbehandlas. I dagsläget är ungefär 90 % av plastmaterialet på marknaden producerat av fossil råolja, vilket är en ändlig resurs som uppskattas vara förbrukad om 50 år om detta inte förändras. Världen över deponeras eller förbränns majoriteten av plastavfallet som på så sätt ger upphov till negativ miljöpåverkan som växthusgasutsläpp och läckage till mark och vatten. Materialåtervinning av plastavfall sker i en jämförelsevis låg grad och då främst genom mekanisk återvinning. Tekniken är begränsad och av den anledningen har alternativa tekniker, som bland annat kemisk återvinning, uppmärksammats inom politiken och forskning. Det är ett samlingsnamn på ett flertal tekniker som kan användas för materialåtervinning genom att sönderdela materialet till sina minsta beståndsdelar och därigenom framställa en produkt som liknar jungfruligt material. I denna studie har den kemiska återvinningstekniken pyrolys valts ut baserat på sådant som vilken typ av plast tekniken lämpar sig för och dess kommersiella användning på marknaden. Syftet med studien var att undersöka vilka förutsättningar det finns för att upprätta en pyrolysanläggning i Gävleborg med avseende på regionens plastavfallsflöden, dess befintliga infrastruktur samt miljömål och strategier. Gävleborg valdes ut som fokusområde med anledningen av att det för närvarande inte pågår något projekt för etablering av kemisk återvinning i de nordliga delarna av Sverige. Samtliga aktuella projekt är lokaliserade i syd- och mellansverige, framför allt i anslutning till plasttillverkaren Borealis som har en anläggning i Stenungsund, Göteborg. Inom studien tog författarna fram två teoretiska scenarion för hur en pyrolysbehandling av plastavfall inom regionen kan möjliggöras. Scenario 1 utgår från att pyrolysanläggningen tar emot avfall bestående av enbart plast som identifierats inom regionen, vilket sedan sorteras i anslutning till pyrolysanläggningen. I scenario 2 upprättas en extern sorteringsanläggning för att möjliggöra att plasten från samtliga avfallsflöden och näringar samlas in och sorteras. Därifrån transporteras lämpligt plastmaterial till pyrolysanläggningen. En slutsats baserad på studiens frågeställningar och avgränsningar visar att det finns möjligheter för etablering av en pyrolysanläggning i Gävleborg med avseende på infrastruktur, tillgång till plastavfallsflöden och att det potentiellt kan gynna regionens uppsatta mål inom plastavfallshantering. En förutsättning är dock att ett utökat insamlings- och sorteringssystem implementeras för att detta ska vara genomförbart i och med att tekniken kräver ett väldefinierat och rent plastavfallsflöde. / Plastic is a cost-effective and valuable material in the modern society. However, the downside of plastic primarily lies in its production and end-of-life treatment. Roughly 90 % of all plastics are currently manufactured from fossil oil, which is a non-renewable resource, and it is estimated that the global reserves will be depleted in 50 years unless something changes. Worldwide, most plastic waste is landfilled or combusted, which harms the environment due to, among others, reasons such as greenhouse gas emissions and leakage to the ground and waters. The degree of material recycling of plastic waste is comparatively low and is mainly carried out by mechanical recycling. The technology has its limitations and owing to this, politicians and researchers have investigated alternative recycling methods such as chemical recycling. It is an umbrella-term for several technologies that are used to recycle waste by breaking down the material to its smallest components and produce a product of near-virgin quality. This study focused on the chemical recycling method pyrolysis, based on aspects such as the type of plastic it has the capacity to treat and its commercial use. The purpose of this study was to review what potential Gävleborg has for establishing a pyrolysis facility regarding plastic waste flows in the region, its infrastructure and current environmental goals and strategies. Gävleborg was chosen as the focus for the study since there, as of today, are no projects exploring the possibility for establishment of chemical recycling in the northern parts of Sweden. All ongoing projects are situated in proximity to the plastic manufacturer Borealis and its facility in Stenungsund, Gothenburg. The authors formed two hypothetical scenarios as to how plastic waste recycling by pyrolysis can be implemented in Gävleborg. The first scenario assumes that the pyrolysis facility receives waste identified by the region as only consisting of plastic, which then is further sorted at the facility. The second scenario is carried out by establishing an external sorting facility to enable sorting and collection of plastic from all waste flows and industries. Thereafter the suitable plastic waste is transported to the pyrolysis facility. A conclusion drawn from the study’s findings showed that there is potential for establishing a pyrolysis facility in Gävleborg as to infrastructure and plastic waste flows and would as well contribute to the region’s goals relating to plastic waste recycling. However, to make this viable an implementation of an extended collecting and sorting system is required, since the technology is dependent on a clean and well-defined plastic waste flow.

GreenBin propone un modelo de negocio innovador en el Perú, específicamente en Lima metropolitana, el cual consiste en la obtención de un beneficio a ser empleado en el sistema de transporte como resultado de la simple acción de reciclar plástico. Este proyecto nace como consecuencia de haber observado el deficiente sistema de reciclaje en la ciudad, la falta de aprovechamiento del mercado del reciclaje y la escasa cultura de reciclaje en la comunidad. En el desarrollo existen dos actores principales, el cliente proveedor y el cliente empresarial. La característica principal de GreenBin es que busca facilitar el proceso de obtener el plástico mediante el depósito de los ciudadanos en las máquinas recolectoras y venderlo formalmente a una empresa recicladora que se encargue de la logística de traslado y tratamiento. La necesidad identificada de muchas empresas es que la demanda de plástico reciclado no logra ser satisfecha, a pesar de encontrarse mucho material, el mercado informal es muy grande en el reciclaje. El planeamiento estratégico ofrece una visualización del entorno en donde se desarrollará el proyecto. La investigación de mercado brinda una comprensión del usuario y su disposición frente a una nueva propuesta en reciclaje. El plan de marketing plantea las estrategias más acertadas para el target, el plan de operaciones establece distintos procesos y tiempos, la estructura de recursos humanos consolida el régimen de trabajo y las evaluaciones. Finalmente, el análisis económico-financiero muestra la viabilidad del proyecto en una proyección de 5 años. / GreenBin is an innovative business model proposal in Peru, specifically in Lima, it consists in obtaining a profit to be used in the transport system because of a simple action such as recycling plastic. The origin of this project comes from the observation of a deficient recycling system in the city, the lack of exploitation of the recycling market and the shortage of recycling culture in the community. There are two main roles that take part in the development of this project, the supplier customer, and the corporate customer. The main characteristic of GreenBin is that it looks for facilitate the processing of waste by obtaining the plastic through the citizens deposits on the recycling machines and selling it through a formal transaction to recycling corporations and therefore takes the responsibility of logistics and treatment process. The primary need identified of many corporations is that they cannot manage to fulfill the recycled plastic demand, even though there is plenty material, the informal recycling sector is bigger. Strategic planning offers a complete visualization of the environment in which the project is going to develop. The market research focuses on understanding the consumer and its disposition towards a brand new recycling proposal. The marketing plan outlines the most accurate strategies for the business’s target, the operational plan set up differents process and timelines, the structure of Human resources department consolidates the work plan and perfomance review. Finally, the economic and financial analysis displays the business viability in a 5 years projection. / Trabajo de investigación