This thesis reports on research undertaken to investigate the implementation of a Circular approach within the leather industry, through the definition of a framework and development of an economic decision-making support tool. The core objective of the research is to identify the underpinning opportunities and challenges involved in creating recycling solutions for leather waste. The research contributions can be considered in four key areas. The first part of the thesis consists of a review of the use of leather across industry sectors and the existing waste management and recycling systems for leather waste. On consideration of this review it clearly shows a lack of systematic thinking around the creation and optimisation of recovery systems for leather waste. This review concludes that there is significant room for improvement of the current waste management and recycling solutions for leather waste. A variety of value-added products can be recovered from these wastes but only if the leather can be successfully separated from the other materials (such as rubbers and polymers) within end-of-life products and manufacturing wastes. The second part of the research defines a framework for implementing a Circular approach within the leather industry. This framework supports mapping and characterisation of the leather waste stream and the design of recycling and processing strategies for leather waste. The third part of the research is concerned with the development of a decision-support tool for the economic viability of leather recycling systems. The support tool considers all cost factors and combines them to give a single factor upon which the economic effectiveness of different leather recycling scenarios can be evaluated. Finally, the validity of the framework for leather waste recycling is assessed through the completion of two case studies. These case studies demonstrate the flexibility of the framework in supporting both horizontal (across lifecycle) leather recycling and vertical (across industry sector) leather recycling. In summary, the research clearly highlights the need for systematic thinking and flexible strategies when creating leather recycling systems. Failure to incorporate flexibility into future recycling systems puts the recycling industries at risk of being unable to effectively manage future waste streams. Conversely, early consideration and incorporation of flexible processing strategies into recycling systems could enable the recovery of high-quality recycled materials that support a circular approach to manufacturing and resource use.

The idiom goes, "what is one man's trash is another man's treasure." In our 21st century economy, one man's trash is less commonly another's treasure as often as it is pollution. It is well documented that the majority of human waste ends up in on the side of roads, or in forests and oceans if not in landfills or incinerated. The disposability of items in our consumer culture is now commonplace. We are exacerbating our problems by throwing away single-use and barely-used items again and again without a feasible, realistic, and responsible solution for the end their life cycle. While our habitual buying and scrapping is continually increasing, the industrial buildings that process our waste are pushed to the outskirts of urban centers where they are most needed due to aesthetics, noises, and odors. These suburban and rural locations put an enormous economic and resource strain on cities. Architecture has the opportunity and responsibility to play an important role in remedying these issues related to waste facilities and processes. Architecture as an art form has largely abandoned these and similar industrial typologies as building design problems. They are mostly undertaken by engineers who design them for economic and process efficiencies. But there are unique challenges to be overcome with creative solutions, what architects do best. As a part of this process, architects can better design facilities so that they can be located within city limits and fight the "not in my backyard" stigmas associated with waste management. Ultimately architects can strive to improve civic life for citizens while also improving the means and methods of city-maintenance issues related to waste. At this intersection of waste and architecture, this thesis explores how a facility that settles into the dense urban fabric of Washington D.C. can play a role in the city's waste steam in order to benefit the local community and economy. / Master of Architecture / The idiom goes, “what is one man’s trash is another man’s treasure.” In our 21st century economy, one man’s trash is less commonly another’s treasure as often as it is pollution. It is well documented that the majority of human waste ends up in on the side of roads, or in forests and oceans if not in landfills or incinerated. The disposability of items in our consumer culture is now commonplace. We are exacerbating our problems by throwing away single-use and barely-used items again and again without a feasible, realistic, and responsible solution for the end their life cycle. While our habitual buying and scrapping is continually increasing, the industrial buildings that process our waste are pushed to the outskirts of urban centers where they are most needed due to aesthetics, noises, and odors. These suburban and rural locations put an enormous economic and resource strain on cities. Architecture has the opportunity and responsibility to play an important role in remedying these issues related to waste facilities and processes. Architects rarely design waste-management buildings and other industrial-use buildings. Usually it is engineers who undertake these buildings. They tend to design them in ways that put cost and process efficiency above everything else. One of the main skill-set architects have is problem-solving through design. Waste-management buildings face a lot of challenges beyond cost and process efficiency so it would make sense for architects to be a part of this process. Architects can better design these facilities so that they can be located within city limits and fight the “not in my backyard” stigmas associated with waste management. Ultimately architects would strive to improve civic life for citizens while also improving the means and methods of city-maintenance issues related to waste. At this intersection of waste and architecture, this thesis explores how a facility that settles into the dense urban enivironment of Washington D.C. can play a role in the city’s waste steam in order to benefit the local community and economy.

Background: Circular economy (CE) is one of the most recent ways to address environmental sustainability. It aims to extend the value of products, materials, and resources for as long as possible, and minimize waste generation by maintaining them in the economy for as long as possible to mitigate climate change, lowering greenhouse gas emissions, and resource short­ages. Businesses play a crucial part in protecting the environment and have been urged to incorpo­rate CE practices. Leadership and top management have been found crucial for the transi­tion and the CEO has the power to shape strategic plans and directions for the company. Despite the growing research on CE and what influences the transition, literature on individual roles of the top management team is scarce. Existing literature focuses on different factors driv­ing the transition but not the specific roles of the top management team. Purpose: The purpose of this research is to add to the literature regarding CE and how the CEO influences the transition. With this research, we aim to contribute to the current discussion on the transition towards CE, both theoretically and practically. Method: We have conducted a qualitative study with an inductive approach. It follows a relativist ontology and a social constructionism viewpoint. The methodology is an exploratory multi­ple-case study where the companies were selected by purposive sampling. Five companies were selected and in total 16 semi-structured interviews were conducted where we gathered data from both CEOs and their employees. The data was analyzed by combining the Goioa method with Eisenhardt’s multiple case study approach. Conclusion: Based on our findings we identified that the CEO influences the transition towards CE. We distinguished the CEO role within top management and found that they influence CE through strategic management and power. Within strategic management, the CEO influences through setting the strategy, being the decision maker, allocating resources, and setting the direc­tives and goals for the organization. The aspect of power was found to influence the inter­nal organization and external parties. Additionally, we showed how these contributions can be applied practically.

The future of food production contains some challenges. The production needs to increase in order to feed a growing population, but at the same time there is an increased need to transi- tion to more sustainable ways of cultivation. This can be a challenge since increased intensity and sustainability is not always compatible. Agroforestry systems have shown potential as sustainable food production system in previous research. The area where this study was con- ducted, Haraa in Babati District, has a long history of agroforestry. The aim of this study was to answer what resources agroforestry farmers used to manage their farms, to determine if the agroforestry systems could be regarded as sustainable. Circular economy was used as a theo- retical framework and resource flow as an analytical tool. This study investigated how the resource flow looked like on six agroforestry farms in a Haraa, a village in Tanzania. The empirical data was gathered with semi-structured interviews from 8 informants. The analysis showed that the farmers were dependent on few external resources and could produce or pre- form most of the needed resources inside their own system. The farms had a circular flow to a large extent, but some of the farms have room for improvement in the management regarding sustainability.

This project is questioning our modern way of life. With the current capitalistic economy we are draining the world on resources and creating inequality among people. It is often said the the capitalistic system is lifting people out of poverty and there is no better way. However, it is proven to be negative for our ecology and it is important that we find new ways of develop mobility. So our future generations can enjoy the freedom that we today have become so ac-customed to. What can we do to consume less and respect the world we are living by. Is it a matter of consuming green. Or do we need a fundamental change in how we create things. A bright light in these questions is maybe to head into a circular economy. This project therefore explores how a automotive interior would look like when designed with a circular mindset. Could a Universal Basic Income reduce extraction and what is the role of A.I and automation in the development for better mobility. For this project an in depth literature research was carried out to gather information about our economic system and social factors. The research about digitalisation and automatisation have been gathered from highly regard-ed magazines and web news papers. Second part of the research is also web based, and about sustainable materials that could be used in this interior concept. The design phase started with creation of a user in a chinese context, based from the trend analyzer firm Stylus. China was chosen because it’s a rapid growing economy and it’s the main market for the Chinese-owned car brand Lynk & Co. The collaboration partner for this thesis. The design phase followed with sketching to quickly visualize early ideas. These were then brought into a CAID program to fit the chosen package of a small city car. The design was created around a male mannequin to ensure usability. A full-size mockup was built to test functions and validate design around a large male and the smallest female percentile.  The project resulted in a strategic concept of how a new business model would push for a greener development using a circular mindset. From that perspective a interior was created using sustainable materials. The overall struc-ture is covered in a hard cover manufactured in recycled plastic. The seating and dashboard were design with the highly efficient material Abroform in mind. Abroform is based of Lignin which is a byproduct of the paper indus-try. Therefore no additional extraction is needed making it sustainable. Further it had all the positive design charac-teristics from conventional plastics. The soft seat cushions and the front dash was designed with compressed felt, manufactured from organic wool. These parts created a friendly and soft interior and are easy changeable for maintaining purposes. Overall the interior focused on providing smart storage solutions using few materials with an “bolt-on aesthetic”. The design language is using a friendly surface treatment and to include users make the journey pleasant.

The onset of the Water Framework Directive (WFD) will challenge water utilities to further reduce their wastewater phosphorus discharges to < 0.5 mg.L- 1. Whilst conventional treatments, such as chemical dosing, are able to meet these new discharge consents, the strategies are representative of a linear economy model where resources are unrecovered and disposed. An alternative solution which can contribute to the aspiration of a circular economy is microalgae. Microalgae are ubiquitous in wastewater environments and assimilate phosphorus during their growth, to residual concentrations complementary of the WFD. Furthermore, microalgal biomass can be anaerobically digested to produce biomethane offering the potential for an energy neutral approach. However, uptake of microalgal systems are lacking in the UK through limited knowledge of operation; and the belief that such solutions are synonymous to large, shallow open ponds with extensive treatment times. The development of alternative microalgal reactors are increasingly investigated to overcome these implementation challenges. Of these, immobilised microalgae has shown great potential; and whilst within its infancy demonstrates the greatest opportunity for development and optimisation. This thesis determines the critical operational parameters that influence the remediation efficacy of immobilised microalgae for tertiary nutrient removal; including species selection, biomass concentration, treatment period and lighting; with recommendations for optimal performance. These recommendations are then applied to the design and operation of an immobilised bioreactor (IBR) to understand the key design and operating components that influence the overall economic viability. In doing so, the potential for an IBR to be economically viable, within the next decade, in comparison to traditional approaches are discussed.

The cement industry represents nearly 8% of fossil fuel and industrial emissions making it a key area of focus for policymakers around the world. Much of the current effort in cement manufacturing has focused on energy efficiency and material substitution with more recent work focused on carbon dioxide uptake and recycled concrete aggregate use to address greenhouse gas emissions and material conservation, respectively. Currently, no meaningful approach exists for practitioners or policymakers to address greenhouse gas emission reduction for cement manufacturing that incorporates the concepts of material conservation. The Carbon Hierarchy is proposed as a successive stage hierarchy to address this gap. This work is logically and empirically validated using a newly constructed model incorporating the key levers of service life extension, thermal energy decarbonization, limestone substitution, mineral component (MIC), carbon dioxide uptake with consideration for the process flow that incorporated reintroduction of end-of-life (EOL) concrete as raw material or clinker substitution in cement manufacturing and as potential downstream use as aggregate. The Carbon Hierarchy proposed in this research could guide decisions to significantly reduce greenhouse gas emissions for the cement industry while ensuring material conservation. / Thesis / Doctor of Philosophy (PhD)

South Africa has complex environmental and economic challenges as part of its sustainable development. These include depleting natural resources, significant waste generation and high carbon emissions, compounded with an economic growth rate below global growth. Organisations within the supply chain play a key role in purchasing and distributing goods that underpin the economy. Waste generation and carbon emissions drive climate change which has been singled out as a significant risk to humanity. The negative environmental impacts of climate change, resource depletion, waste generation and carbon emissions have compounded the bleak economic outlook for South Africa. Developed countries have implemented circular economy policies that support green innovation within the supply chain. The circular economy is a model that supports waste reduction while improving the economy and the use of natural resources through reducing, reusing and recycling at a basic level. The research area of circular economy in the supply chain is trending globally and is still relatively new from a South African context, particularly around circular business models in the supply chain. Circular economy principles work hand in hand with driving green innovation, as the technology allows for the identification of new ways to reduce waste and cost across the supply chain. The research is qualitative and exploratory within the area of supply chain, with a focus on green innovation and circular economy from a developing country perspective. It intends to understand the key drivers that contribute to companies adopting green innovation strategies. The benefit of the research is for practitioners to understand how South Africa can achieve green in the supply chain and overcome economic issues by adopting circular economy principles. Twelve semi-structured interviews were carried out with managers of large organisations that have embarked on green initiatives within the supply chain. The study established commonalities with existing research on external and internal drivers supporting green innovation and the circular economy in the supply chain. The research established new insights around South African organisations' differences in the supply chain, particularly around operational risk being a critical driver considering water scarcity and electricity instability. It also identified internal drivers to changing business models from linear to circular, particularly around sustainability strategies, network collaboration, sustainability culture and changing the way companies are measured. Recommendations support how business models could be adapted to drive circular business models across supply chain organisations in South Africa. / Mini Dissertation (MBA)--University of Pretoria, 2021. / Gordon Institute of Business Science (GIBS) / MBA / Unrestricted

Renewable materials have been put into the spotlight as the demand for environmentally responsible feedstocks grows yearly. Lignin, an abundant and renewable aromatic polymer, which can source a diverse cast of derivative structures, has yet to rise to the potential it possesses as a material in high technological applications. The expansion of studies and growing interest in its versatility has brought forth materials such as lignin nanoparticles, coatings, films, second generation alcohols, phenolic building blocks for drug synthesis, and many others. Among the many valorization methods thus far pursued, photochemical methods have received relatively low representation, incurring several challenges stemming from less desirable interactions of lignin as a substrate directly with light. As the search for clean, low-emissive processes with high scale-up potential for lignin valorization continued, advances and studies on the benefits and challenges on the use of photochemistry with this class of compounds became the focus of this work. This thesis will primarily aim to highlight our efforts to find photocatalytic materials and systems to achieve lignin valorization, discuss its limitations and benefits, and provide a pathway towards potential applications of these reactions. Our core values were to find conditions that worked well, but also translating that success into systems that could be greener and less dangerous or environmentally impactful. We can report to have achieved single-product yields of over 2% in protolignin valorization reactions using Pd and Au based nanoparticles, supported on niobium-based materials. We have also reached up to 2% yields in visible-light reactions using CdSe quantum dots. While literature reports tend to overwhelmingly focus on lignin models, we have kept ours on real lignin, which while more complex and challenging, does present more relevant results in the long run for this field. These results, in addition to molecular model valorization experiments, present a promising prospect for the application of photocatalysis in lignin valorization for the future.

Discarded furniture constitutes a significant share of bulky waste directed to landfills and incinerators each year in the USA. This has implications for resource consumption, social equity, and other sustainability concerns. Reuse of furniture provides a strategy for waste prevention and enables product life extension and offset of new consumption as part of a circular economy (CE). Using online platforms (e.g., Facebook, Craigslist), users can connect directly to acquire and/or discard used furniture items that would otherwise be disposed. Much of the existing literature focuses on an individual's motivations for disposing/acquiring used products, and not on the mechanics and/or practice of reuse. This study explores reuse practices, perspectives, and individual engagement in the local reuse of furniture through user-to-user (U2U) online platforms using two data sources and methodologies. To understand the characteristics of used furniture available for local reuse via U2U online platforms, web-scraping was conducted on Craigslist posts over a four-month period to collect data regarding furniture type, condition, and location. In parallel, individuals were invited to complete a questionnaire regarding their use of U2U online platforms for acquiring/disposing of used furniture, perceived convenience of using online platforms, and the extent to which reuse transactions were 'local'. This study found that the product type, perceived convenience, and access to information played key roles in the local reuse of furniture. This study has important implications for sustainable consumption systems in a local circular economy. / Master of Science / Every year, millions of tons of furniture is disposed as bulky waste in landfills. The discarded furniture can cover eight thousand football fields with couches, mattresses, and tables. Previous studies show about half of the discarded items can be used again. Reuse is one of the solutions to the furniture waste problem. Depending on where you live, it is now possible to easily match someone who is discarding furniture with someone else who wants to obtain it. This is how the internet enables anyone to participate in furniture reuse. The study looks at how and what types of furniture is being reused locally, i.e., acquired, and discarded for reuse all within twenty-five miles or lesser. The study also seeks to answer how people perceive the use of online platforms for the local reuse of furniture. The research shows that the type of furniture (e.g., chair, table, mattress), convenience of reuse through online platforms, and information about the used furniture item are central to furniture reuse. The results help in understanding what factors promote or hinder the local reuse of furniture, which is important for scaling local reuse. Increased participation in reuse is important for social, economic, and environmental sustainability.