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Limiting microplastic pollution from municipal wastewater treatment : A circular economic approach / Begränsning av mikroplastföroreningar från kommunal avloppsrening : En cirkulär ekonomisk strategivan Osch, Jordy January 2020 (has links)
The increasing amount of microplastics found in the environment have underscored the urgency to identify, develop and deploy scenarios in which municipal wastewater treatment plants (MWWTPs) limit the release of urban microplastics into the environment. Simultaneously, the global trend towards a circular economy has defined the conditions for these scenarios in relation to the water-energy- nutrient nexus. This study has created a novel framework between studies into treatment technologies for microplastics removal in wastewater streams and circular economic objectives from policymakers with regard to the water-energy-nutrient nexus. The results of this study build on the existing evidence that MWWTPs release significant amounts of microplastics to both terrestrial and aquatic environments. This study has demonstrated how Multi-criteria Analysis (MCA) can be applied to analyse wastewater treatment scenarios for their ability to limit microplastic pollution from MWWTPs, whilst taking the water-energy- nutrient nexus into account. The MCA has identified MBR inci-eco as the best performing circular economic scenario for limiting microplastic pollution from MWWTPs in to be constructed plants. This scenario includes a Membrane Bioreactor (MBR) with Anaerobic Digestion, energy recovery through incineration and Phosphorus recovery through Ecophos. If already existing MWWTPs aim to upgrade their facility to limit microplastic pollution, CASPACUF with Pyreg as an energy-nutrient recovery is seen as the best performing scenario. The powder activated carbon with ultra filtration (PAC-UF) system would then be installed as an additional polishing step to an existing conventional activated sludge (CAS) system, significantly reducing upfront investment costs. Academia can build upon these results to initiate additional research into novel microplastic filtration specific technologies, business model innovation for wastewater treatment and microplastic pollution prevention at the source and in stormwaters. National and international policymakers should ban the distribution and sale of biosolids for direct land application to limit the pollution of microplastics from bio-solids. Furthermore, efforts should be put in place to limit microplastic pollution at the source by stimulating policies for a ban on the use of microbeads, limit tyre wear and improving design for e.q. washing machines. / Den ökande mängden mikroplast som finns i miljön har understrukit brådskan i att identifiera, utveckla och tillämpa strategier där kommunala avloppsreningsverk (MWWTP) begränsar utsläpp av urbana mikroplaster. Samtidigt har den globala trenden mot en cirkulär ekonomi definierat villkoren för dessa scenarier i förhållande till vatten-energi-näring-näxan. Denna studie har tagit fram ett nytt ramverk mellan studier om reningsteknologier för avlägsnande av mikroplast i avloppsvattenströmmar och cirkulära ekonomiska mål från beslutsfattare med avseende på water-energy-nutrient nexus. Resultaten av denna studie bygger på befintliga bevis på att kommunala avloppsreningsverk släpper ut betydande mängder mikroplast i både mark- och vattenmiljöer. Denna studie har visat hur Multi-Criteria Analysis (MCA) kan användas för att analysera avloppsreningsscenarier utifrån deras förmåga att begränsa mikroplastföroreningar från reningsverk, samtidigt som man tar hänsyn till vatten-energi-näring-näxan. MCA har identifierat MBR-inci-eco som det bäst presterande cirkulära ekonomiska scenariot för att begränsa mikroplastföroreningar från nya verk. Detta scenario inkluderar en Membrane Bioreactor (MBR) med anaerobisk nebrytning, energiåtervinning genom förbränning och fosforåtervinning genom Ecophos. Om redan befintliga verk ska uppgradera sin anläggning för att begränsa mikroplastföroreningar, ses CASPACUF med Pyreg som energi-näringsåtervinning som det bästa scenariot. Det pulveraktiverade kolet med ultrafiltreringssystemet (PAC-UF) skulle sedan installeras som ett ytterligare poleringssteg till ett befintligt konventionellt system för aktiverat slam (CAS), vilket avsevärt minskar investeringskostnaderna. Framtida forskning kan använda dessa resultat för att undersöka nya mikroplastfiltreringsspecifika tekniker, affärsmodellinnovation för avloppsrening och förebyggande av mikroplastförorening vid källan och i stormvatten. Nationella och internationella beslutsfattare bör förbjuda distribution och försäljning av biosolids för direkt markanvändning för att begränsa mikroplastföroreningar från biosolids. Vidare bör åtgärder vidtas för att begränsa mikroplastföroreningar vid källan genom att stimulera policyer för ett förbud mot användning av mikrokulor, begränsa däckslitage och förbättra designen för e.q. tvättmaskiner.
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Advancing Forward Osmosis for Energy-efficient Wastewater Treatment towards Enhanced Water Reuse and Resource RecoveryZou, Shiqiang 30 May 2019 (has links)
Current treatment of wastewater can effectively remove the contaminants; however, the effluent is still not widely reused because of some undesired substances like pathogens and trace organic chemicals. To promote water reuse, membrane-based technologies have emerged as a robust and more efficient alternative to current treatment practice. Among these membrane processes, forward osmosis (FO) utilizes an osmotic pressure gradient across a semi-permeable membrane to reclaim high-quality water. Still, several key challenges remain to be addressed towards broader FO application, including energy-intensive draw regeneration to yield product water and salinity buildup in the feed solution. To bypass energy-intensive draw regeneration, commercial solid fertilizers was utilized as a regeneration-free draw solute (DS), harvesting fresh water towards direct agricultural irrigation. However, using nutrient-rich fertilizers as DS resulted in an elevated reverse solute flux (RSF). This RSF, known as the cross-membrane diffusion of DS to the feed solution, led to deteriorated solute buildup on the feed side, reduced osmotic driving force, increased fouling propensity, and higher operation cost. To effectively mitigate solute buildup while achieving energy-efficient water reclamation, a parallel electrodialysis (ED) device was integrated to FO for DS recovery in the feed solution. The salinity in the feed solution was consistently controlled below 1 mS cm-1 via the hybrid FO-ED system. Considering solute buildup is merely a consequence of RSF, direct control of RSF was further investigated via operational strategy (i.e., an electrolysis-assisted FO) and membrane modification (i.e., surface coating of zwitterion-functionalized carbon nanotubes). Significantly reduced RSF (> 50% reduction) was obtained in both approaches with minor energy/material investment. With two major bottlenecks being properly addressed for energy-efficient water reclamation, FO was further integrated with a microbial electrolysis cell (MEC) to achieve integrated nutrient-energy-water recovery from high-strength wastewater (i.e., the digestor centrate). The abovementioned research projects are among the earliest efforts to address multiple key challenges of FO during practical application, serving as a cornerstone to facilitate the transformation of current water/wastewater treatment plant to resource recovery hub in order to ensure global food-energy-water security. / Doctor of Philosophy / Exploring alternative water supply, for instance via reusing wastewater, will be essential to deal with the global water crisis. Current wastewater treatment can effectively remove the contaminants; however, the treated wastewater is still not widely reused due to the possible presence of residual contaminants. In recent years, membrane-based technologies have emerged as a promising treatment process to produce clean water. Among all available membrane technologies, forward osmosis (FO) takes advantage of the osmotic pressure difference across a special membrane to extract fresh water from a low-salinity FEED solution (for example, wastewater) to a high-salinity DRAW solution. The reclaimed fresh water can be reused for other applications. Still, the FO process is facing several critical challenges for broader applications. The first challenge is that additional energy is required to separate clean water from the diluted DRAW solution, leading to notably increased energy consumption for the FO process. To bypass this energy-intensive separation, commercial solid fertilizers was utilized as a separation-free DRAW solution for FO process. Once the clean water is extracted to the DRAW solution (fertilizer), the diluted fertilizer solution together with the fresh water can be directly used for agricultural irrigation. The second challenge is that, when fertilizer is applied as the DRAW solution, nutrient rich fertilizers can penetrate the FO membrane and escape to the FEED solution (wastewater). This phenomenon is known as the reverse solute flux (RSF). RSF can result in many adverse effects, such as wastewater contamination and increased operational cost. To prevent this, we used an additional device named electrodialysis to effectively recapture the “escaped” fertilizers in the FEED solution. Besides this indirect approach to recover escaped fertilizers, we also investigated direct approaches to control RSF, including operational strategy and membrane modification. With two major challenges being properly addressed for energy-efficient water reclamation, FO was further combined with a microbial electrolysis cell (MEC) to achieve multiple resource recovery from wastewater, including water, nutrient, and energy components. The above mentioned research projects are among the earliest efforts to address multiple key challenges of FO during water and resource recovery from wastewater to ensure global food-energy-water security.
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Resource recovery development: factors affecting decisionsBlack, Linda January 1987 (has links)
Municipalities are increasingly facing solid waste disposal problems due to lack of sanitary landfill sites, high costs of landfill management and increasingly stringent environmental standards. Consequently, they are turning toward innovative disposal practices to alleviate these problems. However, very little comprehensive information is available to decision makers on the range of options available in resource recovery development and the factors that can influence choices.
This thesis tests the hypothesis that there are a definable set of factors or circumstances that have led resource recovery developers to make specific decisions regarding ownership, operation, financing, system technology, and air pollution control technology. The thesis is divided into three stages: development of case studies on 9 resource recovery facilities in the state of Virginia; development and analysis of a nationwide survey to test the patterns illustrated in these case studies; and finally, the development of a guide for resource recovery developers that will serve as preliminary guidance in their choice of development options. / M. Arch.
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Feasibility of using Waste Heat as a power source to operate Microbial Electrolysis Cells towards Resource RecoveryJain, Akshay 05 May 2020 (has links)
Wastewater treatment has developed as a mature technology over time. However, conventional wastewater treatment is a very energy-intensive process. Bioelectrochemical system (BES) is an emerging technology that can treat wastewater and also recover resources such as energy in the form of electricity/hydrogen gas and nutrients such as nitrogen and phosphorus compounds. Microbial electrolysis cell (MEC) is a type of BES that, in the presence of an additional voltage, can treat wastewater and generate hydrogen gas. This is a promising approach for wastewater treatment and value-added product generation, though it may not be sustainable in the long run, as it relies on fossil fuels to provide that additional energy. Thus, it is important to explore alternative renewable resources that can provide energy to power MEC. Waste heat is one such resource that has not been researched extensively, particularly at the low-temperature spectrum. This was utilized as a renewable resource by converting waste heat to electricity using a device called thermoelectric generator (TEG). TEG converted simulated waste heat from an anaerobic digester to power an MEC. The feasibility of TEG to act as a power source for an MEC was investigated and its performance compared to the external power source. Various cold sources were analyzed to characterize TEG performance. To explore this integrated TEG-MEC system further, a hydraulic connection was added between the two systems. Wastewater was used as a cold source for TEG and it was recirculated to the anode of the MEC. This system showed improved performance with both systems mutually benefitting each other. The operational parameters were analyzed for the optimization of the system. The integrated system could generate hydrogen at a rate of 0.36 ± 0.05 m3 m-3 d-1 for synthetic domestic wastewater treatment. For the practical application, it is necessary to estimate the cost and narrow the focus on the functions of the system. Techno-economic analysis was performed for MEC with cost estimation and net present value model to understand the economic viability of the technology. The application niche of the BES was described and directions for addressing the challenges towards a full-scale operation were discussed. The present system provides a sustainable method for wastewater treatment and resource recovery which can play an important role in human health, social and economic development and a strong ecosystem. / Doctor of Philosophy / An average person produces about 50-75 gallons of wastewater every day. In addition to the households, wastewater is generated from industries and agricultural practices. As the population increases, the quantity of wastewater production will inevitably increase. To keep our rivers and oceans clean and safe, it is essential to treat the wastewater before it is discharged to the water bodies. However, the conventional wastewater treatment is a very energy (and thus cost) intensive process. For low-income and developing parts of the world, it is difficult to adapt the technology everywhere in its present form. Furthermore, as the energy is provided mostly by fossil fuels, their limited reserves and harmful environmental effects make it critical to find alternative methods that can treat the wastewater at a much lower energy input. For a circular and sustainable economy, it is important to realize wastewater as a resource which can provide us energy, nutrients, and water, rather than discard it as a waste. Bioelectrochemical systems (BES) is an emerging technology that can simultaneously treat wastewater and recover resources in the form of electricity/hydrogen gas, and nitrogen and phosphorus compounds. Microbial electrolysis cell (MEC) is a type of BES that is used to treat wastewater and generate hydrogen gas. An additional voltage is supplied to the MEC for producing hydrogen. In the long run, this may not be sustainable as it relies on fossil fuels to provide that additional energy. Thus, it is important to explore alternative renewable resources that can provide energy to power MEC. Waste heat is a byproduct of many industrial processes and widely available. This was utilized as a renewable resource by converting waste heat to electricity using a device called thermoelectric generator (TEG). TEG converted simulated waste heat from an anaerobic digester to power an MEC. The mutual benefit for MEC and TEG was also explored by connecting the system electrically and hydraulically. Cost-estimation of the system was performed to understand the economic viability and functions of the system were developed. The present system provides a sustainable method for wastewater treatment and resource recovery which can play an important role in human health, social and economic development and a strong ecosystem.
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Stadens sopor : Tillvaratagande, förbränning och tippning i Stockholm 1900-1975 / The garbage of the city : Resource recovery, incineration and dumping in Stockholm 1900-1975Sjöstrand, Ylva S. January 2014 (has links)
This thesis deals with perceptions of refuse as an asset or as a liability and the questions of waste management practices. The aim has been to gain new insights into Stockholm’s waste management in the period 1900–1975 by studying change and continuity in municipal practices and the notions that governed the municipal actors’ actions. The central questions are what factors determined the city’s waste management, and how an urban and local (environmental) problem was formulated and addressed by local authorities and political bodies. In answering, I have applied a theory of inertia in large technical–administrative systems and an analytical framework based on the concept of waste management regimes. During the period a resource recovery regime was replaced by an incineration regime. At the turn of the last century, the quantity and type of refuse produced by Stockholm’s rising population was compounded by increasing consumption. In order to modernize the capital’s waste disposal the city invested in resource recovery by introducing source separation. The fall in demand for fertilizer and a changing composition of the waste in the 1920s made it more difficult to get rid of refuse and led to an end of waste separation. Incineration came to be seen as the modern option and in 1938 Sweden’s first modern incineration plant for municipal waste was built outside Stockholm. The amount of waste produced by Stockholm nearly tripled between 1922, when it was at its lowest levels, and the mid-1960s. The late 1960s saw an even more dramatic increase. In the 1960s waste was discussed as an important environmental issue and in the 1970s recycling was implemented in small scale. At the national level recycling was adopted as a waste management aim in 1975.
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Inactivation of Ascaris in Double-Vault Urine-Diverting Composting Latrines in Panama: Methods and Environmental Health Engineering Field ApplicationsGibson, Daragh A. 16 June 2014 (has links)
The United Nations Millennium Development Goals have prioritized improving access to sanitation, but unfortunately about a third of the global population is still without an improved sanitation source and one billion still practice open defecation. Lack of access to adequate and safe sanitation means the proliferation of dangerous pathogens in the environment, especially soil-transmitted helminths (STHs). In the Bocas del Toro Province of Panama (and similar locations in the world), composting latrines have been built in many of the indigenous communities in the area. They are a form of dry or ecological sanitation and are designed to produce an end product that can be used as a soil amendment for agricultural purposes. The issue is that many of these latrines are not working as designed and do not go through the composting process. Instead, they may act as incubators for harmful pathogens, such as Ascaris lumbricoides (roundworm).
This research 1) provides an extensive literature review of the health situation of Panama, focusing on indigenous populations; soil-transmitted helminths and helminthiasis; Ascaris lumbricoides and its implications for wastewater reuse and land application of biosolids/sewage sludge; and inactivation of Ascaris in composting latrines; and 2) develops and proposes an experimental plan, with field-based methods, to assess the inactivation of Ascaris, by urea and solar heat (increased temperature), in composting latrines in Panama. Various experiments have been conducted in the laboratory using urea and increased temperature to inactive Ascaris; however few have been carried out in dry toilet technologies in the field. The contribution of this thesis is the field-based experimental design developed for inactivating Ascaris in composting latrines. The methods build upon previous research carried out both in the laboratory and in the field.
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Solid Waste Generation & Composition in Gaborone, Botswana. Potential for Resource Recovery.Nagabooshnam, Jayesh kumar January 2012 (has links)
An analysis of solid waste management was performed in Gaborone, Botswana to identify the quantity of different types of solid waste that are generated annually and the possible strategies for improved waste management. In order to achieve the objective of the project, present waste management practice in Gaborone was analysed and waste composition study was carried out in Gamodubu landfill, Gaborone. Waste from household, commercial, industrial and others (defence and institutional) stratums were selected for sampling. Different samples were taken and forwarded to sorting analysis. The waste was categorized into 10 categories and one of the categories (plastic) is further divided into 5 Subcategories. The output of the study results the quantity of solid waste generated in Gaborone, composition of solid waste categories from different stratums and its flow to the landfill and the quality of waste, annually. These findings helped in serving the importance and the need of better waste management system in order to improvise the potential for resource recovery under social considerations.
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Water's Dependence on Energy: Analysis of Embodied Energy in Water and Wastewater SystemsMo, Weiwei 01 January 2012 (has links)
Water and wastewater treatment is a critical service provided for protecting human health and the environment. Over the past decade, increasing attention has been placed on energy consumption in water and wastewater systems for the following reasons: (1) Water and energy are two interrelated resources. The nexus between water and energy can intensify the crises of fresh water and fossil fuel shortages; (2) The demand of water/wastewater treatment services is expected to continue to increase with increasing population, economic development and land use change in the foreseeable future; and (3) There is a great potential to mitigate energy use in water and wastewater systems by recovering resources in wastewater treatment systems. As a result, the goal of this dissertation study is to assess the life cycle energy use of both water supply systems and wastewater treatment systems, explore the potential of integrated resource recovery to reduce energy consumption in wastewater systems, and understand the major factors impacting the life cycle energy use of water systems.
To achieve the goal, an input-output-based hybrid embodied energy model was developed for calculating life cycle energy in water and wastewater systems in the US. This approach is more comprehensive and less labor intensive than the traditional life cycle assessment. Additionally, this model is flexible in terms of data availability. It can give a rough estimation of embodied energy in water systems with limited data input. Given more site specific data, the model can modify the embodied energy of different energy paths involved in water related sectors.
Using the input-output-based hybrid embodied energy model, the life cycle energy of a groundwater supply system (Kalamazoo, Michigan) and a surface water supply system (Tampa, Florida) was compared. The two systems evaluated have comparable total energy embodiments based on unit water production. However, the onsite energy use of the groundwater supply system is approximately 27% greater than the surface water supply system. This was primarily due to more extensive pumping requirements. On the other hand, the groundwater system uses approximately 31% less indirect energy than the surface water system, mainly because of fewer chemicals used for treatment. The results from this and other studies were also compiled to provide a relative comparison of embodied energy for major water supply options. The comparison shows that desalination is the most energy intensive option among all the water sources. The embodied energy and benefits of reclaimed water depend on local situations and additional treatment needed to ensure treated wastewater suitable for the desired application.
A review was conducted on the current resource recovery technologies in wastewater treatment systems. It reveals that there are very limited life cycle studies on the resource recovery technologies applied in the municipal wastewater treatment systems and their integrations. Hence, a life cycle study was carried out to investigate the carbon neutrality in a state-of-art wastewater treatment plant in Tampa, FL. Three resource recovery methods were specifically investigated: onsite energy generation through combined heat and power systems, nutrient recycling through biosolids land application, and water reuse for residential irrigation. The embodied energy and the associated carbon footprint were estimated using the input-output-based hybrid embodied energy model and carbon emission factors. It was shown that the integrated resource (energy, nutrient and water) recovery has the potential to offset all the direct operational energy; however, it is not able to offset the total embodied energy of the treatment plant to achieve carbon neutrality. Among the three resource recovery methods, water reuse has the highest potential of offsetting carbon footprint, while nutrient recycling has the lowest.
A final application of the model was to study on the correlation between embodied energy in regional water supply systems and demographic and environmental characteristics. It shows that energy embodied in water supply systems in a region is related to and can be estimated by population, land use patterns, especially percentage of urban land and water source, and water sources. This model provides an alternative way to quickly estimate embodied energy of water supply in a region. The estimated embodied energy of water supply can further be used as a supporting tool for decision making and planning.
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Produktion av bakteriell cellulose genom användning av det symbiotiska förhållandet mellan bakterier och jäst som används vid Kombuchatillverkning / Bacterial cellulose production using the symbiotic relationship of bacteria and yeast found in Kombucha productionJohansson, Matilda January 2019 (has links)
Different factors such as growing environmental awareness due to the increasing negative impact of persistent plastic wastes, the uncontrollable price variations of the raw material and the rapid depletion of reserves have increased the interest in research regarding polymers derived from renewable sources to replace petroleum-based materials. One of the earth’s most abundant macromolecules is cellulose. The production of cellulose from another resource replaces and reduces the demand from plants, the other resource being cellulose from a bacterial system. Bcaterial cellulose film were produced by fermenting apple waste (apple pomace) from cider production donated by Herrljunga Cider in Herrljunga, Sweden and expired fruit juice, produced by LoveJuice Indonesia, containing a mixture of fruits, mainly apple. As inoculum for the fermentations two different Kombucha cultures were used. To optimize the fermentation conditions, factors such as nitrogen source, sugar content, temperature, pH, surface area, sterilization of the substrate, culture condition and fermentation time was varied to obtain the desired result. The bacterial cellulose films were dried at 50-70 °C in an oven, air-dried or freeze-dried to evaluate the impact of drying technique on the final material. The behavior of the microorganism during fermentation was monitored by sampling and observation. The consumption rate of carbohydrates was analyzed using high performance liquid chromatography (HPLC). The properties of the obtained biofilms were analyzed using thermogravimetric analysis (TGA), tensile testing and determination of cellulose content in the obtained biofilms. Two different sugar concentrations (35 g/l and 70 g/l) and three different caffeine concentrations (0 g/l, 150 g/l and 225 g/l) as nitrogen source were investigated to determine the best condition. A control batch of conventional (black tea and 70 g/l table sugar) Kombucha was used as reference. The highest tensile strength (50 MPa) and thermal stability was observed in the biofilms with the highest yield that had been dried in oven. The biofilms obtained by fermenting apple pomace from the cider industry showed the highest tensile strength and highest thermal stability in comparison to fermenting expired fruit juice. The biofilm obtained by fermenting apple waste(sugar concentration 70 g/l) in combination with sterilizing the substrate without adding any nitrogen source, dried in an oven and purified using 0,1 M NaOH resulted in the highest tensile strength, highest thermal stability and the purest biofilm from a visual aspect. The highest yield was observed in the fermentation of apple pomace (sugar concentration 70 g/l) from the cider industry without sterilization of the initial media with an addition of nitrogen of approximately 450 mg/l). The optimal fermentation period was observed to be 14-15 days, at 25-28 °C under static conditions using a glass vessel with a diameter of 20 cm and an initial pH of 5,5.
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Exploring the circular economy of urban organic waste in sub-Saharan Africa: opportunities and challengesDdiba, Daniel January 2020 (has links)
Globally, there is increasing awareness of the importance of applying circular economy principles to the management of organic waste streams through resource recovery. In the urban areas of sub-Saharan Africa which are going to host a significant part of population growth over the next three decades, this is especially relevant. Circular economy approaches for sanitation and waste management can provide incentives to improve infrastructure and consequently contribute resources for water, energy and food that power urban livelihoods. This thesis is situated at the intersection of the circular economy on one hand and sanitation and waste management systems on the other. It aims to contribute to knowledge about the circular economy by investigating the potential contribution of resource-oriented urban sanitation and waste management towards the implementation of a circular economy in sub-Saharan Africa and the opportunities and challenges thereof. In pursuit of the above aim, the thesis employs a mixed methods approach and is operationalized in two case study locations: Kampala (Uganda) and Naivasha (Kenya). The findings reveal the quantities of resource recovery products like biogas, compost and black soldier fly larvae that can be obtained from the organic waste streams collected in a large city, demonstrate the viability of valorizing dried faecal sludge as a solid fuel for industrial applications, and identify the factors that facilitate or impede the governance capacity to implement circular economy approaches to the management of organic waste streams in urban areas in sub-Saharan Africa. The methods used for quantifying the potential for valorizing organic waste streams and for assessing governance capacity demonstrate approaches that could be applied in other urban contexts with interest in implementing circular economy principles. The discussion highlights some key implications of these findings for sanitation and waste management practices, arguing that it is time for a shift in sub-Saharan Africa from designing sanitation and waste management systems for disposal to designing them for resource recovery. / Globalt ökar medvetenheten om vikten av att tillämpa principer för cirkulär ekonomi för att hantera organiska avfallsströmmar genom resursåtervinning. I de urbana områdena i Subssahariska Afrika är detta särskilt relevant, då dessa förväntas stå för en betydande del av befolkningsökningen under de kommande tre decennierna. En mer cirkulärekonomi för sanitet och avfallshantering kan ge incitament för att förbättra infrastrukturen och därmed bidra med resurser till produktion av vatten, energi och mat som driver städernas försörjning. Denna licentiatuppsats befinner sig i skärningspunkten mellan cirkulär ekonomi å ena sidan och sanitets- och avfallshanteringssystem å andra sidan. Syftet är att bidra med kunskap om cirkulär ekonomi genom att undersöka potentialen för resursorienterad stadssanitet och avfallshantering att bidra till genomförandet av cirkulär ekonomi i Subsahariska Afrika, samt dess möjligheter och utmaningar. För att uppnå ovanstående syfte används flera olika metoder och genomförs i två fallstudiestäder: Kampala i Uganda respektive Naivasha i Kenya. Resultaten visar på de mängder av resursåtervinningsprodukter som biogas, kompost och svarta soldatflugelarver som kan erhållas från organiska avfallsströmmar som samlas in i en stor stad. Dessutom visar resultaten livskraftigheten för att valorisera torkat avföringsslam som ett fast bränsle för industriella tillämpningar. Slutligen identifierar resultaten faktorer som underlättar eller hindrar styrningskapaciteten för att genomföra cirkulär ekonomi-strategier för hantering av organiska avfallsströmmar i stadsområden i Subsahariska Afrika. Metoderna som används för att kvantifiera potentialen att valorisera organiska avfallsströmmar och att utvärdera styrningskapacitet är metoder som kan tillämpas i andra urbana sammanhang där det finns intresse för att genomföra cirkulära ekonomiska principer. Diskussionen belyser några viktiga konsekvenser av dessa fynd för sanitets- och avfallshanteringspraxis och argumenterar för att det är dags för en övergång i SSA från att utforma sanitets- och avfallshanteringssystem för bortskaffande till att utforma dem för resursåtervinning. / <p>QC 20200513</p> / UrbanCircle: Urban Waste into Circular Economy Benefits
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