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Exploring the circular economy of urban organic waste in sub-Saharan Africa: opportunities and challenges
KTH, School of Architecture and the Built Environment (ABE), Sustainable development, Environmental science and Engineering, Sustainability Assessment and Management. Stockholm Environment Institute (SEI).ORCID iD: 0000-0001-5908-6417
2020 (English)Licentiate thesis, comprehensive summary (Other academic)
Abstract [en]

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.

Abstract [sv]

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.

Place, publisher, year, edition, pages
Stockholm, Sweden: KTH Royal Institute of Technology, 2020. , p. 61
Series
TRITA-ABE-DLT ; 2016
Keywords [en]
Biowaste; governance capacity; resource recovery; sub-Saharan Africa; sustainable sanitation; sustainable urban development; circular economy
National Category
Other Environmental Engineering Environmental Management
Research subject
Planning and Decision Analysis, Strategies for sustainable development
Identifiers
URN: urn:nbn:se:kth:diva-273025ISBN: 978-91-7873-543-3 (print)OAI: oai:DiVA.org:kth-273025DiVA, id: diva2:1429857
Presentation
2020-06-08, Via Zoom: https://kth-se.zoom.us/webinar/register/WN_8vcAAGzGR0KapHqV6MlWyQ, Du som saknar dator/datorvana kan kontakta goran.finnveden@abe.kth.se för information, Stockholm, Sweden, 13:00 (English)
Opponent
Supervisors
Projects
UrbanCircle: Urban Waste into Circular Economy Benefits
Funder
Swedish Research Council FormasSida - Swedish International Development Cooperation Agency
Note

QC 20200513

Available from: 2020-05-13 Created: 2020-05-12 Last updated: 2020-05-13Bibliographically approved
List of papers
1. The circular economy potential of urban organic waste streams in low- andmiddle-income countries
Open this publication in new window or tab >>The circular economy potential of urban organic waste streams in low- andmiddle-income countries
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(English)Manuscript (preprint) (Other academic)
Abstract [en]

There is growing recognition of the potential environmental and socio-economic benefits of applying a circular economy approach to urban organic waste management through resource recovery. Decisions around planning and implementing circular urban waste systems require estimates of the quantity of resources available in waste streams and their potential market value. However, most case-studies have so-far been conducted in high-income countries and cities in low- and middle-income countries have different challenges when developing a circular economy. The present paper explores these issues by estimating the potential for resource recovery from organic waste streams in the context of low- and middle-income countries, illustrated in Kampala, Uganda. A simplified material flow analysis approach is used to track the transformation of waste streams, namely; faecal sludge, sewage sludge and organic solid waste into the resource recovery products biogas, solid fuel, black soldier fly larvae and compost. Findings indicate that even at current rates of waste collection, the three waste streams combined could annually yield 135,000 tonnes of solid fuel or 39.6 million Nm3 of biogas or 15,000 tonnes of black soldier fly larvae or 108,000 tonnes of compost. Potential revenues from the products could range from 5.1 million USD for compost to 47 million USD for biogas, annually. This case study demonstrates how complex information describing urban waste in specific cities can be presented to facilitate decision-making and planning by stakeholders. By highlighting different resource recovery opportunities, application of this approach could provide an incentive for more sustainable urban sanitation and waste management systems.

Keywords
Resource recovery; Waste reuse; Sustainable sanitation; Waste management; Faecal sludge management
National Category
Other Environmental Engineering
Research subject
Planning and Decision Analysis, Strategies for sustainable development
Identifiers
urn:nbn:se:kth:diva-273023 (URN)
Projects
UrbanCircle
Funder
Sida - Swedish International Development Cooperation AgencySwedish Research Council Formas, 2017-00268
Available from: 2020-05-05 Created: 2020-05-05 Last updated: 2020-05-12
2. Faecal sludge as a solid industrial fuel: a pilot-scale study
Open this publication in new window or tab >>Faecal sludge as a solid industrial fuel: a pilot-scale study
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2017 (English)In: Journal of Water, Sanitation and Hygiene for Development, ISSN 2043-9083, Vol. 7, no 2, p. 243-251Article in journal (Refereed) Published
Abstract [en]

Revenues from faecal sludge (FS) treatment end products could offset treatment costs and contribute to financially viable sanitation. In urban sub-Saharan Africa, energy-producing resource recovery has the potential to generate greater revenue than use as soil conditioner. In contrast with wastewater sludge, the technical feasibility of using dried FS as solid fuel in industries has not been investigated. This study evaluated it through characterization of dried FS from drying beds and by assessing the combustion performance in two pilot-scale kilns, in Kampala and Dakar. Results from the fuel characterization demonstrate that dried FS had comparable fuel characteristics as wastewater sludge considering calorific value and ash content. The calorific values and ash contents were 10.9–13.4 MJ/kg dry matter (DM) and 47.0–58.7%, respectively. Results from pilot-scale experiments suggest that dried FS can be effective in providing energy for industries. Temperatures in pilot-scale kilns fueled by FS were 800 °C, sufficient for curing of clay bricks, and 437 °C, sufficient for waste oil regeneration. In Kampala and Dakar, an estimated 20,000 tons of FS DM per year accumulate. Tapping the industrial fuel market and financial benefits could be realized through optimization of onsite sanitation and treatment technologies.

Place, publisher, year, edition, pages
IWA Publishing, 2017
Keywords
co-combustion, fecal sludge management, heavy metals, resource recovery, sanitation, waste-to-energy
National Category
Other Environmental Engineering
Research subject
Energy Technology
Identifiers
urn:nbn:se:kth:diva-252295 (URN)10.2166/washdev.2017.089 (DOI)000403349000006 ()2-s2.0-85020544782 (Scopus ID)
Note

QC 20190628

Available from: 2019-05-24 Created: 2019-05-24 Last updated: 2020-05-27Bibliographically approved
3. Governing the circular economy: assessing the capacity to implement resource-oriented sanitation and wastemanagement systems in low- and middle-income countries
Open this publication in new window or tab >>Governing the circular economy: assessing the capacity to implement resource-oriented sanitation and wastemanagement systems in low- and middle-income countries
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(English)Manuscript (preprint) (Other academic)
Abstract [en]

Transitioning to a circular economy requires strategic investments in infrastructure, but it also requires policy coherence, coordination and collaboration among stakeholders across sectors and governance levels. In this paper, we aimed to identify the factors that facilitate or impede governance capacity to adopt circularity in the form of resource recovery from urban organic waste streams. We conducted a literature review and semi-structured interviews using the ‘Governance Capacity Framework’ in a case study of Naivasha, Kenya. Our findings emphasize the importance of leadership from the public sector in creating a common vision for circularity and using their convening power to facilitate cross-sectoral collaboration. Moreover, we identify aneed for bridging theoretical circular economy concepts to initiatives in local communities of practice. The insights in this paper are relevant for advancing the understanding of challenges for governance of thecircular economy especially in low-and middle-income country contexts.

Keywords
Governance capacity, bioeconomy, resource recovery, organic waste, biowaste, sustainable urban development
National Category
Environmental Management
Research subject
Planning and Decision Analysis, Strategies for sustainable development
Identifiers
urn:nbn:se:kth:diva-273021 (URN)
Funder
Swedish Research Council Formas, 2017-00268Sida - Swedish International Development Cooperation Agency
Available from: 2020-05-05 Created: 2020-05-05 Last updated: 2020-05-12

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