| 1. |
- Aguilar, Mónica García, et al.
(författare)
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Governance challenges and opportunities for implementing resource recovery from organic waste streams in urban areas of Latin America: insights from Chía, Colombia
- 2022
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Ingår i: Sustainable Production and Consumption. - : Elsevier. - 2352-5509. ; 30, s. 53-63
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Tidskriftsartikel (refereegranskat)abstract
- Across the globe, there is increasing interest in implementing circular approaches to urban sanitation and waste management to mitigate environmental challenges and promote sustainable business opportunities. In Latin America where 80% of the population live in urban areas, there is limited investigation into the enabling factors and governance barriers that are critical to implementing circular economy strategies in urban areas. This paper aims at assessing the governance capacity to implement resource recovery from organic waste streams in the municipality of Chía, Colombia, through applying the Governance Capacity Framework in a participatory process with local stakeholders. The findings highlight the importance of local initiatives for resource recovery that allow experimentation, raise awareness and foster collaboration, as well as mechanisms available for public participation in decision-making processes as enabling factors. Meanwhile, the inadequate monitoring and assessment of environmental strategies and policies, inadequate sharing of information among stakeholders and the relative low awareness of potential benefits of recovering resources from organic waste streams, especially among public sector actors, emerge as key barriers. Beyond Chía, the results provide insights on crucial factors for ensuring sufficient governance capacity in other urban areas in low- and middle-income countries which are considering circular approaches to urban sanitation and waste management. The findings also provide an empirical basis to advance the understanding of the governance conditions necessary for implementing resource recovery from organic waste streams, upon which further applications of the governance capacity framework along with participatory aspects in other similar urban contexts could build.
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| 2. |
- Ddiba, Daniel, 1990-, et al.
(författare)
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A review of how decision support tools address resource recovery in sanitation systems
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Annan publikation (övrigt vetenskapligt/konstnärligt)abstract
- Globally, there is increasing interest in recovering resources from sanitation systems. However, the process of planning and implementing circular sanitation is complex and can necessitate software-based tools to support decision-making. In this paper, we review 24 decision support software tools used for sanitation planning, to generate insights into how they address resource recovery across the sanitation chain. The findings reveal that several tools can address many planning issues around resource recovery in sanitation including analysis of material flows, estimating resource recovery potential and assessing the sustainability, demand and acceptability of resource recovery technologies and products, at various planning stages. The results presented here can guide users in the choice of different tools depending on, for example, what kind of impacts the user is interested in, the stage of the planning process and the sanitation service that are in focus. However, some issues are not adequately covered by the tools including the assessment of the overall level of resource circularity in a sanitation system, the selection of resource recovery products with significant demand in a way that matches the available supply of waste streams in an area and determining the sustainability implications of the use phase of resource recovery products. While there is scope to develop new tools or to modify existing ones to cover these gaps, communication efforts are needed to create awareness about existing tools and how they address resource recovery. It is also important to further integrate the available tools into urban planning processes to move them beyond research and pilots into practice, and hopefully contribute towards more circular sanitation systems.
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| 3. |
- Ddiba, Daniel, 1990-
(författare)
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Exploring the circular economy of urban organic waste in sub-Saharan Africa: opportunities and challenges
- 2020
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Licentiatavhandling (övrigt vetenskapligt/konstnärligt)abstract
- 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.
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| 4. |
- Ddiba, Daniel Isaac Waya, 1990-, et al.
(författare)
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A review of how decision support tools address resource recovery in sanitation systems
- 2023
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Ingår i: Journal of Environmental Management. - : Elsevier BV. - 0301-4797 .- 1095-8630. ; 342
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Forskningsöversikt (refereegranskat)abstract
- Globally, there is increasing interest in recovering resources from sanitation systems. However, the process of planning and implementing circular sanitation is complex and can necessitate software-based tools to support decision-making. In this paper, we review 24 decision support software tools used for sanitation planning, to generate insights into how they address resource recovery across the sanitation chain. The findings reveal that the tools can address many planning issues around resource recovery in sanitation including analysis of material flows, integrating resource recovery technologies and products in the design of sanitation systems, and assessing the sustainability implications of resource recovery. The results and recommendations presented here can guide users in the choice of different tools depending on, for example, what kind of tool features and functions the user is interested in as well as the elements of the planning process and the sanitation service chain that are in focus. However, some issues are not adequately covered and need improvements in the available tools including quantifying the demand for and value of resource recovery products, addressing retrofitting of existing sanitation infrastructure for resource recovery and assessing social impacts of resource recovery from a life cycle perspective. While there is scope to develop new tools or to modify existing ones to cover these gaps, communication efforts are needed to create awareness about existing tools, their functions and how they address resource recovery. It is also important to further integrate the available tools into infrastructure planning and programming processes by e.g. customizing to relevant planning regimes and procedures, to move them beyond research and pilots into practice, and hopefully contribute towards more circular sanitation systems.
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| 5. |
- Ddiba, Daniel Isaac Waya, 1990-, et al.
(författare)
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Governing the circular economy : Assessing the capacity to implement resource-oriented sanitation and waste management systems in low- and middle-income countries
- 2020
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Ingår i: Earth System Governance. - : Elsevier BV. - 2589-8116. ; 4, s. 100063-
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Tidskriftsartikel (refereegranskat)abstract
- 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 co-developing visionary strategies for circularity and using their convening power to facilitate cross-sectoral collaboration. Moreover, we identify a need 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 the circular economy especially in low-and middle-income country contexts.
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| 6. |
- Ddiba, Daniel Isaac Waya, 1990-, et al.
(författare)
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Sustainability assessment of increased circularity of urban organic waste streams
- 2022
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Ingår i: Sustainable Production and Consumption. - : Elsevier BV. - 2352-5509. ; 34, s. 114-129
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Tidskriftsartikel (refereegranskat)abstract
- The circular economy, from an urban organic waste perspective, is seen as an approach to deal with increasing waste streams, while contributing to meeting the increasing demand for water, energy, food and other resources in urban areas. However, there is need for a systematic assessment of the broader environmental and social ben-efits and trade-offs of resource recovery from organic waste streams. This paper presents a framework for assessing the societal impacts of increased circularity in terms of resource recovery from organic waste streams at city scale, building on the design of alternative scenarios for future technology systems. The framework was developed based on a literature review of current frameworks in the area, adapting and combining some of their aspects and adding required features to allow for a broad sustainability assessment. It was also informed by stakeholder interviews. The framework was applied to the case of Naivasha, Kenya to illustrate its applicability and usefulness. The outcome of the application in the Naivasha case indicate potential sustainability improve-ments from increased circularity, where resource recovery could lead to a reduction of greenhouse gas emissions, more efficient natural resource usage and job creation. It indicated also some risks of negative impacts on the health of workers in resource recovery facilities, and, in this specific case, negative impact on smallholder farmers. The framework proved applicable and useful in the case study, and hence could provide input at early stages of planning even with low availability of data. Thereby it could provide policy-relevant insights towards circular economy implementation approaches that harness the benefits while mitigating any identified potential negative impacts.
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| 7. |
- Ddiba, Daniel Isaac Waya, 1990-, et al.
(författare)
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The circular economy potential of urban organic waste streams in low- and middle-income countries
- 2021
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Ingår i: Environment, Development and Sustainability. - : Springer Nature. - 1387-585X .- 1573-2975.
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Tidskriftsartikel (övrigt vetenskapligt/konstnärligt)abstract
- 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.
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| 8. |
- Ddiba, Daniel, 1990-
(författare)
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Implementing resource recovery from urban organic waste in low- and middle-income countries : Tools to support planners and policy makers
- 2022
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Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- Globally, there is increasing awareness of the importance of applying circular economy principles to the management of organic waste streams through resource recovery. This is especially relevant in urban areas of low- and middle-income countries which are going to host a significant part of population growth over the next few decades. 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 aims to contribute new knowledge, methods and tools that are applicable as decision support for the planning and implementation of circular approaches to the management of organic waste streams. The research questions in the thesis focus on three aspects of resource recovery from organic waste streams; (1) how decision support tools estimate its potential to contribute to a circular economy, (2) the governance conditions that facilitate or impede its implementation, and (3) its sustainability implications. The research in this thesis employed a mixed methods approach including literature reviews, semi-structured interviews, field observations, workshops, quantitative modelling, diagnostic governance assessment, scenarios as well as quantitative and qualitative sustainability assessment. The research was operationalized in three case study locations: Chía (Colombia), 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, as well as the available decision support tools that can be used to address various aspects of resource recovery in sanitation systems. In the case study locations of Naivasha and Chía, the existence of entrepreneurial initiatives for resource recovery, the available platforms for collaboration among relevant local stakeholders and the relative affordability of resource recovery products are highlighted as factors enhancing governance capacity to implement resource recovery from organic streams. On the other hand, the inadequacy of monitoring and evaluation systems and the relatively low availability and transparency of information emerged as some of the factors impeding governance capacity. Through a framework that is developed and applied to the Naivasha case, the thesis also identifies the environmental gains that can be made from implementing resource recovery from organic waste streams, as well as the potential negative social impacts that need to be mitigated by local stakeholders. The extent to which various decision support tools address the sustainability implications of resource recovery from sanitation systems is also discussed.By providing new insights on resource recovery from organic waste streams in the case study locations, the tools and frameworks in this research demonstrate approaches that can be applied in a policy and practice context to offer decision support for the implementation of resource recovery from organic waste streams. This is particularly relevant for urban areas in low- and middle-income countries whose stakeholders wish to explore the potential of resource recovery from their organic waste streams, to undertake a diagnostic assessment of their governance capacity and to assess the sustainability implications of implementing more circular approaches in their sanitation and waste management systems.
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| 9. |
- Ddiba, Daniel, 1990-, et al.
(författare)
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Sustainability assessment of increased circularity of urban organic waste streams – with a case on Naivasha, Kenya
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Annan publikation (övrigt vetenskapligt/konstnärligt)abstract
- From an urban organic waste perspective, the circular economy is often seen as an approach to achieve dual outcomes: dealing with increasing waste streams while contributing to meeting the increasing demand for water, energy, food and other resources in urban areas. As the discourse on the circular economy moves from concept to implementation, there is need for assessing the environmental, social and economic benefits and trade-offs of both proposed and implemented strategies, policies, programs and projects for resource recovery from organic waste streams. This paper presents a framework with both conceptual and procedural aspects for assessing the societal impacts of alternative scenarios for resource recovery from organic waste streams at city scale. The framework was applied to the case of Naivasha, Kenya to illustrate its utility in assessing the environmental and social impacts associated with alternative scenarios that involve increasing circularity in the management of organic waste streams. The results highlighted that increasing circularity could potentially lead to a reduction of greenhouse gas emissions, more efficient natural resource usage and job creation, while at the same time leading to impacts on the health of workers in resource recovery facilities and a risk of reduced access to irrigation water for smallholder farmers. The framework also proved a useful way to identify potential positive and negative impacts linked to alternative scenarios and hence provide input at early stages of planning even with low availability of data. It is therefore expected that the framework and case study results could provide policy-relevant insights towards circular economy implementation approaches that harness the benefits while mitigating any identified potential negative impacts.
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| 10. |
- Gold, Moritz, et al.
(författare)
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Faecal sludge as a solid industrial fuel : a pilot-scale study
- 2017
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Ingår i: Journal of Water, Sanitation and Hygiene for Development. - : IWA Publishing. - 2043-9083 .- 2408-9362. ; 7:2, s. 243-251
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Tidskriftsartikel (refereegranskat)abstract
- 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.
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