| 1. |
- 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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| 2. |
- Ekane, Nelson, 1978-, et al.
(författare)
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Resources and Risks : Perceptions on the Application of Sewage Sludge on Agricultural Land in Sweden, a Case Study
- 2021
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Ingår i: Frontiers in Sustainable Food Systems. - : Frontiers Media SA. - 2571-581X. ; 5
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Tidskriftsartikel (refereegranskat)abstract
- To spread or not to spread sewage sludge on agricultural land in Sweden remains the subject of a highly polarized debate among different stakeholders in the Swedish agricultural sector. This article presents insights on how stakeholders in Sweden see and explain the potentials and safety of spreading sewage sludge on agricultural land. This is done by drawing on risk perception literature and qualitative research methods. The findings reveal that fear of contamination and feeling of disgust are major deterrents of the use of sludge as an agricultural input. These are partly explained by unknowns and unfamiliarity about risks of unwanted substances in sludge. The study shows that while actors engaged in the practice amplify benefits of sludge as a resource and reiterate the need for emphasis on upstream measures including improved risk management systems, actors in charge of controlling toxins in society amplify actual and potential risks, highlight gaps in monitoring and minimizing risks, and would rather have a complete ban on the practice. This study highlights the complex combination of technical, environmental, socio-economic, psychological, and political factors influencing judgment and decision-making regarding sludge and its use as fertilizer in agriculture and concludes that the clash between facts and feelings which epitomizes the Swedish sludge debate may have implications for public trust and effective risk communication. As contribution to the Swedish sewage sludge debate, this study emphasizes that the benefits of sludge in agriculture is important but not enough to drive the practice to scale. It is even more important to improve understanding on the controllability and severity of risks in short and long-term.
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| 3. |
- Rosemarin, Arno S., et al.
(författare)
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Circular nutrient solutions for agriculture and wastewater : a review of technologies and practices
- 2020
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Ingår i: Current Opinion in Environmental Sustainability. - : Elsevier B.V.. - 1877-3435 .- 1877-3443. ; 45, s. 78-91
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Tidskriftsartikel (refereegranskat)abstract
- This paper summarizes key findings from a series of systematic reviews and comprehensive efforts to collate evidence and expert opinions on circular solutions for recovery and reuse of nutrients and carbon from different waste streams in the agriculture and wastewater sectors. We identify established and emerging approaches for transformation towards a more circular nutrient economy with relevance to SDGs 6 and 14. The paper cites the example of the Baltic Sea Region which has experienced decades of fertilizer overuse (1950s–1990s) and concomitant urban sources of excessive nutrients. Regulations and incentive policies combining the nitrogen, phosphorus and carbon cycles are necessary if circular nutrient technologies and practices are to be scaled up. Pricing chemical fertilizer at levels to reflect society's call for circularity is a central challenge.
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