While sanitation is fundamental for health and wellbeing, cities of all sizes face growing challenges in providing safe, affordable and functional sanitation systems that are also sustainable. Factors such as limited political will, inadequate technical, financial and institutional capacities and failure to integrate safe sanitation systems into broader urban development have led to a persistence of unsustainable systems and missed opportunities to tackle overlapping and interacting urban challenges. This paper reviews challenges associated with providing sanitation systems in urban areas and explores ways to promote sustainable sanitation in cities. It focuses on opportunities to stimulate sustainable sanitation approaches from a resource recovery perspective, generating added value to society while protecting human and ecosystem health. We show how, if integrated within urban development, sustainable sanitation has great potential to catalyse action and contribute to multiple sustainable development goals.

Phosphorus (P) is one of the essential elements needed for global food security. However, the phosphate life cycle is currently predominantly linear, from P-rock mining to fertiliser production, agriculture, and food consumption, with the P excess ending up in soil and runoff. Eutrophication coupled with limited global commercial phosphorus reserves call for increased efforts toward creating a circular economy for P in many populated drainage basins such as the Baltic Sea region. To identify barriers and opportunities for such a transition, we employ an analytical framework that merges an innovation systems perspective with elements from the socio-technical transitions literature. Combining a literature review with key informant interviews, we find that lack of appropriate policy steering and insufficient knowledge on the performance of technologies for reuse remain key obstacles for closing the P loop. There are, however, structural opportunities presented by the new EU Fertilising Products Regulation that are likely to level the playing field between conventional and waste-derived fertilisers and thereby improve the market opportunities for recovered P. However, the system currently appears to be moving towards a narrow focus on a few new technologies for P recovery and reuse which could lead to new lock-ins. Solutions need to address users' acceptability of the technologies and waste-derived products while the vision of a circular economy needs to be better articulated through government interventions to capture environmental externalities of phosphate mining. The paper further highlights knowledge gaps and proposes recommendations for policy and research related to the circular economy of P.

There is growing recognition of the potential environmental and socio-economic benefits of applying a circular 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, studies assessing circular economy potential have so-far been conducted mostly in high-income countries, yet cities in low- and middle-income countries have different challenges when developing a circular economy. This paper addresses this gap by estimating the resource recovery potential of organic waste streams in the context of low- and middle-income countries, illustrated with the case of 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 and revenues from the products could range from 5.1 million USD from compost to 47 million USD from biogas. The results demonstrate how complex information describing urban waste 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.

The aim of this paper is to enhance understanding of how the resilience of water, sanitation and hygiene (WASH) systems to hazards can be improved. In turn, this aims to inform different strategies for public and private partnerships (PPPs). In a new approach, to acknowledge the multi levelled nature of resilience; risk at the relevant levels are taken into account, (regional/river basin, urban area, and individual). For these levels, we first describe the different components of risk, vulnerability and resilience of the WASH system that influence people׳s exposure to hazards. We illustrate these components using examples from case studies in the literature. Using a social learning lens - a crucial ingredient of resilience - we examine opportunities for reducing risks through improving public–private engagement. These are presented as strategies which could guide investment decisions: As pressures from climate change and development add up, businesses must become aware of the risks involved in operating and investing without considering ecosystem health, both in terms of the services they provide for mitigating floods and droughts, as well as in terms of the development approaches that define how ecosystems are managed (e.g. “making space” for, rather than controlling water). There is a need to develop an institutional culture that strives towards greener and more resilient urban environments with the help of various quality assurance methods. Partnerships must reach the poorer customer base, encourage informal small entrepreneurs, and boost financial mechanisms (e.g. micro-insurance, micro-finance) to support the most vulnerable in society

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.