Legitimacy of source-separating wastewater systems with Swedish water utilities.

Nutrient management is one of the critical challenges for developing sustainable circular economies in cities. Nutrients such as nitrogen and phosphorus from our food end up in our wastewater and pose an environmental threat when they are released in waterways. Yet, these nutrients are essential for crop production and food security. Hince human excreta contains the bulk of nutrients going through the urban ecosystem. Source separation of excreta from the rest of urban wastewater flows can enable safe and efficient nutrient recovery. Yet, source-separating wastewater systems are not yet common in urban areas. The aim of this study is to assess the legitimacy of source-separating wastewater systems from the perspective of wastewater professionals in Sweden. The study uses interviews and a survey to explore the pragmatic, normative, cognitive and regulatory dimensions of legitimacy and how these aspects can vary between different municipalities. Finally, it looks into possible knowledge-based activities to increase legitimacy. The results from this study show variations in legitimacy levels in urban areas in Sweden. Overall opinion appears to be neutral to the concept rather than negative. Although many see multiple barriers to implementation. Normative legitimacy (moral motivation) was relatively high, while cognitive legitimacy (knowledge & experiences) was lowest. Respondents from organizations where source-separation is being implemented, or they believe that it will be implemented within 10 years, generally saw more drivers and fewer barriers. These innovators were also more interested in knowledge-based activities. Overall recommendations to increase cognitive knowledge regarding source-separating systems among multiple stakeholders seems the most promising path forward to increase legitimacy in the Swedish wastewater sector.

Egestabase - An online evidence platform to discover and explore options to recover plant nutrients from human excreta and domestic wastewater for reuse in agriculture.

Restoring nutrient circularity across scales is important for ecosystem integrity as well as nutrient and food security. As such, research and development of technologies to recover plant nutrients from various organic residues has intensified. Yet, this emerging field is diverse and difficult to navigate, especially for newcomers. As an increasing number of actors search for circular solutions to nutrient management, there is a need to simplify access to the latest knowledge. Since the majority of nutrients entering urban areas end up in human excreta, we have chosen to focus on human excreta and domestic wastewater. Through systematic mapping with stakeholder engagement, we compiled and consolidated available evidence from research and practice. In this paper, we present 'Egestabase' - a carefully curated open-access online evidence platform that presents this evidence base in a systematic and accessible manner. We hope that this online evidence platform helps a variety of actors to navigate evidence on circular nutrient solutions for human excreta and domestic wastewater with ease and keep track of new findings.