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Creators/Authors contains: "Merck, Ashton"

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  1. Free, publicly-accessible full text available November 1, 2025
  2. Abstract Urine diversion (UD) is a system-of-systems that involves source separation of waste to maximize recovery of valuable nutrients, including phosphorus. Recent research shows how UD systems offer valuable ecological benefits and can aid in water conservation efforts, and public perception studies suggest that UD systems are generally viewed positively by end-users and the general public. Nevertheless, adoption and implementation of this promising sustainability solution remains limited in many countries, including the United States (U.S.). In this perspective, we argue that in order to scale up adoption in the U.S., UD researchers and innovators must do more to address regulatory barriers. We draw on insights from political science research on ‘regulatory regimes’ to introduce the array of regulations that apply to UD systems, with a focus on commercial and institutional buildings. We examine regulatory regimes all along the UD system-of-systems, beginning at the point of collection and ending at the point of beneficial reuse. We then propose next steps to address current regulatory challenges that impact adoption, with an emphasis on the importance of stakeholder coordination. Throughout, we argue that law and regulation plays a critical role in shaping adoption of UD technologies because: (1) different regulatory regimes will be important at different points in the system-of-systems, (2) there may be multiple regulatory regimes that apply to a single subsystem, and (3) it is important to consider that legal and regulatory definitions of a technology may not match scientific understanding. 
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  3. Phosphorus (P) is a finite resource and necessary nutrient for agriculture. Urine contains a higher concentration of P than domestic wastewater, which can be recovered by source separation and treatment (hereafter urine diversion). Commercial and institutional (CI) buildings are a logical location for urine diversion since restrooms account for a substantial fraction of water use and wastewater generation. This study estimated the potential for P recovery from human urine and water savings from reduced flushing in CI buildings, and proposed an approach to identify building types and community layouts that are amenable to implementing urine diversion. The results showed that urine diversion is most advantageous in CI buildings with either high daily occupancy counts or times, such as hospitals, schools, office buildings, and airports. Per occupant P recovery benchmarks were estimated to be between 0.04–0.68 g/cap·d. Per building P recovery rates were estimated to be between 0.002–5.1 kg/d, and per building water savings were estimated to be between 3 and 23 % by volume. Recovered P in the form of phosphate fertilizer and potable water savings could accrue profits and cost reductions that could offset the capital costs of new urine diversion systems within 5 y of operation. Finally, urine diversion systems can be implemented at different levels of decentralization based on community layout and organizational structure, which will require socioeconomic and policy acceptance for wider adoption. 
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  4. Phosphorus (P) is essential for life on Earth, yet its current management is unsustainable. Stakeholder engagement is urgently needed to help ensure that scientific and technical solutions to improve P sustainability meet the needs of diverse groups, yet there are comparatively few studies that provide insights into stakeholder views, perceptions, or concerns. In this opinion, we use a mass flow diagram of P as a boundary object to understand the complex challenges of sustainable P management. In particular, we map US stakeholder groups onto the mass flow diagram to incorporate human factors into mass flows at a national scale. Our approach is grounded in well-established social–scientific methodologies, such as stakeholder mapping and social network analysis, but is applied in a novel way that can be generalized to other mass flows and geographic areas. We then suggest ways that researchers can use the annotated flow diagram to identify both knowledge gaps and research gaps in stakeholder engagement, especially in interdisciplinary or convergence research contexts. 
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  5. Abstract Our society depends on the effective management of phosphorus (P). Phosphorus is a key component of agricultural fertilizers to improve crop yields, and also plays a critical role in many industrial processes and consumer products. In the past decade, there have been numerous calls for innovative approaches to manage P more sustainably, as it is a nonrenewable resource that can adversely impact aquatic ecosystems from runoff and inefficiencies in P use. To develop more sustainable solutions that will ultimately be adopted, diverse stakeholder perspectives must be recognized, including those in industry, government, academia, non-governmental organizations, and other civil groups. This study responds to this need by identifying stakeholder views, needs, concerns, and challenges regarding P sustainability. An online survey was developed and deployed to individuals identified as P sustainability experts and professionals in the U.S. and abroad. Based on responses from 96 stakeholder participants from a range of sectors, areas of expertise, and geographies, we found that the vast majority of stakeholders considered current P use to be unsustainable and were very concerned about the ability to manage P sustainably. Stakeholder participants did not distinguish between urgent and long-term challenges, and perceived financial and regulatory issues to be of greatest importance. Stakeholder participants expressed a range of needs to improve P management systems, including improved management practices, new technologies, enhanced regulations, and better approaches for engagement. Outcomes from this work can help inform future research, engagement, and policy priorities to ensure sustainable P management solutions based on stakeholder-identified perspectives and needs. 
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  6. Abstract In this Perspective we take an in-depth look at what coordinated stakeholder engagement could entail for phosphorus sustainability. The element phosphorus is critical to life on Earth and to the continued functioning of society as we know it. Yet, how society uses phosphorus is currently unsustainable, both as a resource in support of global food production where inequitable distribution creates food security challenges, but also from an environmental aspect, where mismanagement has led to negative impacts on the quality of agricultural soils, human health, and freshwater and marine ecosystems. A number of initiatives and cross-sector consortia have come together to address sustainable phosphorus management at either global or regional scales. However, these efforts could benefit from a more coordinated approach to stakeholder engagement to identify the diversity of needs and perspectives involved in this complex challenge. Herein we examine some examples of different approaches to developing such coordinated stakeholder engagement in other areas of environmental sustainability. We consider how to apply the lessons learned from those efforts toward stakeholder coordination in the realm of phosphorus sustainability. Particularly, we discuss the value of a coordinating body to manage the communications and knowledge sharing necessary to develop trust and cooperation among diverse stakeholder groups and to transition society to more sustainable phosphorus use. 
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