Hanxia Yu, Jason Reynolds, Veera Koskue, Serhiy Marchuk, Dio Antille, Bernadette McCabe, Cara Beal, Stefano Freguia, Niraj Yadav, Jeff R Powell 

The utilization of nitrogen (N) and phosphorus (P) in agriculture has surpassed the safe-operating thresholds for biogeochemical cycles, necessitating the adoption of more efficient nutrient management strategies to restore this balance. The predominant source of N and P supplementation globally stems from the application of synthetic fertilizers. This study explores the potential of nutrient recovery and recycling from human urine as a viable alternative at sub-global and regional levels. Such an approach could significantly reduce energy consumption associated with fertilizer production and transportation, as well as the demand for precursor materials. Additionally, it would mitigate the risk of eutrophication resulting from the release of excess N and P into the environment via untreated or inadequately treated wastewater. By integrating waste material utilization within the nexus of social and ecological systems, this strategy may enhance socio-ecological resilience, particularly in urban areas. Here, economies of scale could facilitate the successful implementation of urine diversion and conversion initiatives, offering a sustainable solution for nutrient management in densely populated regions.