In a groundbreaking study published in the journal ‘Water Research X’ (translated to English as ‘Water Research New Horizons’), researchers have mapped out the landscape of technologies that recycle nutrients from human waste back into agriculture, offering a promising avenue for enhancing fertilizer production and reducing nutrient losses. The research, led by Robin Harder from the School of Architecture, Design and Civil Engineering at Zurich University of Applied Sciences (ZHAW) in Switzerland, sheds light on the current state and future potential of this circular nutrient economy.
The study, which synthesized insights from over 14,000 research papers, identifies a plethora of technology options for recovering plant nutrients—particularly nitrogen, phosphorus, and potassium—from human excreta and domestic wastewater. These nutrients can then be reused in various agricultural applications, such as crop fertilization, animal feed, or even the production of microbial protein.
“Circular nutrient solutions can make important contributions to improve fertilizer availability and reduce nutrient losses from waste management,” Harder explains. The research highlights that while ongoing research is crucial, there is an even greater need for scaling up the implementation of these technologies.
The study maps technological solutions onto identified technology options, revealing that many solutions are already available on the market. This suggests that the field is ripe for commercialization and large-scale adoption. For the energy sector, this could mean new opportunities for collaboration and innovation, particularly in waste-to-resource initiatives.
One of the key findings is the readiness of various technologies for market adoption. According to Harder, “While there likely still is scope for additional research, it would appear there is even more scope for implementing available circular nutrient solutions at scale.” This indicates a shift from research and development to practical application, which could drive significant commercial impacts.
The study also discusses research trends, providing a comprehensive overview of the current landscape and future directions. By focusing on the recovery of nutrients from human waste, the research aligns with global efforts to create more sustainable and circular economies.
As the world grapples with the challenges of food security and environmental sustainability, this research offers a compelling vision for the future. By recycling nutrients back into agriculture, we can reduce our dependence on synthetic fertilizers, minimize nutrient pollution, and create a more resilient food system.
The study, published in ‘Water Research X’, serves as a call to action for policymakers, industry leaders, and researchers to collaborate and accelerate the adoption of these technologies. As Harder notes, “The potential is there, and the technologies are ready. Now is the time to act.”
In the coming years, we can expect to see significant advancements in this field, driven by the growing demand for sustainable solutions and the increasing recognition of the value of circular nutrient economies. This research not only highlights the current state of the art but also paves the way for future innovations that could transform the way we manage waste and produce food.