In a world where sustainability and resourcefulness are increasingly important, the idea of recycling urine into natural fertiliser might seem like a quirky, niche concept. However, as we'll explore, it's a practice that has the potential to revolutionize how we approach sanitation and agriculture, especially in the context of a world facing rising fertilizer prices and supply shocks.
The Science and the Startup
VunaNexus, a Swiss startup, has developed a process that transforms urine into a certified mineral fertiliser called Aurin. This isn't just a quirky idea; it's a scientifically sound method that mirrors the process of recovering minerals from used electronics. Urine, it turns out, is a concentrated resource rich in nutrients like nitrogen and phosphorus, essential for plant growth.
The process begins with special toilets that separate the urine, sending it down a piping system to a treatment plant. Here, the urine undergoes a series of treatments to remove micropollutants and concentrate valuable nutrients. It's then pasteurized to eliminate potential viruses and pathogens, and the distilled water is recycled for flushing. The end result is Aurin, a liquid fertiliser that's approved for use on all plants by Swiss and French authorities.
Beyond the Hippy Stereotype
David de Chambrier, CEO of VunaNexus, emphasizes that this isn't a hippy fad but a serious recycling initiative. "Separating the urine at the source makes its treatment way easier," he says, drawing a parallel to recycling batteries. This process, he believes, has the potential to increase the resilience of water treatment systems in dense urban areas and reduce the environmental impact of traditional fertilizers.
Global Impact and Challenges
The VunaNexus system is already installed in several large buildings in Europe, including one of Switzerland's largest private banks. The company is also rolling out its technology across a newly developed eco-neighborhood in Paris, the largest project of its kind in Europe. De Chambrier estimates that if all the urine of people in Europe were recycled, it could cover around 30% of the nitrogen need, a significant contribution to the fertiliser market.
However, making this process economically viable on a large scale remains a challenge. In small treatment sites, the cost of producing one kilogram of nitrogen from urine is significantly higher than that of synthetic fertiliser. To become competitive, VunaNexus needs to scale its production and potentially be paid for the wastewater treatment service it provides.
Roots in South Africa
The origins of VunaNexus lie in a pioneering research project in South Africa over a decade ago. The project, called Vuna, aimed to develop an affordable sanitation system that could produce urine-based fertiliser. More than 80,000 urine-diverting dry toilets were installed on the outskirts of Durban, and the project piloted a scheme to collect, treat, and concentrate urine into a natural fertiliser. While the technology worked, the logistical costs made it unviable at scale.
Closing the Loop
In Durban, researchers and NGOs continue to work on delivering improved urban sanitation that can produce fertilisers. One project aims to establish a urine collection system from low-tech urinals installed in a central area where informal workers earn a living without adequate sanitation. The goal is to create a "nice closed loop" where the urine of street vendors is turned into fertiliser, benefiting the farmers growing the vegetables being sold on the street.
A Global Perspective
As the world faces rising fertilizer prices and supply shocks, initiatives like VunaNexus take on a new urgency. The UN has warned that 45 million people are at risk of acute hunger due to the conflict in the Middle East, highlighting the vulnerability of the fertiliser market. In this context, recycling urine into fertiliser could be a game-changer, especially in rural areas where access to fertilisers is limited.
Conclusion
The idea of recycling urine into fertiliser might seem unconventional, but it has the potential to transform how we approach sanitation and agriculture. While challenges remain, especially in terms of scalability and economics, the work of VunaNexus and other initiatives around the world demonstrate the importance of rethinking what we deem as waste and how we can turn it into a valuable resource. As David de Chambrier says, "This is not a hippy thing to do; we are recycling minerals." It's a powerful reminder of the innovative solutions that can emerge when we challenge conventional thinking.
