Innovative Approach to Agricultural Waste Management
Could peeing in the garden be the solution for future agriculture? In Marseille, southern France, an emerging company is working to revive this practice by transforming human urine into large-scale usable fertilizer.
The Process of Stabilizing Urine
For the past three years, two engineers have been developing a process to “stabilize” urine so that it can be “suitable for all plants,” free of unpleasant odors, and in compliance with fertilizer market standards. Stéphane de Lacroix de Lavalette, president of Ehotil, explains this innovative approach.
Moving to Industrial Scale Production
This startup, though not the only one in France working on this sector, has recently moved from a small lab to a large industrial facility north of Marseille, aiming to launch its first production unit.
“The goal is to demonstrate the viability of this project at an industrial scale,” insists Emmanuel Morin, the company’s CEO, during the unveiling of their new facilities in France’s second-largest city.
Logical and Sustainable Solution
According to Fabien Esculier, a bridge and road engineer at the University of Créteil in the Paris region, who coordinates a research program unrelated to Ehotil, betting on urine for future fertilizer is “quite logical.”
Transforming Urine into Valuable Fertilizer
The process involves storing collected urine for several weeks to naturally purify it, as explained by Emmanuel Morin. The crucial step is “nitrification,” where the liquid, placed in a glass tank, gradually oxidizes to stabilize nitrogen molecules.
“The smell of urine is nitrogen that evaporates,” notes de Lacroix de Lavalette. “However, nitrogen is one of the molecules of interest, so we want to preserve it.”
After filtering and concentrating the liquid, a brown, slightly thick liquid similar to conventional fertilizer consistency is obtained.
Reducing Environmental Impact
Currently, fertilizer production relies on nitrogen derived from fossil natural gas, making it highly greenhouse gas-emitting. Phosphorus and potassium are extracted from mines, contributing to environmental pollution.
“Today, (fertilizer) production uses nitrogen from fossil natural gas, which is highly greenhouse gas-emitting, while phosphorus and potassium are extracted from mines,” points out Esculier.
By converting urine into fertilizer, the startup aims to reduce some of this pollution and decrease contamination generated by current wastewater treatment methods.
Currently, 40% of the nitrogen in wastewater continues to pollute rivers, representing significant contamination.
Challenges to Overcome
Despite its potential, several obstacles remain for widespread agricultural urine utilization. One major challenge is collection, which can only be done using dry toilets—an uncommon practice in large cities.
For now, Ehotil uses urine from a local music festival for testing. The company hopes to quickly equip public buildings in the region with dry toilets, such as shopping centers, to ensure a steady supply. However, there is no set date for product commercialization.
Key Questions and Answers
- What is the innovative approach being developed by the French startup? The company is working on a process to stabilize human urine, transforming it into large-scale usable fertilizer.
- Why is using urine for agriculture a logical solution? According to Fabien Esculier, it’s logical because plants obtain their nutrients from the soil in the form of molecules containing nitrogen, phosphorus, and potassium. When we consume grains like wheat, we absorb these molecules but do not retain them in our bodies.
- How does the urine transformation process work? Collected urine is stored for several weeks to naturally purify it. Then, through a process called nitrification, the liquid is gradually oxidized to stabilize nitrogen molecules.
- What environmental benefits does this approach offer? By converting urine into fertilizer, the startup aims to reduce pollution from current wastewater treatment methods and decrease greenhouse gas emissions associated with conventional fertilizer production.
- What challenges does the widespread agricultural urine utilization face? Major obstacles include collection, which requires dry toilets not commonly used in large cities. Currently, urine for testing comes from local music festivals.
