Turning urine into fertilisers: VunaNexus secures three ESA projects

With Aurin, VunaVentures introduced the world’s first officially approved urine-derived fertiliser and has sold more than 10’000 litres. The startup has secured three demonstration projects in Paris, Fribourg and Berlin in collaboration with the European Space Agency, as part of the ESA Space Solutions - Business Applications Programme (BASS).

Urine contains water, urea, and various compounds, including nitrogen, phosphorus, and potassium that are essential for plant growth. Zurich-based startup VunaNexus transforms urine into fertilisers, thus solving the global fertiliser crisis. Based on 15 years of research at Eawag with the help of the MELiSSA Space Research Program, VunaNexus developed technology to enable the recycling of all nutrients contained in urine to transform them into natural fertilisers.

The process begins with collecting and extracting at the source through dry urinals or urine-diverting toilets like the Laufen Save. Stabilisation of the urine follows to avoid bad odours from ammonia and air pollution. With aeration as the only input, bacteria convert half of the total ammonia to nitrate autonomously, thanks to the startup’s patented technology and various sensors. Most organic compounds and some micropollutants are also degraded during the nitrification step. The third and fourth stages involve purifying, concentrating the solution to remove the high-water content of the product and distilling the stabilised and filtered liquid. Due to the high temperatures during distillation, the liquid is pasteurised and possible pathogens are deactivated.

The two outputs of urine treatment are distilled water and the liquid fertiliser, Aurin, the world’s first approved urine-derived fertiliser. “It is approved, with no restriction, in Switzerland and Austria and will be soon in more European countries”, says David de Chambrier, co-founder of VunaNexus. Currently, the startup has produced and sold more than 10’000 litres of Aurin. This is roughly 180’000 litres of urine treated and 160’000 litres of water recycled in the flushing of toilets. Aurin is mainly distributed online and by some small retailers. The city of Zurich and the city of Lausanne have also made bulk purchases of Aurin.

Three ESA demonstration projects
VunaNexus has won three demonstration projects with the European Space Agency - ESA as part of its ESA Space Solutions - Business Applications Programme (BASS). The 24-month project aims to demonstrate that VunaNexus’ decentralized urine treatment systems have environmental and economic benefits.

“Our process would allow recovering precious nutrients for food production during Space missions as well as recycling water. We intend to further develop and commercialise this technology for terrestrial purposes because we believe that the basic idea of a circular economy of nutrients is not only crucial for Space missions but also for agriculture on Earth. We are convinced that processes for nutrient recovery from human and animal excreta will play a crucial role in sustainable agriculture on Earth and help reduce greenhouse gases” says David.

The three projects are:

  1. ESA Headquarters in Paris: includes installing a treatment plant in a refurbished building while reusing the fertiliser as close as possible to its production site.
  2. Bluefactory in Fribourg: is a visionary project applying the concept of sponge cities that will treat and reuse all water streams onsite.
  3. innovativ-zirkulierBAR in Eberswalde, northern of Berlin: aims to create a blueprint to help municipalities set up valorisation plants for the waste coming from mobile toilets at large scale.

Part of the project funding will flow into building a treatment plant in Paris at the ESA headquarters. “The other two projects are self-funded but included in the research project” David explains. The ESA funding is allowing us to develop the fertiliser, acquire market authorisations, industrialise our patented nitrite sensor, and various other features that will benefit the other two treatment sites”, he adds.

Besides the funding from ESA, VunaNexus has this year obtained funding from multiple funding instruments, including Horizon Europe, Innosuisse, and signed collaboration contracts with multiple cities.