Design & Innovation

Why we should use space toilets on Earth – Update on projects

LAUFEN’s urine-separating toilet save! is an ongoing revolution. Here are some examples of current projects around the globe.

The way we handle urine in wastewater management causes one of today’s major environmental problems, i.e. nitrate pollution from nitrogen-containing fertilizers and the eutrophication of bodies of water that result in oxygen-depleted waters called “dead zones”. Yet, urine is a valuable resource for agriculture if the substances within it can be separated and recycled.

Together with the Viennese design team EOOS, LAUFEN has developed the world’s first urine-separating toilet that meets industry standards in the developed world. This innovative toilet is gradually coming into our everyday lives.

Urine as a resource: Learning from the space station

The toilet on the ISS space station is a high-tech machine with a price tag of US$ 23 million.

What it has in common with save! is the separation of urine in the toilet and its reuse as a resource. In outer space, the focus is on the 95 percent water content of human urine that can be used to generate drinking water. With save!, it is rather the other remaining chemical substances nitrogen (N), phosphorus (P) and potassium (K) that are of interest.

On one hand, those substances pose environmental problems. Studies conducted by leading research institutions show that excessive amounts of nitrogen and phosphorus are discharged into rivers and oceans, causing algae bloom and endangering their eco systems.

On the other hand, they are valuable nutrients in fertilizers used in agriculture if they can be filtered out before they can enter wastewater.

Time to rethink wastewater management

The challenge is in the rapid establishment of urine-separating toilets as the standard in many cultures around the world. The use of urine as a resource can be adapted to specific cultural practices and conditions.

In the most remote regions, it makes sense to combine urine with certain bacteria to generate electricity that can power a cell phone, for example. In agricultural areas, urine can be processed to yield water and nutrients for irrigation and fertilizers.

From outer space to Nepal and Europe

EOOS, a well-known Viennese design team dedicated to environmental issues, is the inventor of the “urine trap”, which uses adhesion, known as the “teapot effect”, to separate and drain urine directly in the toilet bowl.

Ensuring the functionality in standing toilets in Nepal and in completely “normal” Western-style toilets was the challenge facing EOOS and LAUFEN. “We have a better chance of implementing this important revolution on a large scale everywhere only if the toilet looks the same as always and requires no changes in the way it is used,” says Harald Gründl, head of EOOS.

The first urine-separating toilet save! for use in industrialized countries has been available for some time. Recently, LAUFEN has begun offering the complete “behind the wall” installation technology.

The first 100 save! units have been installed and thoroughly tested in universities and research institutions. The rollout is underway. From now on, the European Space Agency ESA will use about 80 save! toilets in its new building in Paris and the first purely residential building is being equipped in Vienna. In the Stadtregal project by architects GERNER GERNER PLUS. heri&salli, the collected urine is used to produce fertilizer for the greenery on the façade and the plants on the roof.

Sustainability through perseverance

The toilet save! is the “front-end” that functions in many ways in the circular economy. Among them are water and power generation, fertilizer production, on-site recycling, industrial processing and use. The “back-end” is open, depending on the situation and business model.

Gründl and his team’s staying power is paying off gradually. Developed as part of the Bill and Melinda Gates Foundation’s “Water, Sanitation & Hygiene” program, save! has become a regular feature on the UN World Water Day agenda and recently was presented to the World Bank.

The toilet revolution is gaining momentum in Germany too. One of the next major projects in the pipeline is the “Ecovillage,” a cooperative, social and sustainable neighborhood with 500 apartments in Hanover.


>>  save! – discover more

>>  Presentation with Harald Gründl (ISH 2023)