42.2406° N • 8.7207° W

The bright side of dark waters

Road Trip Project Portugal Vigo black water

Our travellers visit Run4Life, a project that is on course to crack a big nut: How recycling and reusing household waste water at source can not only protect the environment but at the same time contribute significantly to a sustainable agriculture by extracting the waste water’s nutrients.

If you’ve ever been on an airplane, you’ve breathed recycled air. And even higher above our heads, aboard the International Space Station, all air but also all water is filtered and recycled back into use. The astronauts just don’t have the option of turning on the tap – there are no taps.

Not everybody on Earth has access to a tap, either, but here in Europe we tend to be very privileged in this regard. We take luxurious long showers and baths, flush toilets and water gardens and lawns, only questioning the source if there is a water cut. Certainly we never think about what happens to the water after we’ve used it.

In fact, as recently as 25 years ago, a lot of urban and industrial waste water used to be released back into our rivers and lakes untreated or only partially treated, thereby creating a threat to both aquatic ecosystems and human health. Things have improved with legislation from the EU, but not all of Europe’s water bodies are yet safe.

Now some very bright people have looked at waste water and seen in it not a problem but a source of life: the water should be cleaned and used again, astronaut-style, but the recovery process could be taken even further. That’s because there’s a lot of good stuff in domestic wastewater that could be used to – help feed the planet.

Fertilisers are what makes the world’s agriculture go round, but sadly they are either a non-renewable resource or their production is very energy-intense. Nutrients from waste water could do the trick just as well, but so far recovering them has posed a challenge, because by the time the waste water stream reaches a water processing plant it is much too diluted.

Partly funded by the EU’s Horizon 2020 programme, the project Run4Life proposes to collect these nutrients at source, i.e. at home or at the office. At their demonstration sites the waste flow is seperated: “black water” (toilet) “grey water” (non-toilet) and organic kitchen waste) and treated in different, innovative ways to obtain clean water, energy and nutrients to be used as fertilisers.

Yldau and Fabian were given a full tour of the plants and labs in Vigo, even fearlessly getting close to dark water samples at every stage of their processing. They confessed to not having known much about the opportunities of waste water recycling and described their experience at Run4Life as an eye-opener.

Go to Run4Life’s website to find out more about this revolutionary project!

See also


PlantCult is a project that aims to explore prehistoric cuisines of Europe, in particular their plant ingredients and their transformation into meals.

Greetings from Stuttgart, Germany

We’re very excited to start this adventure and grateful for the tips the previous RTP travellers gave us. Oh and, do you like our matching outfits?

Ken is ready!

Ken has checked the last item off his to-do list, and has one important goal to meet: “What does it mean to be a 21st century European? I’m super excited to finally start travelling along the Danube route and find the answer to this question sitting in my head!”