What are the challenges posed by climate change that your consortium's research is responding to?

At the moment, mineral nitrogen fertilisers are produced using the very energy-intensive Haber-Bosch process. We hope to achieve significantly lower emissions in fertiliser production through our recycling process. In addition to fertilisers, we also want to use our recycling process to produce plant carbon, which binds CO₂, and biodegradable bioplastics, for example for agricultural film, as used in agriculture for growing strawberries or asparagus. This is also associated with positive effects for the climate, because biobased resources rather than fossil resources are the basic component of the bioplastics. 

What is the concrete solution your consortium is researching?

The abbreviation RUN stands for "Rural Urban Nutrient Partnership". We want to close the nutrient cycles between urban and rural areas. In urban households, we want to use water-saving vacuum systems in toilets and kitchens, with which we collect wastewater and biowaste. Using various biological, mechanical and chemical processes, we will extract the nutrients phosphorus, potassium and nitrogen for our recycled fertilisers and also plant charcoal and the biopolymers for plastic films from it in the RUN plant we are developing. In short, we don't want to turn agriculture upside down, but rather the production of fertilisers. This makes our approach interesting for both conventional and organic agriculture.

Which social factors does it depend on whether your approach works? 

Often, the higher prices for sustainable products and solutions are a reason why they do not catch on. However, due to high energy prices, less nitrogen fertiliser is currently being produced conventionally, and prices are going through the roof. So the current crisis is also creating an opportunity in agriculture for a change towards more sustainability and climate protection. And very importantly, we also need farmers to accept the new fertilisers. And consumers need to accept agricultural products that are produced with recycled fertiliser from wastewater and waste. That is why we at RUN also investigate and take into account which factors in society promote or inhibit acceptance of the RUN fertiliser.

What needs to be done politically?

Currently, there is still no legal basis for recycling wastewater and waste together. However, we see through our research that it is precisely the mixture that achieves better results. In particular, we need fewer additives to regulate production and thus save even more resources. In addition, our mineral fertilisers could also be interesting for organic farming, but this is not yet permitted. It is important that these paths are cleared legally.

How will the results of the consortia change people's everyday lives?

Our recirculation system works with vacuum toilets instead of ordinary flush toilets, which incidentally also saves water. If the RUN system is adopted, our toilets and kitchen waste grinders will be widely used in buildings, especially in new neighbourhoods. Consumers would become more "prosumers" through their participation in the circular system, i.e. producers and consumers at the same time. The social science research in our interdisciplinary consortium has shown that at the moment we simply trust in the disposal structures without seeing ourselves as an active part of them. Nutrient communities can create awareness that what we dispose of comes back to us in the end. This also changes the sense of responsibility.