This interview with Space for Food researcher Tabea Hertel is written by Sjoerd Ponstein | Marineterrein Amsterdam
It is one of the most important questions in long space travel: how do we ensure that astronauts stay alive when it is simply not possible to carry endless supplies of food and water? The answer is circularity; reusing all possible raw materials from waste (water) to make new nutrients.
The city as a spaceship
But is it possible to apply this concept to cities? After all, there is plenty of waste to use. To create a more circular city, we have to reuse materials and waste. We should consider seeing the city as a spaceship, completely self-sufficient, circular, and without the use of new raw materials.
It's a big task, but the Space for Food project is a step in the right direction. In a bright yellow container at the Marineterrein, tests are currently being conducted. Here is determined whether the wastewater from the Homeland Brewery can be used to feed bacteria that, in turn, can be used as nutrients for plants or crops, for example.
Bacteria as plant nutrition
"It's quite a complicated process,' laughs researcher Tabea Hertel. "In a so-called raceway reactor, we cultivate purple bacteria. To that, we add the brewery's wastewater and the bacteria 'eats' the nutrients contained in that water. In this way, the purple bacteria collect biomass, which can be used to fertilize plants. So, we 'harvest' the bacteria, and then mineralize them to make them suitable as plant nutrients."
Space technology meets vertical farming
The project aims to find out under which conditions the bacteria develops most rapidly. In this way, the possibilities and scalability of space technology in an urban environment can be investigated.
“Think, for example, of fully circular buildings that process their waste into new raw materials and clean water via a 'closed loop'. These materials can then be reused for new purposes such as vertical farming. The nutrients that Space for Food extracts from the brewery's wastewater are being tested for usability as fertilizer in collaboration with GROWx.”
Space for Food researcher Tabea Hertel
On the way to a fully circular society
In line with this project, Tabea dreams of a completely circular society. We have to 'close the loop', as she calls it herself. And that, according to her, is urgently needed. We live on a planet with a finite number of raw materials. Phosphorus, for example, can only be mined in a few places in the world, and in a hundred years the supply will be exhausted. Then we will only be able to obtain it by recovering it from waste. So, the only sustainable solution is circularity and reusing as many materials as possible until we no longer need to use new raw materials.'
Space for Food is coordinated by SEMiLLA IPStar (ESA) in collaboration with the AMS Institute, University of Antwerp, GROWx, and Nijhuis. This project is part of the Amsterdam Marineterrein Living Lab.
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