A Dutch research team has managed to produce protein by reacting the ammonia nitrogen in sewage water with hydrogen and carbon dioxide. This creates a single cell protein that can be used in animal feed and perhaps eventually for human consumption.
Last week, Power to Protein opened its pilot facility in a sewage treatment plant in Enschede, in the East of the Netherlands.
This comes after proving the concept with a 5L reactor, successfully producing a protein “comparable to fishmeal or soymeal”, which are standard animal feed.
In this sewage treatment process, nitrogen ammonia - which would otherwise be considered waste - is given new life as protein. This closes the artificial nitrogen cycle and so represents progress towards a circular economy. Not only this, but - if the pilot is successful and scales - we would have another source of animal feed that would not require the water, land and energy use of growing crops.
There may be some resistance to the idea that protein made from sewage water is safe and edible, but hopefully the sustainable and nutritional credentials of the protein will take precedence.