German engineers have come up with a remarkable machine that turns sewage into charcoal.
If that was not enough of a feat, they say it helps the fight against climate change by locking up carbon from the sewage that would otherwise have gone into the air.
And to make it even more extraordinary, they are feeding the charcoal to plants and claiming that it helps them grow faster.
Helmut Gerber is an Engineer at the University of Applied Sciences, Bingen. He explains how biochar is created.