The University of Belgrade’s Institute for Multidisciplinary Research invented an urban photo-bioreactor. Liquid 3 cleans the air and serves as a bench in the Belgrade city centre.
It’s a tank filled with microalgae, a solar panel on the top generates electricity for USB charging ports for citizens and a pump that pumps air into the tank where the algae process the CO² and produce Oxygen.
https://balkangreenenergynews.com/liquid-tree-to-combat-air-pollution-in-belgrade/
Would be cool to be used on the inside e.g. airports where trees obviously cannot be, if indoor light would be sufficient.