Liquid3

The United Nations Development Programme (UNDP) selected Liquid 3 as an "innovative" solution for "Climate Smart Urban Development," a project produced in partnership with Serbia's Ministry of Environmental Protection and the municipality of Stari Grad.

The glass tank is embedded into a structure that acts as a bench and is outfitted with other utilities such as charging ports.

Similar to other photobioreactors, air is sucked through a pressure pump and fed to the microalgae, with oxygen released as a byproduct.

Additionally, the Liquid 3 bioreactor can filter out heavy metal contaminants in the air and contains a temperature regulation system in case external climate conditions become too extreme for the microalgae.

[2][3][4] The creator of the Liquid 3, Dr. Ivan Spasojevic, was motivated to install it in Belgrade due to the city's struggle with pollution.