LIQIUD 3 – ”Liquid tree” (”tečno drvo”)

The first urban photo-bioreactor in Serbia, LIQUID 3 was installed in front of the Stari Grad Municipality in Makedonska Street in Belgrade. This "liquid tree", as it is called at the Institute for Multidisciplinary Research of the University of Belgrade where it was designed, represents a new biotechnological solution for air purification and reduction of carbon dioxide (CO2) emissions in urban areas, where concentrations are the highest.
The project is designed to be multifunctional, it is designed as a bench, has chargers for mobile phones, as well as a solar panel thanks to which the bench has lighting during the night. The Municipality of Stari Grad has decided to support a project that, through smart and innovative solutions, directly contributes to improving the quality of life of fellow citizens, public health and a cleaner environment.
LIQUID 3 was awarded as one of the 11 best innovative and climate-smart solutions within the project "Local Development Resilient to Climate Change", which is implemented by the United Nations Development Program (UNDP) in partnership with the Ministry of Environmental Protection of Serbia, with the financial support of the Global Environment Facility (GEF). The municipality of Stari Grad, as a partner in the implementation of the project, provided the location and permits for the installation of the system.

Installation of multifunctional photo-bioreactor – LIQUID 3 (''liquid tree'').

The photo-bioreactor works by having algae in a 600l aquarium that binds carbon dioxide and produce pure oxygen through photosynthesis in a direct process.
In addition to purifying the air from CO2, the system uses solar energy for lighting.
The Institute for Multidisciplinary Research used unicellular freshwater algae, which exist in ponds and lakes in Serbia, can grow in tap water, and are resistant to high and low temperatures.
The LIQUID 3 system enables photosynthesis and fixes carbon dioxide in the same way as trees and grass. The advantage of microalgae is that they are 10 to 50 times more efficient than wood. The goal is not to replace forests, but to use this system to fill those urban pockets where there is no space for planting trees. In some conditions of high pollution, the tree cannot even survive, while the algae are not bothered by the pollution.

Not known.

As trees and green areas represent natural air purifiers in urban areas, where free areas for greening are often lacking, LIQUID 3 is seen as an effective and innovative solution for reducing harmful gas emissions and improving air quality.
It replaces two 10-year-old trees or 200m2 of lawn.

Rely on local knowledge and resources in implementing innovative measures.

If there are no opportunities for the use of greenery (for example, densely built-up areas of cities), apply alternative and innovative measures.