Belgrade, the capital of Serbia, has installed a “liquid tree,” an innovative tool to tackle greenhouse gas emissions and improve air quality in the city when planting trees is not an option.
“The microalgae replaces two, 10-year-old trees or 200 square meters of lawn,” explains Dr. Ivan Spasojevic, from the Institute for Multidisciplinary Research at the University of Belgrade and one of the authors of the project. “The advantage of microalgae is that they are 10 to 50 times more efficient than trees.”
Liquid 3 is Serbia’s first urban photo-bioreactor and consists of 600 liters of water with microalgae used to bind carbon dioxide and produce oxygen through photosynthesis. The idea is not to replace forests but rather to fill urban pockets where it is impossible to plant trees. Belgrade is the fourth most-polluted city in Serbia, and technology is coming to its rescue in its fight against dirty air.