They are not only nice to look at, but plants could also help clean up the polluted air in our cities.
In Lyon, one of France’s largest and most polluted cities, tests have been carried with vegetal walls in various sites, including at highway toll booths and underground car parks.
On the deck of the Perrache railway station car park, there are 12 columns of vertical planting.
Pipes located inside the structure suck in polluted air and direct it towards the green columns, whose soil naturally contains millions of bacteria. These bacteria filter and destroy the contaminants, while the plants capture the CO2.
“We found 126 different volatile organic compounds in the air,” explained French professor of microbial ecology Rene Rohr. “After passing through the soil, 70 percent of these have disappeared.”
Plants have also helped change the life of staff working at motorway toll booths in Chamant near Paris. Eighty thousand vehicles pass through this toll booths each day. That’s 80,000 car, lorries and buses stopping and starting – a real health hazard for people working there.
But thanks to green plant-covered cubes erected near the booths, the workers get clean air via a pressurised air system.
And not only do plant walls clean up the air, they also provide acoustic insulation.
Plant walls have only just started burgeoning in Europe, but in countries with high levels of urban pollution such as China and Mexico, they already represent a thriving market.