Science & Nature
Oct 4, 2018
"Urban pollution is an enormous problem in many cities around the world, and poor air quality can mean an increase in chronic conditions like asthma, while also making it difficult for people to walk, bike or enjoy the outdoors."
Until a few years ago, the first proposal to try to fight these effects in the cities – which are one of the main producers of air pollution – was to plant more green spaces, as plants can help to significantly improve air quality and reduce particulate matter, but with the urban real estate becoming more expensive, land has been turned into housing rather than parks.
Green City Solutions is a startup, supported by EIT Climate-KIC, that has developed the CityTree. Its moss-culture technology scrubs pollution from city street air where air flow is poor and pollution is heavy.
The CityTree is a customised solution for urban spaces designed under the criteria of sustainability and combines a vertical plants' display with air purification. The vertical flat-panelled device combines moss and wireless technology, controlling humidity around the moss, which then acts as a filter, taking pollution particles out of the air. The plants can be arranged freely on the CityTree to display visual information like colour logos or a QR-Code, which links to additional digital content.
The modular design ensures the stability of the plants while being space-saving, lightweight and air permeable. A digital monitoring and control system optimizes the climatic air effect and plant care.
Each CityTree holds 1,682 pots of moss which, its creators claim, extract as much particulate matter as 275 trees in one per cent of the space.
The CityTree is a strange mix of bench and hedge, but is very effective at tackling air pollution. Dresden-based Green City Solutions' creation has been installed in cities including Berlin, Paris, Amsterdam and Oslo. And now there's one on Glasshouse Street, near Piccadilly Circus in London.
Bacteria living on the moss digest the particles (PM), and the moss digests the bacteria. Absorbed PM ranges from 0.1 microns wide to ten microns – the smaller particles being the most dangerous, as they can get deep into human lungs and from there enter the bloodstream.
"Polluted air is the cause of one in seven deaths worldwide", says Green City Solutions CEO Dénes Honus. "Just 10µg of pollutants per m³ of air will shorten a life span by half a year".
And it's much-needed help. A joint report issued this week by four Parliamentary select committees concluded that air pollution in the UK caused 40,000 deaths and cost the economy £20 billion per year, and that the government had to do more to solve the issue.
Each CityTree costs €22,000, but buyers might be able to recoup this through advertising, as the units include NFC and iBeacon technology. Also built into the solar powered unit is a Wi-Fi beacon, a rainwater-collection unit, as well as a nutrient tank and irrigation system to allow the assembly to water itself.
The CityTree also contains sensors that gather data from the plants and its surroundings. The frame is customisable too, with options for graffiti protection and a wide range of woods and varnish colours. Everything very digitalis.