This week’s photo series is “The East is Green“. In the run up to Earth Hour this Saturday, and in the wake of officials once again declaring “war” on pollution in China at the “Two Sessions” meetings in Beijing, we’re looking at some of the country’s recent attempts to improve environmental conditions – from grassroots NGOs to technological innovations and more.

Today’s photo is of what is thought to be the world’s largest air purifier, located in Xi’an. The structure made headlines across the globe earlier this year because, well, because it’s massive.

Here’s a bit more background from Caixin:

A poster-child for these innovative attempts is a 60-meter-high (197 feet) smog-sucking chimney, built in the northern Chinese city of Xi’an. […] The $2 million facility was built by the Chinese Academy of Sciences and has been promoted as an affordable model for “mass-scale air filtration.” Although the results from the experiment haven’t been published in any scientific journal, and therefore haven’t undergone peer review, preliminary reports determined the chimney emitted between 5 million cubic meters (176.5 million cubic feet) and 8 million cubic meters of filtered air every day. Monitoring stations located close to the chimney, across an area of 10 square kilometers (3.8 square miles), recorded 19% less particulate matter in the air compared to other parts of the city.

The chimney sits atop a large circular structure. Glass panels near the roof of the structure are heated through solar radiation, and this warms up the air and causes it to rise toward the base of the tower, where it passes through several industrial filters, before being released through the top of the chimney.

Image from IEECAS