'World's biggest air purifier' on trial run in Xian
The lead researcher behind a 100-metre-high experimental smog-sucking tower in Xian (Shaanxi province) claims that the quietly purifying monolith is already making a significant positive impact on the city's air quality, according to the South China Morning Post. The tower, now only in early testing stages, could be a practical and sustainable tool used all across China as a part of the country's efforts to cut down on air pollution.
The current tower is said to work by using solar greenhouses (spanning about half a football pitch) at the base of the tower to heat up dirty air, which then rises up into the tower and through its many filtering systems for cleaning, and then the cleaned air circulates out the top of the tower and throughout the surrounding area. According to the lead researcher, Cao Junji, the tower produces more than 10 million cubic metres of clean air a day and it has an effective area of about 10 square kilometres. Furthermore, Junji states that the tower downgrades severe pollution days to moderate levels with an average PM2.5 reduction of 15 percent.
The tower, which began construction in 2015 and was finished last year for an undisclosed cost, was named the 'world's biggest air purifier' by its research team and operators from Institute of Earth Environment at the Chinese Academy of Sciences. The only other tower close to it in the world is at 798 Arts District in Beijing. It was built by Dutch artist Daan Roosegaarde and his team in September 2016 and stands seven metres tall. The non-experimental version of the tower in Xian is projected to reach 500 metres in height and 200 metres in diameter. Still, one has to remember that forests are also air purifiers. But then again they seem to be getting smaller every year.
The quiet, energy-efficient air purifying towers are a potential cost-efficient solution to China's smog problem. However building many of them to cover a large and dense city could be impractical, considering how much space they require, the one in Xian having been built in one of the city's outer industrial zones. Nonetheless, the towers represent China's continued efforts to aggressively address its air quality problems.