Giant filter towers to clean the air? A WashU expert weighs in

Dubai Architect rendering
A rendering of the 328 feet-high filter towers over Delhi. The "The Smog Project," designed by Dubai-based architecture firm Znera Space, looks at ways the city might alleviate its severe air pollution problem. Image: CNN

“The Smog Project,” designed by Dubai-based architecture firm Znera Space, is an ambitious proposal to clean the air in Delhi, one of the world’s most polluted cities. The project proposes a series of 328 feet-high air filtration towers, each producing more than 353 million cubic feet of clean air per day. The towers would suck air in and pass it through five filtration systems, including charcoal-activated carbon, negative ion generators and electrostatically-charged plasma, to trap airborne particles. Air would then pass through a photocatalyst filter to sterilize it before releasing it back into the atmosphere.

Pratim Biswas, chair of the Department of Energy, Environment and Chemical Engineering at Washington University in St Louis, says the proposed solution has limitations, noting that urban air filtration would work in geographically smaller areas, but not a full megacity. Biswas says cities like Delhi need to focus on deploying effective air quality control technology at the source of the pollution.

Biswas doesn’t dismiss urban air filters entirely though. He describes them as a secondary technique that would be good for regional air cleaning.

Read Biswas’ comments at CNN.