Context:

The Supreme Court had directed the Centre and the Delhi government to prepare a plan to install ‘smog towers’ across the capital to deal with air pollution.

About

• Smog towers are structures designed to work as large-scale air purifiers
• They are usually fitted with multiple layers of air filters, which clean the air of pollutants as it passes through them.
• The 20-meter (65 feet) high tower will trap particulate matter of all sizes suspended in the air.
• Large-scale air filters shall draw in the air through fans installed at the top before passing it through the filters and releasing it near the ground.
• The filters installed in the tower will use carbon Nanofibers as a major component and will be fitted along its peripheries.
• The smog tower is expected to purify around 2,50,000 to 6,00000 cubic meters of air per day and release fresh air in return.

Developed it

• The project is a collaboration between the Indian Institute of Technology (IIT) Bombay, IIT-Delhi, and the University of Minnesota.
• The latter has helped design a similar tower of over 100 meters in China’s Xi’an city.
• The Central Pollution Control Board (CPCB) will also be involved with the project.

Delhi need smog towers

• Delhi has in recent years been battling alarmingly toxic air quality every winter.
• Delhi’s overall AQI in the “severe” category, according to the ministry of earth sciences’ air quality monitor system of air quality and weather forecasting and Research (SAFAR).

Other examples in the world

• China, which has been battling air pollution for years, has two smog towers — in its capital Beijing and in the northern city of Xi’an.
• The Xi’an tower is dubbed the world’s largest and has reportedly brought down PM 2.5 by 19% in an area of around 6 sq km in its vicinity.
• The 100-meter (328 feet) high tower has produced 10 million cubic meters of clean air every day since its launch, and on severely polluted days, is able to bring down smog close to moderate levels.
• The tower in Beijing, built by Dutch artist DaanRoosegaarde, has been able to compress the carbon waste generated during purification to produce gemstones.
• Upon compression for 30 minutes, the smog particles turn into dark gems, which are used for rings and cufflinks.