Delhi is one of the most polluted cities in the world. Delhi administration launches different antipollution campaigns to reduce this pollution. The capital city has the most crucial causes for the distressing levels of air pollution, including the city’s landlocked geographical location, and other severe pollutants. The administration strives to take some sustainable action against pollution, and now it has come up with a unique smog tower to purify the air. Chief Minister of Delhi Arvind Kejriwal has inaugurated India’s first smog tower. Anwar Ali Khan, the senior environmental engineer at the Delhi Pollution Control Committee is in charge of this project.

Delhi has become the first city in India to get a smog tower, which is a technological advancement to support combat air pollution in Delhi. It is an experimental structure worth Rs 20 crore to purify the air in a 1-km radius around the Shivaji Stadium Metro station work in Delhi. This structure is 24m high, about as much as an 80-level building, an 18m concrete tower, topped by a 6m high canopy. At its base are 40 fans, 10 on each side. Each fan can discharge 25 cubic meters per second of air, adding up to 1,000 cubic meters per second for the tower as a whole. Inside the tower in 2 layers are 5000 filters. These filters and fans have been shipped from the US.

Delhi is already quite infamous for its smog. Delhi’s air quality enhanced by approximately 15% between 2019 and 2020 but it still ranked as the 10th most polluted city in the whole world and the most polluted capital in the World Quality Report 2020 survey. With an average annual PM 2.5 concentration of 84.1 micrograms per cubic meter, Delhi surpassed the list of the most polluted capital cities. And to work towards reducing the level of air pollution in some parts, Delhi is starting with smog towers. The new smog tower in Delhi utilizes a downdraft air cleaning system, which is developed by the University of Minnesota. IIT-Bombay has also collaborated with this American university to replicate the technology, which has been implanted by the commercial arm of Tata Projects Limited.

IIT-Bombay’s computational fluid dynamics suggest the smog tower could have an impact on the air quality up to 1km from the tower. The actual impact will be assessed by IIT-Bombay and IIT-Delhi in a two-year pilot study that will also determine how the smog tower functions under different weather conditions, and how levels of OM2.5 vary with the flow of air. With the new smog tower, polluted air is sucked in at a height of 24m, and filtered air is released at the bottom of the tower, at a height of about 10m from the ground. When the fans at the bottom of the tower operate, the negative pressure created sucks in air from the top. The macro layer in the filter traps particles of 10 microns and larger, while the microlayer filters smaller particles of around 0.3 microns.

An automated Supervisory Control and Data Acquisition SCADA system in the tower will monitor air quality. Levels of PM2.5 and PM10, besides temperatures and humidity, will be measured uniformly and will be presented on a board atop the tower. Shortly, monitors will additionally be installed at various distances from the tower to determine its influence at these distances.

The smog tower in Delhi is the first experiment with a large-scale outdoor air-purification system in India. However, experts have stated that there isn’t sufficient evidence that smog towers work and they can be a practical solution for the pollution in Delhi. Karthik Ganesan, a research fellow at the Council of Energy, Environment, and Water has told AFP that this tower is futile and an absolute waste. Tanushree Ganguli, a program lead from the council has told NDTV that there is no scientific evidence to show that the towers can efficiently diminish pollution levels. In January 2020, the Supreme Court directed two towers should be installed by April as a pilot project. The smog tower at Connaught Place is the first of these towers. Currently, the second tower is likewise being constructed at Anand Vihar in east Delhi. And this project aims to produce purified air in localized areas of Delhi, which is quite significant for the region.

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Reference:

• www.iqair.com
• www.ndtv.com