As SC demands roadmap for smog towers, experts debate efficacy and technology

New Delhi: A day after the Supreme Court asking the Centre to come up with a road map on installing smog towers in Delhi-NCR within 10 days to combat rising pollution, officials of the Central Pollution Control Board (CPCB) and the Delhi Pollution Control Committee (DPCC) met in the capital on Tuesday.

“We are deliberating on the project and will come up with a plan on how to implement it. There are various aspects that need to be looked into, as the project involves high costs and adequate space,” said a senior DPCC official.

“We will be meeting experts from the Department of Science and Technology and IIT scientists, who are working on this project, to be able to take a decision,” the official said.

Installation of smog towers to mitigate pollution was first proposed to CPCB in 2018. A proposed pilot project to consider the efficacy of smog towers is being undertaken by IIT-Bombay in collaboration with IIT-Delhi and the University of Minnesota. The US-based institution has helped build a smog tower in Xian, northern China.

“We have proposed a prototype on an experimental basis to deal with ‘severity’ of air pollution. It is to deal with acute situations and not the final solution to pollution. We have identified the University of Minnesota, which has been working in the field of filtration technology for the past 40 years. For the pilot, we will have to import filers from there while all the other work will be done here,” said a senior IIT-Bombay scientist.

Sri Harsha Kota, an assistant professor at the department of civil engineering, IIT- Delhi, who is closely associated with the project, said, “It is on an experimental stage and logistics still have to be decided. There is no data or a model as such to test its feasibility.”

The project is estimated to cost around Rs 10-12 crore, said project members at IIT-Delhi. Also, it would require building a 25-metre high concrete structure with a monitoring station and other equipment.

However, experts questioned the feasibility of the project given that Delhi is a congested city where space is at a premium. Also, they said, there have been no studies to assess the impact of this technology on the ambient air quality.

Santosh Harish, a fellow at the Centre for Policy Research said, smog towers may be the last resort in a place like Delhi, where the nature and scale of the problem is massive, but one must examine the proposal properly before investing in an untested technology.

“It may remove some dust from the vicinity, but controlling pollution at source may not be possible. Even in China, which has two such towers, this technology was not well received or widely implemented,” he said.

D Saha, former head of CPCB air laboratory, said smog towers are not suitable to Delhi’s meteorological conditions. “There is a constant intrusion of dust in Delhi because of various geographical and local factors. How much can a filter suck? A model such as this cannot be successful for a city like Delhi.”