Outdoor purifiers to help assess Delhi’s pollution load

The three locations have been chosen to monitor different public settings, which include a high footfall commercial spot, an industrial location and one with heavy traffic movement

Outdoor air purifiers will soon be installed in Chandni Chowk, Wazirpur and Anand Vihar to assess their impact on ambient air quality, which will be monitored through low-cost sensors, officials said.

While outdoor air purifiers created by a private company will be installed at Wazirpur and Chandni Chowk (in picture), an ionisation-based purifying system created by a second private company will be deployed at a congested traffic intersection in Anand Vihar. (HT Archive)

This will be carried out as a pilot project by IIT-Delhi in collaboration with the central government’s DRIIV (Delhi Research Implementation and Innovation).

The three locations have been chosen to monitor different public settings, which include a high footfall commercial spot, an industrial location and one with heavy traffic movement .

“We will look to deploy different types of outdoor air quality solutions to see the kind of impact they can have when it comes to reducing localised pollution. We are in talks with the local bodies for final permissions, following which these outdoor air purifiers will be deployed in 7-10 days,” said Amrita Dawn, head, tech liaison, DRIIV.

The project has received the approval of the Delhi Pollution Control Committee (DPCC). Two private companies have been roped in to create and deploy sensors on the ground for data collection, officials said. For each air purifying device installed, a sensor to monitor readings in the area will also be installed, with the pilot to be used to assess the reduction in localized PM 2.5 and PM 10.

While outdoor air purifiers created by a private company will be installed at Wazirpur and Chandni Chowk, an ionisation-based purifying system created by a second private company will be deployed at a congested traffic intersection in Anand Vihar.

“These will not be large structures like anti-smog towers, but smaller air purifying systems that can be installed on the ground without causing any disruption to the movement of pedestrians. Chandni Chowk will give us an estimate of a busy marketplace, Wazirpur will cover industrial pollutants and Anand Vihar has heavy traffic owing to it being an ISBT and railway station,” Dawn added. Five filters will be installed at Wazirpur, one at Anand Vihar, while the number of filters at Chandni Chowk will be assessed following PWD permission, she said.

“Since PWD maintains the Chandni Chowk stretch where this is being installed, we have sought the final permission from them. Our sensors will give data on the actual reduction in pollution, which will allow more markets to be covered with similar technology if this is proven successful.” she added.

PWD did not comment on HT’s queries on the installation.

The technological deployment is part of the project SAMEER (Solutions for Air-pollution Mitigation through Engagement, Engineering and Research), which was launched by DRIIV and IIT Delhi in October, 2022.

DRIIV is an initiative of the Office of the Principal Scientific Adviser to the Government of India.

This is not the first time that outdoor air purifiers have been installed in the Capital. In 2018, devices called WAYU (Wind Augmentation and Purification Units) were installed at busy traffic intersections in order to assess efficacy in reducing roadside pollution.

The Delhi government and the Central Government have also installed two 20-metre-high anti-smog towers in Connaught Place and Anand Vihar respectively.

Anumita Roychowdhury, executive director, research and advocacy at the Centre for Science and Environment (CSE) says the use of technology, particularly low-cost sensors, has enormous potential if it is utilised correct. “These sensors can generate data while creating a very dense network of monitoring. We are still awaiting the guidelines to standardize data generation for low-cost sensors, but they can still be used for local monitoring and allow policy making.” she said.

Sunil Dahiya, an analyst at the Centre for Research on Energy and Clean Air (CREA) said while numerous air-purifying technologies existed, there have been no global studies to show they are able to impact the ambient air quality to a suitable enough level. “The project is beneficial if these technologies are deployed indoors, for instance inside classrooms or hospitals. Indoor air pollution is an area where there is a large scope for improvement. When we talk of outdoor pollution, even these giant anti-smog towers have proven to be ineffective, based on government findings.” he said.