WAYU air purifiers on Delhi roads turn dustbins, spittoons

Now, scientists have begun replacing many of these pilot project air purifying units in Delhi with ones, which, apart from promising almost double the efficiency in cleaning air, will also be tamper proof.

Cigarette butts, bidi packets, chewing gums and wires — these are some of things that you would normally expect to find in a garbage bin but certainly not in air purifying units installed on Delhi roads. But that is exactly what officials found while inspecting WAYUs (Wind Augmentation Purifying Units) at different places in the city.

An air pollution control device WAYU at Bhikaji Cama Place, in New Delhi.(Amal KS/HT Photo)

Now, scientists have begun replacing many of these pilot project units with ones, which, apart from promising almost double the efficiency in cleaning air, will also be tamper proof.

“The older version had more openings through which people sometimes used to insert cigarette and bidi ends and other garbage,” said Rakesh Kumar, director of National Environmental Engineering Research Institute (NEERI), a research institute under the Council of Scientific and Industrial Research (CSIR). “This would damage the filter systems and we had to frequently change them. The new machines are covered to prevent people from putting in such garbage.”

Hindustan Times found a chewing gum stuck in one of the machines installed at ITO intersection. Cigarette and bidi ends and gutka packets were scattered near the machines.

More than 70 such WAYU machines were installed last year at some of the most polluted road intersections such as ITO, Anand Vihar, Wazirpur Chowk, Shadipur and Bhikaji Cama. At least 19 old machines have already been replaced by the new version.

Better efficiency

While the old devices could clean 1,250m3 air per hour, the new version can clean 2,500m3 air per hour.

The new version is also sleek and will occupy less space.

“Preliminary results showed that the older version could bring down up to 60% of PM10 and 40% of PM2.5. The new versions are being installed and it would take at least two months to check their performance,” said S Gulia, scientist from NEERI’s Delhi zonal centre who monitors the devices in the national capital.

National Environmental Engineering Research Institute will also analyse the dust trapped in the old device’s filters to determine their source.

Scientists said that different versions of WAYU — one that can clean up to 10,000 sqm of air and a shorter version intended to be used in parking lots and basements — are being developed.

On certain winter days, when the air quality breaches the ‘severe’ mark, concentration of PM10 and PM2.5 in the air shoots up to more than five times the safe standard.

The pilot project is being funded by the central government.

A similar pilot project in which air filter units called ‘Pariyayantra’ have been mounted on the roof of buses is being carried out by Faridabad-based research organisation Manav Rachna International Institute of Research and Studies. “Each machine is trapping more than 50 grams of dust in 10 hours,” said Amit Kumar Singh, a research associate of the institute.