Apparently, Europe is not the only part of the world battling with pollution problem. Asia is also faced with air pollution problems and India recently devices new measures to solve this problem. The pilot study of this program will start with New Delhi which is also one of the worst hit by air pollution.
In 2017, one of the top scientists at Central Pollution Control Board (CPCB) made it clear that the agency would likely use Light Detection and Ranging (LiDAR) to vertically monitor Delhi’s air quality. The two commonly used systems for the vertical monitor of air pollution are Raman LiDAR and Elastic Backscatter LiDAR.
The working principle of LiDAR is simple. Laser beams are projected towards the sky. The interplay between the laser beams and the suspended particles in the air including reflection, absorption, and scattering will be analyzed to determine the composition of the particulate matter in the air.
The New Approach To Fight Air Pollution
The use of LiDAR can be compared to the use of Google Street View cars. They both help you to map the type of pollutants in the air and to some extent the level of pollution but they will not take the pollutants away. You will need to deploy another means to get rid of the pollutants.
According to CPCB, Delhi will be deploying new measures to fight air pollution in the winter of 2018. The new outdoor technologies are basically outdoor air purifiers called Wind Augmentation and Purification Units (WAYU). Three of these devices which will be used for the pilot study will be installed in high traffic zones.
The device was developed by the National Environmental Engineering Research Institute (NEERI) in partnership with Industrial Design Center at IIT (Mumbai). The device converts harmful air pollutants like PM10 and PM2.5, volatile organic compounds, and carbon monoxide into harmless forms. The makers say it can clean 40 – 60 percent of polluted air.
The Working Principle Of The Device
The device brings the expertise of different fields including physics, chemistry, and micrometeorology into a single platform. When active, the device operates in different stages but rely heavily on suction fans. Each of the purifiers is estimated to cost Rs 60,000.
The suction fan draws in the air around the device with all its pollutants. The particulate matter and dust are first filtered off using three filters of different pore sizes and dimensions. The air travels through a special chamber where the hydrocarbon and carbon monoxide pollutants are oxidized to carbon dioxide which is less harmful.
This phase of air purification makes use of activated carbon which is coated with titanium dioxide. The process of oxidation is enhanced by 2 ultraviolet lamps. The final purified air is ejected with a tremendous force into the atmosphere to dilute the atmospheric air of its pollutants.
Specification And Deployment Of The Air Pollutant Filters
According to Rakesh Kumar, the NEERI Director, the filters are 5.5 feet in height and 1 foot wide. Non-woven fabrics were used to make the filters which have an efficiency of 80 – 90% in terms of removing particulate matter and 40 – 50% for poisonous gas. Kumar also claims that it has the ability to lower the value of PM10 to 100 micrograms per cubic meter from 600 micrograms per cubic meter. Another unique feature of the device is that it can filter air within 500 sq. m.
As of August 2018, prototypes of the device have already been installed at Mukarba Chowk in North Delhi and the ITO Junction in Central Delhi. During the unveiling of the prototypes, Harsh Vardhan, the Minister of Science and Technology, promised that fifty-four more units would be positioned at different parts of the city.
The Future OF Wayu
According to Kumar, the institute is currently making efforts to scale up the device in the next 3 months so that its coverage area would increase to 10,000 sq. m. Also, there are plans to increase the capabilities of the device so that it will be able to eliminate other air pollutants unaccounted for by the pilot scale. This will include sulphur and nitrous oxides. The main setback to the use of this device is the high building density in some areas which tend to restrict air flow.