At a time when metropolitan cities are choking due to air pollution, most residents are thinking of installing air purifiers in their households. However, here are a group of college students who have a larger plan — one that will benefit the country and the world at large.
Hoardings draw a lot of attention. For the space that it occupies, a hoarding does not fail to catch one’s attention. Now, what if we told you that a hoarding could do more than just be a huge board, up in the air, shouting out to the world about some product that is in the market? What if we told you that a hoarding can help you breathe fresh air? Sounds unbelievable, doesn’t it! But thanks to these students, who have designed a hoarding that can purify the air we breathe, it may soon be a reality.
Designed by three third-year engineering students, Dhruv Suri (Aeronautical), Priyanshi Somani (Computer Science), and Raahil Nayak (Aeronautical), from Manipal Institute of Technology, this hoarding, called the GreenBoard, can draw impure air from the surroundings and purify it. “We have carbon dioxide scrubbers clubbed in the hoarding. It can draw air from outside, purify it with the help of a compound called sodium hydroxide that runs through the system, and then release this pure air into the atmosphere,” explains Dhruv Suri, one of the students who worked on the project that is funded by the Innovation Centre at Manipal University.
These students have ensured that even the residue that is left behind after purification does not go to waste. The residue, which is formed of carbon dioxide pellets, can be handed over to greenhouses where they can be utilised. The bigger the size of the hoarding, the larger the quantity of air it can purify, Suri adds. “A hoarding of the dimension of 15 by 25 feet is capable of drawing air from a distance of around 750 metres from its location,” he explains.
So, what is the technology behind this idea? The GreenBoard comes equipped with a HEPA filter as well as a scrubber-based air purification system. "Carbon dioxide is easily absorbed by alkalis such as NaOH or sodium hydroxide. The HEPA filter clears the air of microscopic particles that pass through the hoarding from one of its sides. The scrubber system is based on a novel concept involving the application of drip irrigation. The inside of the hoarding consists of absorbent ribbons with an electronic dropper mechanism, continuously keeping the ribbon moistened with the alkali.
"As the air passes through this network of ribbons, the sodium hydroxide absorbs the carbon dioxide in the air to produce sodium carbonate, which remains as a residue inside the hoarding," explains Dhruv, as simple as he can. Seems like a straightforward idea, don’t you think?
