With demand for air-purifiers increasing almost all over India, solar-powered and algae-based air-purifiers, which do not need a regular supply of electricity, are also coming to the market.
A majority of the population caught in the grip of acute as well as chronic respiratory ailments like asthma, especially in urban cities today, has air pollution to blame. And this is just one of the devastating impacts caused by air pollutants resulting from vehicular emissions, exhaust from industries, agricultural activities, and so on. Pollution is pushing every sector to switch from unsustainable methods of development to renewable-energy-based solutions.
To serve a large population, inexpensive yet highly efficient air-purification systems that can cover a large effective area in public places like bus stands, traffic signals, and hospitals are required. In China, such a solar-based air-purification tower approximately a hundred metres high was built to reduce smog levels in Xian in Shaanxi province as an experiment a few years ago. A system of greenhouses around the base of the tower traps the polluted air where it gets heated by solar energy. The hot air thus produced rises through the tower and passes through multiple layers of cleaning filters.
Growing awareness has made companies realise the importance of small-scale air-purifiers for use in homes, cars, offices and other commercial areas, too. These air-purifiers perform the same function as huge air-purification towers, that is, they can be used to get rid of dust particles, dust mites, smoke particles, vehicle emissions, and gaseous pollutants, among others, but their effective area is small. Air-purifiers rely on multiple or compound filters to clean air by removing suspended particulates through mechanical separation.
Making air-purifiers is not enough; care must be taken to ensure there are no hazards that may harm the environment or users’ health. For example, using an ozone air-purifier may not be a good solution; ozone can be dangerous for human health because it can cause breathing issues and, in severe cases, lung damage, according to the Environmental Protection Agency.
Demand for eco-friendly, economical, energy-saving purifiers has led to the rise of solar purifiers. In these purifiers, the purifier is usually powered through electrical mains but solar energy is available as an alternative, which can be highly beneficial in remote households that are off the electrical grid. This also ensures lower electrical consumption and hence lower operational cost.
Solar-powered air-purifier products are highly popular in places like the United States, China, South Korea, and the Netherlands. Portable solar purifiers for cars from manufacturers like Airnasa and Olansi are the most common. In terms of technology used, high-efficiency particulate air (HEPA) filters are the preferred choice due to their advanced purifying process. The popularity of smart air-purifiers is also growing as they can be conveniently controlled via Wi-Fi and Bluetooth remotely.
In developing countries like India, despite high levels of pollution, the purifier market is still in its nascent stage due to high initial cost and additional cost of replacing filters every few months. Also, the alternative charging efficiency of solar purifiers is not that high.
However, their sales are expected to surpass those of developed countries in the coming years, according to a recent report from Research and Markets.
Using solar power is not the only sustainable way when it comes to air-purifiers. Recently, student researchers from Lovely Professional University and Indian Institutes of Science Education and Research (IISER), Mohali, have developed an algae-based air-purifier that increases the amount of oxygen through photosynthesis besides neutralising the air pollutants. It also produces biomass as byproduct, which can be used for energy generation.
