The combined effects of ambient (outdoor) and household air pollution leads to about seven million premature deaths worldwide every year, largely as a result of increased mortality from stroke, heart disease, chronic obstructive pulmonary disease, lung cancer and acute respiratory infections.
A study titled State of Global Air 2019 has reported that on an average the life of a South Asian child growing up under current high levels of air pollution will be shortened by two years and six months, while the global life expectancy loss is 20 months.
Vast tracts of north India, particularly the NCR region and parts of Uttar Pradesh, are among the most polluted areas in the world and air quality further deteriorates during winters due to a variety of reasons.
Concerned over the worsening problem of air pollution, Dr Pradeep Kumar and Dr Saurabh Kulshrestha along with their two students, Kanika Arora and Ankurita, decided to work on a viable household model that would help purify indoor air through harnessing Nature itself.
The Indoor Green Air Purifier harnesses the potential of microalgae and moss to degrade the toxic pollutants present in air like CO2, NO2, SO2, VOCs heavy metals and most significantly PM2.5 and PM10.
Professor, School of Biotechnology, Faculty of Applied Sciences and Biotechnology, Dr Kulshrestha said that the model prepared by them would be handy and can be kept on a small table with a structure like that of lava lamp. He said the purifier would cost around Rs 15,000 to Rs 20,000 and it will work for whole life as it can be replenished with algae and moss in every 2 months.
We can also install Internet of Things (IoT)-based system in it so that we can check out the PPM of air we are breathing via mobiles, he said and added that even the campany concerned will get an alarm alert if the system is releasing polluted air i.e. air with pollutants above the set values, he added.
The system, he said, would need a sparger system, light source and an exhaust fan for output air. Patent has been granted for microalgae bioreactor but is pending for the combination of moss and microalgae consortium.
The researchers focussed on microalgae Chlorella pyrenoidosa that needs CO2 (the major greenhouse gas), sunlight and wastewater containing nutrients to photosynthesis and grow. The other one is the lush green moss Ceratodon purpureus. Being a rootless bryophyte, it takes its entire nutritional requirement from atmosphere and chiefly targets CO2, SO2, SPM PM2.5, PM10, heavy metals and VOCs present in the polluted air.
The leftover biomass can be used for extraction of various bioactive compounds like super antioxidant astaxanthin and for biofuel production. Further the slurry can be used as biofertilizer agricultural farmlands.
The purifier works as microalgae culture and gets aerated via sparger system which is connected to an aeration pump. Thereby, dissolve various harmful gases in the media for microalgae to utilize it for photosynthesis using LED source that are muffled around the glass to optimize the growth conditions by meeting both heat and light requirement.
Dr Kulshrestha said the exhaust placed on the top of the bioreactor will force the air through moss layer which is grown in aeroponics and placed just above the algae media. This results in restoring the clean and fresh air to the indoor environment. The model is used for curbing the most deadly and profound problem of air pollution that leads to 7 million deaths per year due to its health effects.
This purifier will not only decrease AQI of the ambient atmosphere to a great extent but also gives the most reliable, efficient, natural and frugal alternative to the society for addressing the most concerned challenge worldwide.