The Air-Cleaning Potential of Algae

Pollution is a growing problem within today’s world. Cars, factories, and other human activities release various pollutants into the atmosphere. One of these is carbon dioxide. While this gas is naturally produced by humans and animals, too much of it traps heat into the atmosphere, speeding up global warming and slowly destroying the environment.

The most common method of removing excess carbon dioxide from the atmosphere is through planting trees. This is because plants and trees can convert carbon dioxide into oxygen in a process called photosynthesis. Photosynthesis is very important in balancing an ecosystem, since plants can absorb the excess carbon dioxide produced by humans and animals and in turn produce oxygen for those humans and animals to breathe. For this reason, plants and trees are described as the "lungs of the earth."

The most common method of removing excess carbon dioxide from the atmosphere is through planting trees. This is because plants and trees can convert carbon dioxide into oxygen in a process called photosynthesis. Photosynthesis is very important in balancing an ecosystem, since plants can absorb the excess carbon dioxide produced by humans and animals and in turn produce oxygen for those humans and animals to breathe. For this reason, plants and trees are described as the "lungs of the earth."

Hopefully, after reading through our research, you will get to see the amazing potential that algae holds in helping the environment. Who knows; maybe future scientists such as you will be able to make innovations with algae in the future!

The main reason why algae produce so much oxygen is because of their high photosynthetic efficiency. Photosynthetic efficiency means the amount light a plant captures and successfully converts into useful products (Park, 2007), including oxygen. They are more efficient at photosynthesis because they have more pigments that capture solar energy and are better at concentrating carbon dioxide, specifically around their RuBisCO enzyme (Ma et al., 2023). The result of this is that algae have a photosynthetic efficiency of 10-20%, while plants have an efficiency of about 1-2%. That means algae can produce about 10x more oxygen than plants can! Isn't that awesome?

Algae also have several other benefits. According to a 2013 study by Singh and Ahluwalia, they are more tolerant of carbon dioxide, meaning that they can be used in highly polluted areas. They have low light intensity requirements, they are not as constrained by land as plants are, and do not require herbicides or pesticides. Algae also grow at incredible rates—some species can grow to double their size injust 3.5 hours!

A group of scientists from the University of Belgrade in Serbia have recently made an innovation that could prove the potential of algae in cleaning the atmosphere.

Dubbed by the Internet as "liquid trees", LIQUID3 is a "photo-bio reactor" that uses algae to clean the atmosphere, especially in highly polluted cities such as the Serbian capital of Belgrade. It is designed to be an innovative and practical way of reducing pollution, especially in cities where there isn't enough space to plant trees.

Additionally, in the Pittsburgh Airport, the company AlgenAir installed a similar algae air purifier that they call the "aerium". According to them, it uses 125 gallons of Spirulina algae and has the photosynthetic capacity of 5000 houseplants (Kite-Powell, 2022). They also sell smaller versions of the aerium for use inside homes and personal spaces. They claim that this purifier has the photosynthetic capability of 25 plants, and when the algae inside needs to be refilled, they also advise users to recycle the used algae as fertilizer for houseplants (AlgenAir, n.d.).

These innovations show that algae air purifiers are viable in public urban settings where they are needed the most, and we hope that with further time and research, such purifiers will be found cleaning the air in cities all over the world.

This technology is new so there is plenty of room for improvements and some restraints. For example, the indoor air quality can be affected by the quality of the device, which is problematic in densely populated cities. Additionally, as of now, tree planting is easier and cheaper to implement in most cases, even though algae are better at cleaning the air. This is because there are still several issues that need to be worked on, especially in terms of trying to scale up the use of algae as an air purifier. Onyeaka et al. (2021) identified several of these issues, such as how algae might handle unexpected environmental factors, the high cost and complex process of culturing microalgae, and the risk of parasites and pathogens such as aphelids and Chytridiomycota fungi.

There are also many studies looking to further increase the photosynthetic efficiency of algae, not only to clean the air but also to use them as sustainable fuels to replace coal and petroleum. Most of these studies plan on using cutting-edge molecular engineering and genetic engineering technology to improve the photosynthetic structures of algae.

Algae holds a lot of potential in our fight against climate change and greenhouse gases. They produce 10 times more oxygen than plants, and thus capture 10 times more carbon dioxide from the atmosphere. They have several benefits that make them practical for use in highly-polluted urban areas where planting trees is not always feasible. They have already seen use all over the world, and they will be a key part of our fight against climate change in the near future.

AlgenAir. (n.d.). AlgenAir. https://algenair.com/

Castim, D. (2022, January 6). A Liquid Tree? Scientists in Serbia Make Incredible Innovation - World Bio Market Insights. World Bio Market Insights. https://worldbiomarketinsights.com/a-liquid-tree-scientists-in-serbia-make-incredible-innovation/

Kite-Powell, J. (2022, October 10). Pittsburgh International Airport Just Installed A Giant Algae Air Purifier. Forbes. https://www.forbes.com/sites/jenniferhicks/2022/10/09/pittsburgh-international-airport-just-installed-a-giant-algae-air-purifier/amp/

Ma, W., Liu, L., Wang, Q., Duanmu, D., & Qiu, B. (2023). Editorial: Algal photosynthesis. Frontiers in Microbiology, 13. https://doi.org/10.3389/fmicb.2022.1112301

NOAA. (2021, February 26). How much oxygen comes from the ocean? oceanservice.noaa.gov. https://oceanservice.noaa.gov/facts/ocean-oxygen.html

Onyeaka, H., Miri, T., Obileke, K., Hart, A., Anumudu, C., & Al-Sharify, Z. T. (2021). Minimizing carbon footprint via microalgae as a biological capture. Carbon Capture Science & Technology, 1, 100007. https://doi.org/10.1016/j.ccst.2021.100007

Park, C. (2007). A Dictionary of Environment and Conservation. Oxford University Press, USA. Singh, U. P., & Ahluwalia, A. S. (2013). Microalgae: a promising tool for carbon sequestration. Mitigation and Adaptation Strategies for Global Change, 18(1), 73–95. //doi.org/10.1007/s11027-012-9393-3

Mata, T. M., Oliveira, G. M., Monteiro, H., Silva, G. V., Caetano, N. S., & Martins, A. A. (2021). Indoor air quality improvement using nature-based solutions: Design Proposals to greener cities. International Journal of Environmental Research and Public Health, 18(16), 8472. https://doi.org/10.3390/ijerph18168472