How the Technology Works

active plant unit living green walls in various urban locations cleaning the air in london
Active Plants Units can be integrated into existing urban street furniture.

An Active Plant Unit (APU) is a robust, reusable and recyclable enclosure filled with plants and containing the Aerogation® green wall system that can be mounted indoors or easily attached to roadside structures. Through enhancing the process of phytoremediation, 2sqm of APU can provide over 430,000 litres of purified air in 24 hours.

The primary benefit of an APU is that it needs far less surface area to deliver the same results as larger ‘passive’ green walls. In some cases, the effect is magnified by over 100 times.  A 300-plant APU can have the same air cleansing ability as 60,000 houseplants.

What is Phytoremediation?

Phytoremediation is a natural process, which we enhance with well-placed technology. The word comes from the Ancient Greek φυτό (phyto) meaning ‘plant’ and Latin remedium, meaning ‘restoring balance’, It refers to the use of living plants to clean up soil, air and water that has been contaminated with hazardous contaminants.

This process takes place with plants and also with their associated beneficial bacteria and soil microbes. Plants absorb carbon dioxide and emit oxygen, but they also absorb carcinogenic volatile organic compounds (VOCs) and break these down into harmless molecules.

Knowledge of phytoremediation has really begun to emerge in recent years, and with it biological and engineering strategies to optimize and improve on the process.

AEROGATION® green wall technology gives Mother Nature a significant helping hand by delivering polluted air directly to the root zone of plants. Although leaves and plant stems clean air and emit oxygen, this is where their air cleaning qualities are most efficient. Controlled delivery of water, air and temperature provides a consistent root environment to maximize plant health.

We have volatile organic compounds and carcinogens such as carbon dioxide, formaldehyde, benzene and trichloroethylene all around us. AEROGATION®green wall technology draws these compounds in and returns purified air back into the environment. This is all done at a local level for the immediate wellbeing benefit of building inhabitants and passers-by. Monitoring and maintaining plant health and applying a sound deployment strategy enables us to reduce harmful pollutants 24 hours a day.

Because the plants’ powers of phytoremediation, no plastic man-made filters are required, meaning our green wall APUs avoid the unnecessary landfill created by mechanical air purifiers.


To learn more about the technology that drives our innovative green wall solutions, along with other project information and research, please get in touch here. Please feel free to connect with us and share any other useful insights, data and case studies.