During 1960's 70's NASA was investigating how to create closed breathing environments for astronauts, to be able to live on Mars or on the Moon. A place where plants, humans and microorganisms could live collaborating, as on earth. According to their research, they found that when air passes through the soil of the plant, microorganisms that live near the root can absorb several toxic elements that are present in the environment. Getting to filter between 70 to 100 times more than just what the plant could absorbs through the leaves.
The air purifier is made of 2 containers. One for the ground and the plant, and one for the components, to generate a "vacuum chamber." All parts are removable and can be cleaned.