Biofiltration is the use of natural processes to control air pollution. This is accomplished through the use of microorganisms who feed on the contaminants found in air or water.
In the process, air is passed through a filter made up of moisture and microorganisms. As the polluted air passes through the filter, the pollutants become trapped within the filter. The microorganisms then process the pollutants, turning them into carbon dioxide and water.
Biofiltration. http://www.cpeo.org/techtree/ttdescript/biofil.htm. Accessed July 25, 2016.
Anit, Selvi B. and Robert J. Artuz. Biofiltration of Air. https://www.rpi.edu/dept/chem-eng/Biotech-Environ/MISC/biofilt/biofiltration.htm. Accessed July 25, 2016.