Biofilters - History of Biofilters
The biofilter was first proposed by a German scientist named H. Bach in 1923. Bach's idea was to use living organisms to break down hydrogen sulfide, a poisonous gas, which was made by waste water treatment facilities. Over time, biofilters and bioreactors have been adopted as naturally-based ways to control pollution. Many micro-organisms, like algae and bacteria, are able to absorb and break down chemicals that are harmful to us. Biofilters take advantage of their abilities to clean our air and water.
The first biofilter to be installed was in Long Beach, California, in 1953. This was a soil bed, which controlled odors from a sewer main using the microbes that live in soil. The patent for this design was issued to Richard Pomeroy in 1957. A similar soil bed was installed at a waste water facility in Nuremburg, Germany, in 1959.
- Biofilters are now very common as part of waste water management, but they have a variety of other uses. Many factories clean their air to remove Volatile Organic Compounds (VOCs) using biofilters. VOCs are gases that are not only smelly, but dangerous to humans and animals. Micro-organisms can absorb and oxidize these, turning them in to less harmful gases.
- New uses continue to be developed. The harmful gases and chemicals biofilters are used to break down include sulfides, alcohols, ammonia, acrylate, organic acids, amines, and hydrocarbons.
- Biofilters can take the form of soil beds, bioreactors containing large numbers of bacteria, and water "trickling plants" containing algae and other organisms, to name a few types.
- The deepest operating biofiltration plant in the world is 1.3 miles (2 kilometers) underground at SNOLAB, a particle physics laboratory in Sudbury, Ontario, Canada. Their waste water treatment bioreactor allows the large underground laboratory to have the world's deepest flush toilets.