Biotrickling Filters

As mentioned in Chapter 3, biotreatment for air pollution control started in the 1950s using soil beds. The technology has since matured and industrial applications of biofilters are numerous. More recently research has focused on a variation of biofilters called biotrickling filter, or trickling biofilter. Biotrickling filters work in a similar manner to biofilters, except that an aqueous phase is trickled over the packing, and that the packing is usually made of some synthetic or inert material, such as, among others, plastic rings, open pore foam, lava rock. The trickling solution contains essential inorganic nutrients such as nitrogen, phosphorous, potassium, etc. and is usually recycled.