Abstract

The most common biological waste gas treatment techniques are biofilters, biotrickling filters, and bioscrubbers. These bioreactors are used at full scale for waste gas treatment. Other bioreactors such as membrane bioreactors, rotating biological contactors, and two-phase bioreactors are currently under laboratory and pilot-scale investigation. All these techniques rely on the activity of microorganisms to degrade contaminants transferred from a gas stream into a liquid phase. They differ by the presence or absence of a mobile liquid phase and the nature of the packing/carrier material. This entry provides an overview of the fundamental and applied aspects of these biological waste gas treatment processes.