Biofiltration: An Emerging Technology

Abstract

Gas biofiltration is a relatively new technology used to purify contaminated air from volatile organic and inorganic compounds (VOCs and VIes). This biotechnological process is now gaining popularity among industries due to its low cost, operational simplicity, removal efficiency, comprehension, modeling and mainly because it is intrinsically clean, as it reduces or eliminates the need for additional treatment of the end-products. Since 1980s different chemical processes have been utilizing biofiltration with different flow rates, up to 200 thousand m³hr^-1, Technologies considered being forms of biological gas purification include bioscrubbers, biotrickling filters and biofilters, operating with the same fundamental mechanisms of biodegradation. Biofilters, subject of this review, can be regarded as solid fermenters, The polluted gas is forced to flow through a bed packed support on which microorganisms are immobilized or attached as a biofilm. As a biological purification process, it is based on the ability of microorganisms to degrade organic and inorganic compounds, and their complete oxidation to generate energy. This review describes and evaluates some techniques, apparatus and support media used for biofiltration of gases, focusing industrial applications. The encapsulation of microbial cells has also been considered.