ABSTRACT
Many physico-chemical and operational factors influence performance, treatment costs, and long-term stability of biofilters for air pollution control. This chapter focuses on identifying factors that affect biofiltration, explains their influence, and provides guidelines on how to control these factors to optimize operation. In general, the three most important parameters for an efficient biofilter are medium moisture content, pH, and bed temperature. The fundamental means of treatment in biofilters is the action of pollutant-degrading microorganisms. This means that controlling operating parameters in a biofilter is an attempt to control the activity of the process culture. Microbial activity and biofilter success are strongly influenced by temperature. A microorganism is a tiny bag of chemicals and enzymes, and life is a myriad of chemical reactions that run faster as the temperature rises. While some microorganisms are active at temperatures near the freezing point of water, and many can survive freezing, none can be active while frozen.
