Role of biofiltration in the treatment of sewage

The process of biofiltration involves the separation of fluids (i.e., water/gases) of interest from its heterogeneous mixture, fluids from the particulates/colloids with the aid of heterogeneous/homogeneous microbial culture immobilized on a permeable/semipermeable/impermeable surface or medium. It is a conglomeration of physical, chemical, and microbial action in the presence of moisture/water, macronutrients, and micronutrients. This technique has been widely applied for the decomposition of easily degradable and persistent aquatic pollutants, energy generation via anaerobic digestion, physical separation of particulate matter from water, reduction in the population of pathogenic microbes in wastewater and drinking water, fractionation of gases, removal of impurities from the air, and scrubbing of the foul odor from gases. This review chapter aims to present a basic understanding of the biofiltration technique and its application toward the treatment of wastewater. The chapter also discusses the application of a variety of biofilters such as anaerobic, aerobic, bacterial, algal, and mixotrophic biofilters for sewage treatment.