Packed Bed Biofilm Reactors: Design

A simplified design method is applied to the design of submerged filter and expanded bed biofilm reactors. Typical design parameters as well as kinetic and mass transfer coefficients are listed for several bacterial reactions including fermentation, aerobic respiration, nitrification and denitrification. The Monod maximum utilization rate appears to be smaller for biofilm reactors than for suspended growth reactors. However, biofilm reactors have much larger substrate removal rates per unit volume than suspended growth reactors due to the larger organism concentration. The expanded bed reactor has greater substrate removal rates than the submerged filter due to larger surface areas, less trapping of influent suspended solids, and smaller stagnant liquid layer depths.