Rotating Biological Contactor
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The Rotating Biological Contactor Process (RBC) consists of a series of discs attached to a common shaft. The discs are partially submerged in a trough of continuously flowing wastewater. As the discs rotate, a film of microorganisms growing on the discs consume oxygen from the air and substrate from the wastewater. In this way, organic materials (substrate) are removed from the wastewater. The rotation of the RBC disks can be achieved by a motor and drive system on each shaft or by an air drive system with a coarse bubble diffuser at the bottom of the tank supplying air that is caught by the air cups attached to the disks. The rotation of the disks imparts a shear force to the biofilm, keeping its thickness relatively constant by removing the cells generated by consumption of the substrates. Rotation of the disks also serves to provide oxygen required for the growth of biomass and substrate degradation. A settling tank is normally required to remove the biomass from the effluent.
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