Rotating Biological Contactors are an efficient fixed-film wastewater technology well suited for secondary and/or advanced biological treatment. The long-term reliability of this process is evident in the more than 6,000 units from Evoqua in operation today. Evoqua owns most of the key industry brands of RBCs including Envirex®, Lyco, and Autotrol, and provides OEM (Original Equipment Manufacturer) parts, process expertise, and complete turnkey replacements to help equipment owners maintain equipment performance.
The RBC process consists of a large disc with radial and concentric passages slowly rotating in a concrete tank. During the rotation, 40 percent of the media surface area is in the wastewater. The rotation and subsequent exposure to oxygen allows organisms to multiply and form a thin layer of biomass. This large, active population causes the biological degradation of organic pollutants. Excess biomass shears off at a steady rate and is carried through the system for removal in a clarifier.