Rotating biological contactors is a remediation technology used in the secondary treatment of wastewater. Rotating biological contactors are fixed-film reactors. This technology involves allowing wastewater to come in contact with a biological medium in order to facilitate the removal of contaminants. The support media for microbial growth are the slowly rotating discs that are partially submerged in flowing wastewater in the reactor. A rotating discs contactor is an agitated column extractor that can carry out liquid-to-liquid extraction processes. Advantages
Short contact periods are required because of the large active surface
They are capable of handling a wide range of flows
Sloughed biomass generally has good settling characteristics and can easily be separated from waste stream
Operating costs are low because little skill is required in plant operation
Short retention time
Low power requirements
Elimination of the channeling to which conventional percolators are susceptible
Low sludge production and excellent process control
Application
Can be used for large quantity of wastewater flow where biological treatment is required