Rotating biological contactor

A rotating biological contactor or RBC is a biological treatment process used in the treatment of wastewater following primary treatment.cite book|author=C.P. Leslie Grady, Glenn T. Daigger and Henry C. Lim|title=Biological wastewater Treatment|edition=2nd Edition|publisher=CRC Press|year=1998|id=ISBN 0-8247-8919-9] cite book|author=C.C. Lee and Shun Dar Lin|title=Handbook of Environmental Engineering Calculations|edition=1st Edition|publisher=McGraw Hill|year=2000|id=ISBN 0-07-038183-6] cite book|author=Tchobanoglous, G., Burton, F.L., and Stensel, H.D.|title=Wastewater Engineering (Treatment Disposal Reuse) / Metcalf & Eddy, Inc.|edition=4th Edition|publisher=McGraw-Hill Book Company|year=2003|id=ISBN 0-07-041878-0] cite book|author=Frank R. Spellman|title=Spellman's Standard Handbook for Wastewater Operators|edition= |publisher=CRC Press|year=2000|id=ISBN 1-56676-835-7] [ [https://aerade.cranfield.ac.uk/bitstream/1826/1086/1/Mechanical+evolution+of+the+rotating.pdf "Mechanical Evolution of the Rotating Biological Contactor Into the 21st Century"] by D. Mba, School of Engineering, Cranfield University] The primary treatment process removes the grit and other solids through a screening process followed by a period of settlement. The RBC process involves allowing the wastewater to come in contact with a biological medium in order to remove pollutants in the wastewater before discharge of the treated wastewater to the environment, usually a a body of water (river, lake or ocean). A rotating biological contactor is a type of secondary treatment process. It consists of a series of closely spaced, parallel discs mounted on a rotating shaft which is supported just above the surface of the waste water. Microorganisms grow on the surface of the discs where biological degradation of the wastewater pollutants takes place.

The rotating packs of disks (known as the media) are contained in a tank or trough. Commonly used plastics for the media are polythene, PVC and expanded polystyrene. The shaft is aligned with the flow of wastewater so that the discs rotate at right angles to the flow with several packs usually combined to make up a treatment train. About 40% of the disc area is immersed in the wastewater.

Biofilms, which are biological growths that become attached to the discs, assimilate the organic materials in the wastewater. Aeration is provided by the rotating action, which exposes the media to the air after contacting them with the wastewater, facilitating the degradation of the pollutants being removed. The degree of wastewater treatment is related to the amount of media surface area and the quality and volume of the inflowing wastewater.

See also

*Activated sludge
*Aerated lagoon
*Trickling filter
*Industrial wastewater treatment
*List of waste water treatment technologies
*Sewage treatment

References

External links

* [http://www.state.sd.us/denr/des/P&s/designcriteria/design-10.html Design Criteria for Rotating Biological Contactors]
* [http://www.coe.org.mt/html/Ryan%20Falzon%20FM%20Env%20COE%20140405up.ppt Implementing Rotating Biological Contactor Solutions]
* [http://www.waow.net/Brochures/RBC.pdf Applying the Rotating Biological Contactor Process]