The activated sludge process: State of the art

The activated sludge process has been employed for the treatment of municipal and industrial wastewaters for many years. Modifications and improvements to the process have been the result of extensive research from both a theoretical and practical viewpoint. This article reviews the activated sludge process as it is presently applied. Design approaches are developed including examples for both municipal and industrial wastewaters. Special consideration for industrial wastewaters are discussed. Process modifications including nitrification denitrification and priority pollutant removal are considered.