Definition: Activated sludge system (independent secondary waste water treatment)

Category: Environment

Process for the biological treatment of waste water in which a mixture of waste water and suspended biological mass is agitated and aerated. The activated sludge is subsequently separated from the treated waste water by secondary settlement and is returned into the aeration tank or removed as excess sludge (based on CEN definition).
OECD/Eurostat Joint Questionnaire - Inland Waters