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ac·ti·vat·ed sludge meth·od
a method of sewage disposal in which sewage is treated with 15% bacterially active liquid sludge, which is produced by repeated vigorous aeration of fresh sewage to form floccules or sediment; when this flocculation process is complete, the resulting activated sludge contains large numbers of bacteria, together with yeasts, molds, and protozoa, which actively effect the oxidation of organic compounds; this mixture is piped to a sedimentation tank, the effluent from which is completely treated sewage.
Farlex Partner Medical Dictionary © Farlex 2012
activated sludgeany living material used in sewage treatment, consisting mainly of bacteria and protozoans, that breaks down organic matter in the sewage and increases by multiplication during the process. Part of the new sludge is used in the continuing treatment of the sewage.
Collins Dictionary of Biology, 3rd ed. © W. G. Hale, V. A. Saunders, J. P. Margham 2005