What does activated sludge mean?

activated sludge meaning in Law Dictionary

When sewage mixes with micro-organisms and portozoa leading to oxidation. It decreases pollution.

activated sludge meaning in Business Dictionary

Sewage combined with micro-organisms and protozoa that thrive and boost on it and lead to its oxidation (see biological oxygen need). Activation reduces the organic pollution that raw sewage otherwise will enforce from the body of water that it really is discharged.