Question

8) During secondary aerobic wastewater treatment, some of the activated sludge goes ________ while the rest goes ________.

A) back to the aerator / to the anoxic sludge digestor
B) back to the primary system / to the aerator
C) to the anoxic digestor / back to the primary system
D) back to the primary system / to the tertiary digestor

Answer 1

In secondary aerobic wastewater treatment, part of the activated sludge is returned to the aerator to maintain microbial populations while the remainder is sent to the anoxic sludge digestor for further processing.

Step-by-step explanation:

During secondary aerobic wastewater treatment, some of the activated sludge goes back to the aerator to help break down contaminants by introducing additional microorganisms into the wastewater. The rest of the activated sludge goes to the anoxic sludge digestor where it undergoes further breakdown, often through anaerobic processes, which can include the production of methane as a byproduct.