During secondary aerobic wastewater treatment, some of the activated sludge goes ________ while the rest goes ________.
A) back to the aerator / to the anoxic sludge digester
B) back to the primary system / to the aerator
C) to the anoxic digester / back to the primary system
D) back to the primary system / to the tertiary digester

Question

Quizplus · Accepted Answer

In secondary aerobic wastewater treatment, part of the activated sludge is recycled back to the aerator for further treatment and to maintain the microbial population, while the excess sludge is often sent to an anoxic sludge digester for stabilization and reduction of organic matter under anoxic conditions.

During Secondary Aerobic Wastewater Treatment, Some of the Activated Sludge