The trickling-filter system and the activated-sludge system both require
A)high levels of oxygen to promote aerobic decomposition.
B)high levels of carbon dioxide to adjust the pH of the water for bacterial action.
C)the addition of large amounts of chlorine to kill pathogens.
D)the addition of large amounts of ammonia as nutrients to support decomposers.

Question

Quizplus · Accepted Answer

Both the trickling-filter system and the activated-sludge system rely on aerobic decomposition, which requires high levels of oxygen.

The Trickling-Filter System and the Activated-Sludge System Both Require