Question 4013 of 234 · California Wastewater Operator Exam
Foam that is thick, brown, and greasy on an aeration tank is often caused by
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Correct answer to question 4013
- D: Nocardia or Microthrix type organisms in old sludge usually
Explanation
Brown, stable, scummy foam is typically from filamentous organisms like Nocardia that grow in old sludge. Reducing MCRT and removing foam from the system helps.
More questions: Secondary Treatment (Activated Sludge, Trickling Filters, RBC)
- 4014White, billowy foam on an aeration tank is most often a sign of
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- 4018A trickling filter is a
- 4019Sloughing in a trickling filter refers to