It does depend on what is ...
Published by Don Sharpe
It does depend on what is being broken down, how difficult it is to break down by the activated sludge process and what are the consent levels for discharge. It will also depend on the type of system you have for oxygenation i.e. fine-bubble as against coarse air or even oxygen where unless air is used to remove CO2 the pH drops and it becomes sub-optimal for growth. So it is a very open question.