Hi, the analogy to car fuel ...

Published by

Hi,

the analogy to car fuel consumption in order to get from A to B might be a good one. This is not only a function of the geographic position and height differences, as one could assume. Additionally, this is a function of car condition, driver's style, air quality, weather, traffic jams, etc.

The same way BOD reflects the amount of oxygen needed to get the sludge treated as desired (A to B). 

I hope approach was quite poetical  :)