BIMR is it correct to conclude then that raw sewage (black water) in itself does not contain the required bacteria to be treated properly? that you need storm water that has come into contact with earth to seed the sludge with the needed aerobic bacteria?
It is really an issue of time. The activated sludge process can be considered as a high rate natural process. The activated sludge process uses a huge volume of acclimated microorganisms to speed up what is a natural process of decomposition.
One method to initiate the activated sludge process is to deposit some soil in the activated sludge basin.
A better method is to transfer mixed liquor (using a tanker tank) from an operating activated sludge system. This method works faster since you are starting with a greater quantity of acclimated bacteria.
My understanding is that the source of the microorganisms in the gut is from the mother and that the microorganisms are transferred at the time of birth.
The microorganisms that thrive in the activated sludge basin will do so naturally because the enviromental conditions are ideal for those particular microorganisms. Since the environmental conditions in the gut are quite different, one would not expect that the same microorganisms that predominate in the gut would be the same microorganisms that predominate in the activated sludge process.