The basic processes involved in treatment by suspended microorganisms are uniform stirring of the wastewater and suspended microorganisms for a fixed time, and supplying the oxygen required by the microorganisms for waste water treatment.

Thus the basic elements required for economical, efficient treatment of wastewater are as follows.

1. A microorganism reactor basin of simple construction, enabling minimal construction costs (basin construction)
2. A type of water flow enabling uniform mixing with minimal motions (water flow model).
3. An efficient, controllable aerator (aerator system).
4. Equipment for accurate estimation of the state of the microorganism processing (an automatic control system).