In the course of investigations in order to control the efficiency of aeration equipment or to judge the loading of technical activated sludge plants the oxygenation capacity under operating conditions has been evaluated. Plants for industrial as well as for domestic waste water have been investigated.
The investigations were conducted on the oxygenation characteristics - the connection between oxygenation efficiency and specific power consumption, the flexibility of aeration control and adaptability of the aeration equipment to varying demands. Besides these parameters that can be classified quantitatively, practical experiences from the operational point of view as well as the aging properties will be dealt with. Moreover criteria for the selection of compressors and pumps as well as problems of air distribution at compressed air aeration systems, with the related problems for measurements and control of air flow, will be discussed.