EXPERIENCES IN EVALUATING AND SPECIFYING AERATION EQUIPMENT

Abstract

To assure adequate aeration capacity in activated sludge plants, aeration systems must be properly selected, specified, and tested. All of this has been made possible by the develop ment of testing methods over a period of years. It has been the experience of the authors that careful specifying followed by compre hensive testing of aeration equipment is well justified. In 16 different aeration tests wit nessed in the past several years, only in seven instances did the aeration equipment pass on the-first try. One aeration system required two retests and another required three. Of the nine that failed the first try, five required major field modification of the equipment. Many consulting firms began requiring performance testing of aeration systems only in the last few years. The performance claims of many aera tion equipment manufacturers have dropped significantly as a result of the testing. This paper will trace the development of aeration theory and the evolution of theory into methods of specifying and testing aeration equipment. While not encompassing all as pects of equipment specifying and testing, it is hoped that some points will be beneficial to both the manufacturer and the design engineer.