Field Techniques for Evaluating Aerators

Abstract

Rational design and operation of an aerated biological unit requires a knowledge of the oxygen-transfer capacity of the aeration systems either under consideration or installed. Detailed methods are described for use by operating engineers in collecting the required performance data through tests of commercial aerators installed in full-scale basins. The essential features of oxygen-transfer theory are reviewed together with the relationships needed to adjust the test data to specified conditions. The important test conditions, the required auxiliary measurements, and the basic oxygen-transfer measurements are enumerated. The results of full-scale tests based on reoxygenation rates, gas-stream oxygen balances, sulfite-ion depletion rates, and biological oxygen-uptake rates are presented for large sparged turbine and entrainment aerators. The ASCE Committee on Sanitary Engineering Research is considering means of collecting, correlating, and publishing the results obtained by plant engineers and their consultants in using these techniques to conduct aerator tests.