Efficient operation of inverted umbrella aerator: The effect of operating parameters on oxygenation performance

This study presents experimental research about inverted umbrella aerator, which widely used in Wastewater Treatment Plants (WWTPs), with a focus on the interplay between rotational speed, immersion depth, and motor load rate. This study systematically compares two distinct types of aerator designs (type 1# and type 2#) under varying conditions, analyzing oxygen transfer coefficients, standard oxygen-transfer rates, and standard dynamic efficiency (Es). And the orthogonal experimental method was employed to analyze the effects of different parameters on Es. Key results show that: (1) A positive correlation was observed between the motor load rate and rotational speed; however, two types of aerators operate at different speeds under the same motor load; (2) At an immersion depth of 0 mm, the oxygenation performance of type 2# is superior to that of type 1#, but significant variations were observed with varying immersion depths. (3) The effect of motor load rate for Es is greater than the effect of immersion depth, which is a critical guidance that can guide the optimization of operational parameters. These results can provide valuable insight into the energy efficient design and operation, and enhance the understanding of the oxygenation performance of inverted umbrella aerators.