Subsurface Aeration Evaluation

To separate performance of subsurface aeration devices from the mass-transfer evaluation for standardized evaluations, a mass-transfer model consistent with the subsurface aeration process phenomenon was developed for examining submerged aeration equipment. As an independent check, the oxygen-transfer rate determined by the model at test conditions was compared with the rate obtained from the slope of a nonlinear least-squares curve fit of the data at zero dissolved oxygen. This latter technique provided an accurate indication of the transfer rate at test conditions without defining a mass-transfer coefficient or driving force as does the model. The mass-transfer model then allows translation of the test results to standard conditions.