Gas Transfer Kinetics of Pure Oxygen System

A mathematical model is described which determines the gas and liquid phase of oxygen, nitrogen, and carbon dioxide concentrations along with the variation in gas flow and pH in a completely mixed, staged, pure oxygen system. Model verification was accomplished using existing field data. The model was then utilized to determine the effects of varying BOD loads and alkalinities on a previously designed system. Lower waste-water alkalinities and pHs not only resulted in lower mixed liquor pH values, but also lower dissolved oxygen concentrations. The respiratory quotient was seen to have a significant effect on the system. To obtain a desired DO level, the trade-off between increasing gas flow and aerator horsepower is presented.