THE USE OF INDEPENDENTLY SEALED MICROPOROUS HOLLOW FIBER MEMBRANES FOR OXYGENATION OF WATER - MODEL DEVELOPMENT

Mass transfer in a hollow fiber membrane aerator was studied. Individually-sealed hollow fibers are filled with oxygen and immersed in a flowing stream of water. Gas diffuses across the membrane wall and dissolves directly into the water without forming bubbles. Earlier studied found that mass transfer performance depended on the oxygen partial pressure inside the membrane. In this paper a model describes changes in gas composition along the fiber length that result from the back diffusion of gases, such as nitrogen, from the water into the fiber. The results of experimental studies verify model predictions. The model estimates an average saturation oxygen concentration along the fiber which predicts the mass transfer performance of the aerator under different conditions.