Gas transfer starts with the basic principle that the concentration of dissolved gasses in water is proportional to the partial pressure of these gasses in contact with the liquid.
In this scenario, the partial pressure of oxygen at atmospheric condition is 0.21 bar (3 PSI). If the partial pressure of gases in contact with the water changes, then the partial pressure of the oxygen in the water will also change. Deaeration Using Hollow Fiber Membranes Liqui-Cel® degassing contactors (Diagram 2) create a very large surface area within a small volume. Membrane degasifiers use a hollow fiber membrane to provide the surface area for the liquid and gas phases to come in contact with each other. Because the membrane is hydrophobic, the water will not pass through the membrane. Dissolved gasses, however, can easily pass through the membrane.
To obtain maximum gas transfer efficiency a central baffle forces the liquid to flow radially over the membrane which increases the surface contact.