Combining air sparging and the use of a static mixer in cross-flow ultrafiltration of oil/water emulsion

The simultaneous use of a static mixer and air sparging technique has been investigated during cross-flow ultrafiltration of oil/water emulsion. It is found that the use of a static mixer leads to a considerable increase in the permeate flux. However, the presence of a static mixer reduced hold-up in the feed channel leading to a high pressure drop along the length of the membrane and therefore the increase in energy consumption. Combining air sparging and the use of a static mixer demonstrated that a high permeate flux can be obtained at a relatively low energy consumption. The results suggest that the simultaneous use of these techniques could be interesting in membrane processes which already use gas injection, such as aerobic membrane bioreactors.