A device and method for enriching and/or depleting substances in a liquid is disclosed. An exemplary device comprises a membrane module that consists essentially of concentric elements and that has a separation element in which the substance to be enriched and/or depleted is carried, and whereby the liquid is carried outside of the separation element. The exemplary device also comprises a drive module that encompasses a drive unit for driving a conveying element that conveys the liquid, the drive unit having a radial magnetic coupling for a central impeller located on the inside. The exemplary device further comprises a conveying module for conveying the liquid through the device, housing the conveying element, whereby the drive module is adapted to be inserted into and removed from the membrane module with a liquid-tight closure. The exemplary device further an oxygenator having an outside fiber bundle and an inside fiber bundle. Finally, the exemplary device comprises an electromagnetic drive unit disposed between the outside fiber bundle and the inside fiber bundle.
