Abstract: Device for treating a fluid, including a number of columns which are arranged on a support frame and through which the fluid is guided. This support frame rotates with respect to the environment and communication with the environment is achieved by means of a valve. This valve encompasses a plate which is rotationally fixed to the support frame and opposite to which there is a plate whose feed and discharge is in communication with the environment. This latter plate, or auxiliary member, can execute a limited reciprocating rotation, in order to achieve an indexing movement with respect to the first plate. These movements are realized with electromotors and wherein position sensors are provided.