High Performance I/O: PVFS2 for Clusters

A method of improving the backwashing of fixed beds formed of granular materials and used during waste water purification or water treatment, wherein the fixed bed, during the course of the backwashing thereof, is maintained during a predetermined time duration filled with a quiescent liquid. This liquid contains at least one substance which is distributed as uniformly as possible therein. In the presence of a spontaneous, catalytically triggered decomposition reaction, this substance releases a gaseous component. Then, the fixed bed is backwashed with water.