摘要 |
A method of improving the operation of backwashable fixed beds formed of granular materials and used during purification of waste water of sewage or during water treatment, wherein the fixed bed is conditioned during a last step of the backwashing operation by filling the fixed bed with a liquid for a predetermined time duration. The liquid contains distributed as uniformly as possible therein at least one substance which in the presence of a catalytically triggered decomposition reaction gives off a gaseous component and thereafter the liquid to be treated is filtered. |