Methods for improving filtration performance of hollow fiber membranes

In accordance with the present invention, there are provided methods for improving performance of hollow fiber filtration membrane modules. Invention methods comprise a unique backwashing technique wherein the hollow fiber membranes within the module are pressurized with a gas on the feed side at specified times during the backwash. Periodic use of invention methods effectively removes fouling components from the hollow-fiber membranes, thereby providing stable permeability and low trans-membrane pressures, which results in an efficient and economic filtration process. In addition, there are provided methods for cleaning hollow fiber membranes and increasing filtrate flow rate through membranes.