Improved methods of cleaning membrane modules

摘要

A method and apparatus for backwashing a membrane filtration system is disclosed. The method includes the steps of using permeate remaining present in the filtration system when the filtration process is stopped or suspended to provide liquid for backwashing the membrane pores during a backwashing process; and using a pressurized gas to push the remaining permeate through the membrane pores during backwashing of the membranes, wherein the pressure of the gas applied to the remaining liquid permeate is less than the bubble point of the membrane so that gas does not penetrate into the membrane pores.