METHOD FOR CLEANING THE SUBMERGED MEMBRANES AND MEMBRANE FILTRATION TANKS

摘要

A method for cleaning submerged membranes in a membrane filtration tank is provided to perform a cleaning process without a separate cleaning tank, improve a cleaning effect of the membranes by controlling backwashing or chemical cleaning according to operation circumstances, and treat sediments in the membrane filtration tank efficiently by discharging contaminants settled in the membrane filtration tank to the outside while injecting a cleaning liquid, membrane-filtered water, or raw water into the membrane filtration tank. A method for cleaning submerged membranes(7) in a membrane filtration tank(3) installed within a reactor of a water treatment apparatus comprises the steps of: discharging the cleaning water presenting in the membranes and a cleaning target material to the outside of the membranes by stopping a membrane filtration flow and injecting membrane-filtered cleaning water in the direction opposite to the membrane filtration flow to clean inner and outer parts of target membranes; injecting a cleaning solution and a cleaning liquid oppositely to the membrane filtration direction to discharge filtered clean water in the membranes, the cleaning liquid, and cleaning-required material to the outside of the membranes; discharging cleaning liquid and contaminants remained in the membranes to the outside of the membranes by injecting membrane-filtered water into the membranes after injecting the cleaning liquid into the membranes for a predetermined time; and discharging cleaning liquid and contaminants remained in the membranes to the outside of the membranes by injecting air instead of the membrane-filtered water into the membranes after injecting the cleaning liquid into the membranes for a predetermined time.