IMMERSED MEMBRANE FILTRATION SYSTEM AND OVERFLOW PROCESS

摘要

Modules of ultrafiltration or microfiltration membranes are arranged in a tank open to the atmosphere to substantially cover the cross sectional area of the tank. A filtration cycle has permeation steps and deconcentration steps. During permeation, supply of feed substantially equals feed removed and little if any aeration is used. During deconcentration, aeration with scouring bubbles is provided with one or both of backwashing and feed flushing. In feed flushing, feed water is supplied to the tank from below the modules. Excess tank water created during deconcentration flows generally upwards through the modules and out through a retentate outlet or overflow at the top of the tank.