(185c) Gas Sparging for Membrane Fouling Control

Membrane systems are increasingly being used in water and wastewater treatment applications because of their ability to effectively retain particulate and soluble contamiants of concern.  However, some of the retained material (i.e. foulants) can accumulate on or in the membrane.  Unless controlled, this accumulation can significantly increase the resistance to the permeate flow through the membrane, and result in an increase in the capital and operating costs for the system. 

Gas sprging is commonly used in submerged membrane systems to limit the accumulation of foulants at the membrane surface.  The effects of gas sparging on the mass transfer of foulants at membrane surfaces are reviewed, and the sparging conditions that minimize the accumulation of foulants are presented.   Emphasis is placed on the effect of the membrane system configuration and sparging scanario as they can significantly affect the power costs associated fouling control.   This is of particular importance since the power costs associated with gas sparging can account for up to 40% of the operating cost of a membrane system.