Shear stress and fouling control in hollow fiber membrane systems under different gas sparging conditions

The shear stress created by gas sparging has been widely recognized as a controlling factor in the fouling of submerged membrane systems. Effective gas sparging can significantly reduce the fouling and improve the membrane performance. Several factors, such as membrane module configuration, gas sparging tank configuration, gas sparging pattern and temperature, affect the hydrodynamic conditions around the membrane. Chan et al. (2011) reported that different types of shear profiles exist inside the submerged hollow fiber membrane module, and the different types of shear conditions have different effects on fouling control. In this thesis, the relationship between the shear stress generated by conventional sparging and a novel sparging approach on fouling control were studied. The results indicate that, to achieve the similar fouling control (fouling rate), only a quarter of energy (i.e air flow rate) input was required for the novel slug bubble sparger, compared to the conventional coarse bubble sparger.Applied Science, Faculty ofCivil Engineering, Department ofGraduat