EFFECTS OF AERATION PORE DIAMETER AND AERAT ION INTENSITY ON HYDRODYNAMIC CHARACTERISTICS IN SUBMERGED MEMBRANE BIO-REACTORS

摘要

Submerged membrane bio-reactor (SMBR) is a well-developed waste-water treatment process that has been widely used by municipalities and industries. Nonetheless, concentration polarization and membrane fouling are the two important problems preventing their wide applications. In the present study, the most effective strategy to improve the membrane performance was found to generate the gas-liquid two-phase cross-flow through aeration. However, the optimum operating parameters such as the pore size and intensity of aeration were still unclear. Optimizing operating parameter is essential to reduce the operational costs and to improve filtration efficiency. This study investigated the hydrodynamic characteristics of hollow fiber membrane surface in SMBR under different conditions using the particle image velocity (PIV) technique and the effects of the different experimental parameters on the membrane performance.The results indicate that aeration pore size of 1.0 mm and 140L/h aeration intensity is considered the optimum operating parameters,because it can provide higher shear stress and highly dissolved oxygen. The subject laid a theoretical foundation for the optimization of flow field in submerged membrane bio-reactor so as to control the membrane fouling problem.