Analyze and control fouling in an airlift membrane bioreactor: CFD simulation and experimental studies

作者：Khalili Garakani Amirhossein; Mehrnia Mohammad Reza^*; Mostoufi Navid; Sarrafzadeh Mohammad Hossein

来源：Process Biochemistry, 2011, 46(5): 1138-1145.

DOI：10.1016/j.procbio.2011.01.036

• Airlift membrane bioreactor
• Fouling control
• Shear stress

In this study, experiments and computational fluid dynamics were used to evaluate the fouling of membrane surfaces. Based on the resistance-in-series model, the total filtration resistance (R(t)) was divided into cake resistance (R(c)), adsorption resistance (R(a)), internal-plugging (pore-blockage) resistance (R(pb)) and intrinsic-membrane resistance (R(m)). The values of each resistance and their relative percentages as a function of the operating parameters were experimentally determined. The effect of inlet air-flow rate and the baffle angle on the resistances were also investigated. It was then shown that the permeate flux and resistances could be related to the wall shear stresses of air and liquid flows at the membrane surface. Average shear stress was found to increase by increasing the air-flow rate. The change in baffle angle from 90 degrees to 85 degrees increased the shear stress of air on the membrane surface. At low air-flow rates there was a lower meandering of air as well as the area of the membrane, which is not subject to high-shear increases. The shear stresses of air and liquid on the membrane surface were determined by computational fluid dynamics and correlations were proposed for estimating each resistance of the membrane from these shear stresses.

• 出版日期2011-5