Membrane fouling in a membrane bioreactor: A novel method for membrane surface morphology construction and its application in interaction energy assessment

A novel method was developed to construct membrane surface morphology in this study. The method was based on fractal geometry theory, and involved a modified Weierstrass-Mandelbrot (WM) function for modeling surface topography. With MATLAB programming, membrane surface could be graphically modeled. It was found that the fractal dimension (D-f) and cutoff frequency (L-s) were the two key parameters affecting the topography, and the membrane surface constructed by this method could be very close to the real situation. The method was then applied in interaction energy assessment regarding membrane fouling in a membrane bioreactor. The procedure which combines membrane surface topography construction, surface element integration (SEI) method and the composite Simpson's rule was theoretically proposed. The surface properties of foulant and membrane were experimentally measured. Accordingly, a membrane surface was reconstructed for interaction energy assessment. With these data, quantitatively assessing interfacial interactions between foulant particles and a nearly-real rough membrane surface is expected to be firstly realized. This study provided a complete solution for quantitative assessment of interaction energies between a foulant particle and rough membrane surface. (C) 2016 Elsevier B.V. All rights reserved.