Collision efficiency of colloidal particles and morphology of deposits: Implications for membrane filtration
Tarabara, Volodymyr Valentinovich
Wiesner, Mark R.
Master of Science
On-lattice Monte Carlo simulations were performed to investigate the effect of collision efficiencies alpha of particles on the morphology of heterodeposits. The model predicts that the structure and surface chemistry of such deposits are determined by particles with large and small values of alpha, correspondingly. The case of homodeposition onto a rough substrate was also studied. The best "memory" of the deposit measured as a rate of decay of the Fourier amplitude corresponding to the wavelength of the initial roughness, was found to correspond to intermediate values of alpha. Cross-flow membrane filtration experiments using monodisperse latex suspensions were performed for validation of the Sethi's extended model. A slightly more complex structure at the cake-suspension interface was hypothesized to explain differences between model calculations and experiments. A representation of the cake with a gradually changing solids concentration allowed for better matching of the extended model and experimental results for particles diffusively depositing onto membrane.