Modeling mass transfer using surface morphology in full-scale reverse osmosis membrane processes
Abbreviated Journal Title
Desalin. Water Treat.
Membrane active-layer; Reverse osmosis; Mass transfer coefficients; Concentration polarization; Mathematical models; CONCENTRATION POLARIZATION; SYSTEMS; RO; Engineering, Chemical; Water Resources
The influence of surface characteristics on membrane process performance is considered significant and is not well understood. Current mass transport models generally assume constant mass transfer coefficients (MTCs) based on a homogeneous flat surface. This study evaluated membrane mass transfer by incorporating surface morphology into a diffusion-based model assuming that the MTCs are dependent on the thickness variation of the membrane's active layer. Concentration polarization is also affected by this nonuniform surface property and was incorporated into the model. A simulation was performed using parameters from a full-scale 4.5million gallon per day brackish water reverse osmosis membrane process. The process was simulated by modeling one thousand uniform slices of the membrane channel and the permeate water quality was determined locally through a finite difference approach. It was determined that solute mass transport is controlled by diffusion in the nonhomogeneous thinner regions (membrane valleys) of the active layer. This nonuniform surface affected the concentration polarization layer, where more solutes tended to accumulate within the valleys than on the ridges. Prediction of the permeate total dissolved solids concentration was accurate, ranging between 5 and 15%, as measured as an average percent difference between predicted and actual values.
Desalination and Water Treatment
"Modeling mass transfer using surface morphology in full-scale reverse osmosis membrane processes" (2013). Faculty Bibliography 2010s. 3963.