Vacuum assisted removal of volatile to semi volatile organic contaminants from water using hollow fiber membrane contactors: II: A hybrid numerical-analytical modeling approach

Applying a new hybrid numerical and analytical approach in the finite element simulator RockFlow/GeoSys for hydraulic flow and mass transport, the efficiency of the removal of organic contaminants from water using a microporous polypropylene hollow fiber membrane module (HFM) was accurately modeled for a large range of operating conditions. The modeling results were validated against 177 experimental measurements under a wide range of operating conditions for 12 organic compounds with different diffusion coefficients and a wide variety of Henryʹs law constants, from Naphthalene at circa 0.017 to 1,1-dichloroethene with circa 1.19. The hybrid numerical analytical approach enables prediction of the removal efficiencies within a few minutes, whereas a pure numerical approach would require several hours to days due to numerical stability controls. The input parameters for the model are defined by the geometry of the HFM and the operating conditions, no empirical formulations are applied. This model allows the investigation of the main factors controlling the removal characteristics, e.g., the dependency on Henryʹs law coefficient, gas side diffusional resistance, and aqueous diffusion limitation, and also enables the efficient design of further organic removal systems based on the HFM technology.