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چکیده
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Our study was designed to simulate the separation of oil/water emulsions using a crossflow ultrafiltration polysulfone/polyvinylpyrrolidone (PSF-PVP) membrane. The phase inversion method was used to produce the membrane, which consisted of a polysulfone (PSF) polymer base, a polyvinylpyrrolidone (PVP) additive, and a dimethylformamide (DMF) solvent. The oil phase included soybean oil at a constant concentration of 400 ppm in a liter of bi-distilled water. The experiments assessed the permeate flux and rejection variations over about 480 min. The data were analyzed to validate the model predictions. The process of membrane fouling was identified using a modified Hermia's model. By comparing the experimental data with Hermia's model, it is evident that fouling completely follows the complete blocking model. Hermia's modified model for complete blocking filtration in terms of time was used to simulate permeation and rejection variations. A complete pore blocking resistance model was used to connect the rejection, feed, and permeate fluxes. Model estimations for transient permeate flux and rejection in turbulent flow regimes agree with the experimental observations. Finally, a time-step and mesh-independent model was developed to model the connection between flow rate and filtering time in an oil/water UF system. The modeling results show that increasing the transmembrane pressure (TMP) and temperature improves the permeate flux. However, TMP lowers oil rejection while increasing the temperature increases oil rejection. Additionally, TMP accelerates the fouling of membranes. Furthermore, a simple estimate of permeation using the average inlet/outlet pressures in the well-known Darcy equation corresponded well with the CFD results.
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