Modeling of cross flow hollow fiber ultrafiltration for treatment of effluent from Railway Workshop

Industrial oily water containing oil, grease and dust has been treated using stage-wise filtration, first by sand bed followed by cross-flow ultrafiltration hollow fiber membrane. The sand bed removes majority of suspended particles and reduces the turbidity from 13.6 NTU to 2.6 NTU. Effects of transmembrane pressure drop and cross flow rate on ultrafiltration performance were investigated. A transport phenomena based model under the framework of boundary layer theory was developed to quantify the flux decline and oil transport through the membrane during cross flow filtration in hollow fiber. The model results matched remarkably well with the experimental data. The mechanism of filtration was analyzed and found to be governed by cake formation. Formation of cake-layer was supported by scanning electron micrography of fresh and fouled membranes and Fourier Transform Infrared spectroscopy. The modeling of separation mechanism and estimates system parameters will aid in scaling up of the filtration set-up to industrial scale for treatment of industrial effluent containing oil.