Modelling reactive dye removal by ultrafiltration ceramic membranes

Textile industry effluents pose environmental risks due to the persistence of the additives and dye residues but membrane technology can effectively remove these contaminants. Since membranes, especially ceramic membranes are prone to fouling, which results in reduced membrane performance and increased operational costs, pretreatment may be necessary. Wastewater containing reactive dye (Novacron Orange) was treated with a 1 kDa tubular multichannel ceramic membrane. Several versions of pretreatment solutions were experimented with, including filtration with submerged polyethylene (PE) hollow fiber membrane combined with different concentrations of magnesium chloride as coagulant to test the optimal efficiency. The rate of pollutant removal was characterized with the decrease in total organic carbon (TOC) concentration and color intensity reduction. Modelling removal performance may assist the technology to predict fouling and necessary cleaning frequency. A membrane separation model was developed earlier by the research group to simulate filtration efficiency by combining a fouling model including pore blockage, pore constriction and cake layer formation with a modified Spiegler‐Kedem‐Katchalsky model for ultrafiltration to assess the permeate concentration as a function of the change in permeate flow rate. Experimental data from the treatment of the reactive dye wastewater were fed to the model to test its validity under different conditions. Parameters that are sensitive to the different types of pretreatment (membrane filtration and coagulation) were identified and comparative analysis of the results was carried out to evaluate the robustness of the model and to provide a clear understanding of membrane separation mechanisms regarding reactive dye removal from textile wastewater.