A new low-cost composite ultrafiltration membrane made of polysulfone (PSf) and polystyrene (PS) blend was effectively achieved on the ceramic pozzolan support using dip-coating method. The effect of PS content (5-20 wt%) on membrane properties such as microstructure and filtration performances was investigated. The Fourier-transform infrared spectroscopy, nuclear magnetic resonance, and differential scanning calorimetry analyses confirm that the two polymers lead to physical blend. The morphology analysis shows that PSf/PS membrane layer is homogeneous and strongly adherent on the pozzolan support. Furthermore, the developed membrane was applied for filtration of direct red (DR80) and methyl orange (MO) solutions at a pressure of 3 bar. It was proven that the PS addition significantly enhances the rejection of the membrane companying with a decrease of permeate flux to meet the trade-off selectivity-permeability. The optimized PSf/PS membrane containing 5 wt% of PS has a water permeability of 24 L h À1 m À2 bar À1 , and could reject 91% and 76%, respectively for DR80 and MO. Beside the promising filtration results, the developed membrane is also low-cost thanks to using pozzolan support, and it could be consequently scaled up for the treatment of colored wastewater generated from textile industries.