New UV-photografted nanofiltration membranes for the treatment of colored textile dye effluents

New nanofiltration membranes have been developed by UV-photografting. Sodium p-styrene sulfonate (NaSS) and [2-(acryloyloxy)ethyl]trimethyl ammonium chloride (AC) were used for the modification of a polysulfone ultrafiltration membrane. The membrane cut-off was estimated. The grafted membranes were evaluated for the removal of six different dyes according to their charge in the aim of reusing the water in the process house. The effects of various parameters such as dye class, pressure, pH and the presence of salt were evaluated. It was observed that the newly developed membranes showed acceptable performance both in terms of flux and rejection. Dye retention was higher than 96% and hydraulic permeability was 0.48–0.56 m3 m−2 day−1 at 0.4 MPa. The influence of pH and salt on the performance of membranes in terms of fouling and retention was established and compared to a commercial membrane (Desal 5 DK).