Reuse of textile effluents treated with nanofiltration membranes

Abstract

The reactive dye Cibacron Yellow S-3R was selected for the membrane filtration study, to evaluate the feasibility of nanofiltration membranes to treat textile wastewater. Synthetic effluents were treated by means of two nanofiltration membranes, Hydracore10 and Hydracore50, manufactured by Hydranautics. The membranes provided a high quality permeate, able to be reused in new dyeings. Up to 98% of dye removal was achieved. The influence of salt concentration and pH on membrane treatment was studied. The best conditions for dye removal were pH 3 and 60g·L-1 of NaCl. After the membrane filtration, the treated permeates were reused in new dyeing process. 100% of the obtained permeate was reused to perform different dyeings with four reactive dyes. Finally fabrics dyed with the reused water were evaluated respect to references carried out with softened tap water. The colour differences obtained were lower than 0.5, being 1 the maximum value generally accepted by the industry