Performance evaluation of direct nanofiltration process to fouling by treating rinsing-bath effluents for water reuse

AbstractIn this study, experiments were carried out to evaluate a direct nanofiltration membrane process performance in terms of flux, rejection, and resistance to fouling, for treating two real textile dyeing rinsing waters (indigo blue and sulfur black) collected from rinsing baths of Ksar Hellal factory (SITEX). Based on permeate flux efficiencies and regarding permeate quality in terms of pollutant rejections, indigo blue permeate presented better performances than sulfur black. During volume reduction factor experiments, an average of 99% reduction in turbidity, 97% in COD removal, and a colorless permeate were observed in the case of indigo blue, whereas for sulfur black permeate, these rejections values reached only 67, 86, and 52%, respectively, in terms of turbidity, COD and color removal efficiencies. However, low salt rejection rates were obtained that did not exceed 34% for both rinsing effluents. These results confirm the fouling problem of NF HL membrane; even it presented a significant impr...