Study of the behaviour of different NF membranes for the reclamation of a secondary textile effluent in rinsing processes.

More demanding legal regulations for the wastewater disposal and water scarcity make necessary wastewater reuse in the industry. In particular, textile industry generates large amounts of wastewater with a high concentration of pollutants. Even though present biological or physical-chemical treatments are broadly in place, the quality of the final effluent is not good enough to allow its direct reuse. Consequently, a complementary membrane process is required in order to improve wastewater characteristics. In this work, six NF membranes were tested at different volume concentration factors in order to select the most appropriate one. The main studied criteria were the permeate quality for its reuse in the textile processes and the minimum membrane fouling effect. The different results obtained for the tested membranes were explained by membrane characterization parameters as contact angle, roughness and size exclusion. Taking these factors into consideration, TFC-SR2 has shown the overall best results because of the high permeate flux and the minimum fouling (in terms of the normalised flux reduction).