Experimental campaigns on textile wastewater for reuse by means of different membrane processes

The experimental results of the pilot scale application of different membrane technologies, supported by clariflocculation and ozonization, for textile wastewater reuse are described. The investigation has been carried out by treating two different textile effluents: a secondary effluent coming from a biological activated plant and a wastewater coming directly from several textile departments. In the first case the pilot plant used sand filtration and microflitration (MF) as pre-treatments for nanofiltration (NF). The MF and NF membranes tested were of the spiral wound type. The NF permeate can be reused in all production steps, including dyeing with light coloration. In the second case, the chemical-physical pre-treatment and the advanced treatment of water have been experimented for different kind of wastewater (from the carbonising process, from dyeing and fulling). The most interesting experimental results were obtained from the treatment of wastewater from the carbonising process. A scheme process in which ultrafiltration (UF) with flat membranes operating under vacuum is placed downstream an ozonization treatment has been evaluated. The UF permeate quality was suitable to the reuse in production processes.