When comparing the permeate fluxes of water with the initial and final permeate fluxes of synthetic wastewater wasobserved a large difference between the values obtained. Itis important to remark that the values for the initial fluxes obtained in this work are comparable to those from otherauthors when they used similar effluents (Cassano et al.,2003; Molinari et al., 2004). Indeed, Molinari et al. (2004)reported a permeate flux of water of 55 L/m2h, at TMP 10 bar for NF membrane NF 70, while in trials with the effluent from exhausted tanning baths, the initial permeate flux was8.00 L/m2h and the final permeate flux was 2.24 L/m2h at TMP 5 bar.