An experimental study for removal of Cr (VI) from industrial water effluents and surface waters using activated composite membranes (ACMs) based on the separation of Cr (VI) species in an ACM separate unit cell is described. Methyltricaprylammonium chloride (Aliquat 336) was used as 'carrier' in the activated composite membranes. Atomic Absorption Spectrometer (FAAS) was utilized for measuring the concentrations of metal: in feed solutions, the concentration of metal ranged from 25 to 120 mg L-1 and the pH was higher than 3.00 that decreased the probability that Cr (VI) reduced to Cr (fit). Consequently, the effects of the pH and the carrier concentration in the membrane were discussed. The results seemed to prove the efficiency of the activated composite membranes such these: the membrane capacity (11,01 cm(-2)), the metal concentration (mg L-1) in feed and permeate solutions and the enrichment factor of Cr (VI) in permeate solutions. After 7 and 25 h of treatment with membrane of polluted water with Cr (VI) the water became unpolluted. (C) 2008 Elsevier B.V. All rights reserved.