the effect of contact time on the adsorption of acid dyes onto CTMAB-Bent. It was clear the initial adsorption process of AB93, ATBA and AGYG was relatively fast, and the adsorption reached equilibrium in less than 10 min. However, the
curve of AB25 by CTMAB-Bent indicated that the adsorption was slow growth up to equilibrium at 50 min. Then in the
following experiments, 60 min was selected to ensure adsorption equilibrium.As shown above, the best experimental conditions achieved for 100 mg/L AB25, 150 mg/L AB93, 100 mg/L ATBA and 100 mg/L AGYG were: CTMAB-Bent dosages of 0.05 g, 0.10 g, 0.10 g and 0.06 g, respectively, contact time of 60 min and natural dye solution pH