Effects of raw bentonite and CTMAB-Bent dosage on the four acid dyes adsorption were listed inFig. 3. The adsorption amount of the acid dyes by CTMAB-Bent increased with the increasing amount of adsorbent. For AB25 and AB93, the adsorption ratio could reach up to 80% when the adsorption dosage was only 0.02 g. For ATBA and AGYG, the adsorption ratio rose quickly, and the equilibrium state was achieved at 0.05 g. At thefixed concentration of AB25 (100 mg/L), AB93 (150 mg/L), ATBA (100 mg/L) and AGYG (100 mg/L) with CTMAB-Bent dosages of 0.10 g, the maximum remove ratios were 88.71%, 93.30%, 97.62% and 94.42%, respectively, while the adsorption ratios were all below 30% for raw bentonite. These results indicated that the capacity of CTMAB-Bent to the four acid dyes was strongly reinforced after being surfactant modified, since the surface properties
changed from hydrophilic to hydrophobic.