Adsorption of Acid Red 18 Using Bentonite Modified by a Cationic Surface Active Agent (Hyamine)

In this research, firstly Bentonite was treated by Hyamine, a cationic surface active agent, and then its capacity for the adsorption of acidic dyes was investigated. Correlation coefficient of equilibrium adsorption study showed that the surfactant adsorption is predominantly described by Freundlich adsorption isotherm. The maximum adsorption capacity was calculated about 94.7 mg/g at 30 oC. This was measured for the adsorption of the dye onto the modified adsorbent around 86.3 mg/g at 30 oC which was higher than the ones obtained at room temperature and 40 oC. Kinetics of adsorption significantly fitted by pseudo second order equation for both Hyamine and acid dye adsorption onto the adsorbent. Initial adsorption rate was increased by increasing of temperature. Intraparticle diffusion study revealed that the diffusion of the cationic surface active agent and the acid dye in the related adsorption structure was concurrently done by film diffusion.