Isotherm and Kinetic Evaluation of Acid Blue ۸۰ Dye Adsorption on Surfactant-modified Bentonite

Background: Dyes are among the most hazardous chemical compounds, which are found in industrial effluents. The removal of dyes before the discharge of wastewater to the environment could reduce these environmental hazards. The present study aimed to evaluate the efficiency of cetyltrimethylammonium bromide-modified bentonite (CTAB-MB) surfactant in the adsorption of acid blue ۸۰ (AB۸۰) dye. Methods: This experimental study was conducted using a shaker (۱۰۰ rpm) at room temperature and fixed pH of ۷ using conical flasks (۲۰۰ ml) containing the dye solution (۱۰۰ ml) to assess the adsorption conditions. In addition, five concentrations of the reactive blue dye were prepared to evaluate the effects of the initial dye concentration on adsorption.  Results: The experimental data indicated that the AB۸۰ removal procedure was fitted with the Langmuir isotherm. The Langmuir adsorption capacities (qe) were ۳۸.۱۵ and ۲۱.۷۶ mg/g for ۱ and ۲ g/l of the adsorbent, respectively. Moreover, three kinetic models were selected to fit the kinetic data, including the pseudo-first-order and pseudo-second-order models and intra-particle diffusion. AB۸۰ was fitted with the pseudo-second-order model at all the concentrations.  Conclusion: According to the results, CTAB-MB was an affordable alternative to the removal of dyes from industrial wastewater.

Keywords:

Adsorption Behavior , Acid Blue ۸۰ , Isotherms , Kinetics Words