Isotherm and Kinetic Evaluation of Acid Blue 80 Dye Adsorption on Surfactant-modified Bentonite

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 80 (AB80) dye. This experimental study was conducted using a shaker (100 rpm) at room temperature and fixed pH of 7 using conical flasks (200 ml) containing the dye solution (100 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. The experimental data indicated that the AB80 removal procedure was fitted with the Langmuir isotherm. The Langmuir adsorption capacities (qe) were 38.15 and 21.76 mg/g for 1 and 2 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. AB80 was fitted with the pseudo-second-order model at all the concentrations. According to the results, CTAB-MB was an affordable alternative to the removal of dyes from industrial wastewater